Bug Summary

File:llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp
Warning:line 181, column 8
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name GCOVProfiling.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -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 -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -mframe-pointer=none -fmath-errno -fno-rounding-math -masm-verbose -mconstructor-aliases -munwind-tables -target-cpu x86-64 -dwarf-column-info -fno-split-dwarf-inlining -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-11/lib/clang/11.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/lib/Transforms/Instrumentation -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Instrumentation -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/include -I /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-11/lib/clang/11.0.0/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++14 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/build-llvm/lib/Transforms/Instrumentation -fdebug-prefix-map=/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fobjc-runtime=gcc -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2020-03-09-184146-41876-1 -x c++ /build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp
1//===- GCOVProfiling.cpp - Insert edge counters for gcov profiling --------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This pass implements GCOV-style profiling. When this pass is run it emits
10// "gcno" files next to the existing source, and instruments the code that runs
11// to records the edges between blocks that run and emit a complementary "gcda"
12// file on exit.
13//
14//===----------------------------------------------------------------------===//
15
16#include "llvm/ADT/DenseMap.h"
17#include "llvm/ADT/Hashing.h"
18#include "llvm/ADT/STLExtras.h"
19#include "llvm/ADT/Sequence.h"
20#include "llvm/ADT/Statistic.h"
21#include "llvm/ADT/StringExtras.h"
22#include "llvm/ADT/StringMap.h"
23#include "llvm/Analysis/EHPersonalities.h"
24#include "llvm/Analysis/TargetLibraryInfo.h"
25#include "llvm/IR/CFG.h"
26#include "llvm/IR/DebugInfo.h"
27#include "llvm/IR/DebugLoc.h"
28#include "llvm/IR/IRBuilder.h"
29#include "llvm/IR/InstIterator.h"
30#include "llvm/IR/Instructions.h"
31#include "llvm/IR/IntrinsicInst.h"
32#include "llvm/IR/Module.h"
33#include "llvm/InitializePasses.h"
34#include "llvm/Pass.h"
35#include "llvm/Support/CommandLine.h"
36#include "llvm/Support/Debug.h"
37#include "llvm/Support/FileSystem.h"
38#include "llvm/Support/Path.h"
39#include "llvm/Support/Regex.h"
40#include "llvm/Support/raw_ostream.h"
41#include "llvm/Transforms/Instrumentation.h"
42#include "llvm/Transforms/Instrumentation/GCOVProfiler.h"
43#include "llvm/Transforms/Utils/ModuleUtils.h"
44#include <algorithm>
45#include <memory>
46#include <string>
47#include <utility>
48using namespace llvm;
49
50#define DEBUG_TYPE"insert-gcov-profiling" "insert-gcov-profiling"
51
52static cl::opt<std::string>
53DefaultGCOVVersion("default-gcov-version", cl::init("402*"), cl::Hidden,
54 cl::ValueRequired);
55static cl::opt<bool> DefaultExitBlockBeforeBody("gcov-exit-block-before-body",
56 cl::init(false), cl::Hidden);
57
58GCOVOptions GCOVOptions::getDefault() {
59 GCOVOptions Options;
60 Options.EmitNotes = true;
61 Options.EmitData = true;
62 Options.UseCfgChecksum = false;
63 Options.NoRedZone = false;
64 Options.FunctionNamesInData = true;
65 Options.ExitBlockBeforeBody = DefaultExitBlockBeforeBody;
66
67 if (DefaultGCOVVersion.size() != 4) {
68 llvm::report_fatal_error(std::string("Invalid -default-gcov-version: ") +
69 DefaultGCOVVersion);
70 }
71 memcpy(Options.Version, DefaultGCOVVersion.c_str(), 4);
72 return Options;
73}
74
75namespace {
76class GCOVFunction;
77
78class GCOVProfiler {
79public:
80 GCOVProfiler() : GCOVProfiler(GCOVOptions::getDefault()) {}
81 GCOVProfiler(const GCOVOptions &Opts) : Options(Opts) {
82 assert((Options.EmitNotes || Options.EmitData) &&(((Options.EmitNotes || Options.EmitData) && "GCOVProfiler asked to do nothing?"
) ? static_cast<void> (0) : __assert_fail ("(Options.EmitNotes || Options.EmitData) && \"GCOVProfiler asked to do nothing?\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp"
, 83, __PRETTY_FUNCTION__))
83 "GCOVProfiler asked to do nothing?")(((Options.EmitNotes || Options.EmitData) && "GCOVProfiler asked to do nothing?"
) ? static_cast<void> (0) : __assert_fail ("(Options.EmitNotes || Options.EmitData) && \"GCOVProfiler asked to do nothing?\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp"
, 83, __PRETTY_FUNCTION__));
84 ReversedVersion[0] = Options.Version[3];
85 ReversedVersion[1] = Options.Version[2];
86 ReversedVersion[2] = Options.Version[1];
87 ReversedVersion[3] = Options.Version[0];
88 ReversedVersion[4] = '\0';
89 }
90 bool
91 runOnModule(Module &M,
92 std::function<const TargetLibraryInfo &(Function &F)> GetTLI);
93
94private:
95 // Create the .gcno files for the Module based on DebugInfo.
96 void emitProfileNotes();
97
98 // Modify the program to track transitions along edges and call into the
99 // profiling runtime to emit .gcda files when run.
100 bool emitProfileArcs();
101
102 bool isFunctionInstrumented(const Function &F);
103 std::vector<Regex> createRegexesFromString(StringRef RegexesStr);
104 static bool doesFilenameMatchARegex(StringRef Filename,
105 std::vector<Regex> &Regexes);
106
107 // Get pointers to the functions in the runtime library.
108 FunctionCallee getStartFileFunc(const TargetLibraryInfo *TLI);
109 FunctionCallee getEmitFunctionFunc(const TargetLibraryInfo *TLI);
110 FunctionCallee getEmitArcsFunc(const TargetLibraryInfo *TLI);
111 FunctionCallee getSummaryInfoFunc();
112 FunctionCallee getEndFileFunc();
113
114 // Add the function to write out all our counters to the global destructor
115 // list.
116 Function *
117 insertCounterWriteout(ArrayRef<std::pair<GlobalVariable *, MDNode *>>);
118 Function *insertFlush(ArrayRef<std::pair<GlobalVariable *, MDNode *>>);
119
120 void AddFlushBeforeForkAndExec();
121
122 enum class GCovFileType { GCNO, GCDA };
123 std::string mangleName(const DICompileUnit *CU, GCovFileType FileType);
124
125 GCOVOptions Options;
126
127 // Reversed, NUL-terminated copy of Options.Version.
