Bug Summary

File:tools/clang/lib/CodeGen/CGExprConstant.cpp
Warning:line 645, column 42
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name CGExprConstant.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-eagerly-assume -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -mrelocation-model pic -pic-level 2 -mthread-model posix -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-7/lib/clang/7.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-7~svn338205/build-llvm/tools/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-7~svn338205/tools/clang/include -I /build/llvm-toolchain-snapshot-7~svn338205/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-7~svn338205/build-llvm/include -I /build/llvm-toolchain-snapshot-7~svn338205/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/x86_64-linux-gnu/c++/8 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/x86_64-linux-gnu/c++/8 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/8/../../../../include/c++/8/backward -internal-isystem /usr/include/clang/7.0.0/include/ -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-7/lib/clang/7.0.0/include -internal-externc-isystem /usr/lib/gcc/x86_64-linux-gnu/8/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-class-memaccess -Wno-comment -std=c++11 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-7~svn338205/build-llvm/tools/clang/lib/CodeGen -ferror-limit 19 -fmessage-length 0 -fvisibility-inlines-hidden -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-2018-07-29-043837-17923-1 -x c++ /build/llvm-toolchain-snapshot-7~svn338205/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::ConstantStruct *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::ConstantStruct *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(static_cast <bool> (NextFieldOffsetInChars <= FieldOffsetInChars
&& "Field offset mismatch!") ? void (0) : __assert_fail
("NextFieldOffsetInChars <= FieldOffsetInChars && \"Field offset mismatch!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 111, __extension__ __PRETTY_FUNCTION__))
111 && "Field offset mismatch!")(static_cast <bool> (NextFieldOffsetInChars <= FieldOffsetInChars
&& "Field offset mismatch!") ? void (0) : __assert_fail
("NextFieldOffsetInChars <= FieldOffsetInChars && \"Field offset mismatch!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 111, __extension__ __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 &&(static_cast <bool> (NextFieldOffsetInChars == FieldOffsetInChars
&& "Did not add enough padding!") ? void (0) : __assert_fail
("NextFieldOffsetInChars == FieldOffsetInChars && \"Did not add enough padding!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 124, __extension__ __PRETTY_FUNCTION__))
124 "Did not add enough padding!")(static_cast <bool> (NextFieldOffsetInChars == FieldOffsetInChars
&& "Did not add enough padding!") ? void (0) : __assert_fail
("NextFieldOffsetInChars == FieldOffsetInChars && \"Did not add enough padding!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 124, __extension__ __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!")(static_cast <bool> (!Packed && "Alignment is wrong even with a packed struct!"
) ? void (0) : __assert_fail ("!Packed && \"Alignment is wrong even with a packed struct!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 131, __extension__ __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 &&(static_cast <bool> (NextFieldOffsetInChars == FieldOffsetInChars
&& "Did not add enough padding!") ? void (0) : __assert_fail
("NextFieldOffsetInChars == FieldOffsetInChars && \"Did not add enough padding!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 142, __extension__ __PRETTY_FUNCTION__))
142 "Did not add enough padding!")(static_cast <bool> (NextFieldOffsetInChars == FieldOffsetInChars
&& "Did not add enough padding!") ? void (0) : __assert_fail
("NextFieldOffsetInChars == FieldOffsetInChars && \"Did not add enough padding!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 142, __extension__ __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() &&(static_cast <bool> (LLVMStructAlignment == CharUnits::
One() && "Packed struct not byte-aligned!") ? void (0
) : __assert_fail ("LLVMStructAlignment == CharUnits::One() && \"Packed struct not byte-aligned!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 154, __extension__ __PRETTY_FUNCTION__))
154 "Packed struct not byte-aligned!")(static_cast <bool> (LLVMStructAlignment == CharUnits::
One() && "Packed struct not byte-aligned!") ? void (0
) : __assert_fail ("LLVMStructAlignment == CharUnits::One() && \"Packed struct not byte-aligned!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 154, __extension__ __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!")(static_cast <bool> (!Elements.empty() && "Elements can't be empty!"
