Bug Summary

File:lib/CodeGen/AsmPrinter/AsmPrinter.cpp
Warning:line 2326, column 44
Called C++ object pointer is null

Annotated Source Code

Press '?' to see keyboard shortcuts

clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name AsmPrinter.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-eagerly-assume -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -mrelocation-model pic -pic-level 2 -mthread-model posix -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -dwarf-column-info -debugger-tuning=gdb -momit-leaf-frame-pointer -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-7/lib/clang/7.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-7~svn329677/build-llvm/lib/CodeGen/AsmPrinter -I /build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter -I /build/llvm-toolchain-snapshot-7~svn329677/build-llvm/include -I /build/llvm-toolchain-snapshot-7~svn329677/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/x86_64-linux-gnu/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/x86_64-linux-gnu/c++/7.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.3.0/../../../../include/c++/7.3.0/backward -internal-isystem /usr/include/clang/7.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-7/lib/clang/7.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-7~svn329677/build-llvm/lib/CodeGen/AsmPrinter -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-checker optin.performance.Padding -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-04-11-031539-24776-1 -x c++ /build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
1//===- AsmPrinter.cpp - Common AsmPrinter code ----------------------------===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the AsmPrinter class.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/CodeGen/AsmPrinter.h"
15#include "AsmPrinterHandler.h"
16#include "CodeViewDebug.h"
17#include "DwarfDebug.h"
18#include "DwarfException.h"
19#include "WinCFGuard.h"
20#include "WinException.h"
21#include "llvm/ADT/APFloat.h"
22#include "llvm/ADT/APInt.h"
23#include "llvm/ADT/DenseMap.h"
24#include "llvm/ADT/STLExtras.h"
25#include "llvm/ADT/SmallPtrSet.h"
26#include "llvm/ADT/SmallString.h"
27#include "llvm/ADT/SmallVector.h"
28#include "llvm/ADT/Statistic.h"
29#include "llvm/ADT/StringRef.h"
30#include "llvm/ADT/Triple.h"
31#include "llvm/ADT/Twine.h"
32#include "llvm/Analysis/ConstantFolding.h"
33#include "llvm/Analysis/EHPersonalities.h"
34#include "llvm/Analysis/OptimizationRemarkEmitter.h"
35#include "llvm/BinaryFormat/Dwarf.h"
36#include "llvm/BinaryFormat/ELF.h"
37#include "llvm/CodeGen/GCMetadata.h"
38#include "llvm/CodeGen/GCMetadataPrinter.h"
39#include "llvm/CodeGen/GCStrategy.h"
40#include "llvm/CodeGen/MachineBasicBlock.h"
41#include "llvm/CodeGen/MachineConstantPool.h"
42#include "llvm/CodeGen/MachineDominators.h"
43#include "llvm/CodeGen/MachineFrameInfo.h"
44#include "llvm/CodeGen/MachineFunction.h"
45#include "llvm/CodeGen/MachineFunctionPass.h"
46#include "llvm/CodeGen/MachineInstr.h"
47#include "llvm/CodeGen/MachineInstrBundle.h"
48#include "llvm/CodeGen/MachineJumpTableInfo.h"
49#include "llvm/CodeGen/MachineLoopInfo.h"
50#include "llvm/CodeGen/MachineMemOperand.h"
51#include "llvm/CodeGen/MachineModuleInfo.h"
52#include "llvm/CodeGen/MachineModuleInfoImpls.h"
53#include "llvm/CodeGen/MachineOperand.h"
54#include "llvm/CodeGen/MachineOptimizationRemarkEmitter.h"
55#include "llvm/CodeGen/TargetFrameLowering.h"
56#include "llvm/CodeGen/TargetInstrInfo.h"
57#include "llvm/CodeGen/TargetLowering.h"
58#include "llvm/CodeGen/TargetOpcodes.h"
59#include "llvm/CodeGen/TargetRegisterInfo.h"
60#include "llvm/CodeGen/TargetSubtargetInfo.h"
61#include "llvm/IR/BasicBlock.h"
62#include "llvm/IR/Comdat.h"
63#include "llvm/IR/Constant.h"
64#include "llvm/IR/Constants.h"
65#include "llvm/IR/DataLayout.h"
66#include "llvm/IR/DebugInfoMetadata.h"
67#include "llvm/IR/DerivedTypes.h"
68#include "llvm/IR/Function.h"
69#include "llvm/IR/GlobalAlias.h"
70#include "llvm/IR/GlobalIFunc.h"
71#include "llvm/IR/GlobalIndirectSymbol.h"
72#include "llvm/IR/GlobalObject.h"
73#include "llvm/IR/GlobalValue.h"
74#include "llvm/IR/GlobalVariable.h"
75#include "llvm/IR/Instruction.h"
76#include "llvm/IR/Mangler.h"
77#include "llvm/IR/Metadata.h"
78#include "llvm/IR/Module.h"
79#include "llvm/IR/Operator.h"
80#include "llvm/IR/Type.h"
81#include "llvm/IR/Value.h"
82#include "llvm/MC/MCAsmInfo.h"
83#include "llvm/MC/MCCodePadder.h"
84#include "llvm/MC/MCContext.h"
85#include "llvm/MC/MCDirectives.h"
86#include "llvm/MC/MCDwarf.h"
87#include "llvm/MC/MCExpr.h"
88#include "llvm/MC/MCInst.h"
89#include "llvm/MC/MCSection.h"
90#include "llvm/MC/MCSectionELF.h"
91#include "llvm/MC/MCSectionMachO.h"
92#include "llvm/MC/MCStreamer.h"
93#include "llvm/MC/MCSubtargetInfo.h"
94#include "llvm/MC/MCSymbol.h"
95#include "llvm/MC/MCSymbolELF.h"
96#include "llvm/MC/MCTargetOptions.h"
97#include "llvm/MC/MCValue.h"
98#include "llvm/MC/SectionKind.h"
99#include "llvm/Pass.h"
100#include "llvm/Support/Casting.h"
101#include "llvm/Support/CommandLine.h"
102#include "llvm/Support/Compiler.h"
103#include "llvm/Support/ErrorHandling.h"
104#include "llvm/Support/Format.h"
105#include "llvm/Support/MathExtras.h"
106#include "llvm/Support/Path.h"
107#include "llvm/Support/TargetRegistry.h"
108#include "llvm/Support/Timer.h"
109#include "llvm/Support/raw_ostream.h"
110#include "llvm/Target/TargetLoweringObjectFile.h"
111#include "llvm/Target/TargetMachine.h"
112#include "llvm/Target/TargetOptions.h"
113#include <algorithm>
114#include <cassert>
115#include <cinttypes>
116#include <cstdint>
117#include <iterator>
118#include <limits>
119#include <memory>
120#include <string>
121#include <utility>
122#include <vector>
123
124using namespace llvm;
125
126#define DEBUG_TYPE"asm-printer" "asm-printer"
127
128static const char *const DWARFGroupName = "dwarf";
129static const char *const DWARFGroupDescription = "DWARF Emission";
130static const char *const DbgTimerName = "emit";
131static const char *const DbgTimerDescription = "Debug Info Emission";
132static const char *const EHTimerName = "write_exception";
133static const char *const EHTimerDescription = "DWARF Exception Writer";
134static const char *const CFGuardName = "Control Flow Guard";
135static const char *const CFGuardDescription = "Control Flow Guard Tables";
136static const char *const CodeViewLineTablesGroupName = "linetables";
137static const char *const CodeViewLineTablesGroupDescription =
138 "CodeView Line Tables";
139
140STATISTIC(EmittedInsts, "Number of machine instrs printed")static llvm::Statistic EmittedInsts = {"asm-printer", "EmittedInsts"
, "Number of machine instrs printed", {0}, {false}}
;
141
142static cl::opt<bool>
143 PrintSchedule("print-schedule", cl::Hidden, cl::init(false),
144 cl::desc("Print 'sched: [latency:throughput]' in .s output"));
145
146char AsmPrinter::ID = 0;
147
148using gcp_map_type = DenseMap<GCStrategy *, std::unique_ptr<GCMetadataPrinter>>;
149
150static gcp_map_type &getGCMap(void *&P) {
151 if (!P)
152 P = new gcp_map_type();
153 return *(gcp_map_type*)P;
154}
155
156/// getGVAlignmentLog2 - Return the alignment to use for the specified global
157/// value in log2 form. This rounds up to the preferred alignment if possible
158/// and legal.
159static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &DL,
160 unsigned InBits = 0) {
161 unsigned NumBits = 0;
162 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
163 NumBits = DL.getPreferredAlignmentLog(GVar);
164
165 // If InBits is specified, round it to it.
166 if (InBits > NumBits)
167 NumBits = InBits;
168
169 // If the GV has a specified alignment, take it into account.
170 if (GV->getAlignment() == 0)
171 return NumBits;
172
173 unsigned GVAlign = Log2_32(GV->getAlignment());
174
175 // If the GVAlign is larger than NumBits, or if we are required to obey
176 // NumBits because the GV has an assigned section, obey it.
177 if (GVAlign > NumBits || GV->hasSection())
178 NumBits = GVAlign;
179 return NumBits;
180}
181
182AsmPrinter::AsmPrinter(TargetMachine &tm, std::unique_ptr<MCStreamer> Streamer)
183 : MachineFunctionPass(ID), TM(tm), MAI(tm.getMCAsmInfo()),
184 OutContext(Streamer->getContext()), OutStreamer(std::move(Streamer)) {
185 VerboseAsm = OutStreamer->isVerboseAsm();
186}
187
188AsmPrinter::~AsmPrinter() {
189 assert(!DD && Handlers.empty() && "Debug/EH info didn't get finalized")(static_cast <bool> (!DD && Handlers.empty() &&
"Debug/EH info didn't get finalized") ? void (0) : __assert_fail
("!DD && Handlers.empty() && \"Debug/EH info didn't get finalized\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 189, __extension__ __PRETTY_FUNCTION__))
;
190
191 if (GCMetadataPrinters) {
192 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
193
194 delete &GCMap;
195 GCMetadataPrinters = nullptr;
196 }
197}
198
199bool AsmPrinter::isPositionIndependent() const {
200 return TM.isPositionIndependent();
201}
202
203/// getFunctionNumber - Return a unique ID for the current function.
204unsigned AsmPrinter::getFunctionNumber() const {
205 return MF->getFunctionNumber();
206}
207
208const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
209 return *TM.getObjFileLowering();
210}
211
212const DataLayout &AsmPrinter::getDataLayout() const {
213 return MMI->getModule()->getDataLayout();
214}
215
216// Do not use the cached DataLayout because some client use it without a Module
217// (dsymutil, llvm-dwarfdump).
218unsigned AsmPrinter::getPointerSize() const {
219 return TM.getPointerSize(0); // FIXME: Default address space
220}
221
222const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const {
223 assert(MF && "getSubtargetInfo requires a valid MachineFunction!")(static_cast <bool> (MF && "getSubtargetInfo requires a valid MachineFunction!"
) ? void (0) : __assert_fail ("MF && \"getSubtargetInfo requires a valid MachineFunction!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 223, __extension__ __PRETTY_FUNCTION__))
;
224 return MF->getSubtarget<MCSubtargetInfo>();
225}
226
227void AsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) {
228 S.EmitInstruction(Inst, getSubtargetInfo());
229}
230
231/// getCurrentSection() - Return the current section we are emitting to.
232const MCSection *AsmPrinter::getCurrentSection() const {
233 return OutStreamer->getCurrentSectionOnly();
234}
235
236void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
237 AU.setPreservesAll();
238 MachineFunctionPass::getAnalysisUsage(AU);
239 AU.addRequired<MachineModuleInfo>();
240 AU.addRequired<MachineOptimizationRemarkEmitterPass>();
241 AU.addRequired<GCModuleInfo>();
242}
243
244bool AsmPrinter::doInitialization(Module &M) {
245 MMI = getAnalysisIfAvailable<MachineModuleInfo>();
246
247 // Initialize TargetLoweringObjectFile.
248 const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
249 .Initialize(OutContext, TM);
250
251 OutStreamer->InitSections(false);
252
253 // Emit the version-min deployment target directive if needed.
254 //
255 // FIXME: If we end up with a collection of these sorts of Darwin-specific
256 // or ELF-specific things, it may make sense to have a platform helper class
257 // that will work with the target helper class. For now keep it here, as the
258 // alternative is duplicated code in each of the target asm printers that
259 // use the directive, where it would need the same conditionalization
260 // anyway.
261 const Triple &Target = TM.getTargetTriple();
262 OutStreamer->EmitVersionForTarget(Target);
263
264 // Allow the target to emit any magic that it wants at the start of the file.
265 EmitStartOfAsmFile(M);
266
267 // Very minimal debug info. It is ignored if we emit actual debug info. If we
268 // don't, this at least helps the user find where a global came from.
269 if (MAI->hasSingleParameterDotFile()) {
270 // .file "foo.c"
271 OutStreamer->EmitFileDirective(
272 llvm::sys::path::filename(M.getSourceFileName()));
273 }
274
275 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
276 assert(MI && "AsmPrinter didn't require GCModuleInfo?")(static_cast <bool> (MI && "AsmPrinter didn't require GCModuleInfo?"
) ? void (0) : __assert_fail ("MI && \"AsmPrinter didn't require GCModuleInfo?\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 276, __extension__ __PRETTY_FUNCTION__))
;
277 for (auto &I : *MI)
278 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
279 MP->beginAssembly(M, *MI, *this);
280
281 // Emit module-level inline asm if it exists.
282 if (!M.getModuleInlineAsm().empty()) {
283 // We're at the module level. Construct MCSubtarget from the default CPU
284 // and target triple.
285 std::unique_ptr<MCSubtargetInfo> STI(TM.getTarget().createMCSubtargetInfo(
286 TM.getTargetTriple().str(), TM.getTargetCPU(),
287 TM.getTargetFeatureString()));
288 OutStreamer->AddComment("Start of file scope inline assembly");
289 OutStreamer->AddBlankLine();
290 EmitInlineAsm(M.getModuleInlineAsm()+"\n",
291 OutContext.getSubtargetCopy(*STI), TM.Options.MCOptions);
292 OutStreamer->AddComment("End of file scope inline assembly");
293 OutStreamer->AddBlankLine();
294 }
295
296 if (MAI->doesSupportDebugInformation()) {
297 bool EmitCodeView = MMI->getModule()->getCodeViewFlag();
298 if (EmitCodeView && (TM.getTargetTriple().isKnownWindowsMSVCEnvironment() ||
299 TM.getTargetTriple().isWindowsItaniumEnvironment())) {
300 Handlers.push_back(HandlerInfo(new CodeViewDebug(this),
301 DbgTimerName, DbgTimerDescription,
302 CodeViewLineTablesGroupName,
303 CodeViewLineTablesGroupDescription));
304 }
305 if (!EmitCodeView || MMI->getModule()->getDwarfVersion()) {
306 DD = new DwarfDebug(this, &M);
307 DD->beginModule();
308 Handlers.push_back(HandlerInfo(DD, DbgTimerName, DbgTimerDescription,
309 DWARFGroupName, DWARFGroupDescription));
310 }
311 }
312
313 switch (MAI->getExceptionHandlingType()) {
314 case ExceptionHandling::SjLj:
315 case ExceptionHandling::DwarfCFI:
316 case ExceptionHandling::ARM:
317 isCFIMoveForDebugging = true;
318 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI)
319 break;
320 for (auto &F: M.getFunctionList()) {
321 // If the module contains any function with unwind data,
322 // .eh_frame has to be emitted.
323 // Ignore functions that won't get emitted.
324 if (!F.isDeclarationForLinker() && F.needsUnwindTableEntry()) {
325 isCFIMoveForDebugging = false;
326 break;
327 }
328 }
329 break;
330 default:
331 isCFIMoveForDebugging = false;
332 break;
333 }
334
335 EHStreamer *ES = nullptr;
336 switch (MAI->getExceptionHandlingType()) {
337 case ExceptionHandling::None:
338 break;
339 case ExceptionHandling::SjLj:
340 case ExceptionHandling::DwarfCFI:
341 ES = new DwarfCFIException(this);
342 break;
343 case ExceptionHandling::ARM:
344 ES = new ARMException(this);
345 break;
346 case ExceptionHandling::WinEH:
347 switch (MAI->getWinEHEncodingType()) {
348 default: llvm_unreachable("unsupported unwinding information encoding")::llvm::llvm_unreachable_internal("unsupported unwinding information encoding"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 348)
;
349 case WinEH::EncodingType::Invalid:
350 break;
351 case WinEH::EncodingType::X86:
352 case WinEH::EncodingType::Itanium:
353 ES = new WinException(this);
354 break;
355 }
356 break;
357 case ExceptionHandling::Wasm:
358 // TODO to prevent warning
359 break;
360 }
361 if (ES)
362 Handlers.push_back(HandlerInfo(ES, EHTimerName, EHTimerDescription,
363 DWARFGroupName, DWARFGroupDescription));
364
365 if (mdconst::extract_or_null<ConstantInt>(
366 MMI->getModule()->getModuleFlag("cfguard")))
367 Handlers.push_back(HandlerInfo(new WinCFGuard(this), CFGuardName,
368 CFGuardDescription, DWARFGroupName,
369 DWARFGroupDescription));
370
371 return false;
372}
373
374static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) {
375 if (!MAI.hasWeakDefCanBeHiddenDirective())
376 return false;
377
378 return GV->canBeOmittedFromSymbolTable();
379}
380
381void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const {
382 GlobalValue::LinkageTypes Linkage = GV->getLinkage();
383 switch (Linkage) {
384 case GlobalValue::CommonLinkage:
385 case GlobalValue::LinkOnceAnyLinkage:
386 case GlobalValue::LinkOnceODRLinkage:
387 case GlobalValue::WeakAnyLinkage:
388 case GlobalValue::WeakODRLinkage:
389 if (MAI->hasWeakDefDirective()) {
390 // .globl _foo
391 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
392
393 if (!canBeHidden(GV, *MAI))
394 // .weak_definition _foo
395 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
396 else
397 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate);
398 } else if (MAI->hasLinkOnceDirective()) {
399 // .globl _foo
400 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
401 //NOTE: linkonce is handled by the section the symbol was assigned to.