128 char ReversedVersion[5];
129 // Checksum, produced by hash of EdgeDestinations
130 SmallVector<uint32_t, 4> FileChecksums;
131
132 Module *M = nullptr;
133 std::function<const TargetLibraryInfo &(Function &F)> GetTLI;
134 LLVMContext *Ctx = nullptr;
135 SmallVector<std::unique_ptr<GCOVFunction>, 16> Funcs;
136 std::vector<Regex> FilterRe;
137 std::vector<Regex> ExcludeRe;
138 StringMap<bool> InstrumentedFiles;
139};
140
141class GCOVProfilerLegacyPass : public ModulePass {
142public:
143 static char ID;
144 GCOVProfilerLegacyPass()
145 : GCOVProfilerLegacyPass(GCOVOptions::getDefault()) {}
146 GCOVProfilerLegacyPass(const GCOVOptions &Opts)
147 : ModulePass(ID), Profiler(Opts) {
148 initializeGCOVProfilerLegacyPassPass(*PassRegistry::getPassRegistry());
149 }
150 StringRef getPassName() const override { return "GCOV Profiler"; }
151
152 bool runOnModule(Module &M) override {
153 return Profiler.runOnModule(M, [this](Function &F) -> TargetLibraryInfo & {
154 return getAnalysis<TargetLibraryInfoWrapperPass>().getTLI(F);
155 });
156 }
157
158 void getAnalysisUsage(AnalysisUsage &AU) const override {
159 AU.addRequired<TargetLibraryInfoWrapperPass>();
160 }
161
162private:
163 GCOVProfiler Profiler;
164};
165}
166
167char GCOVProfilerLegacyPass::ID = 0;
168INITIALIZE_PASS_BEGIN(static void *initializeGCOVProfilerLegacyPassPassOnce(PassRegistry
&Registry) {
169 GCOVProfilerLegacyPass, "insert-gcov-profiling",static void *initializeGCOVProfilerLegacyPassPassOnce(PassRegistry
&Registry) {
170 "Insert instrumentation for GCOV profiling", false, false)static void *initializeGCOVProfilerLegacyPassPassOnce(PassRegistry
&Registry) {
171INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)initializeTargetLibraryInfoWrapperPassPass(Registry);
172INITIALIZE_PASS_END(PassInfo *PI = new PassInfo( "Insert instrumentation for GCOV profiling"
, "insert-gcov-profiling", &GCOVProfilerLegacyPass::ID, PassInfo
::NormalCtor_t(callDefaultCtor<GCOVProfilerLegacyPass>)
, false, false); Registry.registerPass(*PI, true); return PI;
} static llvm::once_flag InitializeGCOVProfilerLegacyPassPassFlag
; void llvm::initializeGCOVProfilerLegacyPassPass(PassRegistry
&Registry) { llvm::call_once(InitializeGCOVProfilerLegacyPassPassFlag
, initializeGCOVProfilerLegacyPassPassOnce, std::ref(Registry
)); }
173 GCOVProfilerLegacyPass, "insert-gcov-profiling",PassInfo *PI = new PassInfo( "Insert instrumentation for GCOV profiling"
, "insert-gcov-profiling", &GCOVProfilerLegacyPass::ID, PassInfo
::NormalCtor_t(callDefaultCtor<GCOVProfilerLegacyPass>)
, false, false); Registry.registerPass(*PI, true); return PI;
} static llvm::once_flag InitializeGCOVProfilerLegacyPassPassFlag
; void llvm::initializeGCOVProfilerLegacyPassPass(PassRegistry
&Registry) { llvm::call_once(InitializeGCOVProfilerLegacyPassPassFlag
, initializeGCOVProfilerLegacyPassPassOnce, std::ref(Registry
)); }
174 "Insert instrumentation for GCOV profiling", false, false)PassInfo *PI = new PassInfo( "Insert instrumentation for GCOV profiling"
, "insert-gcov-profiling", &GCOVProfilerLegacyPass::ID, PassInfo
::NormalCtor_t(callDefaultCtor<GCOVProfilerLegacyPass>)
, false, false); Registry.registerPass(*PI, true); return PI;
} static llvm::once_flag InitializeGCOVProfilerLegacyPassPassFlag
; void llvm::initializeGCOVProfilerLegacyPassPass(PassRegistry
&Registry) { llvm::call_once(InitializeGCOVProfilerLegacyPassPassFlag
, initializeGCOVProfilerLegacyPassPassOnce, std::ref(Registry
)); }
175
176ModulePass *llvm::createGCOVProfilerPass(const GCOVOptions &Options) {
177 return new GCOVProfilerLegacyPass(Options);
178}
179
180static StringRef getFunctionName(const DISubprogram *SP) {
181 if (!SP->getLinkageName().empty())
29
←
Called C++ object pointer is null
182 return SP->getLinkageName();
183 return SP->getName();
184}
185
186/// Extract a filename for a DISubprogram.
187///
188/// Prefer relative paths in the coverage notes. Clang also may split
189/// up absolute paths into a directory and filename component. When
190/// the relative path doesn't exist, reconstruct the absolute path.
191static SmallString<128> getFilename(const DISubprogram *SP) {
192 SmallString<128> Path;
193 StringRef RelPath = SP->getFilename();
194 if (sys::fs::exists(RelPath))
195 Path = RelPath;
196 else
197 sys::path::append(Path, SP->getDirectory(), SP->getFilename());
198 return Path;
199}
200
201namespace {
202 class GCOVRecord {
203 protected:
204 static const char *const LinesTag;
205 static const char *const FunctionTag;
206 static const char *const BlockTag;
207 static const char *const EdgeTag;
208
209 GCOVRecord() = default;
210
211 void writeBytes(const char *Bytes, int Size) {
212 os->write(Bytes, Size);
213 }
214
215 void write(uint32_t i) {
216 writeBytes(reinterpret_cast<char*>(&i), 4);
217 }
218
219 // Returns the length measured in 4-byte blocks that will be used to
220 // represent this string in a GCOV file
221 static unsigned lengthOfGCOVString(StringRef s) {
222 // A GCOV string is a length, followed by a NUL, then between 0 and 3 NULs
223 // padding out to the next 4-byte word. The length is measured in 4-byte
224 // words including padding, not bytes of actual string.
225 return (s.size() / 4) + 1;
226 }
227
228 void writeGCOVString(StringRef s) {
229 uint32_t Len = lengthOfGCOVString(s);
230 write(Len);
231 writeBytes(s.data(), s.size());
232
233 // Write 1 to 4 bytes of NUL padding.
234 assert((unsigned)(4 - (s.size() % 4)) > 0)(((unsigned)(4 - (s.size() % 4)) > 0) ? static_cast<void
> (0) : __assert_fail ("(unsigned)(4 - (s.size() % 4)) > 0"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp"
, 234, __PRETTY_FUNCTION__));
235 assert((unsigned)(4 - (s.size() % 4)) <= 4)(((unsigned)(4 - (s.size() % 4)) <= 4) ? static_cast<void
> (0) : __assert_fail ("(unsigned)(4 - (s.size() % 4)) <= 4"
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp"
, 235, __PRETTY_FUNCTION__));
236 writeBytes("\0\0\0\0", 4 - (s.size() % 4));
237 }
238
239 raw_ostream *os;
240 };
241 const char *const GCOVRecord::LinesTag = "\0\0\x45\x01";
242 const char *const GCOVRecord::FunctionTag = "\0\0\0\1";
243 const char *const GCOVRecord::BlockTag = "\0\0\x41\x01";
244 const char *const GCOVRecord::EdgeTag = "\0\0\x43\x01";
245
246 class GCOVFunction;
247 class GCOVBlock;
248
249 // Constructed only by requesting it from a GCOVBlock, this object stores a
250 // list of line numbers and a single filename, representing lines that belong
251 // to the block.
252 class GCOVLines : public GCOVRecord {
253 public:
254 void addLine(uint32_t Line) {
255 assert(Line != 0 && "Line zero is not a valid real line number.")((Line != 0 && "Line zero is not a valid real line number."
) ? static_cast<void> (0) : __assert_fail ("Line != 0 && \"Line zero is not a valid real line number.\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp"
, 255, __PRETTY_FUNCTION__));
256 Lines.push_back(Line);
257 }
258
259 uint32_t length() const {
260 // Here 2 = 1 for string length + 1 for '0' id#.
261 return lengthOfGCOVString(Filename) + 2 + Lines.size();
262 }
263
264 void writeOut() {
265 write(0);
266 writeGCOVString(Filename);
267 for (int i = 0, e = Lines.size(); i != e; ++i)
268 write(Lines[i]);
269 }
270
271 GCOVLines(StringRef F, raw_ostream *os) : Filename(std::string(F)) {
272 this->os = os;
273 }
274
275 private:
276 std::string Filename;
277 SmallVector<uint32_t, 32> Lines;
278 };
279
280
281 // Represent a basic block in GCOV. Each block has a unique number in the
282 // function, number of lines belonging to each block, and a set of edges to
283 // other blocks.
