Bug Summary

File:tools/clang/lib/CodeGen/CGExprConstant.cpp
Warning:line 1716, column 21
Value stored to 'C' during its initialization is never read

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 CGExprConstant.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 -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mthread-model posix -relaxed-aliasing -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-8/lib/clang/8.0.0 -D CLANG_VENDOR="Debian " -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-8~svn350071/build-llvm/tools/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-8~svn350071/tools/clang/include -I /build/llvm-toolchain-snapshot-8~svn350071/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-8~svn350071/build-llvm/include -I /build/llvm-toolchain-snapshot-8~svn350071/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/include/clang/8.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-8/lib/clang/8.0.0/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-8~svn350071/build-llvm/tools/clang/lib/CodeGen -fdebug-prefix-map=/build/llvm-toolchain-snapshot-8~svn350071=. -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -stack-protector 2 -fobjc-runtime=gcc -fno-common -fdiagnostics-show-option -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -o /tmp/scan-build-2018-12-27-042839-1215-1 -x c++ /build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp -faddrsig
1//===--- CGExprConstant.cpp - Emit LLVM Code from Constant Expressions ----===//
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 contains code to emit Constant Expr nodes as LLVM code.
11//
12//===----------------------------------------------------------------------===//
13
14#include "CodeGenFunction.h"
15#include "CGCXXABI.h"
16#include "CGObjCRuntime.h"
17#include "CGRecordLayout.h"
18#include "CodeGenModule.h"
19#include "ConstantEmitter.h"
20#include "TargetInfo.h"
21#include "clang/AST/APValue.h"
22#include "clang/AST/ASTContext.h"
23#include "clang/AST/RecordLayout.h"
24#include "clang/AST/StmtVisitor.h"
25#include "clang/Basic/Builtins.h"
26#include "llvm/IR/Constants.h"
27#include "llvm/IR/DataLayout.h"
28#include "llvm/IR/Function.h"
29#include "llvm/IR/GlobalVariable.h"
30using namespace clang;
31using namespace CodeGen;
32
33//===----------------------------------------------------------------------===//
34// ConstStructBuilder
35//===----------------------------------------------------------------------===//
36
37namespace {
38class ConstExprEmitter;
39class ConstStructBuilder {
40 CodeGenModule &CGM;
41 ConstantEmitter &Emitter;
42
43 bool Packed;
44 CharUnits NextFieldOffsetInChars;
45 CharUnits LLVMStructAlignment;
46 SmallVector<llvm::Constant *, 32> Elements;
47public:
48 static llvm::Constant *BuildStruct(ConstantEmitter &Emitter,
49 ConstExprEmitter *ExprEmitter,
50 llvm::Constant *Base,
51 InitListExpr *Updater,
52 QualType ValTy);
53 static llvm::Constant *BuildStruct(ConstantEmitter &Emitter,
54 InitListExpr *ILE, QualType StructTy);
55 static llvm::Constant *BuildStruct(ConstantEmitter &Emitter,
56 const APValue &Value, QualType ValTy);
57
58private:
59 ConstStructBuilder(ConstantEmitter &emitter)
60 : CGM(emitter.CGM), Emitter(emitter), Packed(false),
61 NextFieldOffsetInChars(CharUnits::Zero()),
62 LLVMStructAlignment(CharUnits::One()) { }
63
64 void AppendField(const FieldDecl *Field, uint64_t FieldOffset,
65 llvm::Constant *InitExpr);
66
67 void AppendBytes(CharUnits FieldOffsetInChars, llvm::Constant *InitCst);
68
69 void AppendBitField(const FieldDecl *Field, uint64_t FieldOffset,
70 llvm::ConstantInt *InitExpr);
71
72 void AppendPadding(CharUnits PadSize);
73
74 void AppendTailPadding(CharUnits RecordSize);
75
76 void ConvertStructToPacked();
77
78 bool Build(InitListExpr *ILE);
79 bool Build(ConstExprEmitter *Emitter, llvm::Constant *Base,
80 InitListExpr *Updater);
81 bool Build(const APValue &Val, const RecordDecl *RD, bool IsPrimaryBase,
82 const CXXRecordDecl *VTableClass, CharUnits BaseOffset);
83 llvm::Constant *Finalize(QualType Ty);
84
85 CharUnits getAlignment(const llvm::Constant *C) const {
86 if (Packed) return CharUnits::One();
87 return CharUnits::fromQuantity(
88 CGM.getDataLayout().getABITypeAlignment(C->getType()));
89 }
90
91 CharUnits getSizeInChars(const llvm::Constant *C) const {
92 return CharUnits::fromQuantity(
93 CGM.getDataLayout().getTypeAllocSize(C->getType()));
94 }
95};
96
97void ConstStructBuilder::
98AppendField(const FieldDecl *Field, uint64_t FieldOffset,
99 llvm::Constant *InitCst) {
100 const ASTContext &Context = CGM.getContext();
101
102 CharUnits FieldOffsetInChars = Context.toCharUnitsFromBits(FieldOffset);
103
104 AppendBytes(FieldOffsetInChars, InitCst);
105}
106
107void ConstStructBuilder::
108AppendBytes(CharUnits FieldOffsetInChars, llvm::Constant *InitCst) {
109
110 assert(NextFieldOffsetInChars <= FieldOffsetInChars((NextFieldOffsetInChars <= FieldOffsetInChars && "Field offset mismatch!"
) ? static_cast<void> (0) : __assert_fail ("NextFieldOffsetInChars <= FieldOffsetInChars && \"Field offset mismatch!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 111, __PRETTY_FUNCTION__))
111 && "Field offset mismatch!")((NextFieldOffsetInChars <= FieldOffsetInChars && "Field offset mismatch!"
) ? static_cast<void> (0) : __assert_fail ("NextFieldOffsetInChars <= FieldOffsetInChars && \"Field offset mismatch!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 111, __PRETTY_FUNCTION__))
;
112
113 CharUnits FieldAlignment = getAlignment(InitCst);
114
115 // Round up the field offset to the alignment of the field type.
116 CharUnits AlignedNextFieldOffsetInChars =
117 NextFieldOffsetInChars.alignTo(FieldAlignment);
118
119 if (AlignedNextFieldOffsetInChars < FieldOffsetInChars) {
120 // We need to append padding.
121 AppendPadding(FieldOffsetInChars - NextFieldOffsetInChars);
122
123 assert(NextFieldOffsetInChars == FieldOffsetInChars &&((NextFieldOffsetInChars == FieldOffsetInChars && "Did not add enough padding!"
) ? static_cast<void> (0) : __assert_fail ("NextFieldOffsetInChars == FieldOffsetInChars && \"Did not add enough padding!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 124, __PRETTY_FUNCTION__))
124 "Did not add enough padding!")((NextFieldOffsetInChars == FieldOffsetInChars && "Did not add enough padding!"
) ? static_cast<void> (0) : __assert_fail ("NextFieldOffsetInChars == FieldOffsetInChars && \"Did not add enough padding!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 124, __PRETTY_FUNCTION__))
;
125
126 AlignedNextFieldOffsetInChars =
127 NextFieldOffsetInChars.alignTo(FieldAlignment);
128 }
129
130 if (AlignedNextFieldOffsetInChars > FieldOffsetInChars) {
131 assert(!Packed && "Alignment is wrong even with a packed struct!")((!Packed && "Alignment is wrong even with a packed struct!"
) ? static_cast<void> (0) : __assert_fail ("!Packed && \"Alignment is wrong even with a packed struct!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 131, __PRETTY_FUNCTION__))
;
132
133 // Convert the struct to a packed struct.
134 ConvertStructToPacked();
135
136 // After we pack the struct, we may need to insert padding.
137 if (NextFieldOffsetInChars < FieldOffsetInChars) {
138 // We need to append padding.
139 AppendPadding(FieldOffsetInChars - NextFieldOffsetInChars);
140
141 assert(NextFieldOffsetInChars == FieldOffsetInChars &&((NextFieldOffsetInChars == FieldOffsetInChars && "Did not add enough padding!"
) ? static_cast<void> (0) : __assert_fail ("NextFieldOffsetInChars == FieldOffsetInChars && \"Did not add enough padding!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 142, __PRETTY_FUNCTION__))
142 "Did not add enough padding!")((NextFieldOffsetInChars == FieldOffsetInChars && "Did not add enough padding!"
) ? static_cast<void> (0) : __assert_fail ("NextFieldOffsetInChars == FieldOffsetInChars && \"Did not add enough padding!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 142, __PRETTY_FUNCTION__))
;
143 }
144 AlignedNextFieldOffsetInChars = NextFieldOffsetInChars;
145 }
146
147 // Add the field.
148 Elements.push_back(InitCst);
149 NextFieldOffsetInChars = AlignedNextFieldOffsetInChars +
150 getSizeInChars(InitCst);
151
152 if (Packed)
153 assert(LLVMStructAlignment == CharUnits::One() &&((LLVMStructAlignment == CharUnits::One() && "Packed struct not byte-aligned!"
) ? static_cast<void> (0) : __assert_fail ("LLVMStructAlignment == CharUnits::One() && \"Packed struct not byte-aligned!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 154, __PRETTY_FUNCTION__))
154 "Packed struct not byte-aligned!")((LLVMStructAlignment == CharUnits::One() && "Packed struct not byte-aligned!"
) ? static_cast<void> (0) : __assert_fail ("LLVMStructAlignment == CharUnits::One() && \"Packed struct not byte-aligned!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 154, __PRETTY_FUNCTION__))
;
155 else
156 LLVMStructAlignment = std::max(LLVMStructAlignment, FieldAlignment);
157}
158
159void ConstStructBuilder::AppendBitField(const FieldDecl *Field,
160 uint64_t FieldOffset,
161 llvm::ConstantInt *CI) {
162 const ASTContext &Context = CGM.getContext();
163 const uint64_t CharWidth = Context.getCharWidth();
164 uint64_t NextFieldOffsetInBits = Context.toBits(NextFieldOffsetInChars);
165 if (FieldOffset > NextFieldOffsetInBits) {
166 // We need to add padding.
167 CharUnits PadSize = Context.toCharUnitsFromBits(
168 llvm::alignTo(FieldOffset - NextFieldOffsetInBits,
169 Context.getTargetInfo().getCharAlign()));
170
171 AppendPadding(PadSize);
172 }
173
174 uint64_t FieldSize = Field->getBitWidthValue(Context);
175
176 llvm::APInt FieldValue = CI->getValue();
177
178 // Promote the size of FieldValue if necessary
179 // FIXME: This should never occur, but currently it can because initializer
180 // constants are cast to bool, and because clang is not enforcing bitfield
181 // width limits.
182 if (FieldSize > FieldValue.getBitWidth())
183 FieldValue = FieldValue.zext(FieldSize);
184
185 // Truncate the size of FieldValue to the bit field size.
186 if (FieldSize < FieldValue.getBitWidth())
187 FieldValue = FieldValue.trunc(FieldSize);
188
189 NextFieldOffsetInBits = Context.toBits(NextFieldOffsetInChars);
190 if (FieldOffset < NextFieldOffsetInBits) {
191 // Either part of the field or the entire field can go into the previous
192 // byte.
193 assert(!Elements.empty() && "Elements can't be empty!")((!Elements.empty() && "Elements can't be empty!") ? static_cast
<void> (0) : __assert_fail ("!Elements.empty() && \"Elements can't be empty!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 193, __PRETTY_FUNCTION__))
;
194
195 unsigned BitsInPreviousByte = NextFieldOffsetInBits - FieldOffset;
196
197 bool FitsCompletelyInPreviousByte =
198 BitsInPreviousByte >= FieldValue.getBitWidth();
199
200 llvm::APInt Tmp = FieldValue;
201
202 if (!FitsCompletelyInPreviousByte) {
203 unsigned NewFieldWidth = FieldSize - BitsInPreviousByte;
204
205 if (CGM.getDataLayout().isBigEndian()) {
206 Tmp.lshrInPlace(NewFieldWidth);
207 Tmp = Tmp.trunc(BitsInPreviousByte);
208
209 // We want the remaining high bits.
210 FieldValue = FieldValue.trunc(NewFieldWidth);
211 } else {
212 Tmp = Tmp.trunc(BitsInPreviousByte);
213
214 // We want the remaining low bits.
215 FieldValue.lshrInPlace(BitsInPreviousByte);
216 FieldValue = FieldValue.trunc(NewFieldWidth);
217 }
218 }
219
220 Tmp = Tmp.zext(CharWidth);
221 if (CGM.getDataLayout().isBigEndian()) {
222 if (FitsCompletelyInPreviousByte)
223 Tmp = Tmp.shl(BitsInPreviousByte - FieldValue.getBitWidth());
224 } else {
225 Tmp = Tmp.shl(CharWidth - BitsInPreviousByte);
226 }
227
228 // 'or' in the bits that go into the previous byte.
229 llvm::Value *LastElt = Elements.back();
230 if (llvm::ConstantInt *Val = dyn_cast<llvm::ConstantInt>(LastElt))
231 Tmp |= Val->getValue();
232 else {
233 assert(isa<llvm::UndefValue>(LastElt))((isa<llvm::UndefValue>(LastElt)) ? static_cast<void
> (0) : __assert_fail ("isa<llvm::UndefValue>(LastElt)"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 233, __PRETTY_FUNCTION__))
;
234 // If there is an undef field that we're adding to, it can either be a
235 // scalar undef (in which case, we just replace it with our field) or it
236 // is an array. If it is an array, we have to pull one byte off the
237 // array so that the other undef bytes stay around.
238 if (!isa<llvm::IntegerType>(LastElt->getType())) {
239 // The undef padding will be a multibyte array, create a new smaller
240 // padding and then an hole for our i8 to get plopped into.