402 } else {
403 // .weak _foo
404 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Weak);
405 }
406 return;
407 case GlobalValue::ExternalLinkage:
408 // If external, declare as a global symbol: .globl _foo
409 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Global);
410 return;
411 case GlobalValue::PrivateLinkage:
412 case GlobalValue::InternalLinkage:
413 return;
414 case GlobalValue::AppendingLinkage:
415 case GlobalValue::AvailableExternallyLinkage:
416 case GlobalValue::ExternalWeakLinkage:
417 llvm_unreachable("Should never emit this")::llvm::llvm_unreachable_internal("Should never emit this", "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 417)
;
418 }
419 llvm_unreachable("Unknown linkage type!")::llvm::llvm_unreachable_internal("Unknown linkage type!", "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 419)
;
420}
421
422void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name,
423 const GlobalValue *GV) const {
424 TM.getNameWithPrefix(Name, GV, getObjFileLowering().getMangler());
425}
426
427MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const {
428 return TM.getSymbol(GV);
429}
430
431/// EmitGlobalVariable - Emit the specified global variable to the .s file.
432void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
433 bool IsEmuTLSVar = TM.useEmulatedTLS() && GV->isThreadLocal();
2
Assuming the condition is false
434 assert(!(IsEmuTLSVar && GV->hasCommonLinkage()) &&(static_cast <bool> (!(IsEmuTLSVar && GV->hasCommonLinkage
()) && "No emulated TLS variables in the common section"
) ? void (0) : __assert_fail ("!(IsEmuTLSVar && GV->hasCommonLinkage()) && \"No emulated TLS variables in the common section\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 435, __extension__ __PRETTY_FUNCTION__))
435 "No emulated TLS variables in the common section")(static_cast <bool> (!(IsEmuTLSVar && GV->hasCommonLinkage
()) && "No emulated TLS variables in the common section"
) ? void (0) : __assert_fail ("!(IsEmuTLSVar && GV->hasCommonLinkage()) && \"No emulated TLS variables in the common section\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 435, __extension__ __PRETTY_FUNCTION__))
;
436
437 // Never emit TLS variable xyz in emulated TLS model.
438 // The initialization value is in __emutls_t.xyz instead of xyz.
439 if (IsEmuTLSVar)
3
Taking false branch
440 return;
441
442 if (GV->hasInitializer()) {
4
Taking false branch
443 // Check to see if this is a special global used by LLVM, if so, emit it.
444 if (EmitSpecialLLVMGlobal(GV))
445 return;
446
447 // Skip the emission of global equivalents. The symbol can be emitted later
448 // on by emitGlobalGOTEquivs in case it turns out to be needed.
449 if (GlobalGOTEquivs.count(getSymbol(GV)))
450 return;
451
452 if (isVerbose()) {
453 // When printing the control variable __emutls_v.*,
454 // we don't need to print the original TLS variable name.
455 GV->printAsOperand(OutStreamer->GetCommentOS(),
456 /*PrintType=*/false, GV->getParent());
457 OutStreamer->GetCommentOS() << '\n';
458 }
459 }
460
461 MCSymbol *GVSym = getSymbol(GV);
462 MCSymbol *EmittedSym = GVSym;
463
464 // getOrCreateEmuTLSControlSym only creates the symbol with name and default
465 // attributes.
466 // GV's or GVSym's attributes will be used for the EmittedSym.
467 EmitVisibility(EmittedSym, GV->getVisibility(), !GV->isDeclaration());
5
Assuming the condition is false
468
469 if (!GV->hasInitializer()) // External globals require no extra code.
6
Taking false branch
470 return;
471
472 GVSym->redefineIfPossible();
473 if (GVSym->isDefined() || GVSym->isVariable())
7
Taking false branch
474 report_fatal_error("symbol '" + Twine(GVSym->getName()) +
475 "' is already defined");
476
477 if (MAI->hasDotTypeDotSizeDirective())
8
Assuming the condition is false
9
Taking false branch
478 OutStreamer->EmitSymbolAttribute(EmittedSym, MCSA_ELF_TypeObject);
479
480 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
481
482 const DataLayout &DL = GV->getParent()->getDataLayout();
483 uint64_t Size = DL.getTypeAllocSize(GV->getType()->getElementType());
484
485 // If the alignment is specified, we *must* obey it. Overaligning a global
486 // with a specified alignment is a prompt way to break globals emitted to
487 // sections and expected to be contiguous (e.g. ObjC metadata).
488 unsigned AlignLog = getGVAlignmentLog2(GV, DL);
489
490 for (const HandlerInfo &HI : Handlers) {
10
Assuming '__begin1' is equal to '__end1'
491 NamedRegionTimer T(HI.TimerName, HI.TimerDescription,
492 HI.TimerGroupName, HI.TimerGroupDescription,
493 TimePassesIsEnabled);
494 HI.Handler->setSymbolSize(GVSym, Size);
495 }
496
497 // Handle common symbols
498 if (GVKind.isCommon()) {
11
Taking false branch
499 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it.
500 unsigned Align = 1 << AlignLog;
501 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
502 Align = 0;
503
504 // .comm _foo, 42, 4
505 OutStreamer->EmitCommonSymbol(GVSym, Size, Align);
506 return;
507 }
508
509 // Determine to which section this global should be emitted.
510 MCSection *TheSection = getObjFileLowering().SectionForGlobal(GV, GVKind, TM);
511
512 // If we have a bss global going to a section that supports the
513 // zerofill directive, do so here.
514 if (GVKind.isBSS() && MAI->hasMachoZeroFillDirective() &&
515 TheSection->isVirtualSection()) {
516 if (Size == 0)
517 Size = 1; // zerofill of 0 bytes is undefined.
518 unsigned Align = 1 << AlignLog;
519 EmitLinkage(GV, GVSym);
520 // .zerofill __DATA, __bss, _foo, 400, 5
521 OutStreamer->EmitZerofill(TheSection, GVSym, Size, Align);
522 return;
523 }
524
525 // If this is a BSS local symbol and we are emitting in the BSS
526 // section use .lcomm/.comm directive.
527 if (GVKind.isBSSLocal() &&
528 getObjFileLowering().getBSSSection() == TheSection) {
529 if (Size == 0)
530 Size = 1; // .comm Foo, 0 is undefined, avoid it.
531 unsigned Align = 1 << AlignLog;
532
533 // Use .lcomm only if it supports user-specified alignment.
534 // Otherwise, while it would still be correct to use .lcomm in some
535 // cases (e.g. when Align == 1), the external assembler might enfore
536 // some -unknown- default alignment behavior, which could cause
537 // spurious differences between external and integrated assembler.
538 // Prefer to simply fall back to .local / .comm in this case.
539 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) {
540 // .lcomm _foo, 42
541 OutStreamer->EmitLocalCommonSymbol(GVSym, Size, Align);
542 return;
543 }
544
545 if (!getObjFileLowering().getCommDirectiveSupportsAlignment())
546 Align = 0;
547
548 // .local _foo
549 OutStreamer->EmitSymbolAttribute(GVSym, MCSA_Local);
550 // .comm _foo, 42, 4
551 OutStreamer->EmitCommonSymbol(GVSym, Size, Align);
552 return;
553 }
554
555 // Handle thread local data for mach-o which requires us to output an
556 // additional structure of data and mangle the original symbol so that we
557 // can reference it later.
558 //
559 // TODO: This should become an "emit thread local global" method on TLOF.
560 // All of this macho specific stuff should be sunk down into TLOFMachO and
561 // stuff like "TLSExtraDataSection" should no longer be part of the parent
562 // TLOF class. This will also make it more obvious that stuff like
563 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho
564 // specific code.
565 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
566 // Emit the .tbss symbol
567 MCSymbol *MangSym =
568 OutContext.getOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
569
570 if (GVKind.isThreadBSS()) {
571 TheSection = getObjFileLowering().getTLSBSSSection();
572 OutStreamer->EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
573 } else if (GVKind.isThreadData()) {
574 OutStreamer->SwitchSection(TheSection);
575
576 EmitAlignment(AlignLog, GV);
577 OutStreamer->EmitLabel(MangSym);
578
579 EmitGlobalConstant(GV->getParent()->getDataLayout(),
580 GV->getInitializer());
581 }
582
583 OutStreamer->AddBlankLine();
584
585 // Emit the variable struct for the runtime.
586 MCSection *TLVSect = getObjFileLowering().getTLSExtraDataSection();
587
588 OutStreamer->SwitchSection(TLVSect);
589 // Emit the linkage here.
590 EmitLinkage(GV, GVSym);
591 OutStreamer->EmitLabel(GVSym);
592
593 // Three pointers in size:
594 // - __tlv_bootstrap - used to make sure support exists
595 // - spare pointer, used when mapped by the runtime
596 // - pointer to mangled symbol above with initializer
597 unsigned PtrSize = DL.getPointerTypeSize(GV->getType());
598 OutStreamer->EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"),
599 PtrSize);
600 OutStreamer->EmitIntValue(0, PtrSize);
601 OutStreamer->EmitSymbolValue(MangSym, PtrSize);
602
603 OutStreamer->AddBlankLine();
604 return;
605 }
606
607 MCSymbol *EmittedInitSym = GVSym;
608
609 OutStreamer->SwitchSection(TheSection);
610
611 EmitLinkage(GV, EmittedInitSym);
612 EmitAlignment(AlignLog, GV);
613
614 OutStreamer->EmitLabel(EmittedInitSym);
615
616 EmitGlobalConstant(GV->getParent()->getDataLayout(), GV->getInitializer());
12
Calling 'AsmPrinter::EmitGlobalConstant'
617
618 if (MAI->hasDotTypeDotSizeDirective())
619 // .size foo, 42
620 OutStreamer->emitELFSize(EmittedInitSym,
621 MCConstantExpr::create(Size, OutContext));
622
623 OutStreamer->AddBlankLine();
624}
625
626/// Emit the directive and value for debug thread local expression
627///
628/// \p Value - The value to emit.
629/// \p Size - The size of the integer (in bytes) to emit.
630void AsmPrinter::EmitDebugThreadLocal(const MCExpr *Value,
631 unsigned Size) const {
632 OutStreamer->EmitValue(Value, Size);
633}
634
635/// EmitFunctionHeader - This method emits the header for the current
636/// function.
637void AsmPrinter::EmitFunctionHeader() {
638 const Function &F = MF->getFunction();
639
640 if (isVerbose())
641 OutStreamer->GetCommentOS()
642 << "-- Begin function "
643 << GlobalValue::dropLLVMManglingEscape(F.getName()) << '\n';
644
645 // Print out constants referenced by the function
646 EmitConstantPool();
647
648 // Print the 'header' of function.
649 OutStreamer->SwitchSection(getObjFileLowering().SectionForGlobal(&F, TM));
650 EmitVisibility(CurrentFnSym, F.getVisibility());
651
652 EmitLinkage(&F, CurrentFnSym);
653 if (MAI->hasFunctionAlignment())
654 EmitAlignment(MF->getAlignment(), &F);
655
656 if (MAI->hasDotTypeDotSizeDirective())
657 OutStreamer->EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
658
659 if (isVerbose()) {
660 F.printAsOperand(OutStreamer->GetCommentOS(),
661 /*PrintType=*/false, F.getParent());
662 OutStreamer->GetCommentOS() << '\n';
663 }
664
665 // Emit the prefix data.
666 if (F.hasPrefixData()) {
667 if (MAI->hasSubsectionsViaSymbols()) {
668 // Preserving prefix data on platforms which use subsections-via-symbols
669 // is a bit tricky. Here we introduce a symbol for the prefix data
670 // and use the .alt_entry attribute to mark the function's real entry point
671 // as an alternative entry point to the prefix-data symbol.
672 MCSymbol *PrefixSym = OutContext.createLinkerPrivateTempSymbol();
673 OutStreamer->EmitLabel(PrefixSym);
674
675 EmitGlobalConstant(F.getParent()->getDataLayout(), F.getPrefixData());
676
677 // Emit an .alt_entry directive for the actual function symbol.
678 OutStreamer->EmitSymbolAttribute(CurrentFnSym, MCSA_AltEntry);
679 } else {
680 EmitGlobalConstant(F.getParent()->getDataLayout(), F.getPrefixData());
681 }
682 }
683
684 // Emit the CurrentFnSym. This is a virtual function to allow targets to
685 // do their wild and crazy things as required.
686 EmitFunctionEntryLabel();
687
688 // If the function had address-taken blocks that got deleted, then we have
689 // references to the dangling symbols. Emit them at the start of the function
690 // so that we don't get references to undefined symbols.
691 std::vector<MCSymbol*> DeadBlockSyms;
692 MMI->takeDeletedSymbolsForFunction(&F, DeadBlockSyms);
693 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
694 OutStreamer->AddComment("Address taken block that was later removed");
695 OutStreamer->EmitLabel(DeadBlockSyms[i]);
696 }
697
698 if (CurrentFnBegin) {
699 if (MAI->useAssignmentForEHBegin()) {
700 MCSymbol *CurPos = OutContext.createTempSymbol();
701 OutStreamer->EmitLabel(CurPos);
702 OutStreamer->EmitAssignment(CurrentFnBegin,
703 MCSymbolRefExpr::create(CurPos, OutContext));
704 } else {
705 OutStreamer->EmitLabel(CurrentFnBegin);
706 }
707 }
708
709 // Emit pre-function debug and/or EH information.
710 for (const HandlerInfo &HI : Handlers) {
711 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
712 HI.TimerGroupDescription, TimePassesIsEnabled);
713 HI.Handler->beginFunction(MF);
714 }
715
716 // Emit the prologue data.
717 if (F.hasPrologueData())
718 EmitGlobalConstant(F.getParent()->getDataLayout(), F.getPrologueData());
719}
720
721/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
722/// function. This can be overridden by targets as required to do custom stuff.
723void AsmPrinter::EmitFunctionEntryLabel() {
724 CurrentFnSym->redefineIfPossible();
725
726 // The function label could have already been emitted if two symbols end up
727 // conflicting due to asm renaming. Detect this and emit an error.
728 if (CurrentFnSym->isVariable())
729 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
730 "' is a protected alias");
731 if (CurrentFnSym->isDefined())
732 report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
733 "' label emitted multiple times to assembly file");
734
735 return OutStreamer->EmitLabel(CurrentFnSym);
736}
737
738/// emitComments - Pretty-print comments for instructions.
739/// It returns true iff the sched comment was emitted.
740/// Otherwise it returns false.
741static bool emitComments(const MachineInstr &MI, raw_ostream &CommentOS,
742 AsmPrinter *AP) {
743 const MachineFunction *MF = MI.getMF();
744 const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
745
746 // Check for spills and reloads
747 int FI;
748
749 const MachineFrameInfo &MFI = MF->getFrameInfo();
750 bool Commented = false;
751
752 // We assume a single instruction only has a spill or reload, not
753 // both.
754 const MachineMemOperand *MMO;
755 if (TII->isLoadFromStackSlotPostFE(MI, FI)) {
756 if (MFI.isSpillSlotObjectIndex(FI)) {
757 MMO = *MI.memoperands_begin();
758 CommentOS << MMO->getSize() << "-byte Reload";
759 Commented = true;
760 }
761 } else if (TII->hasLoadFromStackSlot(MI, MMO, FI)) {
762 if (MFI.isSpillSlotObjectIndex(FI)) {
763 CommentOS << MMO->getSize() << "-byte Folded Reload";
764 Commented = true;
765 }
766 } else if (TII->isStoreToStackSlotPostFE(MI, FI)) {
767 if (MFI.isSpillSlotObjectIndex(FI)) {
768 MMO = *MI.memoperands_begin();
769 CommentOS << MMO->getSize() << "-byte Spill";
770 Commented = true;
771 }
772 } else if (TII->hasStoreToStackSlot(MI, MMO, FI)) {
773 if (MFI.isSpillSlotObjectIndex(FI)) {
774 CommentOS << MMO->getSize() << "-byte Folded Spill";
775 Commented = true;
776 }
777 }
778
779 // Check for spill-induced copies
780 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse)) {
781 Commented = true;
782 CommentOS << " Reload Reuse";
783 }
784
785 if (Commented) {
786 if (AP->EnablePrintSchedInfo) {
787 // If any comment was added above and we need sched info comment then add
788 // this new comment just after the above comment w/o "\n" between them.