284 class GCOVBlock : public GCOVRecord {
285 public:
286 GCOVLines &getFile(StringRef Filename) {
287 return LinesByFile.try_emplace(Filename, Filename, os).first->second;
288 }
289
290 void addEdge(GCOVBlock &Successor) {
291 OutEdges.push_back(&Successor);
292 }
293
294 void writeOut() {
295 uint32_t Len = 3;
296 SmallVector<StringMapEntry<GCOVLines> *, 32> SortedLinesByFile;
297 for (auto &I : LinesByFile) {
298 Len += I.second.length();
299 SortedLinesByFile.push_back(&I);
300 }
301
302 writeBytes(LinesTag, 4);
303 write(Len);
304 write(Number);
305
306 llvm::sort(SortedLinesByFile, [](StringMapEntry<GCOVLines> *LHS,
307 StringMapEntry<GCOVLines> *RHS) {
308 return LHS->getKey() < RHS->getKey();
309 });
310 for (auto &I : SortedLinesByFile)
311 I->getValue().writeOut();
312 write(0);
313 write(0);
314 }
315
316 GCOVBlock(const GCOVBlock &RHS) : GCOVRecord(RHS), Number(RHS.Number) {
317 // Only allow copy before edges and lines have been added. After that,
318 // there are inter-block pointers (eg: edges) that won't take kindly to
319 // blocks being copied or moved around.
320 assert(LinesByFile.empty())((LinesByFile.empty()) ? static_cast<void> (0) : __assert_fail
("LinesByFile.empty()", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp"
, 320, __PRETTY_FUNCTION__));
321 assert(OutEdges.empty())((OutEdges.empty()) ? static_cast<void> (0) : __assert_fail
("OutEdges.empty()", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp"
, 321, __PRETTY_FUNCTION__));
322 }
323
324 private:
325 friend class GCOVFunction;
326
327 GCOVBlock(uint32_t Number, raw_ostream *os)
328 : Number(Number) {
329 this->os = os;
330 }
331
332 uint32_t Number;
333 StringMap<GCOVLines> LinesByFile;
334 SmallVector<GCOVBlock *, 4> OutEdges;
335 };
336
337 // A function has a unique identifier, a checksum (we leave as zero) and a
338 // set of blocks and a map of edges between blocks. This is the only GCOV
339 // object users can construct, the blocks and lines will be rooted here.
340 class GCOVFunction : public GCOVRecord {
341 public:
342 GCOVFunction(const DISubprogram *SP, Function *F, raw_ostream *os,
343 uint32_t Ident, bool UseCfgChecksum, bool ExitBlockBeforeBody)
344 : SP(SP), Ident(Ident), UseCfgChecksum(UseCfgChecksum), CfgChecksum(0),
345 ReturnBlock(1, os) {
346 this->os = os;
347
348 LLVM_DEBUG(dbgs() << "Function: " << getFunctionName(SP) << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("insert-gcov-profiling")) { dbgs() << "Function: " <<
getFunctionName(SP) << "\n"; } } while (false);
349
350 uint32_t i = 0;
351 for (auto &BB : *F) {
352 // Skip index 1 if it's assigned to the ReturnBlock.
353 if (i == 1 && ExitBlockBeforeBody)
354 ++i;
355 Blocks.insert(std::make_pair(&BB, GCOVBlock(i++, os)));
356 }
357 if (!ExitBlockBeforeBody)
358 ReturnBlock.Number = i;
359
360 std::string FunctionNameAndLine;
361 raw_string_ostream FNLOS(FunctionNameAndLine);
362 FNLOS << getFunctionName(SP) << SP->getLine();
363 FNLOS.flush();
364 FuncChecksum = hash_value(FunctionNameAndLine);
365 }
366
367 GCOVBlock &getBlock(BasicBlock *BB) {
368 return Blocks.find(BB)->second;
369 }
370
371 GCOVBlock &getReturnBlock() {
372 return ReturnBlock;
373 }
374
375 std::string getEdgeDestinations() {
376 std::string EdgeDestinations;
377 raw_string_ostream EDOS(EdgeDestinations);
378 Function *F = Blocks.begin()->first->getParent();
379 for (BasicBlock &I : *F) {
380 GCOVBlock &Block = getBlock(&I);
381 for (int i = 0, e = Block.OutEdges.size(); i != e; ++i)
382 EDOS << Block.OutEdges[i]->Number;
383 }
384 return EdgeDestinations;
385 }
386
387 uint32_t getFuncChecksum() const {
388 return FuncChecksum;
389 }
390
391 void setCfgChecksum(uint32_t Checksum) {
392 CfgChecksum = Checksum;
393 }
394
395 void writeOut() {
396 writeBytes(FunctionTag, 4);
397 SmallString<128> Filename = getFilename(SP);
398 uint32_t BlockLen = 1 + 1 + 1 + lengthOfGCOVString(getFunctionName(SP)) +
399 1 + lengthOfGCOVString(Filename) + 1;
400 if (UseCfgChecksum)
401 ++BlockLen;
402 write(BlockLen);
403 write(Ident);
404 write(FuncChecksum);
405 if (UseCfgChecksum)
406 write(CfgChecksum);
407 writeGCOVString(getFunctionName(SP));
408 writeGCOVString(Filename);
409 write(SP->getLine());
410
411 // Emit count of blocks.
412 writeBytes(BlockTag, 4);
413 write(Blocks.size() + 1);
414 for (int i = 0, e = Blocks.size() + 1; i != e; ++i) {
415 write(0); // No flags on our blocks.
416 }
417 LLVM_DEBUG(dbgs() << Blocks.size() << " blocks.\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("insert-gcov-profiling")) { dbgs() << Blocks.size() <<
" blocks.\n"; } } while (false);
418
419 // Emit edges between blocks.
420 if (Blocks.empty()) return;
421 Function *F = Blocks.begin()->first->getParent();
422 for (BasicBlock &I : *F) {
423 GCOVBlock &Block = getBlock(&I);
424 if (Block.OutEdges.empty()) continue;
425
426 writeBytes(EdgeTag, 4);
427 write(Block.OutEdges.size() * 2 + 1);
428 write(Block.Number);
429 for (int i = 0, e = Block.OutEdges.size(); i != e; ++i) {
430 LLVM_DEBUG(dbgs() << Block.Number << " -> "do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("insert-gcov-profiling")) { dbgs() << Block.Number <<
" -> " << Block.OutEdges[i]->Number << "\n"
; } } while (false)
431 << Block.OutEdges[i]->Number << "\n")do { if (::llvm::DebugFlag && ::llvm::isCurrentDebugType
("insert-gcov-profiling")) { dbgs() << Block.Number <<
" -> " << Block.OutEdges[i]->Number << "\n"
; } } while (false);
432 write(Block.OutEdges[i]->Number);
433 write(0); // no flags
434 }
435 }
436
437 // Emit lines for each block.
438 for (BasicBlock &I : *F)
439 getBlock(&I).writeOut();
440 }
441
442 private:
443 const DISubprogram *SP;
444 uint32_t Ident;
445 uint32_t FuncChecksum;
446 bool UseCfgChecksum;
447 uint32_t CfgChecksum;
448 DenseMap<BasicBlock *, GCOVBlock> Blocks;
449 GCOVBlock ReturnBlock;
450 };
451}
452
453// RegexesStr is a string containing differents regex separated by a semi-colon.
454// For example "foo\..*$;bar\..*$".
455std::vector<Regex> GCOVProfiler::createRegexesFromString(StringRef RegexesStr) {
456 std::vector<Regex> Regexes;
457 while (!RegexesStr.empty()) {
458 std::pair<StringRef, StringRef> HeadTail = RegexesStr.split(';');
459 if (!HeadTail.first.empty()) {
460 Regex Re(HeadTail.first);
461 std::string Err;
462 if (!Re.isValid(Err)) {
463 Ctx->emitError(Twine("Regex ") + HeadTail.first +
464 " is not valid: " + Err);
465 }
466 Regexes.emplace_back(std::move(Re));
467 }
468 RegexesStr = HeadTail.second;
469 }
470 return Regexes;
471}
472
473bool GCOVProfiler::doesFilenameMatchARegex(StringRef Filename,
474 std::vector<Regex> &Regexes) {
475 for (Regex &Re : Regexes) {
476 if (Re.match(Filename)) {
477 return true;
478 }
479 }
480 return false;
481}
482
483bool GCOVProfiler::isFunctionInstrumented(const Function &F) {
484 if (FilterRe.empty() && ExcludeRe.empty()) {
485 return true;
486 }
487 SmallString<128> Filename = getFilename(F.getSubprogram());
488 auto It = InstrumentedFiles.find(Filename);
489 if (It != InstrumentedFiles.end()) {
490 return It->second;
491 }
492
493 SmallString<256> RealPath;
494 StringRef RealFilename;
495
496 // Path can be
497 // /usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/bits/*.h so for
498 // such a case we must get the real_path.