241 assert(isa<llvm::ArrayType>(LastElt->getType()) &&((isa<llvm::ArrayType>(LastElt->getType()) &&
"Expected array padding of undefs") ? static_cast<void>
(0) : __assert_fail ("isa<llvm::ArrayType>(LastElt->getType()) && \"Expected array padding of undefs\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 242, __PRETTY_FUNCTION__))
242 "Expected array padding of undefs")((isa<llvm::ArrayType>(LastElt->getType()) &&
"Expected array padding of undefs") ? static_cast<void>
(0) : __assert_fail ("isa<llvm::ArrayType>(LastElt->getType()) && \"Expected array padding of undefs\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 242, __PRETTY_FUNCTION__))
;
243 llvm::ArrayType *AT = cast<llvm::ArrayType>(LastElt->getType());
244 assert(AT->getElementType()->isIntegerTy(CharWidth) &&((AT->getElementType()->isIntegerTy(CharWidth) &&
AT->getNumElements() != 0 && "Expected non-empty array padding of undefs"
) ? static_cast<void> (0) : __assert_fail ("AT->getElementType()->isIntegerTy(CharWidth) && AT->getNumElements() != 0 && \"Expected non-empty array padding of undefs\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 246, __PRETTY_FUNCTION__))
245 AT->getNumElements() != 0 &&((AT->getElementType()->isIntegerTy(CharWidth) &&
AT->getNumElements() != 0 && "Expected non-empty array padding of undefs"
) ? static_cast<void> (0) : __assert_fail ("AT->getElementType()->isIntegerTy(CharWidth) && AT->getNumElements() != 0 && \"Expected non-empty array padding of undefs\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 246, __PRETTY_FUNCTION__))
246 "Expected non-empty array padding of undefs")((AT->getElementType()->isIntegerTy(CharWidth) &&
AT->getNumElements() != 0 && "Expected non-empty array padding of undefs"
) ? static_cast<void> (0) : __assert_fail ("AT->getElementType()->isIntegerTy(CharWidth) && AT->getNumElements() != 0 && \"Expected non-empty array padding of undefs\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 246, __PRETTY_FUNCTION__))
;
247
248 // Remove the padding array.
249 NextFieldOffsetInChars -= CharUnits::fromQuantity(AT->getNumElements());
250 Elements.pop_back();
251
252 // Add the padding back in two chunks.
253 AppendPadding(CharUnits::fromQuantity(AT->getNumElements()-1));
254 AppendPadding(CharUnits::One());
255 assert(isa<llvm::UndefValue>(Elements.back()) &&((isa<llvm::UndefValue>(Elements.back()) && Elements
.back()->getType()->isIntegerTy(CharWidth) && "Padding addition didn't work right"
) ? static_cast<void> (0) : __assert_fail ("isa<llvm::UndefValue>(Elements.back()) && Elements.back()->getType()->isIntegerTy(CharWidth) && \"Padding addition didn't work right\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 257, __PRETTY_FUNCTION__))
256 Elements.back()->getType()->isIntegerTy(CharWidth) &&((isa<llvm::UndefValue>(Elements.back()) && Elements
.back()->getType()->isIntegerTy(CharWidth) && "Padding addition didn't work right"
) ? static_cast<void> (0) : __assert_fail ("isa<llvm::UndefValue>(Elements.back()) && Elements.back()->getType()->isIntegerTy(CharWidth) && \"Padding addition didn't work right\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 257, __PRETTY_FUNCTION__))
257 "Padding addition didn't work right")((isa<llvm::UndefValue>(Elements.back()) && Elements
.back()->getType()->isIntegerTy(CharWidth) && "Padding addition didn't work right"
) ? static_cast<void> (0) : __assert_fail ("isa<llvm::UndefValue>(Elements.back()) && Elements.back()->getType()->isIntegerTy(CharWidth) && \"Padding addition didn't work right\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 257, __PRETTY_FUNCTION__))
;
258 }
259 }
260
261 Elements.back() = llvm::ConstantInt::get(CGM.getLLVMContext(), Tmp);
262
263 if (FitsCompletelyInPreviousByte)
264 return;
265 }
266
267 while (FieldValue.getBitWidth() > CharWidth) {
268 llvm::APInt Tmp;
269
270 if (CGM.getDataLayout().isBigEndian()) {
271 // We want the high bits.
272 Tmp =
273 FieldValue.lshr(FieldValue.getBitWidth() - CharWidth).trunc(CharWidth);
274 } else {
275 // We want the low bits.
276 Tmp = FieldValue.trunc(CharWidth);
277
278 FieldValue.lshrInPlace(CharWidth);
279 }
280
281 Elements.push_back(llvm::ConstantInt::get(CGM.getLLVMContext(), Tmp));
282 ++NextFieldOffsetInChars;
283
284 FieldValue = FieldValue.trunc(FieldValue.getBitWidth() - CharWidth);
285 }
286
287 assert(FieldValue.getBitWidth() > 0 &&((FieldValue.getBitWidth() > 0 && "Should have at least one bit left!"
) ? static_cast<void> (0) : __assert_fail ("FieldValue.getBitWidth() > 0 && \"Should have at least one bit left!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 288, __PRETTY_FUNCTION__))
288 "Should have at least one bit left!")((FieldValue.getBitWidth() > 0 && "Should have at least one bit left!"
) ? static_cast<void> (0) : __assert_fail ("FieldValue.getBitWidth() > 0 && \"Should have at least one bit left!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 288, __PRETTY_FUNCTION__))
;
289 assert(FieldValue.getBitWidth() <= CharWidth &&((FieldValue.getBitWidth() <= CharWidth && "Should not have more than a byte left!"
) ? static_cast<void> (0) : __assert_fail ("FieldValue.getBitWidth() <= CharWidth && \"Should not have more than a byte left!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 290, __PRETTY_FUNCTION__))
290 "Should not have more than a byte left!")((FieldValue.getBitWidth() <= CharWidth && "Should not have more than a byte left!"
) ? static_cast<void> (0) : __assert_fail ("FieldValue.getBitWidth() <= CharWidth && \"Should not have more than a byte left!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 290, __PRETTY_FUNCTION__))
;
291
292 if (FieldValue.getBitWidth() < CharWidth) {
293 if (CGM.getDataLayout().isBigEndian()) {
294 unsigned BitWidth = FieldValue.getBitWidth();
295
296 FieldValue = FieldValue.zext(CharWidth) << (CharWidth - BitWidth);
297 } else
298 FieldValue = FieldValue.zext(CharWidth);
299 }
300
301 // Append the last element.
302 Elements.push_back(llvm::ConstantInt::get(CGM.getLLVMContext(),
303 FieldValue));
304 ++NextFieldOffsetInChars;
305}
306
307void ConstStructBuilder::AppendPadding(CharUnits PadSize) {
308 if (PadSize.isZero())
309 return;
310
311 llvm::Type *Ty = CGM.Int8Ty;
312 if (PadSize > CharUnits::One())
313 Ty = llvm::ArrayType::get(Ty, PadSize.getQuantity());
314
315 llvm::Constant *C = llvm::UndefValue::get(Ty);
316 Elements.push_back(C);
317 assert(getAlignment(C) == CharUnits::One() &&((getAlignment(C) == CharUnits::One() && "Padding must have 1 byte alignment!"
) ? static_cast<void> (0) : __assert_fail ("getAlignment(C) == CharUnits::One() && \"Padding must have 1 byte alignment!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 318, __PRETTY_FUNCTION__))
318 "Padding must have 1 byte alignment!")((getAlignment(C) == CharUnits::One() && "Padding must have 1 byte alignment!"
) ? static_cast<void> (0) : __assert_fail ("getAlignment(C) == CharUnits::One() && \"Padding must have 1 byte alignment!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 318, __PRETTY_FUNCTION__))
;
319
320 NextFieldOffsetInChars += getSizeInChars(C);
321}
322
323void ConstStructBuilder::AppendTailPadding(CharUnits RecordSize) {
324 assert(NextFieldOffsetInChars <= RecordSize &&((NextFieldOffsetInChars <= RecordSize && "Size mismatch!"
) ? static_cast<void> (0) : __assert_fail ("NextFieldOffsetInChars <= RecordSize && \"Size mismatch!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 325, __PRETTY_FUNCTION__))
325 "Size mismatch!")((NextFieldOffsetInChars <= RecordSize && "Size mismatch!"
) ? static_cast<void> (0) : __assert_fail ("NextFieldOffsetInChars <= RecordSize && \"Size mismatch!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 325, __PRETTY_FUNCTION__))
;
326
327 AppendPadding(RecordSize - NextFieldOffsetInChars);
328}
329
330void ConstStructBuilder::ConvertStructToPacked() {
331 SmallVector<llvm::Constant *, 16> PackedElements;
332 CharUnits ElementOffsetInChars = CharUnits::Zero();
333
334 for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
335 llvm::Constant *C = Elements[i];
336
337 CharUnits ElementAlign = CharUnits::fromQuantity(
338 CGM.getDataLayout().getABITypeAlignment(C->getType()));
339 CharUnits AlignedElementOffsetInChars =
340 ElementOffsetInChars.alignTo(ElementAlign);
341
342 if (AlignedElementOffsetInChars > ElementOffsetInChars) {
343 // We need some padding.
344 CharUnits NumChars =
345 AlignedElementOffsetInChars - ElementOffsetInChars;
346
347 llvm::Type *Ty = CGM.Int8Ty;
348 if (NumChars > CharUnits::One())
349 Ty = llvm::ArrayType::get(Ty, NumChars.getQuantity());
350
351 llvm::Constant *Padding = llvm::UndefValue::get(Ty);
352 PackedElements.push_back(Padding);
353 ElementOffsetInChars += getSizeInChars(Padding);
354 }
355
356 PackedElements.push_back(C);
357 ElementOffsetInChars += getSizeInChars(C);
358 }
359
360 assert(ElementOffsetInChars == NextFieldOffsetInChars &&((ElementOffsetInChars == NextFieldOffsetInChars && "Packing the struct changed its size!"
) ? static_cast<void> (0) : __assert_fail ("ElementOffsetInChars == NextFieldOffsetInChars && \"Packing the struct changed its size!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 361, __PRETTY_FUNCTION__))
361 "Packing the struct changed its size!")((ElementOffsetInChars == NextFieldOffsetInChars && "Packing the struct changed its size!"
) ? static_cast<void> (0) : __assert_fail ("ElementOffsetInChars == NextFieldOffsetInChars && \"Packing the struct changed its size!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 361, __PRETTY_FUNCTION__))
;
362
363 Elements.swap(PackedElements);
364 LLVMStructAlignment = CharUnits::One();
365 Packed = true;
366}
367
368bool ConstStructBuilder::Build(InitListExpr *ILE) {
369 RecordDecl *RD = ILE->getType()->getAs<RecordType>()->getDecl();
370 const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
371
372 unsigned FieldNo = 0;
373 unsigned ElementNo = 0;
374
375 // Bail out if we have base classes. We could support these, but they only
376 // arise in C++1z where we will have already constant folded most interesting
377 // cases. FIXME: There are still a few more cases we can handle this way.
378 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
379 if (CXXRD->getNumBases())
380 return false;
381
382 for (RecordDecl::field_iterator Field = RD->field_begin(),
383 FieldEnd = RD->field_end(); Field != FieldEnd; ++Field, ++FieldNo) {
384 // If this is a union, skip all the fields that aren't being initialized.
385 if (RD->isUnion() && ILE->getInitializedFieldInUnion() != *Field)
386 continue;
387
388 // Don't emit anonymous bitfields, they just affect layout.
389 if (Field->isUnnamedBitfield())
390 continue;
391
392 // Get the initializer. A struct can include fields without initializers,
393 // we just use explicit null values for them.
394 llvm::Constant *EltInit;
395 if (ElementNo < ILE->getNumInits())
396 EltInit = Emitter.tryEmitPrivateForMemory(ILE->getInit(ElementNo++),
397 Field->getType());
398 else
399 EltInit = Emitter.emitNullForMemory(Field->getType());
400
401 if (!EltInit)
402 return false;
403
404 if (!Field->isBitField()) {
405 // Handle non-bitfield members.
406 AppendField(*Field, Layout.getFieldOffset(FieldNo), EltInit);
407 } else {
408 // Otherwise we have a bitfield.
409 if (auto *CI = dyn_cast<llvm::ConstantInt>(EltInit)) {
410 AppendBitField(*Field, Layout.getFieldOffset(FieldNo), CI);
411 } else {
412 // We are trying to initialize a bitfield with a non-trivial constant,
413 // this must require run-time code.
414 return false;
415 }
416 }
417 }
418
419 return true;
420}
421
422namespace {
423struct BaseInfo {
424 BaseInfo(const CXXRecordDecl *Decl, CharUnits Offset, unsigned Index)
425 : Decl(Decl), Offset(Offset), Index(Index) {
426 }
427
428 const CXXRecordDecl *Decl;
429 CharUnits Offset;
430 unsigned Index;
431
432 bool operator<(const BaseInfo &O) const { return Offset < O.Offset; }
433};
434}
435
436bool ConstStructBuilder::Build(const APValue &Val, const RecordDecl *RD,
437 bool IsPrimaryBase,
438 const CXXRecordDecl *VTableClass,
439 CharUnits Offset) {
440 const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
441
442 if (const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD)) {
443 // Add a vtable pointer, if we need one and it hasn't already been added.
444 if (CD->isDynamicClass() && !IsPrimaryBase) {
445 llvm::Constant *VTableAddressPoint =
446 CGM.getCXXABI().getVTableAddressPointForConstExpr(
447 BaseSubobject(CD, Offset), VTableClass);
448 AppendBytes(Offset, VTableAddressPoint);
449 }
450
451 // Accumulate and sort bases, in order to visit them in address order, which
452 // may not be the same as declaration order.
453 SmallVector<BaseInfo, 8> Bases;
454 Bases.reserve(CD->getNumBases());
455 unsigned BaseNo = 0;
456 for (CXXRecordDecl::base_class_const_iterator Base = CD->bases_begin(),
457 BaseEnd = CD->bases_end(); Base != BaseEnd; ++Base, ++BaseNo) {
458 assert(!Base->isVirtual() && "should not have virtual bases here")((!Base->isVirtual() && "should not have virtual bases here"
) ? static_cast<void> (0) : __assert_fail ("!Base->isVirtual() && \"should not have virtual bases here\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 458, __PRETTY_FUNCTION__))
;
459 const CXXRecordDecl *BD = Base->getType()->getAsCXXRecordDecl();
460 CharUnits BaseOffset = Layout.getBaseClassOffset(BD);
461 Bases.push_back(BaseInfo(BD, BaseOffset, BaseNo));
462 }
463 std::stable_sort(Bases.begin(), Bases.end());
464
465 for (unsigned I = 0, N = Bases.size(); I != N; ++I) {
466 BaseInfo &Base = Bases[I];
467
468 bool IsPrimaryBase = Layout.getPrimaryBase() == Base.Decl;
469 Build(Val.getStructBase(Base.Index), Base.Decl, IsPrimaryBase,
470 VTableClass, Offset + Base.Offset);
471 }
472 }
473
474 unsigned FieldNo = 0;
475 uint64_t OffsetBits = CGM.getContext().toBits(Offset);
476
477 for (RecordDecl::field_iterator Field = RD->field_begin(),
478 FieldEnd = RD->field_end(); Field != FieldEnd; ++Field, ++FieldNo) {
479 // If this is a union, skip all the fields that aren't being initialized.