) ? void (0) : __assert_fail ("!Elements.empty() && \"Elements can't be empty!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 193, __extension__ __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))(static_cast <bool> (isa<llvm::UndefValue>(LastElt
)) ? void (0) : __assert_fail ("isa<llvm::UndefValue>(LastElt)"
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 233, __extension__ __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()) &&(static_cast <bool> (isa<llvm::ArrayType>(LastElt
->getType()) && "Expected array padding of undefs"
) ? void (0) : __assert_fail ("isa<llvm::ArrayType>(LastElt->getType()) && \"Expected array padding of undefs\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 242, __extension__ __PRETTY_FUNCTION__))
242 "Expected array padding of undefs")(static_cast <bool> (isa<llvm::ArrayType>(LastElt
->getType()) && "Expected array padding of undefs"
) ? void (0) : __assert_fail ("isa<llvm::ArrayType>(LastElt->getType()) && \"Expected array padding of undefs\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 242, __extension__ __PRETTY_FUNCTION__))
;
243 llvm::ArrayType *AT = cast<llvm::ArrayType>(LastElt->getType());
244 assert(AT->getElementType()->isIntegerTy(CharWidth) &&(static_cast <bool> (AT->getElementType()->isIntegerTy
(CharWidth) && AT->getNumElements() != 0 &&
"Expected non-empty array padding of undefs") ? void (0) : __assert_fail
("AT->getElementType()->isIntegerTy(CharWidth) && AT->getNumElements() != 0 && \"Expected non-empty array padding of undefs\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 246, __extension__ __PRETTY_FUNCTION__))
245 AT->getNumElements() != 0 &&(static_cast <bool> (AT->getElementType()->isIntegerTy
(CharWidth) && AT->getNumElements() != 0 &&
"Expected non-empty array padding of undefs") ? void (0) : __assert_fail
("AT->getElementType()->isIntegerTy(CharWidth) && AT->getNumElements() != 0 && \"Expected non-empty array padding of undefs\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 246, __extension__ __PRETTY_FUNCTION__))
246 "Expected non-empty array padding of undefs")(static_cast <bool> (AT->getElementType()->isIntegerTy
(CharWidth) && AT->getNumElements() != 0 &&
"Expected non-empty array padding of undefs") ? void (0) : __assert_fail
("AT->getElementType()->isIntegerTy(CharWidth) && AT->getNumElements() != 0 && \"Expected non-empty array padding of undefs\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 246, __extension__ __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()) &&(static_cast <bool> (isa<llvm::UndefValue>(Elements
.back()) && Elements.back()->getType()->isIntegerTy
(CharWidth) && "Padding addition didn't work right") ?
void (0) : __assert_fail ("isa<llvm::UndefValue>(Elements.back()) && Elements.back()->getType()->isIntegerTy(CharWidth) && \"Padding addition didn't work right\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 257, __extension__ __PRETTY_FUNCTION__))
256 Elements.back()->getType()->isIntegerTy(CharWidth) &&(static_cast <bool> (isa<llvm::UndefValue>(Elements
.back()) && Elements.back()->getType()->isIntegerTy
(CharWidth) && "Padding addition didn't work right") ?
void (0) : __assert_fail ("isa<llvm::UndefValue>(Elements.back()) && Elements.back()->getType()->isIntegerTy(CharWidth) && \"Padding addition didn't work right\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 257, __extension__ __PRETTY_FUNCTION__))
257 "Padding addition didn't work right")(static_cast <bool> (isa<llvm::UndefValue>(Elements
.back()) && Elements.back()->getType()->isIntegerTy
(CharWidth) && "Padding addition didn't work right") ?