499 if (sys::fs::real_path(Filename, RealPath)) {
500 // real_path can fail with path like "foo.c".
501 RealFilename = Filename;
502 } else {
503 RealFilename = RealPath;
504 }
505
506 bool ShouldInstrument;
507 if (FilterRe.empty()) {
508 ShouldInstrument = !doesFilenameMatchARegex(RealFilename, ExcludeRe);
509 } else if (ExcludeRe.empty()) {
510 ShouldInstrument = doesFilenameMatchARegex(RealFilename, FilterRe);
511 } else {
512 ShouldInstrument = doesFilenameMatchARegex(RealFilename, FilterRe) &&
513 !doesFilenameMatchARegex(RealFilename, ExcludeRe);
514 }
515 InstrumentedFiles[Filename] = ShouldInstrument;
516 return ShouldInstrument;
517}
518
519std::string GCOVProfiler::mangleName(const DICompileUnit *CU,
520 GCovFileType OutputType) {
521 bool Notes = OutputType == GCovFileType::GCNO;
522
523 if (NamedMDNode *GCov = M->getNamedMetadata("llvm.gcov")) {
524 for (int i = 0, e = GCov->getNumOperands(); i != e; ++i) {
525 MDNode *N = GCov->getOperand(i);
526 bool ThreeElement = N->getNumOperands() == 3;
527 if (!ThreeElement && N->getNumOperands() != 2)
528 continue;
529 if (dyn_cast<MDNode>(N->getOperand(ThreeElement ? 2 : 1)) != CU)
530 continue;
531
532 if (ThreeElement) {
533 // These nodes have no mangling to apply, it's stored mangled in the
534 // bitcode.
535 MDString *NotesFile = dyn_cast<MDString>(N->getOperand(0));
536 MDString *DataFile = dyn_cast<MDString>(N->getOperand(1));
537 if (!NotesFile || !DataFile)
538 continue;
539 return std::string(Notes ? NotesFile->getString()
540 : DataFile->getString());
541 }
542
543 MDString *GCovFile = dyn_cast<MDString>(N->getOperand(0));
544 if (!GCovFile)
545 continue;
546
547 SmallString<128> Filename = GCovFile->getString();
548 sys::path::replace_extension(Filename, Notes ? "gcno" : "gcda");
549 return std::string(Filename.str());
550 }
551 }
552
553 SmallString<128> Filename = CU->getFilename();
554 sys::path::replace_extension(Filename, Notes ? "gcno" : "gcda");
555 StringRef FName = sys::path::filename(Filename);
556 SmallString<128> CurPath;
557 if (sys::fs::current_path(CurPath))
558 return std::string(FName);
559 sys::path::append(CurPath, FName);
560 return std::string(CurPath.str());
561}
562
563bool GCOVProfiler::runOnModule(
564 Module &M, std::function<const TargetLibraryInfo &(Function &F)> GetTLI) {
565 this->M = &M;
566 this->GetTLI = std::move(GetTLI);
567 Ctx = &M.getContext();
568
569 AddFlushBeforeForkAndExec();
570
571 FilterRe = createRegexesFromString(Options.Filter);
572 ExcludeRe = createRegexesFromString(Options.Exclude);
573
574 if (Options.EmitNotes) emitProfileNotes();
2
←
Assuming field 'EmitNotes' is false
→
3
←
Taking false branch
→
575 if (Options.EmitData) return emitProfileArcs();
4
←
Assuming field 'EmitData' is true
→
5
←
Taking true branch
→
6
←
Calling 'GCOVProfiler::emitProfileArcs'
→
576 return false;
577}
578
579PreservedAnalyses GCOVProfilerPass::run(Module &M,
580 ModuleAnalysisManager &AM) {
581
582 GCOVProfiler Profiler(GCOVOpts);
583 FunctionAnalysisManager &FAM =
584 AM.getResult<FunctionAnalysisManagerModuleProxy>(M).getManager();
585
586 if (!Profiler.runOnModule(M, [&](Function &F) -> TargetLibraryInfo & {
1
Calling 'GCOVProfiler::runOnModule'
→
587 return FAM.getResult<TargetLibraryAnalysis>(F);
588 }))
589 return PreservedAnalyses::all();
590
591 return PreservedAnalyses::none();
592}
593
594static bool functionHasLines(Function &F) {
595 // Check whether this function actually has any source lines. Not only
596 // do these waste space, they also can crash gcov.
597 for (auto &BB : F) {
598 for (auto &I : BB) {
599 // Debug intrinsic locations correspond to the location of the
600 // declaration, not necessarily any statements or expressions.
601 if (isa<DbgInfoIntrinsic>(&I)) continue;
602
603 const DebugLoc &Loc = I.getDebugLoc();
604 if (!Loc)
605 continue;
606
607 // Artificial lines such as calls to the global constructors.
608 if (Loc.getLine() == 0) continue;
609
610 return true;
611 }
612 }
613 return false;
614}
615
616static bool isUsingScopeBasedEH(Function &F) {
617 if (!F.hasPersonalityFn()) return false;
618
619 EHPersonality Personality = classifyEHPersonality(F.getPersonalityFn());
620 return isScopedEHPersonality(Personality);
621}
622
623static bool shouldKeepInEntry(BasicBlock::iterator It) {
624 if (isa<AllocaInst>(*It)) return true;
625 if (isa<DbgInfoIntrinsic>(*It)) return true;
626 if (auto *II = dyn_cast<IntrinsicInst>(It)) {
627 if (II->getIntrinsicID() == llvm::Intrinsic::localescape) return true;
628 }
629
630 return false;
631}
632
633void GCOVProfiler::AddFlushBeforeForkAndExec() {
634 SmallVector<Instruction *, 2> ForkAndExecs;
635 for (auto &F : M->functions()) {
636 auto *TLI = &GetTLI(F);
637 for (auto &I : instructions(F)) {
638 if (CallInst *CI = dyn_cast<CallInst>(&I)) {
639 if (Function *Callee = CI->getCalledFunction()) {
640 LibFunc LF;
641 if (TLI->getLibFunc(*Callee, LF) &&
642 (LF == LibFunc_fork || LF == LibFunc_execl ||
643 LF == LibFunc_execle || LF == LibFunc_execlp ||
644 LF == LibFunc_execv || LF == LibFunc_execvp ||
645 LF == LibFunc_execve || LF == LibFunc_execvpe ||
646 LF == LibFunc_execvP)) {
647 ForkAndExecs.push_back(&I);
648 }
649 }
650 }
651 }
652 }
653
654 // We need to split the block after the fork/exec call
655 // because else the counters for the lines after will be
656 // the same as before the call.
657 for (auto I : ForkAndExecs) {
658 IRBuilder<> Builder(I);
659 FunctionType *FTy = FunctionType::get(Builder.getVoidTy(), {}, false);
660 FunctionCallee GCOVFlush = M->getOrInsertFunction("__gcov_flush", FTy);
661 Builder.CreateCall(GCOVFlush);
662 I->getParent()->splitBasicBlock(I);
663 }
664}
665
666void GCOVProfiler::emitProfileNotes() {
667 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
668 if (!CU_Nodes) return;
669
670 for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
671 // Each compile unit gets its own .gcno file. This means that whether we run
672 // this pass over the original .o's as they're produced, or run it after
673 // LTO, we'll generate the same .gcno files.
674
675 auto *CU = cast<DICompileUnit>(CU_Nodes->getOperand(i));
676
677 // Skip module skeleton (and module) CUs.