480 if (RD->isUnion() && Val.getUnionField() != *Field)
481 continue;
482
483 // Don't emit anonymous bitfields, they just affect layout.
484 if (Field->isUnnamedBitfield())
485 continue;
486
487 // Emit the value of the initializer.
488 const APValue &FieldValue =
489 RD->isUnion() ? Val.getUnionValue() : Val.getStructField(FieldNo);
490 llvm::Constant *EltInit =
491 Emitter.tryEmitPrivateForMemory(FieldValue, Field->getType());
492 if (!EltInit)
493 return false;
494
495 if (!Field->isBitField()) {
496 // Handle non-bitfield members.
497 AppendField(*Field, Layout.getFieldOffset(FieldNo) + OffsetBits, EltInit);
498 } else {
499 // Otherwise we have a bitfield.
500 AppendBitField(*Field, Layout.getFieldOffset(FieldNo) + OffsetBits,
501 cast<llvm::ConstantInt>(EltInit));
502 }
503 }
504
505 return true;
506}
507
508llvm::Constant *ConstStructBuilder::Finalize(QualType Ty) {
509 RecordDecl *RD = Ty->getAs<RecordType>()->getDecl();
510 const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
511
512 CharUnits LayoutSizeInChars = Layout.getSize();
513
514 if (NextFieldOffsetInChars > LayoutSizeInChars) {
515 // If the struct is bigger than the size of the record type,
516 // we must have a flexible array member at the end.
517 assert(RD->hasFlexibleArrayMember() &&((RD->hasFlexibleArrayMember() && "Must have flexible array member if struct is bigger than type!"
) ? static_cast<void> (0) : __assert_fail ("RD->hasFlexibleArrayMember() && \"Must have flexible array member if struct is bigger than type!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 518, __PRETTY_FUNCTION__))
518 "Must have flexible array member if struct is bigger than type!")((RD->hasFlexibleArrayMember() && "Must have flexible array member if struct is bigger than type!"
) ? static_cast<void> (0) : __assert_fail ("RD->hasFlexibleArrayMember() && \"Must have flexible array member if struct is bigger than type!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 518, __PRETTY_FUNCTION__))
;
519
520 // No tail padding is necessary.
521 } else {
522 // Append tail padding if necessary.
523 CharUnits LLVMSizeInChars =
524 NextFieldOffsetInChars.alignTo(LLVMStructAlignment);
525
526 if (LLVMSizeInChars != LayoutSizeInChars)
527 AppendTailPadding(LayoutSizeInChars);
528
529 LLVMSizeInChars = NextFieldOffsetInChars.alignTo(LLVMStructAlignment);
530
531 // Check if we need to convert the struct to a packed struct.
532 if (NextFieldOffsetInChars <= LayoutSizeInChars &&
533 LLVMSizeInChars > LayoutSizeInChars) {
534 assert(!Packed && "Size mismatch!")((!Packed && "Size mismatch!") ? static_cast<void>
(0) : __assert_fail ("!Packed && \"Size mismatch!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 534, __PRETTY_FUNCTION__))
;
535
536 ConvertStructToPacked();
537 assert(NextFieldOffsetInChars <= LayoutSizeInChars &&((NextFieldOffsetInChars <= LayoutSizeInChars && "Converting to packed did not help!"
) ? static_cast<void> (0) : __assert_fail ("NextFieldOffsetInChars <= LayoutSizeInChars && \"Converting to packed did not help!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 538, __PRETTY_FUNCTION__))
538 "Converting to packed did not help!")((NextFieldOffsetInChars <= LayoutSizeInChars && "Converting to packed did not help!"
) ? static_cast<void> (0) : __assert_fail ("NextFieldOffsetInChars <= LayoutSizeInChars && \"Converting to packed did not help!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 538, __PRETTY_FUNCTION__))
;
539 }
540
541 LLVMSizeInChars = NextFieldOffsetInChars.alignTo(LLVMStructAlignment);
542
543 assert(LayoutSizeInChars == LLVMSizeInChars &&((LayoutSizeInChars == LLVMSizeInChars && "Tail padding mismatch!"
) ? static_cast<void> (0) : __assert_fail ("LayoutSizeInChars == LLVMSizeInChars && \"Tail padding mismatch!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 544, __PRETTY_FUNCTION__))
544 "Tail padding mismatch!")((LayoutSizeInChars == LLVMSizeInChars && "Tail padding mismatch!"
) ? static_cast<void> (0) : __assert_fail ("LayoutSizeInChars == LLVMSizeInChars && \"Tail padding mismatch!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 544, __PRETTY_FUNCTION__))
;
545 }
546
547 // Pick the type to use. If the type is layout identical to the ConvertType
548 // type then use it, otherwise use whatever the builder produced for us.
549 llvm::StructType *STy =
550 llvm::ConstantStruct::getTypeForElements(CGM.getLLVMContext(),
551 Elements, Packed);
552 llvm::Type *ValTy = CGM.getTypes().ConvertType(Ty);
553 if (llvm::StructType *ValSTy = dyn_cast<llvm::StructType>(ValTy)) {
554 if (ValSTy->isLayoutIdentical(STy))
555 STy = ValSTy;
556 }
557
558 llvm::Constant *Result = llvm::ConstantStruct::get(STy, Elements);
559
560 assert(NextFieldOffsetInChars.alignTo(getAlignment(Result)) ==((NextFieldOffsetInChars.alignTo(getAlignment(Result)) == getSizeInChars
(Result) && "Size mismatch!") ? static_cast<void>
(0) : __assert_fail ("NextFieldOffsetInChars.alignTo(getAlignment(Result)) == getSizeInChars(Result) && \"Size mismatch!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 562, __PRETTY_FUNCTION__))
561 getSizeInChars(Result) &&((NextFieldOffsetInChars.alignTo(getAlignment(Result)) == getSizeInChars
(Result) && "Size mismatch!") ? static_cast<void>
(0) : __assert_fail ("NextFieldOffsetInChars.alignTo(getAlignment(Result)) == getSizeInChars(Result) && \"Size mismatch!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 562, __PRETTY_FUNCTION__))
562 "Size mismatch!")((NextFieldOffsetInChars.alignTo(getAlignment(Result)) == getSizeInChars
(Result) && "Size mismatch!") ? static_cast<void>
(0) : __assert_fail ("NextFieldOffsetInChars.alignTo(getAlignment(Result)) == getSizeInChars(Result) && \"Size mismatch!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 562, __PRETTY_FUNCTION__))
;
563
564 return Result;
565}
566
567llvm::Constant *ConstStructBuilder::BuildStruct(ConstantEmitter &Emitter,
568 ConstExprEmitter *ExprEmitter,
569 llvm::Constant *Base,
570 InitListExpr *Updater,
571 QualType ValTy) {
572 ConstStructBuilder Builder(Emitter);
573 if (!Builder.Build(ExprEmitter, Base, Updater))
574 return nullptr;
575 return Builder.Finalize(ValTy);
576}
577
578llvm::Constant *ConstStructBuilder::BuildStruct(ConstantEmitter &Emitter,
579 InitListExpr *ILE,
580 QualType ValTy) {
581 ConstStructBuilder Builder(Emitter);
582
583 if (!Builder.Build(ILE))
584 return nullptr;
585
586 return Builder.Finalize(ValTy);
587}
588
589llvm::Constant *ConstStructBuilder::BuildStruct(ConstantEmitter &Emitter,
590 const APValue &Val,
591 QualType ValTy) {
592 ConstStructBuilder Builder(Emitter);
593
594 const RecordDecl *RD = ValTy->castAs<RecordType>()->getDecl();
595 const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD);
596 if (!Builder.Build(Val, RD, false, CD, CharUnits::Zero()))
597 return nullptr;
598
599 return Builder.Finalize(ValTy);
600}
601
602
603//===----------------------------------------------------------------------===//
604// ConstExprEmitter
605//===----------------------------------------------------------------------===//
606
607static ConstantAddress tryEmitGlobalCompoundLiteral(CodeGenModule &CGM,
608 CodeGenFunction *CGF,
609 const CompoundLiteralExpr *E) {
610 CharUnits Align = CGM.getContext().getTypeAlignInChars(E->getType());
611 if (llvm::GlobalVariable *Addr =
612 CGM.getAddrOfConstantCompoundLiteralIfEmitted(E))
613 return ConstantAddress(Addr, Align);
614
615 LangAS addressSpace = E->getType().getAddressSpace();
616
617 ConstantEmitter emitter(CGM, CGF);
618 llvm::Constant *C = emitter.tryEmitForInitializer(E->getInitializer(),
619 addressSpace, E->getType());
620 if (!C) {
621 assert(!E->isFileScope() &&((!E->isFileScope() && "file-scope compound literal did not have constant initializer!"
) ? static_cast<void> (0) : __assert_fail ("!E->isFileScope() && \"file-scope compound literal did not have constant initializer!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 622, __PRETTY_FUNCTION__))
622 "file-scope compound literal did not have constant initializer!")((!E->isFileScope() && "file-scope compound literal did not have constant initializer!"
) ? static_cast<void> (0) : __assert_fail ("!E->isFileScope() && \"file-scope compound literal did not have constant initializer!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 622, __PRETTY_FUNCTION__))
;
623 return ConstantAddress::invalid();
624 }
625
626 auto GV = new llvm::GlobalVariable(CGM.getModule(), C->getType(),
627 CGM.isTypeConstant(E->getType(), true),
628 llvm::GlobalValue::InternalLinkage,
629 C, ".compoundliteral", nullptr,
630 llvm::GlobalVariable::NotThreadLocal,
631 CGM.getContext().getTargetAddressSpace(addressSpace));
632 emitter.finalize(GV);
633 GV->setAlignment(Align.getQuantity());
634 CGM.setAddrOfConstantCompoundLiteral(E, GV);
635 return ConstantAddress(GV, Align);
636}
637
638static llvm::Constant *
639EmitArrayConstant(CodeGenModule &CGM, const ConstantArrayType *DestType,
640 llvm::Type *CommonElementType, unsigned ArrayBound,
641 SmallVectorImpl<llvm::Constant *> &Elements,
642 llvm::Constant *Filler) {
643 // Figure out how long the initial prefix of non-zero elements is.
644 unsigned NonzeroLength = ArrayBound;
645 if (Elements.size() < NonzeroLength && Filler->isNullValue())
646 NonzeroLength = Elements.size();
647 if (NonzeroLength == Elements.size()) {
648 while (NonzeroLength > 0 && Elements[NonzeroLength - 1]->isNullValue())
649 --NonzeroLength;
650 }
651
652 if (NonzeroLength == 0) {
653 return llvm::ConstantAggregateZero::get(
654 CGM.getTypes().ConvertType(QualType(DestType, 0)));
655 }
656
657 // Add a zeroinitializer array filler if we have lots of trailing zeroes.
658 unsigned TrailingZeroes = ArrayBound - NonzeroLength;
659 if (TrailingZeroes >= 8) {
660 assert(Elements.size() >= NonzeroLength &&((Elements.size() >= NonzeroLength && "missing initializer for non-zero element"
) ? static_cast<void> (0) : __assert_fail ("Elements.size() >= NonzeroLength && \"missing initializer for non-zero element\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 661, __PRETTY_FUNCTION__))
661 "missing initializer for non-zero element")((Elements.size() >= NonzeroLength && "missing initializer for non-zero element"
) ? static_cast<void> (0) : __assert_fail ("Elements.size() >= NonzeroLength && \"missing initializer for non-zero element\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 661, __PRETTY_FUNCTION__))
;
662
663 // If all the elements had the same type up to the trailing zeroes, emit a
664 // struct of two arrays (the nonzero data and the zeroinitializer).
665 if (CommonElementType && NonzeroLength >= 8) {
666 llvm::Constant *Initial = llvm::ConstantArray::get(
667 llvm::ArrayType::get(CommonElementType, NonzeroLength),
668 makeArrayRef(Elements).take_front(NonzeroLength));
669 Elements.resize(2);
670 Elements[0] = Initial;
671 } else {
672 Elements.resize(NonzeroLength + 1);
673 }
674
675 auto *FillerType =
676 CommonElementType
677 ? CommonElementType
678 : CGM.getTypes().ConvertType(DestType->getElementType());
679 FillerType = llvm::ArrayType::get(FillerType, TrailingZeroes);
680 Elements.back() = llvm::ConstantAggregateZero::get(FillerType);
681 CommonElementType = nullptr;
682 } else if (Elements.size() != ArrayBound) {
683 // Otherwise pad to the right size with the filler if necessary.
684 Elements.resize(ArrayBound, Filler);
685 if (Filler->getType() != CommonElementType)
686 CommonElementType = nullptr;
687 }
688
689 // If all elements have the same type, just emit an array constant.
690 if (CommonElementType)
691 return llvm::ConstantArray::get(
692 llvm::ArrayType::get(CommonElementType, ArrayBound), Elements);
693
694 // We have mixed types. Use a packed struct.
695 llvm::SmallVector<llvm::Type *, 16> Types;
696 Types.reserve(Elements.size());
697 for (llvm::Constant *Elt : Elements)
698 Types.push_back(Elt->getType());
699 llvm::StructType *SType =
700 llvm::StructType::get(CGM.getLLVMContext(), Types, true);
701 return llvm::ConstantStruct::get(SType, Elements);
702}
703
704/// This class only needs to handle two cases:
705/// 1) Literals (this is used by APValue emission to emit literals).
706/// 2) Arrays, structs and unions (outside C++11 mode, we don't currently
707/// constant fold these types).
708class ConstExprEmitter :
709 public StmtVisitor<ConstExprEmitter, llvm::Constant*, QualType> {
710 CodeGenModule &CGM;
711 ConstantEmitter &Emitter;
712 llvm::LLVMContext &VMContext;
713public:
714 ConstExprEmitter(ConstantEmitter &emitter)
715 : CGM(emitter.CGM), Emitter(emitter), VMContext(CGM.getLLVMContext()) {
716 }
717
718 //===--------------------------------------------------------------------===//
719 // Visitor Methods
720 //===--------------------------------------------------------------------===//
721
722 llvm::Constant *VisitStmt(Stmt *S, QualType T) {
723 return nullptr;
724 }
725
726 llvm::Constant *VisitConstantExpr(ConstantExpr *CE, QualType T) {
727 return Visit(CE->getSubExpr(), T);
728 }
729
730 llvm::Constant *VisitParenExpr(ParenExpr *PE, QualType T) {
731 return Visit(PE->getSubExpr(), T);
732 }
733
734 llvm::Constant *
735 VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *PE,
736 QualType T) {
737 return Visit(PE->getReplacement(), T);
738 }
739
740 llvm::Constant *VisitGenericSelectionExpr(GenericSelectionExpr *GE,
741 QualType T) {
742 return Visit(GE->getResultExpr(), T);
743 }
744
745 llvm::Constant *VisitChooseExpr(ChooseExpr *CE, QualType T) {
746 return Visit(CE->getChosenSubExpr(), T);
747 }
748
749 llvm::Constant *VisitCompoundLiteralExpr(CompoundLiteralExpr *E, QualType T) {
750 return Visit(E->getInitializer(), T);
751 }
752
753 llvm::Constant *VisitCastExpr(CastExpr *E, QualType destType) {
754 if (const auto *ECE = dyn_cast<ExplicitCastExpr>(E))
755 CGM.EmitExplicitCastExprType(ECE, Emitter.CGF);
756 Expr *subExpr = E->getSubExpr();
757
758 switch (E->getCastKind()) {
759 case CK_ToUnion: {
760 // GCC cast to union extension
761 assert(E->getType()->isUnionType() &&((E->getType()->isUnionType() && "Destination type is not union type!"