void (0) : __assert_fail ("isa<llvm::UndefValue>(Elements.back()) && Elements.back()->getType()->isIntegerTy(CharWidth) && \"Padding addition didn't work right\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 257, __extension__ __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 &&(static_cast <bool> (FieldValue.getBitWidth() > 0 &&
"Should have at least one bit left!") ? void (0) : __assert_fail
("FieldValue.getBitWidth() > 0 && \"Should have at least one bit left!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 288, __extension__ __PRETTY_FUNCTION__))
288 "Should have at least one bit left!")(static_cast <bool> (FieldValue.getBitWidth() > 0 &&
"Should have at least one bit left!") ? void (0) : __assert_fail
("FieldValue.getBitWidth() > 0 && \"Should have at least one bit left!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 288, __extension__ __PRETTY_FUNCTION__))
;
289 assert(FieldValue.getBitWidth() <= CharWidth &&(static_cast <bool> (FieldValue.getBitWidth() <= CharWidth
&& "Should not have more than a byte left!") ? void (
0) : __assert_fail ("FieldValue.getBitWidth() <= CharWidth && \"Should not have more than a byte left!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 290, __extension__ __PRETTY_FUNCTION__))
290 "Should not have more than a byte left!")(static_cast <bool> (FieldValue.getBitWidth() <= CharWidth
&& "Should not have more than a byte left!") ? void (
0) : __assert_fail ("FieldValue.getBitWidth() <= CharWidth && \"Should not have more than a byte left!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 290, __extension__ __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() &&(static_cast <bool> (getAlignment(C) == CharUnits::One(
) && "Padding must have 1 byte alignment!") ? void (0
) : __assert_fail ("getAlignment(C) == CharUnits::One() && \"Padding must have 1 byte alignment!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 318, __extension__ __PRETTY_FUNCTION__))
318 "Padding must have 1 byte alignment!")(static_cast <bool> (getAlignment(C) == CharUnits::One(
) && "Padding must have 1 byte alignment!") ? void (0
) : __assert_fail ("getAlignment(C) == CharUnits::One() && \"Padding must have 1 byte alignment!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 318, __extension__ __PRETTY_FUNCTION__))
;
319
320 NextFieldOffsetInChars += getSizeInChars(C);
321}
322
323void ConstStructBuilder::AppendTailPadding(CharUnits RecordSize) {
324 assert(NextFieldOffsetInChars <= RecordSize &&(static_cast <bool> (NextFieldOffsetInChars <= RecordSize
&& "Size mismatch!") ? void (0) : __assert_fail ("NextFieldOffsetInChars <= RecordSize && \"Size mismatch!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 325, __extension__ __PRETTY_FUNCTION__))
325 "Size mismatch!")(static_cast <bool> (NextFieldOffsetInChars <= RecordSize
&& "Size mismatch!") ? void (0) : __assert_fail ("NextFieldOffsetInChars <= RecordSize && \"Size mismatch!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 325, __extension__ __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 &&(static_cast <bool> (ElementOffsetInChars == NextFieldOffsetInChars
&& "Packing the struct changed its size!") ? void (0
) : __assert_fail ("ElementOffsetInChars == NextFieldOffsetInChars && \"Packing the struct changed its size!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 361, __extension__ __PRETTY_FUNCTION__))
361 "Packing the struct changed its size!")(static_cast <bool> (ElementOffsetInChars == NextFieldOffsetInChars
&& "Packing the struct changed its size!") ? void (0
) : __assert_fail ("ElementOffsetInChars == NextFieldOffsetInChars && \"Packing the struct changed its size!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 361, __extension__ __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")(static_cast <bool> (!Base->isVirtual() && "should not have virtual bases here"
) ? void (0) : __assert_fail ("!Base->isVirtual() && \"should not have virtual bases here\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 458, __extension__ __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() &&(static_cast <bool> (RD->hasFlexibleArrayMember() &&
"Must have flexible array member if struct is bigger than type!"
) ? void (0) : __assert_fail ("RD->hasFlexibleArrayMember() && \"Must have flexible array member if struct is bigger than type!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 518, __extension__ __PRETTY_FUNCTION__))
518 "Must have flexible array member if struct is bigger than type!")(static_cast <bool> (RD->hasFlexibleArrayMember() &&
"Must have flexible array member if struct is bigger than type!"
) ? void (0) : __assert_fail ("RD->hasFlexibleArrayMember() && \"Must have flexible array member if struct is bigger than type!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 518, __extension__ __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!")(static_cast <bool> (!Packed && "Size mismatch!"