678 if (CU->getDWOId())
679 continue;
680
681 std::error_code EC;
682 raw_fd_ostream out(mangleName(CU, GCovFileType::GCNO), EC,
683 sys::fs::OF_None);
684 if (EC) {
685 Ctx->emitError(Twine("failed to open coverage notes file for writing: ") +
686 EC.message());
687 continue;
688 }
689
690 std::string EdgeDestinations;
691
692 unsigned FunctionIdent = 0;
693 for (auto &F : M->functions()) {
694 DISubprogram *SP = F.getSubprogram();
695 if (!SP) continue;
696 if (!functionHasLines(F) || !isFunctionInstrumented(F))
697 continue;
698 // TODO: Functions using scope-based EH are currently not supported.
699 if (isUsingScopeBasedEH(F)) continue;
700
701 // gcov expects every function to start with an entry block that has a
702 // single successor, so split the entry block to make sure of that.
703 BasicBlock &EntryBlock = F.getEntryBlock();
704 BasicBlock::iterator It = EntryBlock.begin();
705 while (shouldKeepInEntry(It))
706 ++It;
707 EntryBlock.splitBasicBlock(It);
708
709 Funcs.push_back(std::make_unique<GCOVFunction>(SP, &F, &out, FunctionIdent++,
710 Options.UseCfgChecksum,
711 Options.ExitBlockBeforeBody));
712 GCOVFunction &Func = *Funcs.back();
713
714 // Add the function line number to the lines of the entry block
715 // to have a counter for the function definition.
716 uint32_t Line = SP->getLine();
717 auto Filename = getFilename(SP);
718
719 // Artificial functions such as global initializers
720 if (!SP->isArtificial())
721 Func.getBlock(&EntryBlock).getFile(Filename).addLine(Line);
722
723 for (auto &BB : F) {
724 GCOVBlock &Block = Func.getBlock(&BB);
725 Instruction *TI = BB.getTerminator();
726 if (int successors = TI->getNumSuccessors()) {
727 for (int i = 0; i != successors; ++i) {
728 Block.addEdge(Func.getBlock(TI->getSuccessor(i)));
729 }
730 } else if (isa<ReturnInst>(TI)) {
731 Block.addEdge(Func.getReturnBlock());
732 }
733
734 for (auto &I : BB) {
735 // Debug intrinsic locations correspond to the location of the
736 // declaration, not necessarily any statements or expressions.
737 if (isa<DbgInfoIntrinsic>(&I)) continue;
738
739 const DebugLoc &Loc = I.getDebugLoc();
740 if (!Loc)
741 continue;
742
743 // Artificial lines such as calls to the global constructors.
744 if (Loc.getLine() == 0 || Loc.isImplicitCode())
745 continue;
746
747 if (Line == Loc.getLine()) continue;
748 Line = Loc.getLine();
749 if (SP != getDISubprogram(Loc.getScope()))
750 continue;
751
752 GCOVLines &Lines = Block.getFile(Filename);
753 Lines.addLine(Loc.getLine());
754 }
755 Line = 0;
756 }
757 EdgeDestinations += Func.getEdgeDestinations();
758 }
759
760 FileChecksums.push_back(hash_value(EdgeDestinations));
761 out.write("oncg", 4);
762 out.write(ReversedVersion, 4);
763 out.write(reinterpret_cast<char*>(&FileChecksums.back()), 4);
764
765 for (auto &Func : Funcs) {
766 Func->setCfgChecksum(FileChecksums.back());
767 Func->writeOut();
768 }
769
770 out.write("\0\0\0\0\0\0\0\0", 8); // EOF
771 out.close();
772 }
773}
774
775bool GCOVProfiler::emitProfileArcs() {
776 NamedMDNode *CU_Nodes = M->getNamedMetadata("llvm.dbg.cu");
777 if (!CU_Nodes) return false;
7
←
Assuming 'CU_Nodes' is non-null
→
8
←
Taking false branch
→
778
779 bool Result = false;
780 for (unsigned i = 0, e = CU_Nodes->getNumOperands(); i != e; ++i) {
9
←
Assuming 'i' is not equal to 'e'
→
10
←
Loop condition is true. Entering loop body
→
781 SmallVector<std::pair<GlobalVariable *, MDNode *>, 8> CountersBySP;
782 for (auto &F : M->functions()) {
783 DISubprogram *SP = F.getSubprogram();
784 if (!SP) continue;
785 if (!functionHasLines(F) || !isFunctionInstrumented(F))
786 continue;
787 // TODO: Functions using scope-based EH are currently not supported.
788 if (isUsingScopeBasedEH(F)) continue;
789 if (!Result) Result = true;
790
791 DenseMap<std::pair<BasicBlock *, BasicBlock *>, unsigned> EdgeToCounter;
792 unsigned Edges = 0;
793 for (auto &BB : F) {
794 Instruction *TI = BB.getTerminator();
795 if (isa<ReturnInst>(TI)) {
796 EdgeToCounter[{&BB, nullptr}] = Edges++;
797 } else {
798 for (BasicBlock *Succ : successors(TI)) {
799 EdgeToCounter[{&BB, Succ}] = Edges++;
800 }
801 }
802 }
803
804 ArrayType *CounterTy =
805 ArrayType::get(Type::getInt64Ty(*Ctx), Edges);
806 GlobalVariable *Counters =
807 new GlobalVariable(*M, CounterTy, false,
808 GlobalValue::InternalLinkage,
809 Constant::getNullValue(CounterTy),
810 "__llvm_gcov_ctr");
811 CountersBySP.push_back(std::make_pair(Counters, SP));
812
813 // If a BB has several predecessors, use a PHINode to select
814 // the correct counter.
815 for (auto &BB : F) {
816 const unsigned EdgeCount =
817 std::distance(pred_begin(&BB), pred_end(&BB));
818 if (EdgeCount) {
819 // The phi node must be at the begin of the BB.
820 IRBuilder<> BuilderForPhi(&*BB.begin());
821 Type *Int64PtrTy = Type::getInt64PtrTy(*Ctx);
822 PHINode *Phi = BuilderForPhi.CreatePHI(Int64PtrTy, EdgeCount);
823 for (BasicBlock *Pred : predecessors(&BB)) {
824 auto It = EdgeToCounter.find({Pred, &BB});
825 assert(It != EdgeToCounter.end())((It != EdgeToCounter.end()) ? static_cast<void> (0) : __assert_fail
("It != EdgeToCounter.end()", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp"
, 825, __PRETTY_FUNCTION__));
826 const unsigned Edge = It->second;
827 Value *EdgeCounter = BuilderForPhi.CreateConstInBoundsGEP2_64(
828 Counters->getValueType(), Counters, 0, Edge);
829 Phi->addIncoming(EdgeCounter, Pred);
830 }
831
832 // Skip phis, landingpads.
833 IRBuilder<> Builder(&*BB.getFirstInsertionPt());
834 Value *Count = Builder.CreateLoad(Builder.getInt64Ty(), Phi);
835 Count = Builder.CreateAdd(Count, Builder.getInt64(1));
836 Builder.CreateStore(Count, Phi);
837
838 Instruction *TI = BB.getTerminator();
839 if (isa<ReturnInst>(TI)) {
840 auto It = EdgeToCounter.find({&BB, nullptr});
841 assert(It != EdgeToCounter.end())((It != EdgeToCounter.end()) ? static_cast<void> (0) : __assert_fail
("It != EdgeToCounter.end()", "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp"
, 841, __PRETTY_FUNCTION__));
842 const unsigned Edge = It->second;
843 Value *Counter = Builder.CreateConstInBoundsGEP2_64(
844 Counters->getValueType(), Counters, 0, Edge);
845 Value *Count = Builder.CreateLoad(Builder.getInt64Ty(), Counter);
846 Count = Builder.CreateAdd(Count, Builder.getInt64(1));
847 Builder.CreateStore(Count, Counter);
848 }
849 }
850 }
851 }
852
853 Function *WriteoutF = insertCounterWriteout(CountersBySP);
11
←
Calling 'GCOVProfiler::insertCounterWriteout'
→
854 Function *FlushF = insertFlush(CountersBySP);
855
856 // Create a small bit of code that registers the "__llvm_gcov_writeout" to
857 // be executed at exit and the "__llvm_gcov_flush" function to be executed
858 // when "__gcov_flush" is called.