) ? static_cast<void> (0) : __assert_fail ("E->getType()->isUnionType() && \"Destination type is not union type!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 762, __PRETTY_FUNCTION__))
762 "Destination type is not union type!")((E->getType()->isUnionType() && "Destination type is not union type!"
) ? static_cast<void> (0) : __assert_fail ("E->getType()->isUnionType() && \"Destination type is not union type!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 762, __PRETTY_FUNCTION__))
;
763
764 auto field = E->getTargetUnionField();
765
766 auto C = Emitter.tryEmitPrivateForMemory(subExpr, field->getType());
767 if (!C) return nullptr;
768
769 auto destTy = ConvertType(destType);
770 if (C->getType() == destTy) return C;
771
772 // Build a struct with the union sub-element as the first member,
773 // and padded to the appropriate size.
774 SmallVector<llvm::Constant*, 2> Elts;
775 SmallVector<llvm::Type*, 2> Types;
776 Elts.push_back(C);
777 Types.push_back(C->getType());
778 unsigned CurSize = CGM.getDataLayout().getTypeAllocSize(C->getType());
779 unsigned TotalSize = CGM.getDataLayout().getTypeAllocSize(destTy);
780
781 assert(CurSize <= TotalSize && "Union size mismatch!")((CurSize <= TotalSize && "Union size mismatch!") ?
static_cast<void> (0) : __assert_fail ("CurSize <= TotalSize && \"Union size mismatch!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 781, __PRETTY_FUNCTION__))
;
782 if (unsigned NumPadBytes = TotalSize - CurSize) {
783 llvm::Type *Ty = CGM.Int8Ty;
784 if (NumPadBytes > 1)
785 Ty = llvm::ArrayType::get(Ty, NumPadBytes);
786
787 Elts.push_back(llvm::UndefValue::get(Ty));
788 Types.push_back(Ty);
789 }
790
791 llvm::StructType *STy = llvm::StructType::get(VMContext, Types, false);
792 return llvm::ConstantStruct::get(STy, Elts);
793 }
794
795 case CK_AddressSpaceConversion: {
796 auto C = Emitter.tryEmitPrivate(subExpr, subExpr->getType());
797 if (!C) return nullptr;
798 LangAS destAS = E->getType()->getPointeeType().getAddressSpace();
799 LangAS srcAS = subExpr->getType()->getPointeeType().getAddressSpace();
800 llvm::Type *destTy = ConvertType(E->getType());
801 return CGM.getTargetCodeGenInfo().performAddrSpaceCast(CGM, C, srcAS,
802 destAS, destTy);
803 }
804
805 case CK_LValueToRValue:
806 case CK_AtomicToNonAtomic:
807 case CK_NonAtomicToAtomic:
808 case CK_NoOp:
809 case CK_ConstructorConversion:
810 return Visit(subExpr, destType);
811
812 case CK_IntToOCLSampler:
813 llvm_unreachable("global sampler variables are not generated")::llvm::llvm_unreachable_internal("global sampler variables are not generated"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 813)
;
814
815 case CK_Dependent: llvm_unreachable("saw dependent cast!")::llvm::llvm_unreachable_internal("saw dependent cast!", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 815)
;
816
817 case CK_BuiltinFnToFnPtr:
818 llvm_unreachable("builtin functions are handled elsewhere")::llvm::llvm_unreachable_internal("builtin functions are handled elsewhere"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 818)
;
819
820 case CK_ReinterpretMemberPointer:
821 case CK_DerivedToBaseMemberPointer:
822 case CK_BaseToDerivedMemberPointer: {
823 auto C = Emitter.tryEmitPrivate(subExpr, subExpr->getType());
824 if (!C) return nullptr;
825 return CGM.getCXXABI().EmitMemberPointerConversion(E, C);
826 }
827
828 // These will never be supported.
829 case CK_ObjCObjectLValueCast:
830 case CK_ARCProduceObject:
831 case CK_ARCConsumeObject:
832 case CK_ARCReclaimReturnedObject:
833 case CK_ARCExtendBlockObject:
834 case CK_CopyAndAutoreleaseBlockObject:
835 return nullptr;
836
837 // These don't need to be handled here because Evaluate knows how to
838 // evaluate them in the cases where they can be folded.
839 case CK_BitCast:
840 case CK_ToVoid:
841 case CK_Dynamic:
842 case CK_LValueBitCast:
843 case CK_NullToMemberPointer:
844 case CK_UserDefinedConversion:
845 case CK_CPointerToObjCPointerCast:
846 case CK_BlockPointerToObjCPointerCast:
847 case CK_AnyPointerToBlockPointerCast:
848 case CK_ArrayToPointerDecay:
849 case CK_FunctionToPointerDecay:
850 case CK_BaseToDerived:
851 case CK_DerivedToBase:
852 case CK_UncheckedDerivedToBase:
853 case CK_MemberPointerToBoolean:
854 case CK_VectorSplat:
855 case CK_FloatingRealToComplex:
856 case CK_FloatingComplexToReal:
857 case CK_FloatingComplexToBoolean:
858 case CK_FloatingComplexCast:
859 case CK_FloatingComplexToIntegralComplex:
860 case CK_IntegralRealToComplex:
861 case CK_IntegralComplexToReal:
862 case CK_IntegralComplexToBoolean:
863 case CK_IntegralComplexCast:
864 case CK_IntegralComplexToFloatingComplex:
865 case CK_PointerToIntegral:
866 case CK_PointerToBoolean:
867 case CK_NullToPointer:
868 case CK_IntegralCast:
869 case CK_BooleanToSignedIntegral:
870 case CK_IntegralToPointer:
871 case CK_IntegralToBoolean:
872 case CK_IntegralToFloating:
873 case CK_FloatingToIntegral:
874 case CK_FloatingToBoolean:
875 case CK_FloatingCast:
876 case CK_FixedPointCast:
877 case CK_FixedPointToBoolean:
878 case CK_ZeroToOCLOpaqueType:
879 return nullptr;
880 }
881 llvm_unreachable("Invalid CastKind")::llvm::llvm_unreachable_internal("Invalid CastKind", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 881)
;
882 }
883
884 llvm::Constant *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE, QualType T) {
885 return Visit(DAE->getExpr(), T);
886 }
887
888 llvm::Constant *VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE, QualType T) {
889 // No need for a DefaultInitExprScope: we don't handle 'this' in a
890 // constant expression.
891 return Visit(DIE->getExpr(), T);
892 }
893
894 llvm::Constant *VisitExprWithCleanups(ExprWithCleanups *E, QualType T) {
895 if (!E->cleanupsHaveSideEffects())
896 return Visit(E->getSubExpr(), T);
897 return nullptr;
898 }
899
900 llvm::Constant *VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E,
901 QualType T) {
902 return Visit(E->GetTemporaryExpr(), T);
903 }
904
905 llvm::Constant *EmitArrayInitialization(InitListExpr *ILE, QualType T) {
906 auto *CAT = CGM.getContext().getAsConstantArrayType(ILE->getType());
907 assert(CAT && "can't emit array init for non-constant-bound array")((CAT && "can't emit array init for non-constant-bound array"
) ? static_cast<void> (0) : __assert_fail ("CAT && \"can't emit array init for non-constant-bound array\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 907, __PRETTY_FUNCTION__))
;
908 unsigned NumInitElements = ILE->getNumInits();
909 unsigned NumElements = CAT->getSize().getZExtValue();
910
911 // Initialising an array requires us to automatically
912 // initialise any elements that have not been initialised explicitly
913 unsigned NumInitableElts = std::min(NumInitElements, NumElements);
914
915 QualType EltType = CAT->getElementType();
916
917 // Initialize remaining array elements.
918 llvm::Constant *fillC = nullptr;
919 if (Expr *filler = ILE->getArrayFiller()) {
920 fillC = Emitter.tryEmitAbstractForMemory(filler, EltType);
921 if (!fillC)
922 return nullptr;
923 }
924
925 // Copy initializer elements.
926 SmallVector<llvm::Constant*, 16> Elts;
927 if (fillC && fillC->isNullValue())
928 Elts.reserve(NumInitableElts + 1);
929 else
930 Elts.reserve(NumElements);
931
932 llvm::Type *CommonElementType = nullptr;
933 for (unsigned i = 0; i < NumInitableElts; ++i) {
934 Expr *Init = ILE->getInit(i);
935 llvm::Constant *C = Emitter.tryEmitPrivateForMemory(Init, EltType);
936 if (!C)
937 return nullptr;
938 if (i == 0)
939 CommonElementType = C->getType();
940 else if (C->getType() != CommonElementType)
941 CommonElementType = nullptr;
942 Elts.push_back(C);
943 }
944
945 return EmitArrayConstant(CGM, CAT, CommonElementType, NumElements, Elts,
946 fillC);
947 }
948
949 llvm::Constant *EmitRecordInitialization(InitListExpr *ILE, QualType T) {
950 return ConstStructBuilder::BuildStruct(Emitter, ILE, T);
951 }
952
953 llvm::Constant *VisitImplicitValueInitExpr(ImplicitValueInitExpr* E,
954 QualType T) {
955 return CGM.EmitNullConstant(T);
956 }
957
958 llvm::Constant *VisitInitListExpr(InitListExpr *ILE, QualType T) {
959 if (ILE->isTransparent())
960 return Visit(ILE->getInit(0), T);
961
962 if (ILE->getType()->isArrayType())
963 return EmitArrayInitialization(ILE, T);
964
965 if (ILE->getType()->isRecordType())
966 return EmitRecordInitialization(ILE, T);
967
968 return nullptr;
969 }
970
971 llvm::Constant *EmitDesignatedInitUpdater(llvm::Constant *Base,
972 InitListExpr *Updater,
973 QualType destType) {
974 if (auto destAT = CGM.getContext().getAsArrayType(destType)) {
975 llvm::ArrayType *AType = cast<llvm::ArrayType>(ConvertType(destType));
976 llvm::Type *ElemType = AType->getElementType();
977
978 unsigned NumInitElements = Updater->getNumInits();
979 unsigned NumElements = AType->getNumElements();
980
981 std::vector<llvm::Constant *> Elts;
982 Elts.reserve(NumElements);
983
984 QualType destElemType = destAT->getElementType();
985
986 if (auto DataArray = dyn_cast<llvm::ConstantDataArray>(Base))
987 for (unsigned i = 0; i != NumElements; ++i)
988 Elts.push_back(DataArray->getElementAsConstant(i));
989 else if (auto Array = dyn_cast<llvm::ConstantArray>(Base))
990 for (unsigned i = 0; i != NumElements; ++i)
991 Elts.push_back(Array->getOperand(i));
992 else
993 return nullptr; // FIXME: other array types not implemented
994
995 llvm::Constant *fillC = nullptr;
996 if (Expr *filler = Updater->getArrayFiller())
997 if (!isa<NoInitExpr>(filler))
998 fillC = Emitter.tryEmitAbstractForMemory(filler, destElemType);
999 bool RewriteType = (fillC && fillC->getType() != ElemType);
1000
1001 for (unsigned i = 0; i != NumElements; ++i) {
1002 Expr *Init = nullptr;
1003 if (i < NumInitElements)
1004 Init = Updater->getInit(i);
1005
1006 if (!Init && fillC)
1007 Elts[i] = fillC;
1008 else if (!Init || isa<NoInitExpr>(Init))
1009 ; // Do nothing.
1010 else if (InitListExpr *ChildILE = dyn_cast<InitListExpr>(Init))
1011 Elts[i] = EmitDesignatedInitUpdater(Elts[i], ChildILE, destElemType);
1012 else
1013 Elts[i] = Emitter.tryEmitPrivateForMemory(Init, destElemType);
1014
1015 if (!Elts[i])
1016 return nullptr;
1017 RewriteType |= (Elts[i]->getType() != ElemType);
1018 }
1019
1020 if (RewriteType) {
1021 std::vector<llvm::Type *> Types;
1022 Types.reserve(NumElements);
1023 for (unsigned i = 0; i != NumElements; ++i)
1024 Types.push_back(Elts[i]->getType());
1025 llvm::StructType *SType = llvm::StructType::get(AType->getContext(),
1026 Types, true);
1027 return llvm::ConstantStruct::get(SType, Elts);
1028 }
1029
1030 return llvm::ConstantArray::get(AType, Elts);
1031 }
1032
1033 if (destType->isRecordType())
1034 return ConstStructBuilder::BuildStruct(Emitter, this, Base, Updater,
1035 destType);
1036
1037 return nullptr;
1038 }
1039
1040 llvm::Constant *VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E,
1041 QualType destType) {
1042 auto C = Visit(E->getBase(), destType);
1043 if (!C) return nullptr;
1044 return EmitDesignatedInitUpdater(C, E->getUpdater(), destType);
1045 }
1046
1047 llvm::Constant *VisitCXXConstructExpr(CXXConstructExpr *E, QualType Ty) {
1048 if (!E->getConstructor()->isTrivial())
1049 return nullptr;
1050
1051 // FIXME: We should not have to call getBaseElementType here.
1052 const RecordType *RT =
1053 CGM.getContext().getBaseElementType(Ty)->getAs<RecordType>();
1054 const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1055
1056 // If the class doesn't have a trivial destructor, we can't emit it as a
1057 // constant expr.
1058 if (!RD->hasTrivialDestructor())
1059 return nullptr;
1060
1061 // Only copy and default constructors can be trivial.