789 CommentOS << " " << MF->getSubtarget().getSchedInfoStr(MI) << "\n";
790 return true;
791 }
792 CommentOS << "\n";
793 }
794 return false;
795}
796
797/// emitImplicitDef - This method emits the specified machine instruction
798/// that is an implicit def.
799void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const {
800 unsigned RegNo = MI->getOperand(0).getReg();
801
802 SmallString<128> Str;
803 raw_svector_ostream OS(Str);
804 OS << "implicit-def: "
805 << printReg(RegNo, MF->getSubtarget().getRegisterInfo());
806
807 OutStreamer->AddComment(OS.str());
808 OutStreamer->AddBlankLine();
809}
810
811static void emitKill(const MachineInstr *MI, AsmPrinter &AP) {
812 std::string Str;
813 raw_string_ostream OS(Str);
814 OS << "kill:";
815 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
816 const MachineOperand &Op = MI->getOperand(i);
817 assert(Op.isReg() && "KILL instruction must have only register operands")(static_cast <bool> (Op.isReg() && "KILL instruction must have only register operands"
) ? void (0) : __assert_fail ("Op.isReg() && \"KILL instruction must have only register operands\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 817, __extension__ __PRETTY_FUNCTION__))
;
818 OS << ' ' << (Op.isDef() ? "def " : "killed ")
819 << printReg(Op.getReg(), AP.MF->getSubtarget().getRegisterInfo());
820 }
821 AP.OutStreamer->AddComment(OS.str());
822 AP.OutStreamer->AddBlankLine();
823}
824
825/// emitDebugValueComment - This method handles the target-independent form
826/// of DBG_VALUE, returning true if it was able to do so. A false return
827/// means the target will need to handle MI in EmitInstruction.
828static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
829 // This code handles only the 4-operand target-independent form.
830 if (MI->getNumOperands() != 4)
831 return false;
832
833 SmallString<128> Str;
834 raw_svector_ostream OS(Str);
835 OS << "DEBUG_VALUE: ";
836
837 const DILocalVariable *V = MI->getDebugVariable();
838 if (auto *SP = dyn_cast<DISubprogram>(V->getScope())) {
839 StringRef Name = SP->getName();
840 if (!Name.empty())
841 OS << Name << ":";
842 }
843 OS << V->getName();
844 OS << " <- ";
845
846 // The second operand is only an offset if it's an immediate.
847 bool MemLoc = MI->getOperand(0).isReg() && MI->getOperand(1).isImm();
848 int64_t Offset = MemLoc ? MI->getOperand(1).getImm() : 0;
849 const DIExpression *Expr = MI->getDebugExpression();
850 if (Expr->getNumElements()) {
851 OS << '[';
852 bool NeedSep = false;
853 for (auto Op : Expr->expr_ops()) {
854 if (NeedSep)
855 OS << ", ";
856 else
857 NeedSep = true;
858 OS << dwarf::OperationEncodingString(Op.getOp());
859 for (unsigned I = 0; I < Op.getNumArgs(); ++I)
860 OS << ' ' << Op.getArg(I);
861 }
862 OS << "] ";
863 }
864
865 // Register or immediate value. Register 0 means undef.
866 if (MI->getOperand(0).isFPImm()) {
867 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
868 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
869 OS << (double)APF.convertToFloat();
870 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
871 OS << APF.convertToDouble();
872 } else {
873 // There is no good way to print long double. Convert a copy to
874 // double. Ah well, it's only a comment.
875 bool ignored;
876 APF.convert(APFloat::IEEEdouble(), APFloat::rmNearestTiesToEven,
877 &ignored);
878 OS << "(long double) " << APF.convertToDouble();
879 }
880 } else if (MI->getOperand(0).isImm()) {
881 OS << MI->getOperand(0).getImm();
882 } else if (MI->getOperand(0).isCImm()) {
883 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/);
884 } else {
885 unsigned Reg;
886 if (MI->getOperand(0).isReg()) {
887 Reg = MI->getOperand(0).getReg();
888 } else {
889 assert(MI->getOperand(0).isFI() && "Unknown operand type")(static_cast <bool> (MI->getOperand(0).isFI() &&
"Unknown operand type") ? void (0) : __assert_fail ("MI->getOperand(0).isFI() && \"Unknown operand type\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 889, __extension__ __PRETTY_FUNCTION__))
;
890 const TargetFrameLowering *TFI = AP.MF->getSubtarget().getFrameLowering();
891 Offset += TFI->getFrameIndexReference(*AP.MF,
892 MI->getOperand(0).getIndex(), Reg);
893 MemLoc = true;
894 }
895 if (Reg == 0) {
896 // Suppress offset, it is not meaningful here.
897 OS << "undef";
898 // NOTE: Want this comment at start of line, don't emit with AddComment.
899 AP.OutStreamer->emitRawComment(OS.str());
900 return true;
901 }
902 if (MemLoc)
903 OS << '[';
904 OS << printReg(Reg, AP.MF->getSubtarget().getRegisterInfo());
905 }
906
907 if (MemLoc)
908 OS << '+' << Offset << ']';
909
910 // NOTE: Want this comment at start of line, don't emit with AddComment.
911 AP.OutStreamer->emitRawComment(OS.str());
912 return true;
913}
914
915AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() const {
916 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI &&
917 MF->getFunction().needsUnwindTableEntry())
918 return CFI_M_EH;
919
920 if (MMI->hasDebugInfo())
921 return CFI_M_Debug;
922
923 return CFI_M_None;
924}
925
926bool AsmPrinter::needsSEHMoves() {
927 return MAI->usesWindowsCFI() && MF->getFunction().needsUnwindTableEntry();
928}
929
930void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) {
931 ExceptionHandling ExceptionHandlingType = MAI->getExceptionHandlingType();
932 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI &&
933 ExceptionHandlingType != ExceptionHandling::ARM)
934 return;
935
936 if (needsCFIMoves() == CFI_M_None)
937 return;
938
939 // If there is no "real" instruction following this CFI instruction, skip
940 // emitting it; it would be beyond the end of the function's FDE range.
941 auto *MBB = MI.getParent();
942 auto I = std::next(MI.getIterator());
943 while (I != MBB->end() && I->isTransient())
944 ++I;
945 if (I == MBB->instr_end() &&
946 MBB->getReverseIterator() == MBB->getParent()->rbegin())
947 return;
948
949 const std::vector<MCCFIInstruction> &Instrs = MF->getFrameInstructions();
950 unsigned CFIIndex = MI.getOperand(0).getCFIIndex();
951 const MCCFIInstruction &CFI = Instrs[CFIIndex];
952 emitCFIInstruction(CFI);
953}
954
955void AsmPrinter::emitFrameAlloc(const MachineInstr &MI) {
956 // The operands are the MCSymbol and the frame offset of the allocation.
957 MCSymbol *FrameAllocSym = MI.getOperand(0).getMCSymbol();
958 int FrameOffset = MI.getOperand(1).getImm();
959
960 // Emit a symbol assignment.
961 OutStreamer->EmitAssignment(FrameAllocSym,
962 MCConstantExpr::create(FrameOffset, OutContext));
963}
964
965void AsmPrinter::emitStackSizeSection(const MachineFunction &MF) {
966 if (!MF.getTarget().Options.EmitStackSizeSection)
967 return;
968
969 MCSection *StackSizeSection = getObjFileLowering().getStackSizesSection();
970 if (!StackSizeSection)
971 return;
972
973 const MachineFrameInfo &FrameInfo = MF.getFrameInfo();
974 // Don't emit functions with dynamic stack allocations.
975 if (FrameInfo.hasVarSizedObjects())
976 return;
977
978 OutStreamer->PushSection();
979 OutStreamer->SwitchSection(StackSizeSection);
980
981 const MCSymbol *FunctionSymbol = getFunctionBegin();
982 uint64_t StackSize = FrameInfo.getStackSize();
983 OutStreamer->EmitSymbolValue(FunctionSymbol, TM.getProgramPointerSize());
984 OutStreamer->EmitULEB128IntValue(StackSize);
985
986 OutStreamer->PopSection();
987}
988
989static bool needFuncLabelsForEHOrDebugInfo(const MachineFunction &MF,
990 MachineModuleInfo *MMI) {
991 if (!MF.getLandingPads().empty() || MF.hasEHFunclets() || MMI->hasDebugInfo())
992 return true;
993
994 // We might emit an EH table that uses function begin and end labels even if
995 // we don't have any landingpads.
996 if (!MF.getFunction().hasPersonalityFn())
997 return false;
998 return !isNoOpWithoutInvoke(
999 classifyEHPersonality(MF.getFunction().getPersonalityFn()));
1000}
1001
1002/// EmitFunctionBody - This method emits the body and trailer for a
1003/// function.
1004void AsmPrinter::EmitFunctionBody() {
1005 EmitFunctionHeader();
1006
1007 // Emit target-specific gunk before the function body.
1008 EmitFunctionBodyStart();
1009
1010 bool ShouldPrintDebugScopes = MMI->hasDebugInfo();
1011
1012 if (isVerbose()) {
1013 // Get MachineDominatorTree or compute it on the fly if it's unavailable
1014 MDT = getAnalysisIfAvailable<MachineDominatorTree>();
1015 if (!MDT) {
1016 OwnedMDT = make_unique<MachineDominatorTree>();
1017 OwnedMDT->getBase().recalculate(*MF);
1018 MDT = OwnedMDT.get();
1019 }
1020
1021 // Get MachineLoopInfo or compute it on the fly if it's unavailable
1022 MLI = getAnalysisIfAvailable<MachineLoopInfo>();
1023 if (!MLI) {
1024 OwnedMLI = make_unique<MachineLoopInfo>();
1025 OwnedMLI->getBase().analyze(MDT->getBase());
1026 MLI = OwnedMLI.get();
1027 }
1028 }
1029
1030 // Print out code for the function.
1031 bool HasAnyRealCode = false;
1032 int NumInstsInFunction = 0;
1033 for (auto &MBB : *MF) {
1034 // Print a label for the basic block.
1035 EmitBasicBlockStart(MBB);
1036 for (auto &MI : MBB) {
1037 // Print the assembly for the instruction.
1038 if (!MI.isPosition() && !MI.isImplicitDef() && !MI.isKill() &&
1039 !MI.isDebugValue()) {
1040 HasAnyRealCode = true;
1041 ++NumInstsInFunction;
1042 }
1043
1044 if (ShouldPrintDebugScopes) {
1045 for (const HandlerInfo &HI : Handlers) {
1046 NamedRegionTimer T(HI.TimerName, HI.TimerDescription,
1047 HI.TimerGroupName, HI.TimerGroupDescription,
1048 TimePassesIsEnabled);
1049 HI.Handler->beginInstruction(&MI);
1050 }
1051 }
1052
1053 if (isVerbose() && emitComments(MI, OutStreamer->GetCommentOS(), this)) {
1054 MachineInstr *MIP = const_cast<MachineInstr *>(&MI);
1055 MIP->setAsmPrinterFlag(MachineInstr::NoSchedComment);
1056 }
1057
1058 switch (MI.getOpcode()) {
1059 case TargetOpcode::CFI_INSTRUCTION:
1060 emitCFIInstruction(MI);
1061 break;
1062 case TargetOpcode::LOCAL_ESCAPE:
1063 emitFrameAlloc(MI);
1064 break;
1065 case TargetOpcode::EH_LABEL:
1066 case TargetOpcode::GC_LABEL:
1067 OutStreamer->EmitLabel(MI.getOperand(0).getMCSymbol());
1068 break;
1069 case TargetOpcode::INLINEASM:
1070 EmitInlineAsm(&MI);
1071 break;
1072 case TargetOpcode::DBG_VALUE:
1073 if (isVerbose()) {
1074 if (!emitDebugValueComment(&MI, *this))
1075 EmitInstruction(&MI);
1076 }
1077 break;
1078 case TargetOpcode::IMPLICIT_DEF:
1079 if (isVerbose()) emitImplicitDef(&MI);
1080 break;
1081 case TargetOpcode::KILL:
1082 if (isVerbose()) emitKill(&MI, *this);
1083 break;
1084 default:
1085 EmitInstruction(&MI);
1086 break;
1087 }
1088
1089 if (ShouldPrintDebugScopes) {
1090 for (const HandlerInfo &HI : Handlers) {
1091 NamedRegionTimer T(HI.TimerName, HI.TimerDescription,
1092 HI.TimerGroupName, HI.TimerGroupDescription,
1093 TimePassesIsEnabled);
1094 HI.Handler->endInstruction();
1095 }
1096 }
1097 }
1098
1099 EmitBasicBlockEnd(MBB);
1100 }
1101
1102 EmittedInsts += NumInstsInFunction;
1103 MachineOptimizationRemarkAnalysis R(DEBUG_TYPE"asm-printer", "InstructionCount",
1104 MF->getFunction().getSubprogram(),
1105 &MF->front());
1106 R << ore::NV("NumInstructions", NumInstsInFunction)
1107 << " instructions in function";
1108 ORE->emit(R);
1109
1110 // If the function is empty and the object file uses .subsections_via_symbols,
1111 // then we need to emit *something* to the function body to prevent the
1112 // labels from collapsing together. Just emit a noop.
1113 // Similarly, don't emit empty functions on Windows either. It can lead to
1114 // duplicate entries (two functions with the same RVA) in the Guard CF Table
1115 // after linking, causing the kernel not to load the binary:
1116 // https://developercommunity.visualstudio.com/content/problem/45366/vc-linker-creates-invalid-dll-with-clang-cl.html
1117 // FIXME: Hide this behind some API in e.g. MCAsmInfo or MCTargetStreamer.
1118 const Triple &TT = TM.getTargetTriple();
1119 if (!HasAnyRealCode && (MAI->hasSubsectionsViaSymbols() ||
1120 (TT.isOSWindows() && TT.isOSBinFormatCOFF()))) {
1121 MCInst Noop;
1122 MF->getSubtarget().getInstrInfo()->getNoop(Noop);
1123
1124 // Targets can opt-out of emitting the noop here by leaving the opcode
1125 // unspecified.
1126 if (Noop.getOpcode()) {
1127 OutStreamer->AddComment("avoids zero-length function");
1128 OutStreamer->EmitInstruction(Noop, getSubtargetInfo());
1129 }
1130 }
1131
1132 const Function &F = MF->getFunction();
1133 for (const auto &BB : F) {
1134 if (!BB.hasAddressTaken())
1135 continue;
1136 MCSymbol *Sym = GetBlockAddressSymbol(&BB);
1137 if (Sym->isDefined())
1138 continue;
1139 OutStreamer->AddComment("Address of block that was removed by CodeGen");
1140 OutStreamer->EmitLabel(Sym);
1141 }
1142
1143 // Emit target-specific gunk after the function body.
1144 EmitFunctionBodyEnd();
1145
1146 if (needFuncLabelsForEHOrDebugInfo(*MF, MMI) ||
1147 MAI->hasDotTypeDotSizeDirective()) {
1148 // Create a symbol for the end of function.
1149 CurrentFnEnd = createTempSymbol("func_end");
1150 OutStreamer->EmitLabel(CurrentFnEnd);
1151 }
1152
1153 // If the target wants a .size directive for the size of the function, emit
1154 // it.
1155 if (MAI->hasDotTypeDotSizeDirective()) {
1156 // We can get the size as difference between the function label and the
1157 // temp label.
1158 const MCExpr *SizeExp = MCBinaryExpr::createSub(
1159 MCSymbolRefExpr::create(CurrentFnEnd, OutContext),
1160 MCSymbolRefExpr::create(CurrentFnSymForSize, OutContext), OutContext);
1161 OutStreamer->emitELFSize(CurrentFnSym, SizeExp);
1162 }
1163
1164 for (const HandlerInfo &HI : Handlers) {
1165 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
1166 HI.TimerGroupDescription, TimePassesIsEnabled);
1167 HI.Handler->markFunctionEnd();
1168 }
1169
1170 // Print out jump tables referenced by the function.
1171 EmitJumpTableInfo();
1172
1173 // Emit post-function debug and/or EH information.
1174 for (const HandlerInfo &HI : Handlers) {
1175 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
1176 HI.TimerGroupDescription, TimePassesIsEnabled);
1177 HI.Handler->endFunction(MF);
1178 }
1179
1180 // Emit section containing stack size metadata.
1181 emitStackSizeSection(*MF);
1182
1183 if (isVerbose())
1184 OutStreamer->GetCommentOS() << "-- End function\n";
1185
1186 OutStreamer->AddBlankLine();
1187}
1188
1189/// \brief Compute the number of Global Variables that uses a Constant.
1190static unsigned getNumGlobalVariableUses(const Constant *C) {
1191 if (!C)
1192 return 0;
1193
1194 if (isa<GlobalVariable>(C))
1195 return 1;
1196
1197 unsigned NumUses = 0;
1198 for (auto *CU : C->users())
1199 NumUses += getNumGlobalVariableUses(dyn_cast<Constant>(CU));
1200
1201 return NumUses;
1202}
1203
1204/// \brief Only consider global GOT equivalents if at least one user is a
1205/// cstexpr inside an initializer of another global variables. Also, don't
1206/// handle cstexpr inside instructions. During global variable emission,
1207/// candidates are skipped and are emitted later in case at least one cstexpr
1208/// isn't replaced by a PC relative GOT entry access.