859 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
860 Function *F = Function::Create(FTy, GlobalValue::InternalLinkage,
861 "__llvm_gcov_init", M);
862 F->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
863 F->setLinkage(GlobalValue::InternalLinkage);
864 F->addFnAttr(Attribute::NoInline);
865 if (Options.NoRedZone)
866 F->addFnAttr(Attribute::NoRedZone);
867
868 BasicBlock *BB = BasicBlock::Create(*Ctx, "entry", F);
869 IRBuilder<> Builder(BB);
870
871 FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
872 Type *Params[] = {
873 PointerType::get(FTy, 0),
874 PointerType::get(FTy, 0)
875 };
876 FTy = FunctionType::get(Builder.getVoidTy(), Params, false);
877
878 // Initialize the environment and register the local writeout and flush
879 // functions.
880 FunctionCallee GCOVInit = M->getOrInsertFunction("llvm_gcov_init", FTy);
881 Builder.CreateCall(GCOVInit, {WriteoutF, FlushF});
882 Builder.CreateRetVoid();
883
884 appendToGlobalCtors(*M, F, 0);
885 }
886
887 return Result;
888}
889
890FunctionCallee GCOVProfiler::getStartFileFunc(const TargetLibraryInfo *TLI) {
891 Type *Args[] = {
892 Type::getInt8PtrTy(*Ctx), // const char *orig_filename
893 Type::getInt8PtrTy(*Ctx), // const char version[4]
894 Type::getInt32Ty(*Ctx), // uint32_t checksum
895 };
896 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), Args, false);
897 AttributeList AL;
898 if (auto AK = TLI->getExtAttrForI32Param(false))
899 AL = AL.addParamAttribute(*Ctx, 2, AK);
900 FunctionCallee Res = M->getOrInsertFunction("llvm_gcda_start_file", FTy, AL);
901 return Res;
902}
903
904FunctionCallee GCOVProfiler::getEmitFunctionFunc(const TargetLibraryInfo *TLI) {
905 Type *Args[] = {
906 Type::getInt32Ty(*Ctx), // uint32_t ident
907 Type::getInt8PtrTy(*Ctx), // const char *function_name
908 Type::getInt32Ty(*Ctx), // uint32_t func_checksum
909 Type::getInt8Ty(*Ctx), // uint8_t use_extra_checksum
910 Type::getInt32Ty(*Ctx), // uint32_t cfg_checksum
911 };
912 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), Args, false);
913 AttributeList AL;
914 if (auto AK = TLI->getExtAttrForI32Param(false)) {
915 AL = AL.addParamAttribute(*Ctx, 0, AK);
916 AL = AL.addParamAttribute(*Ctx, 2, AK);
917 AL = AL.addParamAttribute(*Ctx, 3, AK);
918 AL = AL.addParamAttribute(*Ctx, 4, AK);
919 }
920 return M->getOrInsertFunction("llvm_gcda_emit_function", FTy);
921}
922
923FunctionCallee GCOVProfiler::getEmitArcsFunc(const TargetLibraryInfo *TLI) {
924 Type *Args[] = {
925 Type::getInt32Ty(*Ctx), // uint32_t num_counters
926 Type::getInt64PtrTy(*Ctx), // uint64_t *counters
927 };
928 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), Args, false);
929 AttributeList AL;
930 if (auto AK = TLI->getExtAttrForI32Param(false))
931 AL = AL.addParamAttribute(*Ctx, 0, AK);
932 return M->getOrInsertFunction("llvm_gcda_emit_arcs", FTy, AL);
933}
934
935FunctionCallee GCOVProfiler::getSummaryInfoFunc() {
936 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
937 return M->getOrInsertFunction("llvm_gcda_summary_info", FTy);
938}
939
940FunctionCallee GCOVProfiler::getEndFileFunc() {
941 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
942 return M->getOrInsertFunction("llvm_gcda_end_file", FTy);
943}
944
945Function *GCOVProfiler::insertCounterWriteout(
946 ArrayRef<std::pair<GlobalVariable *, MDNode *> > CountersBySP) {
947 FunctionType *WriteoutFTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
948 Function *WriteoutF = M->getFunction("__llvm_gcov_writeout");
949 if (!WriteoutF)
12
←
Assuming 'WriteoutF' is non-null
→
13
←
Taking false branch
→
950 WriteoutF = Function::Create(WriteoutFTy, GlobalValue::InternalLinkage,
951 "__llvm_gcov_writeout", M);
952 WriteoutF->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
953 WriteoutF->addFnAttr(Attribute::NoInline);
954 if (Options.NoRedZone)
14
←
Assuming field 'NoRedZone' is false
→
15
←
Taking false branch
→
955 WriteoutF->addFnAttr(Attribute::NoRedZone);
956
957 BasicBlock *BB = BasicBlock::Create(*Ctx, "entry", WriteoutF);
958 IRBuilder<> Builder(BB);
959
960 auto *TLI = &GetTLI(*WriteoutF);
961
962 FunctionCallee StartFile = getStartFileFunc(TLI);
963 FunctionCallee EmitFunction = getEmitFunctionFunc(TLI);
964 FunctionCallee EmitArcs = getEmitArcsFunc(TLI);
965 FunctionCallee SummaryInfo = getSummaryInfoFunc();
966 FunctionCallee EndFile = getEndFileFunc();
967
968 NamedMDNode *CUNodes = M->getNamedMetadata("llvm.dbg.cu");
969 if (!CUNodes) {
16
←
Assuming 'CUNodes' is non-null
→
17
←
Taking false branch
→
970 Builder.CreateRetVoid();
971 return WriteoutF;
972 }
973
974 // Collect the relevant data into a large constant data structure that we can
975 // walk to write out everything.
976 StructType *StartFileCallArgsTy = StructType::create(
977 {Builder.getInt8PtrTy(), Builder.getInt8PtrTy(), Builder.getInt32Ty()});
978 StructType *EmitFunctionCallArgsTy = StructType::create(
979 {Builder.getInt32Ty(), Builder.getInt8PtrTy(), Builder.getInt32Ty(),
980 Builder.getInt8Ty(), Builder.getInt32Ty()});
981 StructType *EmitArcsCallArgsTy = StructType::create(
982 {Builder.getInt32Ty(), Builder.getInt64Ty()->getPointerTo()});
983 StructType *FileInfoTy =
984 StructType::create({StartFileCallArgsTy, Builder.getInt32Ty(),
985 EmitFunctionCallArgsTy->getPointerTo(),
986 EmitArcsCallArgsTy->getPointerTo()});
987
988 Constant *Zero32 = Builder.getInt32(0);
989 // Build an explicit array of two zeros for use in ConstantExpr GEP building.
990 Constant *TwoZero32s[] = {Zero32, Zero32};
991
992 SmallVector<Constant *, 8> FileInfos;
993 for (int i : llvm::seq<int>(0, CUNodes->getNumOperands())) {
994 auto *CU = cast<DICompileUnit>(CUNodes->getOperand(i));
18
←
The object is a 'DICompileUnit'
→
995
996 // Skip module skeleton (and module) CUs.