1062
1063
1064 if (E->getNumArgs()) {
1065 assert(E->getNumArgs() == 1 && "trivial ctor with > 1 argument")((E->getNumArgs() == 1 && "trivial ctor with > 1 argument"
) ? static_cast<void> (0) : __assert_fail ("E->getNumArgs() == 1 && \"trivial ctor with > 1 argument\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1065, __PRETTY_FUNCTION__))
;
1066 assert(E->getConstructor()->isCopyOrMoveConstructor() &&((E->getConstructor()->isCopyOrMoveConstructor() &&
"trivial ctor has argument but isn't a copy/move ctor") ? static_cast
<void> (0) : __assert_fail ("E->getConstructor()->isCopyOrMoveConstructor() && \"trivial ctor has argument but isn't a copy/move ctor\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1067, __PRETTY_FUNCTION__))
1067 "trivial ctor has argument but isn't a copy/move ctor")((E->getConstructor()->isCopyOrMoveConstructor() &&
"trivial ctor has argument but isn't a copy/move ctor") ? static_cast
<void> (0) : __assert_fail ("E->getConstructor()->isCopyOrMoveConstructor() && \"trivial ctor has argument but isn't a copy/move ctor\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1067, __PRETTY_FUNCTION__))
;
1068
1069 Expr *Arg = E->getArg(0);
1070 assert(CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) &&((CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType
()) && "argument to copy ctor is of wrong type") ? static_cast
<void> (0) : __assert_fail ("CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) && \"argument to copy ctor is of wrong type\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1071, __PRETTY_FUNCTION__))
1071 "argument to copy ctor is of wrong type")((CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType
()) && "argument to copy ctor is of wrong type") ? static_cast
<void> (0) : __assert_fail ("CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) && \"argument to copy ctor is of wrong type\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1071, __PRETTY_FUNCTION__))
;
1072
1073 return Visit(Arg, Ty);
1074 }
1075
1076 return CGM.EmitNullConstant(Ty);
1077 }
1078
1079 llvm::Constant *VisitStringLiteral(StringLiteral *E, QualType T) {
1080 return CGM.GetConstantArrayFromStringLiteral(E);
1081 }
1082
1083 llvm::Constant *VisitObjCEncodeExpr(ObjCEncodeExpr *E, QualType T) {
1084 // This must be an @encode initializing an array in a static initializer.
1085 // Don't emit it as the address of the string, emit the string data itself
1086 // as an inline array.
1087 std::string Str;
1088 CGM.getContext().getObjCEncodingForType(E->getEncodedType(), Str);
1089 const ConstantArrayType *CAT = CGM.getContext().getAsConstantArrayType(T);
1090
1091 // Resize the string to the right size, adding zeros at the end, or
1092 // truncating as needed.
1093 Str.resize(CAT->getSize().getZExtValue(), '\0');
1094 return llvm::ConstantDataArray::getString(VMContext, Str, false);
1095 }
1096
1097 llvm::Constant *VisitUnaryExtension(const UnaryOperator *E, QualType T) {
1098 return Visit(E->getSubExpr(), T);
1099 }
1100
1101 // Utility methods
1102 llvm::Type *ConvertType(QualType T) {
1103 return CGM.getTypes().ConvertType(T);
1104 }
1105};
1106
1107} // end anonymous namespace.
1108
1109bool ConstStructBuilder::Build(ConstExprEmitter *ExprEmitter,
1110 llvm::Constant *Base,
1111 InitListExpr *Updater) {
1112 assert(Base && "base expression should not be empty")((Base && "base expression should not be empty") ? static_cast
<void> (0) : __assert_fail ("Base && \"base expression should not be empty\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1112, __PRETTY_FUNCTION__))
;
1113
1114 QualType ExprType = Updater->getType();
1115 RecordDecl *RD = ExprType->getAs<RecordType>()->getDecl();
1116 const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
1117 const llvm::StructLayout *BaseLayout = CGM.getDataLayout().getStructLayout(
1118 cast<llvm::StructType>(Base->getType()));
1119 unsigned FieldNo = -1;
1120 unsigned ElementNo = 0;
1121
1122 // Bail out if we have base classes. We could support these, but they only
1123 // arise in C++1z where we will have already constant folded most interesting
1124 // cases. FIXME: There are still a few more cases we can handle this way.
1125 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
1126 if (CXXRD->getNumBases())
1127 return false;
1128
1129 for (FieldDecl *Field : RD->fields()) {
1130 ++FieldNo;
1131
1132 if (RD->isUnion() && Updater->getInitializedFieldInUnion() != Field)
1133 continue;
1134
1135 // Skip anonymous bitfields.
1136 if (Field->isUnnamedBitfield())
1137 continue;
1138
1139 llvm::Constant *EltInit = Base->getAggregateElement(ElementNo);
1140
1141 // Bail out if the type of the ConstantStruct does not have the same layout
1142 // as the type of the InitListExpr.
1143 if (CGM.getTypes().ConvertType(Field->getType()) != EltInit->getType() ||
1144 Layout.getFieldOffset(ElementNo) !=
1145 BaseLayout->getElementOffsetInBits(ElementNo))
1146 return false;
1147
1148 // Get the initializer. If we encounter an empty field or a NoInitExpr,
1149 // we use values from the base expression.
1150 Expr *Init = nullptr;
1151 if (ElementNo < Updater->getNumInits())
1152 Init = Updater->getInit(ElementNo);
1153
1154 if (!Init || isa<NoInitExpr>(Init))
1155 ; // Do nothing.
1156 else if (InitListExpr *ChildILE = dyn_cast<InitListExpr>(Init))
1157 EltInit = ExprEmitter->EmitDesignatedInitUpdater(EltInit, ChildILE,
1158 Field->getType());
1159 else
1160 EltInit = Emitter.tryEmitPrivateForMemory(Init, Field->getType());
1161
1162 ++ElementNo;
1163
1164 if (!EltInit)
1165 return false;
1166
1167 if (!Field->isBitField())
1168 AppendField(Field, Layout.getFieldOffset(FieldNo), EltInit);
1169 else if (llvm::ConstantInt *CI = dyn_cast<llvm::ConstantInt>(EltInit))
1170 AppendBitField(Field, Layout.getFieldOffset(FieldNo), CI);
1171 else
1172 // Initializing a bitfield with a non-trivial constant?
1173 return false;
1174 }
1175
1176 return true;
1177}
1178
1179llvm::Constant *ConstantEmitter::validateAndPopAbstract(llvm::Constant *C,
1180 AbstractState saved) {
1181 Abstract = saved.OldValue;
1182
1183 assert(saved.OldPlaceholdersSize == PlaceholderAddresses.size() &&((saved.OldPlaceholdersSize == PlaceholderAddresses.size() &&
"created a placeholder while doing an abstract emission?") ?
static_cast<void> (0) : __assert_fail ("saved.OldPlaceholdersSize == PlaceholderAddresses.size() && \"created a placeholder while doing an abstract emission?\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1184, __PRETTY_FUNCTION__))
1184 "created a placeholder while doing an abstract emission?")((saved.OldPlaceholdersSize == PlaceholderAddresses.size() &&
"created a placeholder while doing an abstract emission?") ?
static_cast<void> (0) : __assert_fail ("saved.OldPlaceholdersSize == PlaceholderAddresses.size() && \"created a placeholder while doing an abstract emission?\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1184, __PRETTY_FUNCTION__))
;
1185
1186 // No validation necessary for now.
1187 // No cleanup to do for now.
1188 return C;
1189}
1190
1191llvm::Constant *
1192ConstantEmitter::tryEmitAbstractForInitializer(const VarDecl &D) {
1193 auto state = pushAbstract();
1194 auto C = tryEmitPrivateForVarInit(D);
1195 return validateAndPopAbstract(C, state);
1196}
1197
1198llvm::Constant *
1199ConstantEmitter::tryEmitAbstract(const Expr *E, QualType destType) {
1200 auto state = pushAbstract();
1201 auto C = tryEmitPrivate(E, destType);
1202 return validateAndPopAbstract(C, state);
1203}
1204
1205llvm::Constant *
1206ConstantEmitter::tryEmitAbstract(const APValue &value, QualType destType) {
1207 auto state = pushAbstract();
1208 auto C = tryEmitPrivate(value, destType);
1209 return validateAndPopAbstract(C, state);
1210}
1211
1212llvm::Constant *
1213ConstantEmitter::emitAbstract(const Expr *E, QualType destType) {
1214 auto state = pushAbstract();
1215 auto C = tryEmitPrivate(E, destType);
1216 C = validateAndPopAbstract(C, state);
1217 if (!C) {
1218 CGM.Error(E->getExprLoc(),
1219 "internal error: could not emit constant value \"abstractly\"");
1220 C = CGM.EmitNullConstant(destType);
1221 }
1222 return C;
1223}
1224
1225llvm::Constant *
1226ConstantEmitter::emitAbstract(SourceLocation loc, const APValue &value,
1227 QualType destType) {
1228 auto state = pushAbstract();
1229 auto C = tryEmitPrivate(value, destType);
1230 C = validateAndPopAbstract(C, state);
1231 if (!C) {
1232 CGM.Error(loc,
1233 "internal error: could not emit constant value \"abstractly\"");
1234 C = CGM.EmitNullConstant(destType);
1235 }
1236 return C;
1237}
1238
1239llvm::Constant *ConstantEmitter::tryEmitForInitializer(const VarDecl &D) {
1240 initializeNonAbstract(D.getType().getAddressSpace());
1241 return markIfFailed(tryEmitPrivateForVarInit(D));
1242}
1243
1244llvm::Constant *ConstantEmitter::tryEmitForInitializer(const Expr *E,
1245 LangAS destAddrSpace,
1246 QualType destType) {
1247 initializeNonAbstract(destAddrSpace);
1248 return markIfFailed(tryEmitPrivateForMemory(E, destType));
1249}
1250
1251llvm::Constant *ConstantEmitter::emitForInitializer(const APValue &value,
1252 LangAS destAddrSpace,
1253 QualType destType) {
1254 initializeNonAbstract(destAddrSpace);
1255 auto C = tryEmitPrivateForMemory(value, destType);
1256 assert(C && "couldn't emit constant value non-abstractly?")((C && "couldn't emit constant value non-abstractly?"
) ? static_cast<void> (0) : __assert_fail ("C && \"couldn't emit constant value non-abstractly?\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1256, __PRETTY_FUNCTION__))
;
1257 return C;
1258}
1259
1260llvm::GlobalValue *ConstantEmitter::getCurrentAddrPrivate() {
1261 assert(!Abstract && "cannot get current address for abstract constant")((!Abstract && "cannot get current address for abstract constant"
) ? static_cast<void> (0) : __assert_fail ("!Abstract && \"cannot get current address for abstract constant\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1261, __PRETTY_FUNCTION__))
;
1262
1263
1264
1265 // Make an obviously ill-formed global that should blow up compilation
1266 // if it survives.
1267 auto global = new llvm::GlobalVariable(CGM.getModule(), CGM.Int8Ty, true,
1268 llvm::GlobalValue::PrivateLinkage,
1269 /*init*/ nullptr,
1270 /*name*/ "",
1271 /*before*/ nullptr,
1272 llvm::GlobalVariable::NotThreadLocal,
1273 CGM.getContext().getTargetAddressSpace(DestAddressSpace));
1274
1275 PlaceholderAddresses.push_back(std::make_pair(nullptr, global));
1276
1277 return global;
1278}
1279
1280void ConstantEmitter::registerCurrentAddrPrivate(llvm::Constant *signal,
1281 llvm::GlobalValue *placeholder) {
1282 assert(!PlaceholderAddresses.empty())((!PlaceholderAddresses.empty()) ? static_cast<void> (0
) : __assert_fail ("!PlaceholderAddresses.empty()", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1282, __PRETTY_FUNCTION__))
;
1283 assert(PlaceholderAddresses.back().first == nullptr)((PlaceholderAddresses.back().first == nullptr) ? static_cast
<void> (0) : __assert_fail ("PlaceholderAddresses.back().first == nullptr"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1283, __PRETTY_FUNCTION__))
;
1284 assert(PlaceholderAddresses.back().second == placeholder)((PlaceholderAddresses.back().second == placeholder) ? static_cast
<void> (0) : __assert_fail ("PlaceholderAddresses.back().second == placeholder"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1284, __PRETTY_FUNCTION__))
;
1285 PlaceholderAddresses.back().first = signal;
1286}
1287
1288namespace {
1289 struct ReplacePlaceholders {
1290 CodeGenModule &CGM;
1291
1292 /// The base address of the global.
1293 llvm::Constant *Base;
1294 llvm::Type *BaseValueTy = nullptr;
1295
1296 /// The placeholder addresses that were registered during emission.
1297 llvm::DenseMap<llvm::Constant*, llvm::GlobalVariable*> PlaceholderAddresses;
1298
1299 /// The locations of the placeholder signals.
1300 llvm::DenseMap<llvm::GlobalVariable*, llvm::Constant*> Locations;
1301
1302 /// The current index stack. We use a simple unsigned stack because
1303 /// we assume that placeholders will be relatively sparse in the
1304 /// initializer, but we cache the index values we find just in case.
1305 llvm::SmallVector<unsigned, 8> Indices;
1306 llvm::SmallVector<llvm::Constant*, 8> IndexValues;
1307
1308 ReplacePlaceholders(CodeGenModule &CGM, llvm::Constant *base,
1309 ArrayRef<std::pair<llvm::Constant*,
1310 llvm::GlobalVariable*>> addresses)
1311 : CGM(CGM), Base(base),
1312 PlaceholderAddresses(addresses.begin(), addresses.end()) {
1313 }
1314
1315 void replaceInInitializer(llvm::Constant *init) {
1316 // Remember the type of the top-most initializer.
1317 BaseValueTy = init->getType();
1318
1319 // Initialize the stack.
1320 Indices.push_back(0);
1321 IndexValues.push_back(nullptr);
1322
1323 // Recurse into the initializer.
1324 findLocations(init);
1325
1326 // Check invariants.
1327 assert(IndexValues.size() == Indices.size() && "mismatch")((IndexValues.size() == Indices.size() && "mismatch")
? static_cast<void> (0) : __assert_fail ("IndexValues.size() == Indices.size() && \"mismatch\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1327, __PRETTY_FUNCTION__))
;
1328 assert(Indices.size() == 1 && "didn't pop all indices")((Indices.size() == 1 && "didn't pop all indices") ? static_cast
<void> (0) : __assert_fail ("Indices.size() == 1 && \"didn't pop all indices\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1328, __PRETTY_FUNCTION__))
;
1329
1330 // Do the replacement; this basically invalidates 'init'.
1331 assert(Locations.size() == PlaceholderAddresses.size() &&((Locations.size() == PlaceholderAddresses.size() && "missed a placeholder?"
) ? static_cast<void> (0) : __assert_fail ("Locations.size() == PlaceholderAddresses.size() && \"missed a placeholder?\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1332, __PRETTY_FUNCTION__))
1332 "missed a placeholder?")((Locations.size() == PlaceholderAddresses.size() && "missed a placeholder?"