) ? void (0) : __assert_fail ("!Packed && \"Size mismatch!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 534, __extension__ __PRETTY_FUNCTION__))
;
535
536 ConvertStructToPacked();
537 assert(NextFieldOffsetInChars <= LayoutSizeInChars &&(static_cast <bool> (NextFieldOffsetInChars <= LayoutSizeInChars
&& "Converting to packed did not help!") ? void (0) :
__assert_fail ("NextFieldOffsetInChars <= LayoutSizeInChars && \"Converting to packed did not help!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 538, __extension__ __PRETTY_FUNCTION__))
538 "Converting to packed did not help!")(static_cast <bool> (NextFieldOffsetInChars <= LayoutSizeInChars
&& "Converting to packed did not help!") ? void (0) :
__assert_fail ("NextFieldOffsetInChars <= LayoutSizeInChars && \"Converting to packed did not help!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 538, __extension__ __PRETTY_FUNCTION__))
;
539 }
540
541 LLVMSizeInChars = NextFieldOffsetInChars.alignTo(LLVMStructAlignment);
542
543 assert(LayoutSizeInChars == LLVMSizeInChars &&(static_cast <bool> (LayoutSizeInChars == LLVMSizeInChars
&& "Tail padding mismatch!") ? void (0) : __assert_fail
("LayoutSizeInChars == LLVMSizeInChars && \"Tail padding mismatch!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 544, __extension__ __PRETTY_FUNCTION__))
544 "Tail padding mismatch!")(static_cast <bool> (LayoutSizeInChars == LLVMSizeInChars
&& "Tail padding mismatch!") ? void (0) : __assert_fail
("LayoutSizeInChars == LLVMSizeInChars && \"Tail padding mismatch!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 544, __extension__ __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)) ==(static_cast <bool> (NextFieldOffsetInChars.alignTo(getAlignment
(Result)) == getSizeInChars(Result) && "Size mismatch!"
) ? void (0) : __assert_fail ("NextFieldOffsetInChars.alignTo(getAlignment(Result)) == getSizeInChars(Result) && \"Size mismatch!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 562, __extension__ __PRETTY_FUNCTION__))
561 getSizeInChars(Result) &&(static_cast <bool> (NextFieldOffsetInChars.alignTo(getAlignment
(Result)) == getSizeInChars(Result) && "Size mismatch!"
) ? void (0) : __assert_fail ("NextFieldOffsetInChars.alignTo(getAlignment(Result)) == getSizeInChars(Result) && \"Size mismatch!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 562, __extension__ __PRETTY_FUNCTION__))
562 "Size mismatch!")(static_cast <bool> (NextFieldOffsetInChars.alignTo(getAlignment
(Result)) == getSizeInChars(Result) && "Size mismatch!"
) ? void (0) : __assert_fail ("NextFieldOffsetInChars.alignTo(getAlignment(Result)) == getSizeInChars(Result) && \"Size mismatch!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 562, __extension__ __PRETTY_FUNCTION__))
;
563
564 return Result;
565}
566
567llvm::Constant *ConstStructBuilder::BuildStruct(ConstantEmitter &Emitter,
568 ConstExprEmitter *ExprEmitter,
569 llvm::ConstantStruct *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() &&(static_cast <bool> (!E->isFileScope() && "file-scope compound literal did not have constant initializer!"
) ? void (0) : __assert_fail ("!E->isFileScope() && \"file-scope compound literal did not have constant initializer!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 622, __extension__ __PRETTY_FUNCTION__))
622 "file-scope compound literal did not have constant initializer!")(static_cast <bool> (!E->isFileScope() && "file-scope compound literal did not have constant initializer!"
) ? void (0) : __assert_fail ("!E->isFileScope() && \"file-scope compound literal did not have constant initializer!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 622, __extension__ __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())
12
Assuming the condition is true
13
Called C++ object pointer is null
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 &&(static_cast <bool> (Elements.size() >= NonzeroLength
&& "missing initializer for non-zero element") ? void
(0) : __assert_fail ("Elements.size() >= NonzeroLength && \"missing initializer for non-zero element\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 661, __extension__ __PRETTY_FUNCTION__))
661 "missing initializer for non-zero element")(static_cast <bool> (Elements.size() >= NonzeroLength
&& "missing initializer for non-zero element") ? void
(0) : __assert_fail ("Elements.size() >= NonzeroLength && \"missing initializer for non-zero element\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 661, __extension__ __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 *VisitParenExpr(ParenExpr *PE, QualType T) {