997 if (CU->getDWOId())
19
←
Assuming the condition is false
→
20
←
Taking false branch
→
998 continue;
999
1000 std::string FilenameGcda = mangleName(CU, GCovFileType::GCDA);
1001 uint32_t CfgChecksum = FileChecksums.empty() ? 0 : FileChecksums[i];
21
←
'?' condition is false
→
1002 auto *StartFileCallArgs = ConstantStruct::get(
1003 StartFileCallArgsTy, {Builder.CreateGlobalStringPtr(FilenameGcda),
1004 Builder.CreateGlobalStringPtr(ReversedVersion),
1005 Builder.getInt32(CfgChecksum)});
1006
1007 SmallVector<Constant *, 8> EmitFunctionCallArgsArray;
1008 SmallVector<Constant *, 8> EmitArcsCallArgsArray;
1009 for (int j : llvm::seq<int>(0, CountersBySP.size())) {
1010 auto *SP = cast_or_null<DISubprogram>(CountersBySP[j].second);
22
←
Assuming null pointer is passed into cast
→
23
←
'SP' initialized to a null pointer value
→
1011 uint32_t FuncChecksum = Funcs.empty() ? 0 : Funcs[j]->getFuncChecksum();
24
←
'?' condition is true
→
1012 EmitFunctionCallArgsArray.push_back(ConstantStruct::get(
1013 EmitFunctionCallArgsTy,
1014 {Builder.getInt32(j),
1015 Options.FunctionNamesInData
25
←
Assuming field 'FunctionNamesInData' is true
→
26
←
'?' condition is true
→
1016 ? Builder.CreateGlobalStringPtr(getFunctionName(SP))
27
←
Passing null pointer value via 1st parameter 'SP'
→
28
←
Calling 'getFunctionName'
→
1017 : Constant::getNullValue(Builder.getInt8PtrTy()),
1018 Builder.getInt32(FuncChecksum),
1019 Builder.getInt8(Options.UseCfgChecksum),
1020 Builder.getInt32(CfgChecksum)}));
1021
1022 GlobalVariable *GV = CountersBySP[j].first;
1023 unsigned Arcs = cast<ArrayType>(GV->getValueType())->getNumElements();
1024 EmitArcsCallArgsArray.push_back(ConstantStruct::get(
1025 EmitArcsCallArgsTy,
1026 {Builder.getInt32(Arcs), ConstantExpr::getInBoundsGetElementPtr(
1027 GV->getValueType(), GV, TwoZero32s)}));
1028 }
1029 // Create global arrays for the two emit calls.
1030 int CountersSize = CountersBySP.size();
1031 assert(CountersSize == (int)EmitFunctionCallArgsArray.size() &&((CountersSize == (int)EmitFunctionCallArgsArray.size() &&
"Mismatched array size!") ? static_cast<void> (0) : __assert_fail
("CountersSize == (int)EmitFunctionCallArgsArray.size() && \"Mismatched array size!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp"
, 1032, __PRETTY_FUNCTION__))
1032 "Mismatched array size!")((CountersSize == (int)EmitFunctionCallArgsArray.size() &&
"Mismatched array size!") ? static_cast<void> (0) : __assert_fail
("CountersSize == (int)EmitFunctionCallArgsArray.size() && \"Mismatched array size!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp"
, 1032, __PRETTY_FUNCTION__));
1033 assert(CountersSize == (int)EmitArcsCallArgsArray.size() &&((CountersSize == (int)EmitArcsCallArgsArray.size() &&
"Mismatched array size!") ? static_cast<void> (0) : __assert_fail
("CountersSize == (int)EmitArcsCallArgsArray.size() && \"Mismatched array size!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp"
, 1034, __PRETTY_FUNCTION__))
1034 "Mismatched array size!")((CountersSize == (int)EmitArcsCallArgsArray.size() &&
"Mismatched array size!") ? static_cast<void> (0) : __assert_fail
("CountersSize == (int)EmitArcsCallArgsArray.size() && \"Mismatched array size!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp"
, 1034, __PRETTY_FUNCTION__));
1035 auto *EmitFunctionCallArgsArrayTy =
1036 ArrayType::get(EmitFunctionCallArgsTy, CountersSize);
1037 auto *EmitFunctionCallArgsArrayGV = new GlobalVariable(
1038 *M, EmitFunctionCallArgsArrayTy, /*isConstant*/ true,
1039 GlobalValue::InternalLinkage,
1040 ConstantArray::get(EmitFunctionCallArgsArrayTy,
1041 EmitFunctionCallArgsArray),
1042 Twine("__llvm_internal_gcov_emit_function_args.") + Twine(i));
1043 auto *EmitArcsCallArgsArrayTy =
1044 ArrayType::get(EmitArcsCallArgsTy, CountersSize);
1045 EmitFunctionCallArgsArrayGV->setUnnamedAddr(
1046 GlobalValue::UnnamedAddr::Global);
1047 auto *EmitArcsCallArgsArrayGV = new GlobalVariable(
1048 *M, EmitArcsCallArgsArrayTy, /*isConstant*/ true,
1049 GlobalValue::InternalLinkage,
1050 ConstantArray::get(EmitArcsCallArgsArrayTy, EmitArcsCallArgsArray),
1051 Twine("__llvm_internal_gcov_emit_arcs_args.") + Twine(i));
1052 EmitArcsCallArgsArrayGV->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
1053
1054 FileInfos.push_back(ConstantStruct::get(
1055 FileInfoTy,
1056 {StartFileCallArgs, Builder.getInt32(CountersSize),
1057 ConstantExpr::getInBoundsGetElementPtr(EmitFunctionCallArgsArrayTy,
1058 EmitFunctionCallArgsArrayGV,
1059 TwoZero32s),
1060 ConstantExpr::getInBoundsGetElementPtr(
1061 EmitArcsCallArgsArrayTy, EmitArcsCallArgsArrayGV, TwoZero32s)}));
1062 }
1063
1064 // If we didn't find anything to actually emit, bail on out.
1065 if (FileInfos.empty()) {
1066 Builder.CreateRetVoid();
1067 return WriteoutF;
1068 }
1069
1070 // To simplify code, we cap the number of file infos we write out to fit
1071 // easily in a 32-bit signed integer. This gives consistent behavior between
1072 // 32-bit and 64-bit systems without requiring (potentially very slow) 64-bit
1073 // operations on 32-bit systems. It also seems unreasonable to try to handle
1074 // more than 2 billion files.
1075 if ((int64_t)FileInfos.size() > (int64_t)INT_MAX2147483647)
1076 FileInfos.resize(INT_MAX2147483647);
1077
1078 // Create a global for the entire data structure so we can walk it more
1079 // easily.
1080 auto *FileInfoArrayTy = ArrayType::get(FileInfoTy, FileInfos.size());
1081 auto *FileInfoArrayGV = new GlobalVariable(
1082 *M, FileInfoArrayTy, /*isConstant*/ true, GlobalValue::InternalLinkage,
1083 ConstantArray::get(FileInfoArrayTy, FileInfos),
1084 "__llvm_internal_gcov_emit_file_info");
1085 FileInfoArrayGV->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
1086
1087 // Create the CFG for walking this data structure.
1088 auto *FileLoopHeader =
1089 BasicBlock::Create(*Ctx, "file.loop.header", WriteoutF);
1090 auto *CounterLoopHeader =
1091 BasicBlock::Create(*Ctx, "counter.loop.header", WriteoutF);
1092 auto *FileLoopLatch = BasicBlock::Create(*Ctx, "file.loop.latch", WriteoutF);
1093 auto *ExitBB = BasicBlock::Create(*Ctx, "exit", WriteoutF);
1094
1095 // We always have at least one file, so just branch to the header.
1096 Builder.CreateBr(FileLoopHeader);
1097
1098 // The index into the files structure is our loop induction variable.