1209static bool isGOTEquivalentCandidate(const GlobalVariable *GV,
1210 unsigned &NumGOTEquivUsers) {
1211 // Global GOT equivalents are unnamed private globals with a constant
1212 // pointer initializer to another global symbol. They must point to a
1213 // GlobalVariable or Function, i.e., as GlobalValue.
1214 if (!GV->hasGlobalUnnamedAddr() || !GV->hasInitializer() ||
1215 !GV->isConstant() || !GV->isDiscardableIfUnused() ||
1216 !dyn_cast<GlobalValue>(GV->getOperand(0)))
1217 return false;
1218
1219 // To be a got equivalent, at least one of its users need to be a constant
1220 // expression used by another global variable.
1221 for (auto *U : GV->users())
1222 NumGOTEquivUsers += getNumGlobalVariableUses(dyn_cast<Constant>(U));
1223
1224 return NumGOTEquivUsers > 0;
1225}
1226
1227/// \brief Unnamed constant global variables solely contaning a pointer to
1228/// another globals variable is equivalent to a GOT table entry; it contains the
1229/// the address of another symbol. Optimize it and replace accesses to these
1230/// "GOT equivalents" by using the GOT entry for the final global instead.
1231/// Compute GOT equivalent candidates among all global variables to avoid
1232/// emitting them if possible later on, after it use is replaced by a GOT entry
1233/// access.
1234void AsmPrinter::computeGlobalGOTEquivs(Module &M) {
1235 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
1236 return;
1237
1238 for (const auto &G : M.globals()) {
1239 unsigned NumGOTEquivUsers = 0;
1240 if (!isGOTEquivalentCandidate(&G, NumGOTEquivUsers))
1241 continue;
1242
1243 const MCSymbol *GOTEquivSym = getSymbol(&G);
1244 GlobalGOTEquivs[GOTEquivSym] = std::make_pair(&G, NumGOTEquivUsers);
1245 }
1246}
1247
1248/// \brief Constant expressions using GOT equivalent globals may not be eligible
1249/// for PC relative GOT entry conversion, in such cases we need to emit such
1250/// globals we previously omitted in EmitGlobalVariable.
1251void AsmPrinter::emitGlobalGOTEquivs() {
1252 if (!getObjFileLowering().supportIndirectSymViaGOTPCRel())
1253 return;
1254
1255 SmallVector<const GlobalVariable *, 8> FailedCandidates;
1256 for (auto &I : GlobalGOTEquivs) {
1257 const GlobalVariable *GV = I.second.first;
1258 unsigned Cnt = I.second.second;
1259 if (Cnt)
1260 FailedCandidates.push_back(GV);
1261 }
1262 GlobalGOTEquivs.clear();
1263
1264 for (auto *GV : FailedCandidates)
1265 EmitGlobalVariable(GV);
1266}
1267
1268void AsmPrinter::emitGlobalIndirectSymbol(Module &M,
1269 const GlobalIndirectSymbol& GIS) {
1270 MCSymbol *Name = getSymbol(&GIS);
1271
1272 if (GIS.hasExternalLinkage() || !MAI->getWeakRefDirective())
1273 OutStreamer->EmitSymbolAttribute(Name, MCSA_Global);
1274 else if (GIS.hasWeakLinkage() || GIS.hasLinkOnceLinkage())
1275 OutStreamer->EmitSymbolAttribute(Name, MCSA_WeakReference);
1276 else
1277 assert(GIS.hasLocalLinkage() && "Invalid alias or ifunc linkage")(static_cast <bool> (GIS.hasLocalLinkage() && "Invalid alias or ifunc linkage"
) ? void (0) : __assert_fail ("GIS.hasLocalLinkage() && \"Invalid alias or ifunc linkage\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 1277, __extension__ __PRETTY_FUNCTION__))
;
1278
1279 // Set the symbol type to function if the alias has a function type.
1280 // This affects codegen when the aliasee is not a function.
1281 if (GIS.getType()->getPointerElementType()->isFunctionTy()) {
1282 OutStreamer->EmitSymbolAttribute(Name, MCSA_ELF_TypeFunction);
1283 if (isa<GlobalIFunc>(GIS))
1284 OutStreamer->EmitSymbolAttribute(Name, MCSA_ELF_TypeIndFunction);
1285 }
1286
1287 EmitVisibility(Name, GIS.getVisibility());
1288
1289 const MCExpr *Expr = lowerConstant(GIS.getIndirectSymbol());
1290
1291 if (isa<GlobalAlias>(&GIS) && MAI->hasAltEntry() && isa<MCBinaryExpr>(Expr))
1292 OutStreamer->EmitSymbolAttribute(Name, MCSA_AltEntry);
1293
1294 // Emit the directives as assignments aka .set:
1295 OutStreamer->EmitAssignment(Name, Expr);
1296
1297 if (auto *GA = dyn_cast<GlobalAlias>(&GIS)) {
1298 // If the aliasee does not correspond to a symbol in the output, i.e. the
1299 // alias is not of an object or the aliased object is private, then set the
1300 // size of the alias symbol from the type of the alias. We don't do this in
1301 // other situations as the alias and aliasee having differing types but same
1302 // size may be intentional.
1303 const GlobalObject *BaseObject = GA->getBaseObject();
1304 if (MAI->hasDotTypeDotSizeDirective() && GA->getValueType()->isSized() &&
1305 (!BaseObject || BaseObject->hasPrivateLinkage())) {
1306 const DataLayout &DL = M.getDataLayout();
1307 uint64_t Size = DL.getTypeAllocSize(GA->getValueType());
1308 OutStreamer->emitELFSize(Name, MCConstantExpr::create(Size, OutContext));
1309 }
1310 }
1311}
1312
1313bool AsmPrinter::doFinalization(Module &M) {
1314 // Set the MachineFunction to nullptr so that we can catch attempted
1315 // accesses to MF specific features at the module level and so that
1316 // we can conditionalize accesses based on whether or not it is nullptr.
1317 MF = nullptr;
1318
1319 // Gather all GOT equivalent globals in the module. We really need two
1320 // passes over the globals: one to compute and another to avoid its emission
1321 // in EmitGlobalVariable, otherwise we would not be able to handle cases
1322 // where the got equivalent shows up before its use.
1323 computeGlobalGOTEquivs(M);
1324
1325 // Emit global variables.
1326 for (const auto &G : M.globals())
1327 EmitGlobalVariable(&G);
1
Calling 'AsmPrinter::EmitGlobalVariable'
1328
1329 // Emit remaining GOT equivalent globals.
1330 emitGlobalGOTEquivs();
1331
1332 // Emit visibility info for declarations
1333 for (const Function &F : M) {
1334 if (!F.isDeclarationForLinker())
1335 continue;
1336 GlobalValue::VisibilityTypes V = F.getVisibility();
1337 if (V == GlobalValue::DefaultVisibility)
1338 continue;
1339
1340 MCSymbol *Name = getSymbol(&F);
1341 EmitVisibility(Name, V, false);
1342 }
1343
1344 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
1345
1346 TLOF.emitModuleMetadata(*OutStreamer, M, TM);
1347
1348 if (TM.getTargetTriple().isOSBinFormatELF()) {
1349 MachineModuleInfoELF &MMIELF = MMI->getObjFileInfo<MachineModuleInfoELF>();
1350
1351 // Output stubs for external and common global variables.
1352 MachineModuleInfoELF::SymbolListTy Stubs = MMIELF.GetGVStubList();
1353 if (!Stubs.empty()) {
1354 OutStreamer->SwitchSection(TLOF.getDataSection());
1355 const DataLayout &DL = M.getDataLayout();
1356
1357 EmitAlignment(Log2_32(DL.getPointerSize()));
1358 for (const auto &Stub : Stubs) {
1359 OutStreamer->EmitLabel(Stub.first);
1360 OutStreamer->EmitSymbolValue(Stub.second.getPointer(),
1361 DL.getPointerSize());
1362 }
1363 }
1364 }
1365
1366 // Finalize debug and EH information.
1367 for (const HandlerInfo &HI : Handlers) {
1368 NamedRegionTimer T(HI.TimerName, HI.TimerDescription, HI.TimerGroupName,
1369 HI.TimerGroupDescription, TimePassesIsEnabled);
1370 HI.Handler->endModule();
1371 delete HI.Handler;
1372 }
1373 Handlers.clear();
1374 DD = nullptr;
1375
1376 // If the target wants to know about weak references, print them all.
1377 if (MAI->getWeakRefDirective()) {
1378 // FIXME: This is not lazy, it would be nice to only print weak references
1379 // to stuff that is actually used. Note that doing so would require targets
1380 // to notice uses in operands (due to constant exprs etc). This should
1381 // happen with the MC stuff eventually.
1382
1383 // Print out module-level global objects here.
1384 for (const auto &GO : M.global_objects()) {
1385 if (!GO.hasExternalWeakLinkage())
1386 continue;
1387 OutStreamer->EmitSymbolAttribute(getSymbol(&GO), MCSA_WeakReference);
1388 }
1389 }
1390
1391 OutStreamer->AddBlankLine();
1392
1393 // Print aliases in topological order, that is, for each alias a = b,
1394 // b must be printed before a.
1395 // This is because on some targets (e.g. PowerPC) linker expects aliases in
1396 // such an order to generate correct TOC information.
1397 SmallVector<const GlobalAlias *, 16> AliasStack;
1398 SmallPtrSet<const GlobalAlias *, 16> AliasVisited;
1399 for (const auto &Alias : M.aliases()) {
1400 for (const GlobalAlias *Cur = &Alias; Cur;
1401 Cur = dyn_cast<GlobalAlias>(Cur->getAliasee())) {
1402 if (!AliasVisited.insert(Cur).second)
1403 break;
1404 AliasStack.push_back(Cur);
1405 }
1406 for (const GlobalAlias *AncestorAlias : llvm::reverse(AliasStack))
1407 emitGlobalIndirectSymbol(M, *AncestorAlias);
1408 AliasStack.clear();
1409 }
1410 for (const auto &IFunc : M.ifuncs())
1411 emitGlobalIndirectSymbol(M, IFunc);
1412
1413 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
1414 assert(MI && "AsmPrinter didn't require GCModuleInfo?")(static_cast <bool> (MI && "AsmPrinter didn't require GCModuleInfo?"
) ? void (0) : __assert_fail ("MI && \"AsmPrinter didn't require GCModuleInfo?\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 1414, __extension__ __PRETTY_FUNCTION__))
;
1415 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
1416 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(**--I))
1417 MP->finishAssembly(M, *MI, *this);
1418
1419 // Emit llvm.ident metadata in an '.ident' directive.
1420 EmitModuleIdents(M);
1421
1422 // Emit __morestack address if needed for indirect calls.
1423 if (MMI->usesMorestackAddr()) {
1424 unsigned Align = 1;
1425 MCSection *ReadOnlySection = getObjFileLowering().getSectionForConstant(
1426 getDataLayout(), SectionKind::getReadOnly(),
1427 /*C=*/nullptr, Align);
1428 OutStreamer->SwitchSection(ReadOnlySection);
1429
1430 MCSymbol *AddrSymbol =
1431 OutContext.getOrCreateSymbol(StringRef("__morestack_addr"));
1432 OutStreamer->EmitLabel(AddrSymbol);
1433
1434 unsigned PtrSize = MAI->getCodePointerSize();
1435 OutStreamer->EmitSymbolValue(GetExternalSymbolSymbol("__morestack"),
1436 PtrSize);
1437 }
1438
1439 // Emit .note.GNU-split-stack and .note.GNU-no-split-stack sections if
1440 // split-stack is used.
1441 if (TM.getTargetTriple().isOSBinFormatELF() && MMI->hasSplitStack()) {
1442 OutStreamer->SwitchSection(
1443 OutContext.getELFSection(".note.GNU-split-stack", ELF::SHT_PROGBITS, 0));
1444 if (MMI->hasNosplitStack())
1445 OutStreamer->SwitchSection(
1446 OutContext.getELFSection(".note.GNU-no-split-stack", ELF::SHT_PROGBITS, 0));
1447 }
1448
1449 // If we don't have any trampolines, then we don't require stack memory
1450 // to be executable. Some targets have a directive to declare this.
1451 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
1452 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
1453 if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
1454 OutStreamer->SwitchSection(S);
1455
1456 if (TM.getTargetTriple().isOSBinFormatCOFF()) {
1457 // Emit /EXPORT: flags for each exported global as necessary.
1458 const auto &TLOF = getObjFileLowering();
1459 std::string Flags;
1460
1461 for (const GlobalValue &GV : M.global_values()) {
1462 raw_string_ostream OS(Flags);
1463 TLOF.emitLinkerFlagsForGlobal(OS, &GV);
1464 OS.flush();
1465 if (!Flags.empty()) {
1466 OutStreamer->SwitchSection(TLOF.getDrectveSection());
1467 OutStreamer->EmitBytes(Flags);
1468 }
1469 Flags.clear();
1470 }
1471
1472 // Emit /INCLUDE: flags for each used global as necessary.
1473 if (const auto *LU = M.getNamedGlobal("llvm.used")) {
1474 assert(LU->hasInitializer() &&(static_cast <bool> (LU->hasInitializer() &&
"expected llvm.used to have an initializer") ? void (0) : __assert_fail
("LU->hasInitializer() && \"expected llvm.used to have an initializer\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 1475, __extension__ __PRETTY_FUNCTION__))
1475 "expected llvm.used to have an initializer")(static_cast <bool> (LU->hasInitializer() &&
"expected llvm.used to have an initializer") ? void (0) : __assert_fail
("LU->hasInitializer() && \"expected llvm.used to have an initializer\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 1475, __extension__ __PRETTY_FUNCTION__))
;
1476 assert(isa<ArrayType>(LU->getValueType()) &&(static_cast <bool> (isa<ArrayType>(LU->getValueType
()) && "expected llvm.used to be an array type") ? void
(0) : __assert_fail ("isa<ArrayType>(LU->getValueType()) && \"expected llvm.used to be an array type\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 1477, __extension__ __PRETTY_FUNCTION__))
1477 "expected llvm.used to be an array type")(static_cast <bool> (isa<ArrayType>(LU->getValueType
()) && "expected llvm.used to be an array type") ? void
(0) : __assert_fail ("isa<ArrayType>(LU->getValueType()) && \"expected llvm.used to be an array type\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 1477, __extension__ __PRETTY_FUNCTION__))
;
1478 if (const auto *A = cast<ConstantArray>(LU->getInitializer())) {
1479 for (const Value *Op : A->operands()) {
1480 const auto *GV =
1481 cast<GlobalValue>(Op->stripPointerCastsNoFollowAliases());
1482 // Global symbols with internal or private linkage are not visible to
1483 // the linker, and thus would cause an error when the linker tried to
1484 // preserve the symbol due to the `/include:` directive.
1485 if (GV->hasLocalLinkage())
1486 continue;
1487
1488 raw_string_ostream OS(Flags);
1489 TLOF.emitLinkerFlagsForUsed(OS, GV);
1490 OS.flush();
1491
1492 if (!Flags.empty()) {
1493 OutStreamer->SwitchSection(TLOF.getDrectveSection());
1494 OutStreamer->EmitBytes(Flags);
1495 }
1496 Flags.clear();
1497 }
1498 }
1499 }
1500 }
1501
1502 // Allow the target to emit any magic that it wants at the end of the file,
1503 // after everything else has gone out.
1504 EmitEndOfAsmFile(M);
1505
1506 MMI = nullptr;
1507
1508 OutStreamer->Finish();
1509 OutStreamer->reset();
1510 OwnedMLI.reset();
1511 OwnedMDT.reset();
1512
1513 return false;
1514}
1515
1516MCSymbol *AsmPrinter::getCurExceptionSym() {
1517 if (!CurExceptionSym)
1518 CurExceptionSym = createTempSymbol("exception");
1519 return CurExceptionSym;
1520}
1521
1522void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
1523 this->MF = &MF;
1524 // Get the function symbol.
1525 CurrentFnSym = getSymbol(&MF.getFunction());
1526 CurrentFnSymForSize = CurrentFnSym;
1527 CurrentFnBegin = nullptr;
1528 CurExceptionSym = nullptr;
1529 bool NeedsLocalForSize = MAI->needsLocalForSize();
1530 if (needFuncLabelsForEHOrDebugInfo(MF, MMI) || NeedsLocalForSize ||
1531 MF.getTarget().Options.EmitStackSizeSection) {
1532 CurrentFnBegin = createTempSymbol("func_begin");
1533 if (NeedsLocalForSize)
1534 CurrentFnSymForSize = CurrentFnBegin;
1535 }
1536
1537 ORE = &getAnalysis<MachineOptimizationRemarkEmitterPass>().getORE();
1538
1539 const TargetSubtargetInfo &STI = MF.getSubtarget();
1540 EnablePrintSchedInfo = PrintSchedule.getNumOccurrences()
1541 ? PrintSchedule
1542 : STI.supportPrintSchedInfo();
1543}
1544
1545namespace {
1546
1547// Keep track the alignment, constpool entries per Section.