) ? static_cast<void> (0) : __assert_fail ("Locations.size() == PlaceholderAddresses.size() && \"missed a placeholder?\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1332, __PRETTY_FUNCTION__))
;
1333
1334 // We're iterating over a hashtable, so this would be a source of
1335 // non-determinism in compiler output *except* that we're just
1336 // messing around with llvm::Constant structures, which never itself
1337 // does anything that should be visible in compiler output.
1338 for (auto &entry : Locations) {
1339 assert(entry.first->getParent() == nullptr && "not a placeholder!")((entry.first->getParent() == nullptr && "not a placeholder!"
) ? static_cast<void> (0) : __assert_fail ("entry.first->getParent() == nullptr && \"not a placeholder!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1339, __PRETTY_FUNCTION__))
;
1340 entry.first->replaceAllUsesWith(entry.second);
1341 entry.first->eraseFromParent();
1342 }
1343 }
1344
1345 private:
1346 void findLocations(llvm::Constant *init) {
1347 // Recurse into aggregates.
1348 if (auto agg = dyn_cast<llvm::ConstantAggregate>(init)) {
1349 for (unsigned i = 0, e = agg->getNumOperands(); i != e; ++i) {
1350 Indices.push_back(i);
1351 IndexValues.push_back(nullptr);
1352
1353 findLocations(agg->getOperand(i));
1354
1355 IndexValues.pop_back();
1356 Indices.pop_back();
1357 }
1358 return;
1359 }
1360
1361 // Otherwise, check for registered constants.
1362 while (true) {
1363 auto it = PlaceholderAddresses.find(init);
1364 if (it != PlaceholderAddresses.end()) {
1365 setLocation(it->second);
1366 break;
1367 }
1368
1369 // Look through bitcasts or other expressions.
1370 if (auto expr = dyn_cast<llvm::ConstantExpr>(init)) {
1371 init = expr->getOperand(0);
1372 } else {
1373 break;
1374 }
1375 }
1376 }
1377
1378 void setLocation(llvm::GlobalVariable *placeholder) {
1379 assert(Locations.find(placeholder) == Locations.end() &&((Locations.find(placeholder) == Locations.end() && "already found location for placeholder!"
) ? static_cast<void> (0) : __assert_fail ("Locations.find(placeholder) == Locations.end() && \"already found location for placeholder!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1380, __PRETTY_FUNCTION__))
1380 "already found location for placeholder!")((Locations.find(placeholder) == Locations.end() && "already found location for placeholder!"
) ? static_cast<void> (0) : __assert_fail ("Locations.find(placeholder) == Locations.end() && \"already found location for placeholder!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1380, __PRETTY_FUNCTION__))
;
1381
1382 // Lazily fill in IndexValues with the values from Indices.
1383 // We do this in reverse because we should always have a strict
1384 // prefix of indices from the start.
1385 assert(Indices.size() == IndexValues.size())((Indices.size() == IndexValues.size()) ? static_cast<void
> (0) : __assert_fail ("Indices.size() == IndexValues.size()"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1385, __PRETTY_FUNCTION__))
;
1386 for (size_t i = Indices.size() - 1; i != size_t(-1); --i) {
1387 if (IndexValues[i]) {
1388#ifndef NDEBUG
1389 for (size_t j = 0; j != i + 1; ++j) {
1390 assert(IndexValues[j] &&((IndexValues[j] && isa<llvm::ConstantInt>(IndexValues
[j]) && cast<llvm::ConstantInt>(IndexValues[j])
->getZExtValue() == Indices[j]) ? static_cast<void> (
0) : __assert_fail ("IndexValues[j] && isa<llvm::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue() == Indices[j]"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1393, __PRETTY_FUNCTION__))
1391 isa<llvm::ConstantInt>(IndexValues[j]) &&((IndexValues[j] && isa<llvm::ConstantInt>(IndexValues
[j]) && cast<llvm::ConstantInt>(IndexValues[j])
->getZExtValue() == Indices[j]) ? static_cast<void> (
0) : __assert_fail ("IndexValues[j] && isa<llvm::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue() == Indices[j]"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1393, __PRETTY_FUNCTION__))
1392 cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue()((IndexValues[j] && isa<llvm::ConstantInt>(IndexValues
[j]) && cast<llvm::ConstantInt>(IndexValues[j])
->getZExtValue() == Indices[j]) ? static_cast<void> (
0) : __assert_fail ("IndexValues[j] && isa<llvm::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue() == Indices[j]"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1393, __PRETTY_FUNCTION__))
1393 == Indices[j])((IndexValues[j] && isa<llvm::ConstantInt>(IndexValues
[j]) && cast<llvm::ConstantInt>(IndexValues[j])
->getZExtValue() == Indices[j]) ? static_cast<void> (
0) : __assert_fail ("IndexValues[j] && isa<llvm::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue() == Indices[j]"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1393, __PRETTY_FUNCTION__))
;
1394 }
1395#endif
1396 break;
1397 }
1398
1399 IndexValues[i] = llvm::ConstantInt::get(CGM.Int32Ty, Indices[i]);
1400 }
1401
1402 // Form a GEP and then bitcast to the placeholder type so that the
1403 // replacement will succeed.
1404 llvm::Constant *location =
1405 llvm::ConstantExpr::getInBoundsGetElementPtr(BaseValueTy,
1406 Base, IndexValues);
1407 location = llvm::ConstantExpr::getBitCast(location,
1408 placeholder->getType());
1409
1410 Locations.insert({placeholder, location});
1411 }
1412 };
1413}
1414
1415void ConstantEmitter::finalize(llvm::GlobalVariable *global) {
1416 assert(InitializedNonAbstract &&((InitializedNonAbstract && "finalizing emitter that was used for abstract emission?"
) ? static_cast<void> (0) : __assert_fail ("InitializedNonAbstract && \"finalizing emitter that was used for abstract emission?\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1417, __PRETTY_FUNCTION__))
1417 "finalizing emitter that was used for abstract emission?")((InitializedNonAbstract && "finalizing emitter that was used for abstract emission?"
) ? static_cast<void> (0) : __assert_fail ("InitializedNonAbstract && \"finalizing emitter that was used for abstract emission?\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1417, __PRETTY_FUNCTION__))
;
1418 assert(!Finalized && "finalizing emitter multiple times")((!Finalized && "finalizing emitter multiple times") ?
static_cast<void> (0) : __assert_fail ("!Finalized && \"finalizing emitter multiple times\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1418, __PRETTY_FUNCTION__))
;
1419 assert(global->getInitializer())((global->getInitializer()) ? static_cast<void> (0) :
__assert_fail ("global->getInitializer()", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1419, __PRETTY_FUNCTION__))
;
1420
1421 // Note that we might also be Failed.
1422 Finalized = true;
1423
1424 if (!PlaceholderAddresses.empty()) {
1425 ReplacePlaceholders(CGM, global, PlaceholderAddresses)
1426 .replaceInInitializer(global->getInitializer());
1427 PlaceholderAddresses.clear(); // satisfy
1428 }
1429}
1430
1431ConstantEmitter::~ConstantEmitter() {
1432 assert((!InitializedNonAbstract || Finalized || Failed) &&(((!InitializedNonAbstract || Finalized || Failed) &&
"not finalized after being initialized for non-abstract emission"
) ? static_cast<void> (0) : __assert_fail ("(!InitializedNonAbstract || Finalized || Failed) && \"not finalized after being initialized for non-abstract emission\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1433, __PRETTY_FUNCTION__))
1433 "not finalized after being initialized for non-abstract emission")(((!InitializedNonAbstract || Finalized || Failed) &&
"not finalized after being initialized for non-abstract emission"
) ? static_cast<void> (0) : __assert_fail ("(!InitializedNonAbstract || Finalized || Failed) && \"not finalized after being initialized for non-abstract emission\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1433, __PRETTY_FUNCTION__))
;
1434 assert(PlaceholderAddresses.empty() && "unhandled placeholders")((PlaceholderAddresses.empty() && "unhandled placeholders"
) ? static_cast<void> (0) : __assert_fail ("PlaceholderAddresses.empty() && \"unhandled placeholders\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1434, __PRETTY_FUNCTION__))
;
1435}
1436
1437static QualType getNonMemoryType(CodeGenModule &CGM, QualType type) {
1438 if (auto AT = type->getAs<AtomicType>()) {
1439 return CGM.getContext().getQualifiedType(AT->getValueType(),
1440 type.getQualifiers());
1441 }
1442 return type;
1443}
1444
1445llvm::Constant *ConstantEmitter::tryEmitPrivateForVarInit(const VarDecl &D) {
1446 // Make a quick check if variable can be default NULL initialized
1447 // and avoid going through rest of code which may do, for c++11,
1448 // initialization of memory to all NULLs.
1449 if (!D.hasLocalStorage()) {
1450 QualType Ty = CGM.getContext().getBaseElementType(D.getType());
1451 if (Ty->isRecordType())
1452 if (const CXXConstructExpr *E =
1453 dyn_cast_or_null<CXXConstructExpr>(D.getInit())) {
1454 const CXXConstructorDecl *CD = E->getConstructor();
1455 if (CD->isTrivial() && CD->isDefaultConstructor())
1456 return CGM.EmitNullConstant(D.getType());
1457 }
1458 InConstantContext = true;
1459 }
1460
1461 QualType destType = D.getType();
1462
1463 // Try to emit the initializer. Note that this can allow some things that
1464 // are not allowed by tryEmitPrivateForMemory alone.
1465 if (auto value = D.evaluateValue()) {
1466 return tryEmitPrivateForMemory(*value, destType);
1467 }
1468
1469 // FIXME: Implement C++11 [basic.start.init]p2: if the initializer of a
1470 // reference is a constant expression, and the reference binds to a temporary,
1471 // then constant initialization is performed. ConstExprEmitter will
1472 // incorrectly emit a prvalue constant in this case, and the calling code
1473 // interprets that as the (pointer) value of the reference, rather than the
1474 // desired value of the referee.
1475 if (destType->isReferenceType())
1476 return nullptr;
1477
1478 const Expr *E = D.getInit();
1479 assert(E && "No initializer to emit")((E && "No initializer to emit") ? static_cast<void
> (0) : __assert_fail ("E && \"No initializer to emit\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1479, __PRETTY_FUNCTION__))
;
1480
1481 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1482 auto C =
1483 ConstExprEmitter(*this).Visit(const_cast<Expr*>(E), nonMemoryDestType);
1484 return (C ? emitForMemory(C, destType) : nullptr);
1485}
1486
1487llvm::Constant *
1488ConstantEmitter::tryEmitAbstractForMemory(const Expr *E, QualType destType) {
1489 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1490 auto C = tryEmitAbstract(E, nonMemoryDestType);
1491 return (C ? emitForMemory(C, destType) : nullptr);
1492}
1493
1494llvm::Constant *
1495ConstantEmitter::tryEmitAbstractForMemory(const APValue &value,
1496 QualType destType) {
1497 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1498 auto C = tryEmitAbstract(value, nonMemoryDestType);
1499 return (C ? emitForMemory(C, destType) : nullptr);
1500}
1501
1502llvm::Constant *ConstantEmitter::tryEmitPrivateForMemory(const Expr *E,
1503 QualType destType) {
1504 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1505 llvm::Constant *C = tryEmitPrivate(E, nonMemoryDestType);
1506 return (C ? emitForMemory(C, destType) : nullptr);
1507}
1508
1509llvm::Constant *ConstantEmitter::tryEmitPrivateForMemory(const APValue &value,
1510 QualType destType) {
1511 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1512 auto C = tryEmitPrivate(value, nonMemoryDestType);
1513 return (C ? emitForMemory(C, destType) : nullptr);
1514}
1515
1516llvm::Constant *ConstantEmitter::emitForMemory(CodeGenModule &CGM,
1517 llvm::Constant *C,
1518 QualType destType) {
1519 // For an _Atomic-qualified constant, we may need to add tail padding.
1520 if (auto AT = destType->getAs<AtomicType>()) {
1521 QualType destValueType = AT->getValueType();
1522 C = emitForMemory(CGM, C, destValueType);
1523
1524 uint64_t innerSize = CGM.getContext().getTypeSize(destValueType);
1525 uint64_t outerSize = CGM.getContext().getTypeSize(destType);
1526 if (innerSize == outerSize)
1527 return C;
1528
1529 assert(innerSize < outerSize && "emitted over-large constant for atomic")((innerSize < outerSize && "emitted over-large constant for atomic"
) ? static_cast<void> (0) : __assert_fail ("innerSize < outerSize && \"emitted over-large constant for atomic\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1529, __PRETTY_FUNCTION__))
;
1530 llvm::Constant *elts[] = {
1531 C,
1532 llvm::ConstantAggregateZero::get(
1533 llvm::ArrayType::get(CGM.Int8Ty, (outerSize - innerSize) / 8))
1534 };
1535 return llvm::ConstantStruct::getAnon(elts);
1536 }
1537
1538 // Zero-extend bool.
1539 if (C->getType()->isIntegerTy(1)) {
1540 llvm::Type *boolTy = CGM.getTypes().ConvertTypeForMem(destType);
1541 return llvm::ConstantExpr::getZExt(C, boolTy);
1542 }
1543
1544 return C;
1545}
1546
1547llvm::Constant *ConstantEmitter::tryEmitPrivate(const Expr *E,
1548 QualType destType) {
1549 Expr::EvalResult Result;
1550
1551 bool Success = false;
1552
1553 if (destType->isReferenceType())
1554 Success = E->EvaluateAsLValue(Result, CGM.getContext());
1555 else
1556 Success = E->EvaluateAsRValue(Result, CGM.getContext(), InConstantContext);
1557
1558 llvm::Constant *C;
1559 if (Success && !Result.HasSideEffects)
1560 C = tryEmitPrivate(Result.Val, destType);
1561 else
1562 C = ConstExprEmitter(*this).Visit(const_cast<Expr*>(E), destType);
1563
1564 return C;
1565}
1566
1567llvm::Constant *CodeGenModule::getNullPointer(llvm::PointerType *T, QualType QT) {
1568 return getTargetCodeGenInfo().getNullPointer(*this, T, QT);
1569}
1570
1571namespace {
1572/// A struct which can be used to peephole certain kinds of finalization
1573/// that normally happen during l-value emission.