1099 Builder.SetInsertPoint(FileLoopHeader);
1100 PHINode *IV =
1101 Builder.CreatePHI(Builder.getInt32Ty(), /*NumReservedValues*/ 2);
1102 IV->addIncoming(Builder.getInt32(0), BB);
1103 auto *FileInfoPtr = Builder.CreateInBoundsGEP(
1104 FileInfoArrayTy, FileInfoArrayGV, {Builder.getInt32(0), IV});
1105 auto *StartFileCallArgsPtr =
1106 Builder.CreateStructGEP(FileInfoTy, FileInfoPtr, 0);
1107 auto *StartFileCall = Builder.CreateCall(
1108 StartFile,
1109 {Builder.CreateLoad(StartFileCallArgsTy->getElementType(0),
1110 Builder.CreateStructGEP(StartFileCallArgsTy,
1111 StartFileCallArgsPtr, 0)),
1112 Builder.CreateLoad(StartFileCallArgsTy->getElementType(1),
1113 Builder.CreateStructGEP(StartFileCallArgsTy,
1114 StartFileCallArgsPtr, 1)),
1115 Builder.CreateLoad(StartFileCallArgsTy->getElementType(2),
1116 Builder.CreateStructGEP(StartFileCallArgsTy,
1117 StartFileCallArgsPtr, 2))});
1118 if (auto AK = TLI->getExtAttrForI32Param(false))
1119 StartFileCall->addParamAttr(2, AK);
1120 auto *NumCounters =
1121 Builder.CreateLoad(FileInfoTy->getElementType(1),
1122 Builder.CreateStructGEP(FileInfoTy, FileInfoPtr, 1));
1123 auto *EmitFunctionCallArgsArray =
1124 Builder.CreateLoad(FileInfoTy->getElementType(2),
1125 Builder.CreateStructGEP(FileInfoTy, FileInfoPtr, 2));
1126 auto *EmitArcsCallArgsArray =
1127 Builder.CreateLoad(FileInfoTy->getElementType(3),
1128 Builder.CreateStructGEP(FileInfoTy, FileInfoPtr, 3));
1129 auto *EnterCounterLoopCond =
1130 Builder.CreateICmpSLT(Builder.getInt32(0), NumCounters);
1131 Builder.CreateCondBr(EnterCounterLoopCond, CounterLoopHeader, FileLoopLatch);
1132
1133 Builder.SetInsertPoint(CounterLoopHeader);
1134 auto *JV = Builder.CreatePHI(Builder.getInt32Ty(), /*NumReservedValues*/ 2);
1135 JV->addIncoming(Builder.getInt32(0), FileLoopHeader);
1136 auto *EmitFunctionCallArgsPtr = Builder.CreateInBoundsGEP(
1137 EmitFunctionCallArgsTy, EmitFunctionCallArgsArray, JV);
1138 auto *EmitFunctionCall = Builder.CreateCall(
1139 EmitFunction,
1140 {Builder.CreateLoad(EmitFunctionCallArgsTy->getElementType(0),
1141 Builder.CreateStructGEP(EmitFunctionCallArgsTy,
1142 EmitFunctionCallArgsPtr, 0)),
1143 Builder.CreateLoad(EmitFunctionCallArgsTy->getElementType(1),
1144 Builder.CreateStructGEP(EmitFunctionCallArgsTy,
1145 EmitFunctionCallArgsPtr, 1)),
1146 Builder.CreateLoad(EmitFunctionCallArgsTy->getElementType(2),
1147 Builder.CreateStructGEP(EmitFunctionCallArgsTy,
1148 EmitFunctionCallArgsPtr, 2)),
1149 Builder.CreateLoad(EmitFunctionCallArgsTy->getElementType(3),
1150 Builder.CreateStructGEP(EmitFunctionCallArgsTy,
1151 EmitFunctionCallArgsPtr, 3)),
1152 Builder.CreateLoad(EmitFunctionCallArgsTy->getElementType(4),
1153 Builder.CreateStructGEP(EmitFunctionCallArgsTy,
1154 EmitFunctionCallArgsPtr,
1155 4))});
1156 if (auto AK = TLI->getExtAttrForI32Param(false)) {
1157 EmitFunctionCall->addParamAttr(0, AK);
1158 EmitFunctionCall->addParamAttr(2, AK);
1159 EmitFunctionCall->addParamAttr(3, AK);
1160 EmitFunctionCall->addParamAttr(4, AK);
1161 }
1162 auto *EmitArcsCallArgsPtr =
1163 Builder.CreateInBoundsGEP(EmitArcsCallArgsTy, EmitArcsCallArgsArray, JV);
1164 auto *EmitArcsCall = Builder.CreateCall(
1165 EmitArcs,
1166 {Builder.CreateLoad(
1167 EmitArcsCallArgsTy->getElementType(0),
1168 Builder.CreateStructGEP(EmitArcsCallArgsTy, EmitArcsCallArgsPtr, 0)),
1169 Builder.CreateLoad(EmitArcsCallArgsTy->getElementType(1),
1170 Builder.CreateStructGEP(EmitArcsCallArgsTy,
1171 EmitArcsCallArgsPtr, 1))});
1172 if (auto AK = TLI->getExtAttrForI32Param(false))
1173 EmitArcsCall->addParamAttr(0, AK);
1174 auto *NextJV = Builder.CreateAdd(JV, Builder.getInt32(1));
1175 auto *CounterLoopCond = Builder.CreateICmpSLT(NextJV, NumCounters);
1176 Builder.CreateCondBr(CounterLoopCond, CounterLoopHeader, FileLoopLatch);
1177 JV->addIncoming(NextJV, CounterLoopHeader);
1178
1179 Builder.SetInsertPoint(FileLoopLatch);
1180 Builder.CreateCall(SummaryInfo, {});
1181 Builder.CreateCall(EndFile, {});
1182 auto *NextIV = Builder.CreateAdd(IV, Builder.getInt32(1));
1183 auto *FileLoopCond =
1184 Builder.CreateICmpSLT(NextIV, Builder.getInt32(FileInfos.size()));
1185 Builder.CreateCondBr(FileLoopCond, FileLoopHeader, ExitBB);
1186 IV->addIncoming(NextIV, FileLoopLatch);
1187
1188 Builder.SetInsertPoint(ExitBB);
1189 Builder.CreateRetVoid();
1190
1191 return WriteoutF;
1192}
1193
1194Function *GCOVProfiler::
1195insertFlush(ArrayRef<std::pair<GlobalVariable*, MDNode*> > CountersBySP) {
1196 FunctionType *FTy = FunctionType::get(Type::getVoidTy(*Ctx), false);
1197 Function *FlushF = M->getFunction("__llvm_gcov_flush");
1198 if (!FlushF)
1199 FlushF = Function::Create(FTy, GlobalValue::InternalLinkage,
1200 "__llvm_gcov_flush", M);
1201 else
1202 FlushF->setLinkage(GlobalValue::InternalLinkage);
1203 FlushF->setUnnamedAddr(GlobalValue::UnnamedAddr::Global);
1204 FlushF->addFnAttr(Attribute::NoInline);
1205 if (Options.NoRedZone)
1206 FlushF->addFnAttr(Attribute::NoRedZone);
1207
1208 BasicBlock *Entry = BasicBlock::Create(*Ctx, "entry", FlushF);
1209
1210 // Write out the current counters.
1211 Function *WriteoutF = M->getFunction("__llvm_gcov_writeout");
1212 assert(WriteoutF && "Need to create the writeout function first!")((WriteoutF && "Need to create the writeout function first!"
) ? static_cast<void> (0) : __assert_fail ("WriteoutF && \"Need to create the writeout function first!\""
, "/build/llvm-toolchain-snapshot-11~++20200309111110+2c36c23f347/llvm/lib/Transforms/Instrumentation/GCOVProfiling.cpp"
, 1212, __PRETTY_FUNCTION__));
1213
1214 IRBuilder<> Builder(Entry);
1215 Builder.CreateCall(WriteoutF, {});
1216
1217 // Zero out the counters.
1218 for (const auto &I : CountersBySP) {
1219 GlobalVariable *GV = I.first;
1220 Constant *Null = Constant::getNullValue(GV->getValueType());
1221 Builder.CreateStore(Null, GV);
1222 }
1223
1224 Type *RetTy = FlushF->getReturnType();
1225 if (RetTy == Type::getVoidTy(*Ctx))
1226 Builder.CreateRetVoid();
1227 else if (RetTy->isIntegerTy())
1228 // Used if __llvm_gcov_flush was implicitly declared.
1229 Builder.CreateRet(ConstantInt::get(RetTy, 0));
1230 else
1231 report_fatal_error("invalid return type for __llvm_gcov_flush");
1232
1233 return FlushF;
1234}