727 return Visit(PE->getSubExpr(), T);
728 }
729
730 llvm::Constant *
731 VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *PE,
732 QualType T) {
733 return Visit(PE->getReplacement(), T);
734 }
735
736 llvm::Constant *VisitGenericSelectionExpr(GenericSelectionExpr *GE,
737 QualType T) {
738 return Visit(GE->getResultExpr(), T);
739 }
740
741 llvm::Constant *VisitChooseExpr(ChooseExpr *CE, QualType T) {
742 return Visit(CE->getChosenSubExpr(), T);
743 }
744
745 llvm::Constant *VisitCompoundLiteralExpr(CompoundLiteralExpr *E, QualType T) {
746 return Visit(E->getInitializer(), T);
747 }
748
749 llvm::Constant *VisitCastExpr(CastExpr *E, QualType destType) {
750 if (const auto *ECE = dyn_cast<ExplicitCastExpr>(E))
751 CGM.EmitExplicitCastExprType(ECE, Emitter.CGF);
752 Expr *subExpr = E->getSubExpr();
753
754 switch (E->getCastKind()) {
755 case CK_ToUnion: {
756 // GCC cast to union extension
757 assert(E->getType()->isUnionType() &&(static_cast <bool> (E->getType()->isUnionType() &&
"Destination type is not union type!") ? void (0) : __assert_fail
("E->getType()->isUnionType() && \"Destination type is not union type!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 758, __extension__ __PRETTY_FUNCTION__))
758 "Destination type is not union type!")(static_cast <bool> (E->getType()->isUnionType() &&
"Destination type is not union type!") ? void (0) : __assert_fail
("E->getType()->isUnionType() && \"Destination type is not union type!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 758, __extension__ __PRETTY_FUNCTION__))
;
759
760 auto field = E->getTargetUnionField();
761
762 auto C = Emitter.tryEmitPrivateForMemory(subExpr, field->getType());
763 if (!C) return nullptr;
764
765 auto destTy = ConvertType(destType);
766 if (C->getType() == destTy) return C;
767
768 // Build a struct with the union sub-element as the first member,
769 // and padded to the appropriate size.
770 SmallVector<llvm::Constant*, 2> Elts;
771 SmallVector<llvm::Type*, 2> Types;
772 Elts.push_back(C);
773 Types.push_back(C->getType());
774 unsigned CurSize = CGM.getDataLayout().getTypeAllocSize(C->getType());
775 unsigned TotalSize = CGM.getDataLayout().getTypeAllocSize(destTy);
776
777 assert(CurSize <= TotalSize && "Union size mismatch!")(static_cast <bool> (CurSize <= TotalSize &&
"Union size mismatch!") ? void (0) : __assert_fail ("CurSize <= TotalSize && \"Union size mismatch!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 777, __extension__ __PRETTY_FUNCTION__))
;
778 if (unsigned NumPadBytes = TotalSize - CurSize) {
779 llvm::Type *Ty = CGM.Int8Ty;
780 if (NumPadBytes > 1)
781 Ty = llvm::ArrayType::get(Ty, NumPadBytes);
782
783 Elts.push_back(llvm::UndefValue::get(Ty));
784 Types.push_back(Ty);
785 }
786
787 llvm::StructType *STy = llvm::StructType::get(VMContext, Types, false);
788 return llvm::ConstantStruct::get(STy, Elts);
789 }
790
791 case CK_AddressSpaceConversion: {
792 auto C = Emitter.tryEmitPrivate(subExpr, subExpr->getType());
793 if (!C) return nullptr;
794 LangAS destAS = E->getType()->getPointeeType().getAddressSpace();
795 LangAS srcAS = subExpr->getType()->getPointeeType().getAddressSpace();
796 llvm::Type *destTy = ConvertType(E->getType());
797 return CGM.getTargetCodeGenInfo().performAddrSpaceCast(CGM, C, srcAS,
798 destAS, destTy);
799 }
800
801 case CK_LValueToRValue:
802 case CK_AtomicToNonAtomic:
803 case CK_NonAtomicToAtomic:
804 case CK_NoOp:
805 case CK_ConstructorConversion:
806 return Visit(subExpr, destType);
807
808 case CK_IntToOCLSampler:
809 llvm_unreachable("global sampler variables are not generated")::llvm::llvm_unreachable_internal("global sampler variables are not generated"
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 809)
;
810
811 case CK_Dependent: llvm_unreachable("saw dependent cast!")::llvm::llvm_unreachable_internal("saw dependent cast!", "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 811)
;
812
813 case CK_BuiltinFnToFnPtr:
814 llvm_unreachable("builtin functions are handled elsewhere")::llvm::llvm_unreachable_internal("builtin functions are handled elsewhere"
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 814)
;
815
816 case CK_ReinterpretMemberPointer:
817 case CK_DerivedToBaseMemberPointer:
818 case CK_BaseToDerivedMemberPointer: {
819 auto C = Emitter.tryEmitPrivate(subExpr, subExpr->getType());
820 if (!C) return nullptr;
821 return CGM.getCXXABI().EmitMemberPointerConversion(E, C);
822 }
823
824 // These will never be supported.