1574struct ConstantLValue {
1575 llvm::Constant *Value;
1576 bool HasOffsetApplied;
1577
1578 /*implicit*/ ConstantLValue(llvm::Constant *value,
1579 bool hasOffsetApplied = false)
1580 : Value(value), HasOffsetApplied(false) {}
1581
1582 /*implicit*/ ConstantLValue(ConstantAddress address)
1583 : ConstantLValue(address.getPointer()) {}
1584};
1585
1586/// A helper class for emitting constant l-values.
1587class ConstantLValueEmitter : public ConstStmtVisitor<ConstantLValueEmitter,
1588 ConstantLValue> {
1589 CodeGenModule &CGM;
1590 ConstantEmitter &Emitter;
1591 const APValue &Value;
1592 QualType DestType;
1593
1594 // Befriend StmtVisitorBase so that we don't have to expose Visit*.
1595 friend StmtVisitorBase;
1596
1597public:
1598 ConstantLValueEmitter(ConstantEmitter &emitter, const APValue &value,
1599 QualType destType)
1600 : CGM(emitter.CGM), Emitter(emitter), Value(value), DestType(destType) {}
1601
1602 llvm::Constant *tryEmit();
1603
1604private:
1605 llvm::Constant *tryEmitAbsolute(llvm::Type *destTy);
1606 ConstantLValue tryEmitBase(const APValue::LValueBase &base);
1607
1608 ConstantLValue VisitStmt(const Stmt *S) { return nullptr; }
1609 ConstantLValue VisitConstantExpr(const ConstantExpr *E);
1610 ConstantLValue VisitCompoundLiteralExpr(const CompoundLiteralExpr *E);
1611 ConstantLValue VisitStringLiteral(const StringLiteral *E);
1612 ConstantLValue VisitObjCEncodeExpr(const ObjCEncodeExpr *E);
1613 ConstantLValue VisitObjCStringLiteral(const ObjCStringLiteral *E);
1614 ConstantLValue VisitPredefinedExpr(const PredefinedExpr *E);
1615 ConstantLValue VisitAddrLabelExpr(const AddrLabelExpr *E);
1616 ConstantLValue VisitCallExpr(const CallExpr *E);
1617 ConstantLValue VisitBlockExpr(const BlockExpr *E);
1618 ConstantLValue VisitCXXTypeidExpr(const CXXTypeidExpr *E);
1619 ConstantLValue VisitCXXUuidofExpr(const CXXUuidofExpr *E);
1620 ConstantLValue VisitMaterializeTemporaryExpr(
1621 const MaterializeTemporaryExpr *E);
1622
1623 bool hasNonZeroOffset() const {
1624 return !Value.getLValueOffset().isZero();
1625 }
1626
1627 /// Return the value offset.
1628 llvm::Constant *getOffset() {
1629 return llvm::ConstantInt::get(CGM.Int64Ty,
1630 Value.getLValueOffset().getQuantity());
1631 }
1632
1633 /// Apply the value offset to the given constant.
1634 llvm::Constant *applyOffset(llvm::Constant *C) {
1635 if (!hasNonZeroOffset())
1636 return C;
1637
1638 llvm::Type *origPtrTy = C->getType();
1639 unsigned AS = origPtrTy->getPointerAddressSpace();
1640 llvm::Type *charPtrTy = CGM.Int8Ty->getPointerTo(AS);
1641 C = llvm::ConstantExpr::getBitCast(C, charPtrTy);
1642 C = llvm::ConstantExpr::getGetElementPtr(CGM.Int8Ty, C, getOffset());
1643 C = llvm::ConstantExpr::getPointerCast(C, origPtrTy);
1644 return C;
1645 }
1646};
1647
1648}
1649
1650llvm::Constant *ConstantLValueEmitter::tryEmit() {
1651 const APValue::LValueBase &base = Value.getLValueBase();
1652
1653 // Certain special array initializers are represented in APValue
1654 // as l-values referring to the base expression which generates the
1655 // array. This happens with e.g. string literals. These should
1656 // probably just get their own representation kind in APValue.
1657 if (DestType->isArrayType()) {
1658 assert(!hasNonZeroOffset() && "offset on array initializer")((!hasNonZeroOffset() && "offset on array initializer"
) ? static_cast<void> (0) : __assert_fail ("!hasNonZeroOffset() && \"offset on array initializer\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1658, __PRETTY_FUNCTION__))
;
1659 auto expr = const_cast<Expr*>(base.get<const Expr*>());
1660 return ConstExprEmitter(Emitter).Visit(expr, DestType);
1661 }
1662
1663 // Otherwise, the destination type should be a pointer or reference
1664 // type, but it might also be a cast thereof.
1665 //
1666 // FIXME: the chain of casts required should be reflected in the APValue.
1667 // We need this in order to correctly handle things like a ptrtoint of a
1668 // non-zero null pointer and addrspace casts that aren't trivially
1669 // represented in LLVM IR.
1670 auto destTy = CGM.getTypes().ConvertTypeForMem(DestType);
1671 assert(isa<llvm::IntegerType>(destTy) || isa<llvm::PointerType>(destTy))((isa<llvm::IntegerType>(destTy) || isa<llvm::PointerType
>(destTy)) ? static_cast<void> (0) : __assert_fail (
"isa<llvm::IntegerType>(destTy) || isa<llvm::PointerType>(destTy)"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1671, __PRETTY_FUNCTION__))
;
1672
1673 // If there's no base at all, this is a null or absolute pointer,
1674 // possibly cast back to an integer type.
1675 if (!base) {
1676 return tryEmitAbsolute(destTy);
1677 }
1678
1679 // Otherwise, try to emit the base.
1680 ConstantLValue result = tryEmitBase(base);
1681
1682 // If that failed, we're done.
1683 llvm::Constant *value = result.Value;
1684 if (!value) return nullptr;
1685
1686 // Apply the offset if necessary and not already done.
1687 if (!result.HasOffsetApplied) {
1688 value = applyOffset(value);
1689 }
1690
1691 // Convert to the appropriate type; this could be an lvalue for
1692 // an integer. FIXME: performAddrSpaceCast
1693 if (isa<llvm::PointerType>(destTy))
1694 return llvm::ConstantExpr::getPointerCast(value, destTy);
1695
1696 return llvm::ConstantExpr::getPtrToInt(value, destTy);
1697}
1698
1699/// Try to emit an absolute l-value, such as a null pointer or an integer
1700/// bitcast to pointer type.
1701llvm::Constant *
1702ConstantLValueEmitter::tryEmitAbsolute(llvm::Type *destTy) {
1703 auto offset = getOffset();
1704
1705 // If we're producing a pointer, this is easy.
1706 if (auto destPtrTy = cast<llvm::PointerType>(destTy)) {
1707 if (Value.isNullPointer()) {
1708 // FIXME: integer offsets from non-zero null pointers.
1709 return CGM.getNullPointer(destPtrTy, DestType);
1710 }
1711
1712 // Convert the integer to a pointer-sized integer before converting it
1713 // to a pointer.
1714 // FIXME: signedness depends on the original integer type.
1715 auto intptrTy = CGM.getDataLayout().getIntPtrType(destPtrTy);
1716 llvm::Constant *C = offset;
Value stored to 'C' during its initialization is never read
1717 C = llvm::ConstantExpr::getIntegerCast(getOffset(), intptrTy,
1718 /*isSigned*/ false);
1719 C = llvm::ConstantExpr::getIntToPtr(C, destPtrTy);
1720 return C;
1721 }
1722
1723 // Otherwise, we're basically returning an integer constant.
1724
1725 // FIXME: this does the wrong thing with ptrtoint of a null pointer,
1726 // but since we don't know the original pointer type, there's not much
1727 // we can do about it.
1728
1729 auto C = getOffset();
1730 C = llvm::ConstantExpr::getIntegerCast(C, destTy, /*isSigned*/ false);
1731 return C;
1732}
1733
1734ConstantLValue
1735ConstantLValueEmitter::tryEmitBase(const APValue::LValueBase &base) {
1736 // Handle values.
1737 if (const ValueDecl *D = base.dyn_cast<const ValueDecl*>()) {
1738 if (D->hasAttr<WeakRefAttr>())
1739 return CGM.GetWeakRefReference(D).getPointer();
1740
1741 if (auto FD = dyn_cast<FunctionDecl>(D))
1742 return CGM.GetAddrOfFunction(FD);
1743
1744 if (auto VD = dyn_cast<VarDecl>(D)) {
1745 // We can never refer to a variable with local storage.
1746 if (!VD->hasLocalStorage()) {
1747 if (VD->isFileVarDecl() || VD->hasExternalStorage())
1748 return CGM.GetAddrOfGlobalVar(VD);
1749
1750 if (VD->isLocalVarDecl()) {
1751 return CGM.getOrCreateStaticVarDecl(
1752 *VD, CGM.getLLVMLinkageVarDefinition(VD, /*isConstant=*/false));
1753 }
1754 }
1755 }
1756
1757 return nullptr;
1758 }
1759
1760 // Otherwise, it must be an expression.
1761 return Visit(base.get<const Expr*>());
1762}
1763
1764ConstantLValue
1765ConstantLValueEmitter::VisitConstantExpr(const ConstantExpr *E) {
1766 return Visit(E->getSubExpr());
1767}
1768
1769ConstantLValue
1770ConstantLValueEmitter::VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
1771 return tryEmitGlobalCompoundLiteral(CGM, Emitter.CGF, E);
1772}
1773
1774ConstantLValue
1775ConstantLValueEmitter::VisitStringLiteral(const StringLiteral *E) {
1776 return CGM.GetAddrOfConstantStringFromLiteral(E);
1777}
1778
1779ConstantLValue
1780ConstantLValueEmitter::VisitObjCEncodeExpr(const ObjCEncodeExpr *E) {
1781 return CGM.GetAddrOfConstantStringFromObjCEncode(E);
1782}
1783
1784ConstantLValue
1785ConstantLValueEmitter::VisitObjCStringLiteral(const ObjCStringLiteral *E) {
1786 auto C = CGM.getObjCRuntime().GenerateConstantString(E->getString());
1787 return C.getElementBitCast(CGM.getTypes().ConvertTypeForMem(E->getType()));
1788}
1789
1790ConstantLValue
1791ConstantLValueEmitter::VisitPredefinedExpr(const PredefinedExpr *E) {
1792 if (auto CGF = Emitter.CGF) {
1793 LValue Res = CGF->EmitPredefinedLValue(E);
1794 return cast<ConstantAddress>(Res.getAddress());
1795 }
1796
1797 auto kind = E->getIdentKind();
1798 if (kind == PredefinedExpr::PrettyFunction) {
1799 return CGM.GetAddrOfConstantCString("top level", ".tmp");
1800 }
1801
1802 return CGM.GetAddrOfConstantCString("", ".tmp");
1803}
1804
1805ConstantLValue
1806ConstantLValueEmitter::VisitAddrLabelExpr(const AddrLabelExpr *E) {
1807 assert(Emitter.CGF && "Invalid address of label expression outside function")((Emitter.CGF && "Invalid address of label expression outside function"
) ? static_cast<void> (0) : __assert_fail ("Emitter.CGF && \"Invalid address of label expression outside function\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1807, __PRETTY_FUNCTION__))
;
1808 llvm::Constant *Ptr = Emitter.CGF->GetAddrOfLabel(E->getLabel());
1809 Ptr = llvm::ConstantExpr::getBitCast(Ptr,
1810 CGM.getTypes().ConvertType(E->getType()));
1811 return Ptr;
1812}
1813
1814ConstantLValue
1815ConstantLValueEmitter::VisitCallExpr(const CallExpr *E) {
1816 unsigned builtin = E->getBuiltinCallee();
1817 if (builtin != Builtin::BI__builtin___CFStringMakeConstantString &&
1818 builtin != Builtin::BI__builtin___NSStringMakeConstantString)
1819 return nullptr;
1820
1821 auto literal = cast<StringLiteral>(E->getArg(0)->IgnoreParenCasts());
1822 if (builtin == Builtin::BI__builtin___NSStringMakeConstantString) {
1823 return CGM.getObjCRuntime().GenerateConstantString(literal);
1824 } else {
1825 // FIXME: need to deal with UCN conversion issues.
1826 return CGM.GetAddrOfConstantCFString(literal);
1827 }
1828}
1829
1830ConstantLValue
1831ConstantLValueEmitter::VisitBlockExpr(const BlockExpr *E) {
1832 StringRef functionName;
1833 if (auto CGF = Emitter.CGF)
1834 functionName = CGF->CurFn->getName();
1835 else
1836 functionName = "global";
1837
1838 return CGM.GetAddrOfGlobalBlock(E, functionName);
1839}
1840
1841ConstantLValue
1842ConstantLValueEmitter::VisitCXXTypeidExpr(const CXXTypeidExpr *E) {
1843 QualType T;
1844 if (E->isTypeOperand())
1845 T = E->getTypeOperand(CGM.getContext());
1846 else
1847 T = E->getExprOperand()->getType();
1848 return CGM.GetAddrOfRTTIDescriptor(T);
1849}
1850
1851ConstantLValue
1852ConstantLValueEmitter::VisitCXXUuidofExpr(const CXXUuidofExpr *E) {
1853 return CGM.GetAddrOfUuidDescriptor(E);
1854}
1855
1856ConstantLValue
1857ConstantLValueEmitter::VisitMaterializeTemporaryExpr(
1858 const MaterializeTemporaryExpr *E) {
1859 assert(E->getStorageDuration() == SD_Static)((E->getStorageDuration() == SD_Static) ? static_cast<void
> (0) : __assert_fail ("E->getStorageDuration() == SD_Static"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1859, __PRETTY_FUNCTION__))
;
1860 SmallVector<const Expr *, 2> CommaLHSs;
1861 SmallVector<SubobjectAdjustment, 2> Adjustments;
1862 const Expr *Inner = E->GetTemporaryExpr()
1863 ->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
1864 return CGM.GetAddrOfGlobalTemporary(E, Inner);
1865}
1866
1867llvm::Constant *ConstantEmitter::tryEmitPrivate(const APValue &Value,
1868 QualType DestType) {
1869 switch (Value.getKind()) {
1870 case APValue::Uninitialized:
1871 llvm_unreachable("Constant expressions should be initialized.")::llvm::llvm_unreachable_internal("Constant expressions should be initialized."
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1871)
;
1872 case APValue::LValue:
1873 return ConstantLValueEmitter(*this, Value, DestType).tryEmit();
1874 case APValue::Int:
1875 return llvm::ConstantInt::get(CGM.getLLVMContext(), Value.getInt());
1876 case APValue::ComplexInt: {
1877 llvm::Constant *Complex[2];
1878
1879 Complex[0] = llvm::ConstantInt::get(CGM.getLLVMContext(),
1880 Value.getComplexIntReal());
1881 Complex[1] = llvm::ConstantInt::get(CGM.getLLVMContext(),
1882 Value.getComplexIntImag());
1883
1884 // FIXME: the target may want to specify that this is packed.