1548 struct SectionCPs {
1549 MCSection *S;
1550 unsigned Alignment;
1551 SmallVector<unsigned, 4> CPEs;
1552
1553 SectionCPs(MCSection *s, unsigned a) : S(s), Alignment(a) {}
1554 };
1555
1556} // end anonymous namespace
1557
1558/// EmitConstantPool - Print to the current output stream assembly
1559/// representations of the constants in the constant pool MCP. This is
1560/// used to print out constants which have been "spilled to memory" by
1561/// the code generator.
1562void AsmPrinter::EmitConstantPool() {
1563 const MachineConstantPool *MCP = MF->getConstantPool();
1564 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
1565 if (CP.empty()) return;
1566
1567 // Calculate sections for constant pool entries. We collect entries to go into
1568 // the same section together to reduce amount of section switch statements.
1569 SmallVector<SectionCPs, 4> CPSections;
1570 for (unsigned i = 0, e = CP.size(); i != e; ++i) {
1571 const MachineConstantPoolEntry &CPE = CP[i];
1572 unsigned Align = CPE.getAlignment();
1573
1574 SectionKind Kind = CPE.getSectionKind(&getDataLayout());
1575
1576 const Constant *C = nullptr;
1577 if (!CPE.isMachineConstantPoolEntry())
1578 C = CPE.Val.ConstVal;
1579
1580 MCSection *S = getObjFileLowering().getSectionForConstant(getDataLayout(),
1581 Kind, C, Align);
1582
1583 // The number of sections are small, just do a linear search from the
1584 // last section to the first.
1585 bool Found = false;
1586 unsigned SecIdx = CPSections.size();
1587 while (SecIdx != 0) {
1588 if (CPSections[--SecIdx].S == S) {
1589 Found = true;
1590 break;
1591 }
1592 }
1593 if (!Found) {
1594 SecIdx = CPSections.size();
1595 CPSections.push_back(SectionCPs(S, Align));
1596 }
1597
1598 if (Align > CPSections[SecIdx].Alignment)
1599 CPSections[SecIdx].Alignment = Align;
1600 CPSections[SecIdx].CPEs.push_back(i);
1601 }
1602
1603 // Now print stuff into the calculated sections.
1604 const MCSection *CurSection = nullptr;
1605 unsigned Offset = 0;
1606 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
1607 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
1608 unsigned CPI = CPSections[i].CPEs[j];
1609 MCSymbol *Sym = GetCPISymbol(CPI);
1610 if (!Sym->isUndefined())
1611 continue;
1612
1613 if (CurSection != CPSections[i].S) {
1614 OutStreamer->SwitchSection(CPSections[i].S);
1615 EmitAlignment(Log2_32(CPSections[i].Alignment));
1616 CurSection = CPSections[i].S;
1617 Offset = 0;
1618 }
1619
1620 MachineConstantPoolEntry CPE = CP[CPI];
1621
1622 // Emit inter-object padding for alignment.
1623 unsigned AlignMask = CPE.getAlignment() - 1;
1624 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
1625 OutStreamer->EmitZeros(NewOffset - Offset);
1626
1627 Type *Ty = CPE.getType();
1628 Offset = NewOffset + getDataLayout().getTypeAllocSize(Ty);
1629
1630 OutStreamer->EmitLabel(Sym);
1631 if (CPE.isMachineConstantPoolEntry())
1632 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
1633 else
1634 EmitGlobalConstant(getDataLayout(), CPE.Val.ConstVal);
1635 }
1636 }
1637}
1638
1639/// EmitJumpTableInfo - Print assembly representations of the jump tables used
1640/// by the current function to the current output stream.
1641void AsmPrinter::EmitJumpTableInfo() {
1642 const DataLayout &DL = MF->getDataLayout();
1643 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
1644 if (!MJTI) return;
1645 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
1646 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1647 if (JT.empty()) return;
1648
1649 // Pick the directive to use to print the jump table entries, and switch to
1650 // the appropriate section.
1651 const Function &F = MF->getFunction();
1652 const TargetLoweringObjectFile &TLOF = getObjFileLowering();
1653 bool JTInDiffSection = !TLOF.shouldPutJumpTableInFunctionSection(
1654 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32,
1655 F);
1656 if (JTInDiffSection) {
1657 // Drop it in the readonly section.
1658 MCSection *ReadOnlySection = TLOF.getSectionForJumpTable(F, TM);
1659 OutStreamer->SwitchSection(ReadOnlySection);
1660 }
1661
1662 EmitAlignment(Log2_32(MJTI->getEntryAlignment(DL)));
1663
1664 // Jump tables in code sections are marked with a data_region directive
1665 // where that's supported.
1666 if (!JTInDiffSection)
1667 OutStreamer->EmitDataRegion(MCDR_DataRegionJT32);
1668
1669 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
1670 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
1671
1672 // If this jump table was deleted, ignore it.
1673 if (JTBBs.empty()) continue;
1674
1675 // For the EK_LabelDifference32 entry, if using .set avoids a relocation,
1676 /// emit a .set directive for each unique entry.
1677 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
1678 MAI->doesSetDirectiveSuppressReloc()) {
1679 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
1680 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1681 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
1682 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
1683 const MachineBasicBlock *MBB = JTBBs[ii];
1684 if (!EmittedSets.insert(MBB).second)
1685 continue;
1686
1687 // .set LJTSet, LBB32-base
1688 const MCExpr *LHS =
1689 MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1690 OutStreamer->EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
1691 MCBinaryExpr::createSub(LHS, Base,
1692 OutContext));
1693 }
1694 }
1695
1696 // On some targets (e.g. Darwin) we want to emit two consecutive labels
1697 // before each jump table. The first label is never referenced, but tells
1698 // the assembler and linker the extents of the jump table object. The
1699 // second label is actually referenced by the code.
1700 if (JTInDiffSection && DL.hasLinkerPrivateGlobalPrefix())
1701 // FIXME: This doesn't have to have any specific name, just any randomly
1702 // named and numbered 'l' label would work. Simplify GetJTISymbol.
1703 OutStreamer->EmitLabel(GetJTISymbol(JTI, true));
1704
1705 OutStreamer->EmitLabel(GetJTISymbol(JTI));
1706
1707 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
1708 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1709 }
1710 if (!JTInDiffSection)
1711 OutStreamer->EmitDataRegion(MCDR_DataRegionEnd);
1712}
1713
1714/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1715/// current stream.
1716void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1717 const MachineBasicBlock *MBB,
1718 unsigned UID) const {
1719 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block")(static_cast <bool> (MBB && MBB->getNumber()
>= 0 && "Invalid basic block") ? void (0) : __assert_fail
("MBB && MBB->getNumber() >= 0 && \"Invalid basic block\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 1719, __extension__ __PRETTY_FUNCTION__))
;
1720 const MCExpr *Value = nullptr;
1721 switch (MJTI->getEntryKind()) {
1722 case MachineJumpTableInfo::EK_Inline:
1723 llvm_unreachable("Cannot emit EK_Inline jump table entry")::llvm::llvm_unreachable_internal("Cannot emit EK_Inline jump table entry"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 1723)
;
1724 case MachineJumpTableInfo::EK_Custom32:
1725 Value = MF->getSubtarget().getTargetLowering()->LowerCustomJumpTableEntry(
1726 MJTI, MBB, UID, OutContext);
1727 break;
1728 case MachineJumpTableInfo::EK_BlockAddress:
1729 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1730 // .word LBB123
1731 Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1732 break;
1733 case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1734 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1735 // with a relocation as gp-relative, e.g.:
1736 // .gprel32 LBB123
1737 MCSymbol *MBBSym = MBB->getSymbol();
1738 OutStreamer->EmitGPRel32Value(MCSymbolRefExpr::create(MBBSym, OutContext));
1739 return;
1740 }
1741
1742 case MachineJumpTableInfo::EK_GPRel64BlockAddress: {
1743 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded
1744 // with a relocation as gp-relative, e.g.:
1745 // .gpdword LBB123
1746 MCSymbol *MBBSym = MBB->getSymbol();
1747 OutStreamer->EmitGPRel64Value(MCSymbolRefExpr::create(MBBSym, OutContext));
1748 return;
1749 }
1750
1751 case MachineJumpTableInfo::EK_LabelDifference32: {
1752 // Each entry is the address of the block minus the address of the jump
1753 // table. This is used for PIC jump tables where gprel32 is not supported.
1754 // e.g.:
1755 // .word LBB123 - LJTI1_2
1756 // If the .set directive avoids relocations, this is emitted as:
1757 // .set L4_5_set_123, LBB123 - LJTI1_2
1758 // .word L4_5_set_123
1759 if (MAI->doesSetDirectiveSuppressReloc()) {
1760 Value = MCSymbolRefExpr::create(GetJTSetSymbol(UID, MBB->getNumber()),
1761 OutContext);
1762 break;
1763 }
1764 Value = MCSymbolRefExpr::create(MBB->getSymbol(), OutContext);
1765 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
1766 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF, UID, OutContext);
1767 Value = MCBinaryExpr::createSub(Value, Base, OutContext);
1768 break;
1769 }
1770 }
1771
1772 assert(Value && "Unknown entry kind!")(static_cast <bool> (Value && "Unknown entry kind!"
) ? void (0) : __assert_fail ("Value && \"Unknown entry kind!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 1772, __extension__ __PRETTY_FUNCTION__))
;
1773
1774 unsigned EntrySize = MJTI->getEntrySize(getDataLayout());
1775 OutStreamer->EmitValue(Value, EntrySize);
1776}
1777
1778/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1779/// special global used by LLVM. If so, emit it and return true, otherwise
1780/// do nothing and return false.
1781bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1782 if (GV->getName() == "llvm.used") {
1783 if (MAI->hasNoDeadStrip()) // No need to emit this at all.
1784 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer()));
1785 return true;
1786 }
1787
1788 // Ignore debug and non-emitted data. This handles llvm.compiler.used.
1789 if (GV->getSection() == "llvm.metadata" ||
1790 GV->hasAvailableExternallyLinkage())
1791 return true;
1792
1793 if (!GV->hasAppendingLinkage()) return false;
1794
1795 assert(GV->hasInitializer() && "Not a special LLVM global!")(static_cast <bool> (GV->hasInitializer() &&
"Not a special LLVM global!") ? void (0) : __assert_fail ("GV->hasInitializer() && \"Not a special LLVM global!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 1795, __extension__ __PRETTY_FUNCTION__))
;
1796
1797 if (GV->getName() == "llvm.global_ctors") {
1798 EmitXXStructorList(GV->getParent()->getDataLayout(), GV->getInitializer(),
1799 /* isCtor */ true);
1800
1801 return true;
1802 }
1803
1804 if (GV->getName() == "llvm.global_dtors") {
1805 EmitXXStructorList(GV->getParent()->getDataLayout(), GV->getInitializer(),
1806 /* isCtor */ false);
1807
1808 return true;
1809 }
1810
1811 report_fatal_error("unknown special variable");
1812}
1813
1814/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1815/// global in the specified llvm.used list for which emitUsedDirectiveFor
1816/// is true, as being used with this directive.
1817void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) {
1818 // Should be an array of 'i8*'.
1819 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1820 const GlobalValue *GV =
1821 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1822 if (GV)
1823 OutStreamer->EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip);
1824 }
1825}
1826
1827namespace {
1828
1829struct Structor {
1830 int Priority = 0;
1831 Constant *Func = nullptr;
1832 GlobalValue *ComdatKey = nullptr;
1833
1834 Structor() = default;
1835};
1836
1837} // end anonymous namespace
1838
1839/// EmitXXStructorList - Emit the ctor or dtor list taking into account the init
1840/// priority.
1841void AsmPrinter::EmitXXStructorList(const DataLayout &DL, const Constant *List,
1842 bool isCtor) {
1843 // Should be an array of '{ int, void ()* }' structs. The first value is the
1844 // init priority.
1845 if (!isa<ConstantArray>(List)) return;
1846
1847 // Sanity check the structors list.
1848 const ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1849 if (!InitList) return; // Not an array!
1850 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType());
1851 // FIXME: Only allow the 3-field form in LLVM 4.0.
1852 if (!ETy || ETy->getNumElements() < 2 || ETy->getNumElements() > 3)
1853 return; // Not an array of two or three elements!
1854 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) ||
1855 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr).
1856 if (ETy->getNumElements() == 3 && !isa<PointerType>(ETy->getTypeAtIndex(2U)))
1857 return; // Not (int, ptr, ptr).
1858
1859 // Gather the structors in a form that's convenient for sorting by priority.
1860 SmallVector<Structor, 8> Structors;
1861 for (Value *O : InitList->operands()) {
1862 ConstantStruct *CS = dyn_cast<ConstantStruct>(O);
1863 if (!CS) continue; // Malformed.
1864 if (CS->getOperand(1)->isNullValue())
1865 break; // Found a null terminator, skip the rest.
1866 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0));
1867 if (!Priority) continue; // Malformed.
1868 Structors.push_back(Structor());
1869 Structor &S = Structors.back();
1870 S.Priority = Priority->getLimitedValue(65535);
1871 S.Func = CS->getOperand(1);
1872 if (ETy->getNumElements() == 3 && !CS->getOperand(2)->isNullValue())
1873 S.ComdatKey =
1874 dyn_cast<GlobalValue>(CS->getOperand(2)->stripPointerCasts());
1875 }
1876
1877 // Emit the function pointers in the target-specific order
1878 unsigned Align = Log2_32(DL.getPointerPrefAlignment());
1879 std::stable_sort(Structors.begin(), Structors.end(),
1880 [](const Structor &L,
1881 const Structor &R) { return L.Priority < R.Priority; });
1882 for (Structor &S : Structors) {
1883 const TargetLoweringObjectFile &Obj = getObjFileLowering();
1884 const MCSymbol *KeySym = nullptr;
1885 if (GlobalValue *GV = S.ComdatKey) {
1886 if (GV->isDeclarationForLinker())
1887 // If the associated variable is not defined in this module
1888 // (it might be available_externally, or have been an
1889 // available_externally definition that was dropped by the
1890 // EliminateAvailableExternally pass), some other TU
1891 // will provide its dynamic initializer.
1892 continue;
1893
1894 KeySym = getSymbol(GV);
1895 }
1896 MCSection *OutputSection =
1897 (isCtor ? Obj.getStaticCtorSection(S.Priority, KeySym)
1898 : Obj.getStaticDtorSection(S.Priority, KeySym));
1899 OutStreamer->SwitchSection(OutputSection);
1900 if (OutStreamer->getCurrentSection() != OutStreamer->getPreviousSection())
1901 EmitAlignment(Align);
1902 EmitXXStructor(DL, S.Func);
1903 }
1904}
1905
1906void AsmPrinter::EmitModuleIdents(Module &M) {
1907 if (!MAI->hasIdentDirective())
1908 return;
1909
1910 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) {
1911 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
1912 const MDNode *N = NMD->getOperand(i);
1913 assert(N->getNumOperands() == 1 &&(static_cast <bool> (N->getNumOperands() == 1 &&
"llvm.ident metadata entry can have only one operand") ? void
(0) : __assert_fail ("N->getNumOperands() == 1 && \"llvm.ident metadata entry can have only one operand\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 1914, __extension__ __PRETTY_FUNCTION__))
1914 "llvm.ident metadata entry can have only one operand")(static_cast <bool> (N->getNumOperands() == 1 &&
"llvm.ident metadata entry can have only one operand") ? void
(0) : __assert_fail ("N->getNumOperands() == 1 && \"llvm.ident metadata entry can have only one operand\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 1914, __extension__ __PRETTY_FUNCTION__))
;
1915 const MDString *S = cast<MDString>(N->getOperand(0));
1916 OutStreamer->EmitIdent(S->getString());
1917 }
1918 }
1919}
1920
1921//===--------------------------------------------------------------------===//
1922// Emission and print routines
1923//
1924
1925/// Emit a byte directive and value.
1926///
1927void AsmPrinter::emitInt8(int Value) const {
1928 OutStreamer->EmitIntValue(Value, 1);
1929}
1930
1931/// Emit a short directive and value.
1932void AsmPrinter::emitInt16(int Value) const {
1933 OutStreamer->EmitIntValue(Value, 2);
1934}
1935
1936/// Emit a long directive and value.
1937void AsmPrinter::emitInt32(int Value) const {
1938 OutStreamer->EmitIntValue(Value, 4);
1939}
1940
1941/// Emit something like ".long Hi-Lo" where the size in bytes of the directive
1942/// is specified by Size and Hi/Lo specify the labels. This implicitly uses
1943/// .set if it avoids relocations.
1944void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1945 unsigned Size) const {
1946 OutStreamer->emitAbsoluteSymbolDiff(Hi, Lo, Size);
1947}
1948
1949/// EmitLabelPlusOffset - Emit something like ".long Label+Offset"
1950/// where the size in bytes of the directive is specified by Size and Label
1951/// specifies the label. This implicitly uses .set if it is available.
1952void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset,
1953 unsigned Size,
1954 bool IsSectionRelative) const {
1955 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) {
1956 OutStreamer->EmitCOFFSecRel32(Label, Offset);
1957 if (Size > 4)
1958 OutStreamer->EmitZeros(Size - 4);
1959 return;
1960 }
1961
1962 // Emit Label+Offset (or just Label if Offset is zero)
1963 const MCExpr *Expr = MCSymbolRefExpr::create(Label, OutContext);
1964 if (Offset)
1965 Expr = MCBinaryExpr::createAdd(
1966 Expr, MCConstantExpr::create(Offset, OutContext), OutContext);
1967
1968 OutStreamer->EmitValue(Expr, Size);
1969}
1970
1971//===----------------------------------------------------------------------===//
1972
1973// EmitAlignment - Emit an alignment directive to the specified power of
1974// two boundary. For example, if you pass in 3 here, you will get an 8
1975// byte alignment. If a global value is specified, and if that global has
1976// an explicit alignment requested, it will override the alignment request
1977// if required for correctness.
1978void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalObject *GV) const {
1979 if (GV)
1980 NumBits = getGVAlignmentLog2(GV, GV->getParent()->getDataLayout(), NumBits);
1981
1982 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment.
1983
1984 assert(NumBits <(static_cast <bool> (NumBits < static_cast<unsigned
>(std::numeric_limits<unsigned>::digits) && "undefined behavior"
) ? void (0) : __assert_fail ("NumBits < static_cast<unsigned>(std::numeric_limits<unsigned>::digits) && \"undefined behavior\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 1986, __extension__ __PRETTY_FUNCTION__))
1985 static_cast<unsigned>(std::numeric_limits<unsigned>::digits) &&(static_cast <bool> (NumBits < static_cast<unsigned
>(std::numeric_limits<unsigned>::digits) && "undefined behavior"
) ? void (0) : __assert_fail ("NumBits < static_cast<unsigned>(std::numeric_limits<unsigned>::digits) && \"undefined behavior\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 1986, __extension__ __PRETTY_FUNCTION__))
1986 "undefined behavior")(static_cast <bool> (NumBits < static_cast<unsigned
>(std::numeric_limits<unsigned>::digits) && "undefined behavior"
) ? void (0) : __assert_fail ("NumBits < static_cast<unsigned>(std::numeric_limits<unsigned>::digits) && \"undefined behavior\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 1986, __extension__ __PRETTY_FUNCTION__))
;
1987 if (getCurrentSection()->getKind().isText())
1988 OutStreamer->EmitCodeAlignment(1u << NumBits);
1989 else
1990 OutStreamer->EmitValueToAlignment(1u << NumBits);
1991}
1992
1993//===----------------------------------------------------------------------===//
1994// Constant emission.
1995//===----------------------------------------------------------------------===//
1996
1997const MCExpr *AsmPrinter::lowerConstant(const Constant *CV) {
1998 MCContext &Ctx = OutContext;
1999
2000 if (CV->isNullValue() || isa<UndefValue>(CV))
2001 return MCConstantExpr::create(0, Ctx);
2002
2003 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
2004 return MCConstantExpr::create(CI->getZExtValue(), Ctx);
2005
2006 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
2007 return MCSymbolRefExpr::create(getSymbol(GV), Ctx);
2008
2009 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
2010 return MCSymbolRefExpr::create(GetBlockAddressSymbol(BA), Ctx);
2011
2012 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
2013 if (!CE) {
2014 llvm_unreachable("Unknown constant value to lower!")::llvm::llvm_unreachable_internal("Unknown constant value to lower!"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2014)
;
2015 }
2016
2017 switch (CE->getOpcode()) {
2018 default:
2019 // If the code isn't optimized, there may be outstanding folding
2020 // opportunities. Attempt to fold the expression using DataLayout as a
2021 // last resort before giving up.
2022 if (Constant *C = ConstantFoldConstant(CE, getDataLayout()))
2023 if (C != CE)
2024 return lowerConstant(C);
2025
2026 // Otherwise report the problem to the user.
2027 {
2028 std::string S;
2029 raw_string_ostream OS(S);
2030 OS << "Unsupported expression in static initializer: ";
2031 CE->printAsOperand(OS, /*PrintType=*/false,
2032 !MF ? nullptr : MF->getFunction().getParent());
2033 report_fatal_error(OS.str());
2034 }
2035 case Instruction::GetElementPtr: {
2036 // Generate a symbolic expression for the byte address
2037 APInt OffsetAI(getDataLayout().getPointerTypeSizeInBits(CE->getType()), 0);
2038 cast<GEPOperator>(CE)->accumulateConstantOffset(getDataLayout(), OffsetAI);
2039
2040 const MCExpr *Base = lowerConstant(CE->getOperand(0));
2041 if (!OffsetAI)
2042 return Base;
2043
2044 int64_t Offset = OffsetAI.getSExtValue();
2045 return MCBinaryExpr::createAdd(Base, MCConstantExpr::create(Offset, Ctx),
2046 Ctx);
2047 }
2048
2049 case Instruction::Trunc:
2050 // We emit the value and depend on the assembler to truncate the generated
2051 // expression properly. This is important for differences between
2052 // blockaddress labels. Since the two labels are in the same function, it
2053 // is reasonable to treat their delta as a 32-bit value.
2054 LLVM_FALLTHROUGH[[clang::fallthrough]];
2055 case Instruction::BitCast:
2056 return lowerConstant(CE->getOperand(0));
2057
2058 case Instruction::IntToPtr: {
2059 const DataLayout &DL = getDataLayout();
2060
2061 // Handle casts to pointers by changing them into casts to the appropriate
2062 // integer type. This promotes constant folding and simplifies this code.
2063 Constant *Op = CE->getOperand(0);
2064 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()),
2065 false/*ZExt*/);
2066 return lowerConstant(Op);
2067 }
2068
2069 case Instruction::PtrToInt: {
2070 const DataLayout &DL = getDataLayout();
2071
2072 // Support only foldable casts to/from pointers that can be eliminated by
2073 // changing the pointer to the appropriately sized integer type.
2074 Constant *Op = CE->getOperand(0);
2075 Type *Ty = CE->getType();
2076
2077 const MCExpr *OpExpr = lowerConstant(Op);
2078
2079 // We can emit the pointer value into this slot if the slot is an
2080 // integer slot equal to the size of the pointer.
2081 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType()))
2082 return OpExpr;
2083
2084 // Otherwise the pointer is smaller than the resultant integer, mask off
2085 // the high bits so we are sure to get a proper truncation if the input is
2086 // a constant expr.
2087 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType());
2088 const MCExpr *MaskExpr = MCConstantExpr::create(~0ULL >> (64-InBits), Ctx);
2089 return MCBinaryExpr::createAnd(OpExpr, MaskExpr, Ctx);
2090 }
2091
2092 case Instruction::Sub: {
2093 GlobalValue *LHSGV;
2094 APInt LHSOffset;
2095 if (IsConstantOffsetFromGlobal(CE->getOperand(0), LHSGV, LHSOffset,
2096 getDataLayout())) {
2097 GlobalValue *RHSGV;
2098 APInt RHSOffset;
2099 if (IsConstantOffsetFromGlobal(CE->getOperand(1), RHSGV, RHSOffset,
2100 getDataLayout())) {
2101 const MCExpr *RelocExpr =
2102 getObjFileLowering().lowerRelativeReference(LHSGV, RHSGV, TM);
2103 if (!RelocExpr)
2104 RelocExpr = MCBinaryExpr::createSub(
2105 MCSymbolRefExpr::create(getSymbol(LHSGV), Ctx),
2106 MCSymbolRefExpr::create(getSymbol(RHSGV), Ctx), Ctx);
2107 int64_t Addend = (LHSOffset - RHSOffset).getSExtValue();
2108 if (Addend != 0)
2109 RelocExpr = MCBinaryExpr::createAdd(
2110 RelocExpr, MCConstantExpr::create(Addend, Ctx), Ctx);
2111 return RelocExpr;
2112 }
2113 }
2114 }
2115 // else fallthrough
2116 LLVM_FALLTHROUGH[[clang::fallthrough]];
2117
2118 // The MC library also has a right-shift operator, but it isn't consistently
2119 // signed or unsigned between different targets.
2120 case Instruction::Add:
2121 case Instruction::Mul:
2122 case Instruction::SDiv:
2123 case Instruction::SRem:
2124 case Instruction::Shl:
2125 case Instruction::And:
2126 case Instruction::Or:
2127 case Instruction::Xor: {
2128 const MCExpr *LHS = lowerConstant(CE->getOperand(0));
2129 const MCExpr *RHS = lowerConstant(CE->getOperand(1));
2130 switch (CE->getOpcode()) {
2131 default: llvm_unreachable("Unknown binary operator constant cast expr")::llvm::llvm_unreachable_internal("Unknown binary operator constant cast expr"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2131)
;
2132 case Instruction::Add: return MCBinaryExpr::createAdd(LHS, RHS, Ctx);
2133 case Instruction::Sub: return MCBinaryExpr::createSub(LHS, RHS, Ctx);
2134 case Instruction::Mul: return MCBinaryExpr::createMul(LHS, RHS, Ctx);
2135 case Instruction::SDiv: return MCBinaryExpr::createDiv(LHS, RHS, Ctx);
2136 case Instruction::SRem: return MCBinaryExpr::createMod(LHS, RHS, Ctx);
2137 case Instruction::Shl: return MCBinaryExpr::createShl(LHS, RHS, Ctx);
2138 case Instruction::And: return MCBinaryExpr::createAnd(LHS, RHS, Ctx);
2139 case Instruction::Or: return MCBinaryExpr::createOr (LHS, RHS, Ctx);
2140 case Instruction::Xor: return MCBinaryExpr::createXor(LHS, RHS, Ctx);
2141 }
2142 }
2143 }
2144}
2145
2146static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *C,
2147 AsmPrinter &AP,
2148 const Constant *BaseCV = nullptr,
2149 uint64_t Offset = 0);
2150
2151static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP);
2152static void emitGlobalConstantFP(APFloat APF, Type *ET, AsmPrinter &AP);
2153
2154/// isRepeatedByteSequence - Determine whether the given value is
2155/// composed of a repeated sequence of identical bytes and return the
2156/// byte value. If it is not a repeated sequence, return -1.
2157static int isRepeatedByteSequence(const ConstantDataSequential *V) {
2158 StringRef Data = V->getRawDataValues();
2159 assert(!Data.empty() && "Empty aggregates should be CAZ node")(static_cast <bool> (!Data.empty() && "Empty aggregates should be CAZ node"
) ? void (0) : __assert_fail ("!Data.empty() && \"Empty aggregates should be CAZ node\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2159, __extension__ __PRETTY_FUNCTION__))
;
2160 char C = Data[0];
2161 for (unsigned i = 1, e = Data.size(); i != e; ++i)
2162 if (Data[i] != C) return -1;
2163 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1.
2164}
2165
2166/// isRepeatedByteSequence - Determine whether the given value is
2167/// composed of a repeated sequence of identical bytes and return the
2168/// byte value. If it is not a repeated sequence, return -1.
2169static int isRepeatedByteSequence(const Value *V, const DataLayout &DL) {
2170 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
2171 uint64_t Size = DL.getTypeAllocSizeInBits(V->getType());
2172 assert(Size % 8 == 0)(static_cast <bool> (Size % 8 == 0) ? void (0) : __assert_fail
("Size % 8 == 0", "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2172, __extension__ __PRETTY_FUNCTION__))
;
2173
2174 // Extend the element to take zero padding into account.
2175 APInt Value = CI->getValue().zextOrSelf(Size);
2176 if (!Value.isSplat(8))
2177 return -1;
2178
2179 return Value.zextOrTrunc(8).getZExtValue();
2180 }
2181 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) {
2182 // Make sure all array elements are sequences of the same repeated
2183 // byte.
2184 assert(CA->getNumOperands() != 0 && "Should be a CAZ")(static_cast <bool> (CA->getNumOperands() != 0 &&
"Should be a CAZ") ? void (0) : __assert_fail ("CA->getNumOperands() != 0 && \"Should be a CAZ\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2184, __extension__ __PRETTY_FUNCTION__))
;
2185 Constant *Op0 = CA->getOperand(0);
2186 int Byte = isRepeatedByteSequence(Op0, DL);
2187 if (Byte == -1)
2188 return -1;
2189
2190 // All array elements must be equal.
2191 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i)
2192 if (CA->getOperand(i) != Op0)
2193 return -1;
2194 return Byte;
2195 }
2196
2197 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V))
2198 return isRepeatedByteSequence(CDS);
2199
2200 return -1;
2201}
2202
2203static void emitGlobalConstantDataSequential(const DataLayout &DL,
2204 const ConstantDataSequential *CDS,
2205 AsmPrinter &AP) {
2206 // See if we can aggregate this into a .fill, if so, emit it as such.
2207 int Value = isRepeatedByteSequence(CDS, DL);
2208 if (Value != -1) {
2209 uint64_t Bytes = DL.getTypeAllocSize(CDS->getType());
2210 // Don't emit a 1-byte object as a .fill.
2211 if (Bytes > 1)
2212 return AP.OutStreamer->emitFill(Bytes, Value);
2213 }
2214
2215 // If this can be emitted with .ascii/.asciz, emit it as such.
2216 if (CDS->isString())
2217 return AP.OutStreamer->EmitBytes(CDS->getAsString());
2218
2219 // Otherwise, emit the values in successive locations.
2220 unsigned ElementByteSize = CDS->getElementByteSize();
2221 if (isa<IntegerType>(CDS->getElementType())) {
2222 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
2223 if (AP.isVerbose())
2224 AP.OutStreamer->GetCommentOS() << format("0x%" PRIx64"l" "x" "\n",
2225 CDS->getElementAsInteger(i));
2226 AP.OutStreamer->EmitIntValue(CDS->getElementAsInteger(i),
2227 ElementByteSize);
2228 }
2229 } else {
2230 Type *ET = CDS->getElementType();
2231 for (unsigned I = 0, E = CDS->getNumElements(); I != E; ++I)
2232 emitGlobalConstantFP(CDS->getElementAsAPFloat(I), ET, AP);
2233 }
2234
2235 unsigned Size = DL.getTypeAllocSize(CDS->getType());
2236 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) *
2237 CDS->getNumElements();
2238 if (unsigned Padding = Size - EmittedSize)
2239 AP.OutStreamer->EmitZeros(Padding);
2240}
2241
2242static void emitGlobalConstantArray(const DataLayout &DL,
2243 const ConstantArray *CA, AsmPrinter &AP,
2244 const Constant *BaseCV, uint64_t Offset) {
2245 // See if we can aggregate some values. Make sure it can be
2246 // represented as a series of bytes of the constant value.
2247 int Value = isRepeatedByteSequence(CA, DL);
2248
2249 if (Value != -1) {
2250 uint64_t Bytes = DL.getTypeAllocSize(CA->getType());
2251 AP.OutStreamer->emitFill(Bytes, Value);
2252 }
2253 else {
2254 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) {
2255 emitGlobalConstantImpl(DL, CA->getOperand(i), AP, BaseCV, Offset);
2256 Offset += DL.getTypeAllocSize(CA->getOperand(i)->getType());
2257 }
2258 }
2259}
2260
2261static void emitGlobalConstantVector(const DataLayout &DL,
2262 const ConstantVector *CV, AsmPrinter &AP) {
2263 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
2264 emitGlobalConstantImpl(DL, CV->getOperand(i), AP);
2265
2266 unsigned Size = DL.getTypeAllocSize(CV->getType());
2267 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) *
2268 CV->getType()->getNumElements();
2269 if (unsigned Padding = Size - EmittedSize)
2270 AP.OutStreamer->EmitZeros(Padding);
2271}
2272
2273static void emitGlobalConstantStruct(const DataLayout &DL,
2274 const ConstantStruct *CS, AsmPrinter &AP,
2275 const Constant *BaseCV, uint64_t Offset) {
2276 // Print the fields in successive locations. Pad to align if needed!
2277 unsigned Size = DL.getTypeAllocSize(CS->getType());
2278 const StructLayout *Layout = DL.getStructLayout(CS->getType());
2279 uint64_t SizeSoFar = 0;
2280 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
2281 const Constant *Field = CS->getOperand(i);
2282
2283 // Print the actual field value.
2284 emitGlobalConstantImpl(DL, Field, AP, BaseCV, Offset + SizeSoFar);
2285
2286 // Check if padding is needed and insert one or more 0s.
2287 uint64_t FieldSize = DL.getTypeAllocSize(Field->getType());
2288 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
2289 - Layout->getElementOffset(i)) - FieldSize;
2290 SizeSoFar += FieldSize + PadSize;
2291
2292 // Insert padding - this may include padding to increase the size of the
2293 // current field up to the ABI size (if the struct is not packed) as well
2294 // as padding to ensure that the next field starts at the right offset.
2295 AP.OutStreamer->EmitZeros(PadSize);
2296 }
2297 assert(SizeSoFar == Layout->getSizeInBytes() &&(static_cast <bool> (SizeSoFar == Layout->getSizeInBytes
() && "Layout of constant struct may be incorrect!") ?
void (0) : __assert_fail ("SizeSoFar == Layout->getSizeInBytes() && \"Layout of constant struct may be incorrect!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2298, __extension__ __PRETTY_FUNCTION__))
2298 "Layout of constant struct may be incorrect!")(static_cast <bool> (SizeSoFar == Layout->getSizeInBytes
() && "Layout of constant struct may be incorrect!") ?
void (0) : __assert_fail ("SizeSoFar == Layout->getSizeInBytes() && \"Layout of constant struct may be incorrect!\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2298, __extension__ __PRETTY_FUNCTION__))
;
2299}
2300
2301static void emitGlobalConstantFP(APFloat APF, Type *ET, AsmPrinter &AP) {
2302 APInt API = APF.bitcastToAPInt();
2303
2304 // First print a comment with what we think the original floating-point value
2305 // should have been.