1885 llvm::StructType *STy =
1886 llvm::StructType::get(Complex[0]->getType(), Complex[1]->getType());
1887 return llvm::ConstantStruct::get(STy, Complex);
1888 }
1889 case APValue::Float: {
1890 const llvm::APFloat &Init = Value.getFloat();
1891 if (&Init.getSemantics() == &llvm::APFloat::IEEEhalf() &&
1892 !CGM.getContext().getLangOpts().NativeHalfType &&
1893 CGM.getContext().getTargetInfo().useFP16ConversionIntrinsics())
1894 return llvm::ConstantInt::get(CGM.getLLVMContext(),
1895 Init.bitcastToAPInt());
1896 else
1897 return llvm::ConstantFP::get(CGM.getLLVMContext(), Init);
1898 }
1899 case APValue::ComplexFloat: {
1900 llvm::Constant *Complex[2];
1901
1902 Complex[0] = llvm::ConstantFP::get(CGM.getLLVMContext(),
1903 Value.getComplexFloatReal());
1904 Complex[1] = llvm::ConstantFP::get(CGM.getLLVMContext(),
1905 Value.getComplexFloatImag());
1906
1907 // FIXME: the target may want to specify that this is packed.
1908 llvm::StructType *STy =
1909 llvm::StructType::get(Complex[0]->getType(), Complex[1]->getType());
1910 return llvm::ConstantStruct::get(STy, Complex);
1911 }
1912 case APValue::Vector: {
1913 unsigned NumElts = Value.getVectorLength();
1914 SmallVector<llvm::Constant *, 4> Inits(NumElts);
1915
1916 for (unsigned I = 0; I != NumElts; ++I) {
1917 const APValue &Elt = Value.getVectorElt(I);
1918 if (Elt.isInt())
1919 Inits[I] = llvm::ConstantInt::get(CGM.getLLVMContext(), Elt.getInt());
1920 else if (Elt.isFloat())
1921 Inits[I] = llvm::ConstantFP::get(CGM.getLLVMContext(), Elt.getFloat());
1922 else
1923 llvm_unreachable("unsupported vector element type")::llvm::llvm_unreachable_internal("unsupported vector element type"
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1923)
;
1924 }
1925 return llvm::ConstantVector::get(Inits);
1926 }
1927 case APValue::AddrLabelDiff: {
1928 const AddrLabelExpr *LHSExpr = Value.getAddrLabelDiffLHS();
1929 const AddrLabelExpr *RHSExpr = Value.getAddrLabelDiffRHS();
1930 llvm::Constant *LHS = tryEmitPrivate(LHSExpr, LHSExpr->getType());
1931 llvm::Constant *RHS = tryEmitPrivate(RHSExpr, RHSExpr->getType());
1932 if (!LHS || !RHS) return nullptr;
1933
1934 // Compute difference
1935 llvm::Type *ResultType = CGM.getTypes().ConvertType(DestType);
1936 LHS = llvm::ConstantExpr::getPtrToInt(LHS, CGM.IntPtrTy);
1937 RHS = llvm::ConstantExpr::getPtrToInt(RHS, CGM.IntPtrTy);
1938 llvm::Constant *AddrLabelDiff = llvm::ConstantExpr::getSub(LHS, RHS);
1939
1940 // LLVM is a bit sensitive about the exact format of the
1941 // address-of-label difference; make sure to truncate after
1942 // the subtraction.
1943 return llvm::ConstantExpr::getTruncOrBitCast(AddrLabelDiff, ResultType);
1944 }
1945 case APValue::Struct:
1946 case APValue::Union:
1947 return ConstStructBuilder::BuildStruct(*this, Value, DestType);
1948 case APValue::Array: {
1949 const ConstantArrayType *CAT =
1950 CGM.getContext().getAsConstantArrayType(DestType);
1951 unsigned NumElements = Value.getArraySize();
1952 unsigned NumInitElts = Value.getArrayInitializedElts();
1953
1954 // Emit array filler, if there is one.
1955 llvm::Constant *Filler = nullptr;
1956 if (Value.hasArrayFiller()) {
1957 Filler = tryEmitAbstractForMemory(Value.getArrayFiller(),
1958 CAT->getElementType());
1959 if (!Filler)
1960 return nullptr;
1961 }
1962
1963 // Emit initializer elements.
1964 SmallVector<llvm::Constant*, 16> Elts;
1965 if (Filler && Filler->isNullValue())
1966 Elts.reserve(NumInitElts + 1);
1967 else
1968 Elts.reserve(NumElements);
1969
1970 llvm::Type *CommonElementType = nullptr;
1971 for (unsigned I = 0; I < NumInitElts; ++I) {
1972 llvm::Constant *C = tryEmitPrivateForMemory(
1973 Value.getArrayInitializedElt(I), CAT->getElementType());
1974 if (!C) return nullptr;
1975
1976 if (I == 0)
1977 CommonElementType = C->getType();
1978 else if (C->getType() != CommonElementType)
1979 CommonElementType = nullptr;
1980 Elts.push_back(C);
1981 }
1982
1983 // This means that the array type is probably "IncompleteType" or some
1984 // type that is not ConstantArray.
1985 if (CAT == nullptr && CommonElementType == nullptr && !NumInitElts) {
1986 const ArrayType *AT = CGM.getContext().getAsArrayType(DestType);
1987 CommonElementType = CGM.getTypes().ConvertType(AT->getElementType());
1988 llvm::ArrayType *AType = llvm::ArrayType::get(CommonElementType,
1989 NumElements);
1990 return llvm::ConstantAggregateZero::get(AType);
1991 }
1992
1993 return EmitArrayConstant(CGM, CAT, CommonElementType, NumElements, Elts,
1994 Filler);
1995 }
1996 case APValue::MemberPointer:
1997 return CGM.getCXXABI().EmitMemberPointer(Value, DestType);
1998 }
1999 llvm_unreachable("Unknown APValue kind")::llvm::llvm_unreachable_internal("Unknown APValue kind", "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1999)
;
2000}
2001
2002llvm::GlobalVariable *CodeGenModule::getAddrOfConstantCompoundLiteralIfEmitted(
2003 const CompoundLiteralExpr *E) {
2004 return EmittedCompoundLiterals.lookup(E);
2005}
2006
2007void CodeGenModule::setAddrOfConstantCompoundLiteral(
2008 const CompoundLiteralExpr *CLE, llvm::GlobalVariable *GV) {
2009 bool Ok = EmittedCompoundLiterals.insert(std::make_pair(CLE, GV)).second;
2010 (void)Ok;
2011 assert(Ok && "CLE has already been emitted!")((Ok && "CLE has already been emitted!") ? static_cast
<void> (0) : __assert_fail ("Ok && \"CLE has already been emitted!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 2011, __PRETTY_FUNCTION__))
;
2012}
2013
2014ConstantAddress
2015CodeGenModule::GetAddrOfConstantCompoundLiteral(const CompoundLiteralExpr *E) {
2016 assert(E->isFileScope() && "not a file-scope compound literal expr")((E->isFileScope() && "not a file-scope compound literal expr"
) ? static_cast<void> (0) : __assert_fail ("E->isFileScope() && \"not a file-scope compound literal expr\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 2016, __PRETTY_FUNCTION__))
;
2017 return tryEmitGlobalCompoundLiteral(*this, nullptr, E);
2018}
2019
2020llvm::Constant *
2021CodeGenModule::getMemberPointerConstant(const UnaryOperator *uo) {
2022 // Member pointer constants always have a very particular form.
2023 const MemberPointerType *type = cast<MemberPointerType>(uo->getType());
2024 const ValueDecl *decl = cast<DeclRefExpr>(uo->getSubExpr())->getDecl();
2025
2026 // A member function pointer.
2027 if (const CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(decl))
2028 return getCXXABI().EmitMemberFunctionPointer(method);
2029
2030 // Otherwise, a member data pointer.
2031 uint64_t fieldOffset = getContext().getFieldOffset(decl);
2032 CharUnits chars = getContext().toCharUnitsFromBits((int64_t) fieldOffset);
2033 return getCXXABI().EmitMemberDataPointer(type, chars);
2034}
2035
2036static llvm::Constant *EmitNullConstantForBase(CodeGenModule &CGM,
2037 llvm::Type *baseType,
2038 const CXXRecordDecl *base);
2039
2040static llvm::Constant *EmitNullConstant(CodeGenModule &CGM,
2041 const RecordDecl *record,
2042 bool asCompleteObject) {
2043 const CGRecordLayout &layout = CGM.getTypes().getCGRecordLayout(record);
2044 llvm::StructType *structure =
2045 (asCompleteObject ? layout.getLLVMType()
2046 : layout.getBaseSubobjectLLVMType());
2047
2048 unsigned numElements = structure->getNumElements();
2049 std::vector<llvm::Constant *> elements(numElements);
2050
2051 auto CXXR = dyn_cast<CXXRecordDecl>(record);
2052 // Fill in all the bases.
2053 if (CXXR) {
2054 for (const auto &I : CXXR->bases()) {
2055 if (I.isVirtual()) {
2056 // Ignore virtual bases; if we're laying out for a complete
2057 // object, we'll lay these out later.
2058 continue;
2059 }
2060
2061 const CXXRecordDecl *base =
2062 cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
2063
2064 // Ignore empty bases.
2065 if (base->isEmpty() ||
2066 CGM.getContext().getASTRecordLayout(base).getNonVirtualSize()
2067 .isZero())
2068 continue;
2069
2070 unsigned fieldIndex = layout.getNonVirtualBaseLLVMFieldNo(base);
2071 llvm::Type *baseType = structure->getElementType(fieldIndex);
2072 elements[fieldIndex] = EmitNullConstantForBase(CGM, baseType, base);
2073 }
2074 }
2075
2076 // Fill in all the fields.
2077 for (const auto *Field : record->fields()) {
2078 // Fill in non-bitfields. (Bitfields always use a zero pattern, which we
2079 // will fill in later.)
2080 if (!Field->isBitField()) {
2081 unsigned fieldIndex = layout.getLLVMFieldNo(Field);
2082 elements[fieldIndex] = CGM.EmitNullConstant(Field->getType());
2083 }
2084
2085 // For unions, stop after the first named field.
2086 if (record->isUnion()) {
2087 if (Field->getIdentifier())
2088 break;
2089 if (const auto *FieldRD = Field->getType()->getAsRecordDecl())
2090 if (FieldRD->findFirstNamedDataMember())
2091 break;
2092 }
2093 }
2094
2095 // Fill in the virtual bases, if we're working with the complete object.
2096 if (CXXR && asCompleteObject) {
2097 for (const auto &I : CXXR->vbases()) {
2098 const CXXRecordDecl *base =
2099 cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
2100
2101 // Ignore empty bases.
2102 if (base->isEmpty())
2103 continue;
2104
2105 unsigned fieldIndex = layout.getVirtualBaseIndex(base);
2106
2107 // We might have already laid this field out.
2108 if (elements[fieldIndex]) continue;
2109
2110 llvm::Type *baseType = structure->getElementType(fieldIndex);
2111 elements[fieldIndex] = EmitNullConstantForBase(CGM, baseType, base);
2112 }
2113 }
2114
2115 // Now go through all other fields and zero them out.
2116 for (unsigned i = 0; i != numElements; ++i) {
2117 if (!elements[i])
2118 elements[i] = llvm::Constant::getNullValue(structure->getElementType(i));
2119 }
2120
2121 return llvm::ConstantStruct::get(structure, elements);
2122}
2123
2124/// Emit the null constant for a base subobject.
2125static llvm::Constant *EmitNullConstantForBase(CodeGenModule &CGM,
2126 llvm::Type *baseType,
2127 const CXXRecordDecl *base) {
2128 const CGRecordLayout &baseLayout = CGM.getTypes().getCGRecordLayout(base);
2129
2130 // Just zero out bases that don't have any pointer to data members.
2131 if (baseLayout.isZeroInitializableAsBase())
2132 return llvm::Constant::getNullValue(baseType);
2133
2134 // Otherwise, we can just use its null constant.
2135 return EmitNullConstant(CGM, base, /*asCompleteObject=*/false);
2136}
2137
2138llvm::Constant *ConstantEmitter::emitNullForMemory(CodeGenModule &CGM,
2139 QualType T) {
2140 return emitForMemory(CGM, CGM.EmitNullConstant(T), T);
2141}
2142
2143llvm::Constant *CodeGenModule::EmitNullConstant(QualType T) {
2144 if (T->getAs<PointerType>())
2145 return getNullPointer(
2146 cast<llvm::PointerType>(getTypes().ConvertTypeForMem(T)), T);
2147
2148 if (getTypes().isZeroInitializable(T))
2149 return llvm::Constant::getNullValue(getTypes().ConvertTypeForMem(T));
2150
2151 if (const ConstantArrayType *CAT = Context.getAsConstantArrayType(T)) {
2152 llvm::ArrayType *ATy =
2153 cast<llvm::ArrayType>(getTypes().ConvertTypeForMem(T));
2154
2155 QualType ElementTy = CAT->getElementType();
2156
2157 llvm::Constant *Element =
2158 ConstantEmitter::emitNullForMemory(*this, ElementTy);
2159 unsigned NumElements = CAT->getSize().getZExtValue();
2160 SmallVector<llvm::Constant *, 8> Array(NumElements, Element);
2161 return llvm::ConstantArray::get(ATy, Array);
2162 }
2163
2164 if (const RecordType *RT = T->getAs<RecordType>())
2165 return ::EmitNullConstant(*this, RT->getDecl(), /*complete object*/ true);
2166
2167 assert(T->isMemberDataPointerType() &&((T->isMemberDataPointerType() && "Should only see pointers to data members here!"
) ? static_cast<void> (0) : __assert_fail ("T->isMemberDataPointerType() && \"Should only see pointers to data members here!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 2168, __PRETTY_FUNCTION__))
2168 "Should only see pointers to data members here!")((T->isMemberDataPointerType() && "Should only see pointers to data members here!"
) ? static_cast<void> (0) : __assert_fail ("T->isMemberDataPointerType() && \"Should only see pointers to data members here!\""
, "/build/llvm-toolchain-snapshot-8~svn350071/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 2168, __PRETTY_FUNCTION__))
;
2169
2170 return getCXXABI().EmitNullMemberPointer(T->castAs<MemberPointerType>());
2171}
2172
2173llvm::Constant *
2174CodeGenModule::EmitNullConstantForBase(const CXXRecordDecl *Record) {
2175 return ::EmitNullConstant(*this, Record, false);
2176}