2306 if (AP.isVerbose()) {
27
Assuming the condition is true
28
Taking true branch
2307 SmallString<8> StrVal;
2308 APF.toString(StrVal);
2309
2310 if (ET)
29
Assuming 'ET' is null
30
Assuming pointer value is null
31
Taking false branch
2311 ET->print(AP.OutStreamer->GetCommentOS());
2312 else
2313 AP.OutStreamer->GetCommentOS() << "Printing <null> Type";
2314 AP.OutStreamer->GetCommentOS() << ' ' << StrVal << '\n';
2315 }
2316
2317 // Now iterate through the APInt chunks, emitting them in endian-correct
2318 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit
2319 // floats).
2320 unsigned NumBytes = API.getBitWidth() / 8;
2321 unsigned TrailingBytes = NumBytes % sizeof(uint64_t);
2322 const uint64_t *p = API.getRawData();
2323
2324 // PPC's long double has odd notions of endianness compared to how LLVM
2325 // handles it: p[0] goes first for *big* endian on PPC.
2326 if (AP.getDataLayout().isBigEndian() && !ET->isPPC_FP128Ty()) {
32
Assuming the condition is true
33
Called C++ object pointer is null
2327 int Chunk = API.getNumWords() - 1;
2328
2329 if (TrailingBytes)
2330 AP.OutStreamer->EmitIntValue(p[Chunk--], TrailingBytes);
2331
2332 for (; Chunk >= 0; --Chunk)
2333 AP.OutStreamer->EmitIntValue(p[Chunk], sizeof(uint64_t));
2334 } else {
2335 unsigned Chunk;
2336 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk)
2337 AP.OutStreamer->EmitIntValue(p[Chunk], sizeof(uint64_t));
2338
2339 if (TrailingBytes)
2340 AP.OutStreamer->EmitIntValue(p[Chunk], TrailingBytes);
2341 }
2342
2343 // Emit the tail padding for the long double.
2344 const DataLayout &DL = AP.getDataLayout();
2345 AP.OutStreamer->EmitZeros(DL.getTypeAllocSize(ET) - DL.getTypeStoreSize(ET));
2346}
2347
2348static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) {
2349 emitGlobalConstantFP(CFP->getValueAPF(), CFP->getType(), AP);
23
Calling 'Value::getType'
24
Returning from 'Value::getType'
25
Passing value via 2nd parameter 'ET'
26
Calling 'emitGlobalConstantFP'
2350}
2351
2352static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) {
2353 const DataLayout &DL = AP.getDataLayout();
2354 unsigned BitWidth = CI->getBitWidth();
2355
2356 // Copy the value as we may massage the layout for constants whose bit width
2357 // is not a multiple of 64-bits.
2358 APInt Realigned(CI->getValue());
2359 uint64_t ExtraBits = 0;
2360 unsigned ExtraBitsSize = BitWidth & 63;
2361
2362 if (ExtraBitsSize) {
2363 // The bit width of the data is not a multiple of 64-bits.
2364 // The extra bits are expected to be at the end of the chunk of the memory.
2365 // Little endian:
2366 // * Nothing to be done, just record the extra bits to emit.
2367 // Big endian:
2368 // * Record the extra bits to emit.
2369 // * Realign the raw data to emit the chunks of 64-bits.
2370 if (DL.isBigEndian()) {
2371 // Basically the structure of the raw data is a chunk of 64-bits cells:
2372 // 0 1 BitWidth / 64
2373 // [chunk1][chunk2] ... [chunkN].
2374 // The most significant chunk is chunkN and it should be emitted first.
2375 // However, due to the alignment issue chunkN contains useless bits.
2376 // Realign the chunks so that they contain only useless information:
2377 // ExtraBits 0 1 (BitWidth / 64) - 1
2378 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN]
2379 ExtraBits = Realigned.getRawData()[0] &
2380 (((uint64_t)-1) >> (64 - ExtraBitsSize));
2381 Realigned.lshrInPlace(ExtraBitsSize);
2382 } else
2383 ExtraBits = Realigned.getRawData()[BitWidth / 64];
2384 }
2385
2386 // We don't expect assemblers to support integer data directives
2387 // for more than 64 bits, so we emit the data in at most 64-bit
2388 // quantities at a time.
2389 const uint64_t *RawData = Realigned.getRawData();
2390 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
2391 uint64_t Val = DL.isBigEndian() ? RawData[e - i - 1] : RawData[i];
2392 AP.OutStreamer->EmitIntValue(Val, 8);
2393 }
2394
2395 if (ExtraBitsSize) {
2396 // Emit the extra bits after the 64-bits chunks.
2397
2398 // Emit a directive that fills the expected size.
2399 uint64_t Size = AP.getDataLayout().getTypeAllocSize(CI->getType());
2400 Size -= (BitWidth / 64) * 8;
2401 assert(Size && Size * 8 >= ExtraBitsSize &&(static_cast <bool> (Size && Size * 8 >= ExtraBitsSize
&& (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize
))) == ExtraBits && "Directive too small for extra bits."
) ? void (0) : __assert_fail ("Size && Size * 8 >= ExtraBitsSize && (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize))) == ExtraBits && \"Directive too small for extra bits.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2403, __extension__ __PRETTY_FUNCTION__))
2402 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize)))(static_cast <bool> (Size && Size * 8 >= ExtraBitsSize
&& (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize
))) == ExtraBits && "Directive too small for extra bits."
) ? void (0) : __assert_fail ("Size && Size * 8 >= ExtraBitsSize && (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize))) == ExtraBits && \"Directive too small for extra bits.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2403, __extension__ __PRETTY_FUNCTION__))
2403 == ExtraBits && "Directive too small for extra bits.")(static_cast <bool> (Size && Size * 8 >= ExtraBitsSize
&& (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize
))) == ExtraBits && "Directive too small for extra bits."
) ? void (0) : __assert_fail ("Size && Size * 8 >= ExtraBitsSize && (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize))) == ExtraBits && \"Directive too small for extra bits.\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2403, __extension__ __PRETTY_FUNCTION__))
;
2404 AP.OutStreamer->EmitIntValue(ExtraBits, Size);
2405 }
2406}
2407
2408/// \brief Transform a not absolute MCExpr containing a reference to a GOT
2409/// equivalent global, by a target specific GOT pc relative access to the
2410/// final symbol.
2411static void handleIndirectSymViaGOTPCRel(AsmPrinter &AP, const MCExpr **ME,
2412 const Constant *BaseCst,
2413 uint64_t Offset) {
2414 // The global @foo below illustrates a global that uses a got equivalent.
2415 //
2416 // @bar = global i32 42
2417 // @gotequiv = private unnamed_addr constant i32* @bar
2418 // @foo = i32 trunc (i64 sub (i64 ptrtoint (i32** @gotequiv to i64),
2419 // i64 ptrtoint (i32* @foo to i64))
2420 // to i32)
2421 //
2422 // The cstexpr in @foo is converted into the MCExpr `ME`, where we actually
2423 // check whether @foo is suitable to use a GOTPCREL. `ME` is usually in the
2424 // form:
2425 //
2426 // foo = cstexpr, where
2427 // cstexpr := <gotequiv> - "." + <cst>
2428 // cstexpr := <gotequiv> - (<foo> - <offset from @foo base>) + <cst>
2429 //
2430 // After canonicalization by evaluateAsRelocatable `ME` turns into:
2431 //
2432 // cstexpr := <gotequiv> - <foo> + gotpcrelcst, where
2433 // gotpcrelcst := <offset from @foo base> + <cst>
2434 MCValue MV;
2435 if (!(*ME)->evaluateAsRelocatable(MV, nullptr, nullptr) || MV.isAbsolute())
2436 return;
2437 const MCSymbolRefExpr *SymA = MV.getSymA();
2438 if (!SymA)
2439 return;
2440
2441 // Check that GOT equivalent symbol is cached.
2442 const MCSymbol *GOTEquivSym = &SymA->getSymbol();
2443 if (!AP.GlobalGOTEquivs.count(GOTEquivSym))
2444 return;
2445
2446 const GlobalValue *BaseGV = dyn_cast_or_null<GlobalValue>(BaseCst);
2447 if (!BaseGV)
2448 return;
2449
2450 // Check for a valid base symbol
2451 const MCSymbol *BaseSym = AP.getSymbol(BaseGV);
2452 const MCSymbolRefExpr *SymB = MV.getSymB();
2453
2454 if (!SymB || BaseSym != &SymB->getSymbol())
2455 return;
2456
2457 // Make sure to match:
2458 //
2459 // gotpcrelcst := <offset from @foo base> + <cst>
2460 //
2461 // If gotpcrelcst is positive it means that we can safely fold the pc rel
2462 // displacement into the GOTPCREL. We can also can have an extra offset <cst>
2463 // if the target knows how to encode it.
2464 int64_t GOTPCRelCst = Offset + MV.getConstant();
2465 if (GOTPCRelCst < 0)
2466 return;
2467 if (!AP.getObjFileLowering().supportGOTPCRelWithOffset() && GOTPCRelCst != 0)
2468 return;
2469
2470 // Emit the GOT PC relative to replace the got equivalent global, i.e.:
2471 //
2472 // bar:
2473 // .long 42
2474 // gotequiv:
2475 // .quad bar
2476 // foo:
2477 // .long gotequiv - "." + <cst>
2478 //
2479 // is replaced by the target specific equivalent to:
2480 //
2481 // bar:
2482 // .long 42
2483 // foo:
2484 // .long bar@GOTPCREL+<gotpcrelcst>
2485 AsmPrinter::GOTEquivUsePair Result = AP.GlobalGOTEquivs[GOTEquivSym];
2486 const GlobalVariable *GV = Result.first;
2487 int NumUses = (int)Result.second;
2488 const GlobalValue *FinalGV = dyn_cast<GlobalValue>(GV->getOperand(0));
2489 const MCSymbol *FinalSym = AP.getSymbol(FinalGV);
2490 *ME = AP.getObjFileLowering().getIndirectSymViaGOTPCRel(
2491 FinalSym, MV, Offset, AP.MMI, *AP.OutStreamer);
2492
2493 // Update GOT equivalent usage information
2494 --NumUses;
2495 if (NumUses >= 0)
2496 AP.GlobalGOTEquivs[GOTEquivSym] = std::make_pair(GV, NumUses);
2497}
2498
2499static void emitGlobalConstantImpl(const DataLayout &DL, const Constant *CV,
2500 AsmPrinter &AP, const Constant *BaseCV,
2501 uint64_t Offset) {
2502 uint64_t Size = DL.getTypeAllocSize(CV->getType());
2503
2504 // Globals with sub-elements such as combinations of arrays and structs
2505 // are handled recursively by emitGlobalConstantImpl. Keep track of the
2506 // constant symbol base and the current position with BaseCV and Offset.
2507 if (!BaseCV && CV->hasOneUse())
16
Assuming the condition is false
17
Taking false branch
2508 BaseCV = dyn_cast<Constant>(CV->user_back());
2509
2510 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV))
18
Taking false branch
2511 return AP.OutStreamer->EmitZeros(Size);
2512
2513 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
19
Taking false branch
2514 switch (Size) {
2515 case 1:
2516 case 2:
2517 case 4:
2518 case 8:
2519 if (AP.isVerbose())
2520 AP.OutStreamer->GetCommentOS() << format("0x%" PRIx64"l" "x" "\n",
2521 CI->getZExtValue());
2522 AP.OutStreamer->EmitIntValue(CI->getZExtValue(), Size);
2523 return;
2524 default:
2525 emitGlobalConstantLargeInt(CI, AP);
2526 return;
2527 }
2528 }
2529
2530 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
20
Assuming 'CFP' is non-null
21
Taking true branch
2531 return emitGlobalConstantFP(CFP, AP);
22
Calling 'emitGlobalConstantFP'
2532
2533 if (isa<ConstantPointerNull>(CV)) {
2534 AP.OutStreamer->EmitIntValue(0, Size);
2535 return;
2536 }
2537
2538 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV))
2539 return emitGlobalConstantDataSequential(DL, CDS, AP);
2540
2541 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
2542 return emitGlobalConstantArray(DL, CVA, AP, BaseCV, Offset);
2543
2544 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
2545 return emitGlobalConstantStruct(DL, CVS, AP, BaseCV, Offset);
2546
2547 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) {
2548 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of
2549 // vectors).
2550 if (CE->getOpcode() == Instruction::BitCast)
2551 return emitGlobalConstantImpl(DL, CE->getOperand(0), AP);
2552
2553 if (Size > 8) {
2554 // If the constant expression's size is greater than 64-bits, then we have
2555 // to emit the value in chunks. Try to constant fold the value and emit it
2556 // that way.
2557 Constant *New = ConstantFoldConstant(CE, DL);
2558 if (New && New != CE)
2559 return emitGlobalConstantImpl(DL, New, AP);
2560 }
2561 }
2562
2563 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
2564 return emitGlobalConstantVector(DL, V, AP);
2565
2566 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it
2567 // thread the streamer with EmitValue.
2568 const MCExpr *ME = AP.lowerConstant(CV);
2569
2570 // Since lowerConstant already folded and got rid of all IR pointer and
2571 // integer casts, detect GOT equivalent accesses by looking into the MCExpr
2572 // directly.
2573 if (AP.getObjFileLowering().supportIndirectSymViaGOTPCRel())
2574 handleIndirectSymViaGOTPCRel(AP, &ME, BaseCV, Offset);
2575
2576 AP.OutStreamer->EmitValue(ME, Size);
2577}
2578
2579/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
2580void AsmPrinter::EmitGlobalConstant(const DataLayout &DL, const Constant *CV) {
2581 uint64_t Size = DL.getTypeAllocSize(CV->getType());
2582 if (Size)
13
Assuming 'Size' is not equal to 0
14
Taking true branch
2583 emitGlobalConstantImpl(DL, CV, *this);
15
Calling 'emitGlobalConstantImpl'
2584 else if (MAI->hasSubsectionsViaSymbols()) {
2585 // If the global has zero size, emit a single byte so that two labels don't
2586 // look like they are at the same location.
2587 OutStreamer->EmitIntValue(0, 1);
2588 }
2589}
2590
2591void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
2592 // Target doesn't support this yet!
2593 llvm_unreachable("Target does not support EmitMachineConstantPoolValue")::llvm::llvm_unreachable_internal("Target does not support EmitMachineConstantPoolValue"
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2593)
;
2594}
2595
2596void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
2597 if (Offset > 0)
2598 OS << '+' << Offset;
2599 else if (Offset < 0)
2600 OS << Offset;
2601}
2602
2603//===----------------------------------------------------------------------===//
2604// Symbol Lowering Routines.
2605//===----------------------------------------------------------------------===//
2606
2607MCSymbol *AsmPrinter::createTempSymbol(const Twine &Name) const {
2608 return OutContext.createTempSymbol(Name, true);
2609}
2610
2611MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
2612 return MMI->getAddrLabelSymbol(BA->getBasicBlock());
2613}
2614
2615MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
2616 return MMI->getAddrLabelSymbol(BB);
2617}
2618
2619/// GetCPISymbol - Return the symbol for the specified constant pool entry.
2620MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
2621 const DataLayout &DL = getDataLayout();
2622 return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
2623 "CPI" + Twine(getFunctionNumber()) + "_" +
2624 Twine(CPID));
2625}
2626
2627/// GetJTISymbol - Return the symbol for the specified jump table entry.
2628MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
2629 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
2630}
2631
2632/// GetJTSetSymbol - Return the symbol for the specified jump table .set
2633/// FIXME: privatize to AsmPrinter.
2634MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
2635 const DataLayout &DL = getDataLayout();
2636 return OutContext.getOrCreateSymbol(Twine(DL.getPrivateGlobalPrefix()) +
2637 Twine(getFunctionNumber()) + "_" +
2638 Twine(UID) + "_set_" + Twine(MBBID));
2639}
2640
2641MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV,
2642 StringRef Suffix) const {
2643 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, TM);
2644}
2645
2646/// Return the MCSymbol for the specified ExternalSymbol.
2647MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
2648 SmallString<60> NameStr;
2649 Mangler::getNameWithPrefix(NameStr, Sym, getDataLayout());
2650 return OutContext.getOrCreateSymbol(NameStr);
2651}
2652
2653/// PrintParentLoopComment - Print comments about parent loops of this one.
2654static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2655 unsigned FunctionNumber) {
2656 if (!Loop) return;
2657 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
2658 OS.indent(Loop->getLoopDepth()*2)
2659 << "Parent Loop BB" << FunctionNumber << "_"
2660 << Loop->getHeader()->getNumber()
2661 << " Depth=" << Loop->getLoopDepth() << '\n';
2662}
2663
2664/// PrintChildLoopComment - Print comments about child loops within
2665/// the loop for this basic block, with nesting.
2666static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
2667 unsigned FunctionNumber) {
2668 // Add child loop information
2669 for (const MachineLoop *CL : *Loop) {
2670 OS.indent(CL->getLoopDepth()*2)
2671 << "Child Loop BB" << FunctionNumber << "_"
2672 << CL->getHeader()->getNumber() << " Depth " << CL->getLoopDepth()
2673 << '\n';
2674 PrintChildLoopComment(OS, CL, FunctionNumber);
2675 }
2676}
2677
2678/// emitBasicBlockLoopComments - Pretty-print comments for basic blocks.
2679static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB,
2680 const MachineLoopInfo *LI,
2681 const AsmPrinter &AP) {
2682 // Add loop depth information
2683 const MachineLoop *Loop = LI->getLoopFor(&MBB);
2684 if (!Loop) return;
2685
2686 MachineBasicBlock *Header = Loop->getHeader();
2687 assert(Header && "No header for loop")(static_cast <bool> (Header && "No header for loop"
) ? void (0) : __assert_fail ("Header && \"No header for loop\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2687, __extension__ __PRETTY_FUNCTION__))
;
2688
2689 // If this block is not a loop header, just print out what is the loop header
2690 // and return.
2691 if (Header != &MBB) {
2692 AP.OutStreamer->AddComment(" in Loop: Header=BB" +
2693 Twine(AP.getFunctionNumber())+"_" +
2694 Twine(Loop->getHeader()->getNumber())+
2695 " Depth="+Twine(Loop->getLoopDepth()));
2696 return;
2697 }
2698
2699 // Otherwise, it is a loop header. Print out information about child and
2700 // parent loops.
2701 raw_ostream &OS = AP.OutStreamer->GetCommentOS();
2702
2703 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
2704
2705 OS << "=>";
2706 OS.indent(Loop->getLoopDepth()*2-2);
2707
2708 OS << "This ";
2709 if (Loop->empty())
2710 OS << "Inner ";
2711 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
2712
2713 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
2714}
2715
2716void AsmPrinter::setupCodePaddingContext(const MachineBasicBlock &MBB,
2717 MCCodePaddingContext &Context) const {
2718 assert(MF != nullptr && "Machine function must be valid")(static_cast <bool> (MF != nullptr && "Machine function must be valid"
) ? void (0) : __assert_fail ("MF != nullptr && \"Machine function must be valid\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2718, __extension__ __PRETTY_FUNCTION__))
;
2719 Context.IsPaddingActive = !MF->hasInlineAsm() &&
2720 !MF->getFunction().optForSize() &&
2721 TM.getOptLevel() != CodeGenOpt::None;
2722 Context.IsBasicBlockReachableViaFallthrough =
2723 std::find(MBB.pred_begin(), MBB.pred_end(), MBB.getPrevNode()) !=
2724 MBB.pred_end();
2725 Context.IsBasicBlockReachableViaBranch =
2726 MBB.pred_size() > 0 && !isBlockOnlyReachableByFallthrough(&MBB);
2727}
2728
2729/// EmitBasicBlockStart - This method prints the label for the specified
2730/// MachineBasicBlock, an alignment (if present) and a comment describing
2731/// it if appropriate.
2732void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const {
2733 // End the previous funclet and start a new one.
2734 if (MBB.isEHFuncletEntry()) {
2735 for (const HandlerInfo &HI : Handlers) {
2736 HI.Handler->endFunclet();
2737 HI.Handler->beginFunclet(MBB);
2738 }
2739 }
2740
2741 // Emit an alignment directive for this block, if needed.
2742 if (unsigned Align = MBB.getAlignment())
2743 EmitAlignment(Align);
2744 MCCodePaddingContext Context;
2745 setupCodePaddingContext(MBB, Context);
2746 OutStreamer->EmitCodePaddingBasicBlockStart(Context);
2747
2748 // If the block has its address taken, emit any labels that were used to
2749 // reference the block. It is possible that there is more than one label
2750 // here, because multiple LLVM BB's may have been RAUW'd to this block after
2751 // the references were generated.
2752 if (MBB.hasAddressTaken()) {
2753 const BasicBlock *BB = MBB.getBasicBlock();
2754 if (isVerbose())
2755 OutStreamer->AddComment("Block address taken");
2756
2757 // MBBs can have their address taken as part of CodeGen without having
2758 // their corresponding BB's address taken in IR
2759 if (BB->hasAddressTaken())
2760 for (MCSymbol *Sym : MMI->getAddrLabelSymbolToEmit(BB))
2761 OutStreamer->EmitLabel(Sym);
2762 }
2763
2764 // Print some verbose block comments.
2765 if (isVerbose()) {
2766 if (const BasicBlock *BB = MBB.getBasicBlock()) {
2767 if (BB->hasName()) {
2768 BB->printAsOperand(OutStreamer->GetCommentOS(),
2769 /*PrintType=*/false, BB->getModule());
2770 OutStreamer->GetCommentOS() << '\n';
2771 }
2772 }
2773
2774 assert(MLI != nullptr && "MachineLoopInfo should has been computed")(static_cast <bool> (MLI != nullptr && "MachineLoopInfo should has been computed"
) ? void (0) : __assert_fail ("MLI != nullptr && \"MachineLoopInfo should has been computed\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2774, __extension__ __PRETTY_FUNCTION__))
;
2775 emitBasicBlockLoopComments(MBB, MLI, *this);
2776 }
2777
2778 // Print the main label for the block.
2779 if (MBB.pred_empty() ||
2780 (isBlockOnlyReachableByFallthrough(&MBB) && !MBB.isEHFuncletEntry())) {
2781 if (isVerbose()) {
2782 // NOTE: Want this comment at start of line, don't emit with AddComment.
2783 OutStreamer->emitRawComment(" %bb." + Twine(MBB.getNumber()) + ":",
2784 false);
2785 }
2786 } else {
2787 OutStreamer->EmitLabel(MBB.getSymbol());
2788 }
2789}
2790
2791void AsmPrinter::EmitBasicBlockEnd(const MachineBasicBlock &MBB) {
2792 MCCodePaddingContext Context;
2793 setupCodePaddingContext(MBB, Context);
2794 OutStreamer->EmitCodePaddingBasicBlockEnd(Context);
2795}
2796
2797void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility,
2798 bool IsDefinition) const {
2799 MCSymbolAttr Attr = MCSA_Invalid;
2800
2801 switch (Visibility) {
2802 default: break;
2803 case GlobalValue::HiddenVisibility:
2804 if (IsDefinition)
2805 Attr = MAI->getHiddenVisibilityAttr();
2806 else
2807 Attr = MAI->getHiddenDeclarationVisibilityAttr();
2808 break;
2809 case GlobalValue::ProtectedVisibility:
2810 Attr = MAI->getProtectedVisibilityAttr();
2811 break;
2812 }
2813
2814 if (Attr != MCSA_Invalid)
2815 OutStreamer->EmitSymbolAttribute(Sym, Attr);
2816}
2817
2818/// isBlockOnlyReachableByFallthough - Return true if the basic block has
2819/// exactly one predecessor and the control transfer mechanism between
2820/// the predecessor and this block is a fall-through.
2821bool AsmPrinter::
2822isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
2823 // If this is a landing pad, it isn't a fall through. If it has no preds,
2824 // then nothing falls through to it.
2825 if (MBB->isEHPad() || MBB->pred_empty())
2826 return false;
2827
2828 // If there isn't exactly one predecessor, it can't be a fall through.
2829 if (MBB->pred_size() > 1)
2830 return false;
2831
2832 // The predecessor has to be immediately before this block.
2833 MachineBasicBlock *Pred = *MBB->pred_begin();
2834 if (!Pred->isLayoutSuccessor(MBB))
2835 return false;
2836
2837 // If the block is completely empty, then it definitely does fall through.
2838 if (Pred->empty())
2839 return true;
2840
2841 // Check the terminators in the previous blocks
2842 for (const auto &MI : Pred->terminators()) {
2843 // If it is not a simple branch, we are in a table somewhere.
2844 if (!MI.isBranch() || MI.isIndirectBranch())
2845 return false;
2846
2847 // If we are the operands of one of the branches, this is not a fall
2848 // through. Note that targets with delay slots will usually bundle
2849 // terminators with the delay slot instruction.
2850 for (ConstMIBundleOperands OP(MI); OP.isValid(); ++OP) {
2851 if (OP->isJTI())
2852 return false;
2853 if (OP->isMBB() && OP->getMBB() == MBB)
2854 return false;
2855 }
2856 }
2857
2858 return true;
2859}
2860
2861GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy &S) {
2862 if (!S.usesMetadata())
2863 return nullptr;
2864
2865 assert(!S.useStatepoints() && "statepoints do not currently support custom"(static_cast <bool> (!S.useStatepoints() && "statepoints do not currently support custom"
" stackmap formats, please see the documentation for a description of"
" the default format. If you really need a custom serialized format,"
" please file a bug") ? void (0) : __assert_fail ("!S.useStatepoints() && \"statepoints do not currently support custom\" \" stackmap formats, please see the documentation for a description of\" \" the default format. If you really need a custom serialized format,\" \" please file a bug\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2868, __extension__ __PRETTY_FUNCTION__))
2866 " stackmap formats, please see the documentation for a description of"(static_cast <bool> (!S.useStatepoints() && "statepoints do not currently support custom"
" stackmap formats, please see the documentation for a description of"
" the default format. If you really need a custom serialized format,"
" please file a bug") ? void (0) : __assert_fail ("!S.useStatepoints() && \"statepoints do not currently support custom\" \" stackmap formats, please see the documentation for a description of\" \" the default format. If you really need a custom serialized format,\" \" please file a bug\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2868, __extension__ __PRETTY_FUNCTION__))
2867 " the default format. If you really need a custom serialized format,"(static_cast <bool> (!S.useStatepoints() && "statepoints do not currently support custom"
" stackmap formats, please see the documentation for a description of"
" the default format. If you really need a custom serialized format,"
" please file a bug") ? void (0) : __assert_fail ("!S.useStatepoints() && \"statepoints do not currently support custom\" \" stackmap formats, please see the documentation for a description of\" \" the default format. If you really need a custom serialized format,\" \" please file a bug\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2868, __extension__ __PRETTY_FUNCTION__))
2868 " please file a bug")(static_cast <bool> (!S.useStatepoints() && "statepoints do not currently support custom"
" stackmap formats, please see the documentation for a description of"
" the default format. If you really need a custom serialized format,"
" please file a bug") ? void (0) : __assert_fail ("!S.useStatepoints() && \"statepoints do not currently support custom\" \" stackmap formats, please see the documentation for a description of\" \" the default format. If you really need a custom serialized format,\" \" please file a bug\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2868, __extension__ __PRETTY_FUNCTION__))
;
2869
2870 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
2871 gcp_map_type::iterator GCPI = GCMap.find(&S);
2872 if (GCPI != GCMap.end())
2873 return GCPI->second.get();
2874
2875 auto Name = S.getName();
2876
2877 for (GCMetadataPrinterRegistry::iterator
2878 I = GCMetadataPrinterRegistry::begin(),
2879 E = GCMetadataPrinterRegistry::end(); I != E; ++I)
2880 if (Name == I->getName()) {
2881 std::unique_ptr<GCMetadataPrinter> GMP = I->instantiate();
2882 GMP->S = &S;
2883 auto IterBool = GCMap.insert(std::make_pair(&S, std::move(GMP)));
2884 return IterBool.first->second.get();
2885 }
2886
2887 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
2888}
2889
2890/// Pin vtable to this file.
2891AsmPrinterHandler::~AsmPrinterHandler() = default;
2892
2893void AsmPrinterHandler::markFunctionEnd() {}
2894
2895// In the binary's "xray_instr_map" section, an array of these function entries
2896// describes each instrumentation point. When XRay patches your code, the index
2897// into this table will be given to your handler as a patch point identifier.
2898void AsmPrinter::XRayFunctionEntry::emit(int Bytes, MCStreamer *Out,
2899 const MCSymbol *CurrentFnSym) const {
2900 Out->EmitSymbolValue(Sled, Bytes);
2901 Out->EmitSymbolValue(CurrentFnSym, Bytes);
2902 auto Kind8 = static_cast<uint8_t>(Kind);
2903 Out->EmitBinaryData(StringRef(reinterpret_cast<const char *>(&Kind8), 1));
2904 Out->EmitBinaryData(
2905 StringRef(reinterpret_cast<const char *>(&AlwaysInstrument), 1));
2906 Out->EmitBinaryData(StringRef(reinterpret_cast<const char *>(&Version), 1));
2907 auto Padding = (4 * Bytes) - ((2 * Bytes) + 3);
2908 assert(Padding >= 0 && "Instrumentation map entry > 4 * Word Size")(static_cast <bool> (Padding >= 0 && "Instrumentation map entry > 4 * Word Size"
) ? void (0) : __assert_fail ("Padding >= 0 && \"Instrumentation map entry > 4 * Word Size\""
, "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2908, __extension__ __PRETTY_FUNCTION__))
;
2909 Out->EmitZeros(Padding);
2910}
2911
2912void AsmPrinter::emitXRayTable() {
2913 if (Sleds.empty())
2914 return;
2915
2916 auto PrevSection = OutStreamer->getCurrentSectionOnly();
2917 const Function &F = MF->getFunction();
2918 MCSection *InstMap = nullptr;
2919 MCSection *FnSledIndex = nullptr;
2920 if (MF->getSubtarget().getTargetTriple().isOSBinFormatELF()) {
2921 auto Associated = dyn_cast<MCSymbolELF>(CurrentFnSym);
2922 assert(Associated != nullptr)(static_cast <bool> (Associated != nullptr) ? void (0) :
__assert_fail ("Associated != nullptr", "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2922, __extension__ __PRETTY_FUNCTION__))
;
2923 auto Flags = ELF::SHF_WRITE | ELF::SHF_ALLOC | ELF::SHF_LINK_ORDER;
2924 std::string GroupName;
2925 if (F.hasComdat()) {
2926 Flags |= ELF::SHF_GROUP;
2927 GroupName = F.getComdat()->getName();
2928 }
2929
2930 auto UniqueID = ++XRayFnUniqueID;
2931 InstMap =
2932 OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS, Flags, 0,
2933 GroupName, UniqueID, Associated);
2934 FnSledIndex =
2935 OutContext.getELFSection("xray_fn_idx", ELF::SHT_PROGBITS, Flags, 0,
2936 GroupName, UniqueID, Associated);
2937 } else if (MF->getSubtarget().getTargetTriple().isOSBinFormatMachO()) {
2938 InstMap = OutContext.getMachOSection("__DATA", "xray_instr_map", 0,
2939 SectionKind::getReadOnlyWithRel());
2940 FnSledIndex = OutContext.getMachOSection("__DATA", "xray_fn_idx", 0,
2941 SectionKind::getReadOnlyWithRel());
2942 } else {
2943 llvm_unreachable("Unsupported target")::llvm::llvm_unreachable_internal("Unsupported target", "/build/llvm-toolchain-snapshot-7~svn329677/lib/CodeGen/AsmPrinter/AsmPrinter.cpp"
, 2943)
;
2944 }
2945
2946 auto WordSizeBytes = MAI->getCodePointerSize();
2947
2948 // Now we switch to the instrumentation map section. Because this is done
2949 // per-function, we are able to create an index entry that will represent the
2950 // range of sleds associated with a function.
2951 MCSymbol *SledsStart = OutContext.createTempSymbol("xray_sleds_start", true);
2952 OutStreamer->SwitchSection(InstMap);
2953 OutStreamer->EmitLabel(SledsStart);
2954 for (const auto &Sled : Sleds)
2955 Sled.emit(WordSizeBytes, OutStreamer.get(), CurrentFnSym);
2956 MCSymbol *SledsEnd = OutContext.createTempSymbol("xray_sleds_end", true);
2957 OutStreamer->EmitLabel(SledsEnd);
2958
2959 // We then emit a single entry in the index per function. We use the symbols
2960 // that bound the instrumentation map as the range for a specific function.
2961 // Each entry here will be 2 * word size aligned, as we're writing down two
2962 // pointers. This should work for both 32-bit and 64-bit platforms.
2963 OutStreamer->SwitchSection(FnSledIndex);
2964 OutStreamer->EmitCodeAlignment(2 * WordSizeBytes);
2965 OutStreamer->EmitSymbolValue(SledsStart, WordSizeBytes, false);
2966 OutStreamer->EmitSymbolValue(SledsEnd, WordSizeBytes, false);
2967 OutStreamer->SwitchSection(PrevSection);
2968 Sleds.clear();
2969}
2970
2971void AsmPrinter::recordSled(MCSymbol *Sled, const MachineInstr &MI,
2972 SledKind Kind, uint8_t Version) {
2973 const Function &F = MI.getMF()->getFunction();
2974 auto Attr = F.getFnAttribute("function-instrument");
2975 bool LogArgs = F.hasFnAttribute("xray-log-args");
2976 bool AlwaysInstrument =
2977 Attr.isStringAttribute() && Attr.getValueAsString() == "xray-always";
2978 if (Kind == SledKind::FUNCTION_ENTER && LogArgs)
2979 Kind = SledKind::LOG_ARGS_ENTER;
2980 Sleds.emplace_back(XRayFunctionEntry{Sled, CurrentFnSym, Kind,
2981 AlwaysInstrument, &F, Version});
2982}
2983
2984uint16_t AsmPrinter::getDwarfVersion() const {
2985 return OutStreamer->getContext().getDwarfVersion();
2986}
2987
2988void AsmPrinter::setDwarfVersion(uint16_t Version) {
2989 OutStreamer->getContext().setDwarfVersion(Version);
2990}