825 case CK_ObjCObjectLValueCast:
826 case CK_ARCProduceObject:
827 case CK_ARCConsumeObject:
828 case CK_ARCReclaimReturnedObject:
829 case CK_ARCExtendBlockObject:
830 case CK_CopyAndAutoreleaseBlockObject:
831 return nullptr;
832
833 // These don't need to be handled here because Evaluate knows how to
834 // evaluate them in the cases where they can be folded.
835 case CK_BitCast:
836 case CK_ToVoid:
837 case CK_Dynamic:
838 case CK_LValueBitCast:
839 case CK_NullToMemberPointer:
840 case CK_UserDefinedConversion:
841 case CK_CPointerToObjCPointerCast:
842 case CK_BlockPointerToObjCPointerCast:
843 case CK_AnyPointerToBlockPointerCast:
844 case CK_ArrayToPointerDecay:
845 case CK_FunctionToPointerDecay:
846 case CK_BaseToDerived:
847 case CK_DerivedToBase:
848 case CK_UncheckedDerivedToBase:
849 case CK_MemberPointerToBoolean:
850 case CK_VectorSplat:
851 case CK_FloatingRealToComplex:
852 case CK_FloatingComplexToReal:
853 case CK_FloatingComplexToBoolean:
854 case CK_FloatingComplexCast:
855 case CK_FloatingComplexToIntegralComplex:
856 case CK_IntegralRealToComplex:
857 case CK_IntegralComplexToReal:
858 case CK_IntegralComplexToBoolean:
859 case CK_IntegralComplexCast:
860 case CK_IntegralComplexToFloatingComplex:
861 case CK_PointerToIntegral:
862 case CK_PointerToBoolean:
863 case CK_NullToPointer:
864 case CK_IntegralCast:
865 case CK_BooleanToSignedIntegral:
866 case CK_IntegralToPointer:
867 case CK_IntegralToBoolean:
868 case CK_IntegralToFloating:
869 case CK_FloatingToIntegral:
870 case CK_FloatingToBoolean:
871 case CK_FloatingCast:
872 case CK_ZeroToOCLEvent:
873 case CK_ZeroToOCLQueue:
874 return nullptr;
875 }
876 llvm_unreachable("Invalid CastKind")::llvm::llvm_unreachable_internal("Invalid CastKind", "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 876)
;
877 }
878
879 llvm::Constant *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE, QualType T) {
880 return Visit(DAE->getExpr(), T);
881 }
882
883 llvm::Constant *VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE, QualType T) {
884 // No need for a DefaultInitExprScope: we don't handle 'this' in a
885 // constant expression.
886 return Visit(DIE->getExpr(), T);
887 }
888
889 llvm::Constant *VisitExprWithCleanups(ExprWithCleanups *E, QualType T) {
890 if (!E->cleanupsHaveSideEffects())
891 return Visit(E->getSubExpr(), T);
892 return nullptr;
893 }
894
895 llvm::Constant *VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E,
896 QualType T) {
897 return Visit(E->GetTemporaryExpr(), T);
898 }
899
900 llvm::Constant *EmitArrayInitialization(InitListExpr *ILE, QualType T) {
901 auto *CAT = CGM.getContext().getAsConstantArrayType(ILE->getType());
902 assert(CAT && "can't emit array init for non-constant-bound array")(static_cast <bool> (CAT && "can't emit array init for non-constant-bound array"
) ? void (0) : __assert_fail ("CAT && \"can't emit array init for non-constant-bound array\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 902, __extension__ __PRETTY_FUNCTION__))
;
903 unsigned NumInitElements = ILE->getNumInits();
904 unsigned NumElements = CAT->getSize().getZExtValue();
905
906 // Initialising an array requires us to automatically
907 // initialise any elements that have not been initialised explicitly
908 unsigned NumInitableElts = std::min(NumInitElements, NumElements);
909
910 QualType EltType = CAT->getElementType();
911
912 // Initialize remaining array elements.
913 llvm::Constant *fillC = nullptr;
5
'fillC' initialized to a null pointer value
914 if (Expr *filler = ILE->getArrayFiller()) {
6
Assuming 'filler' is null
7
Taking false branch
915 fillC = Emitter.tryEmitAbstractForMemory(filler, EltType);
916 if (!fillC)
917 return nullptr;
918 }
919
920 // Copy initializer elements.
921 SmallVector<llvm::Constant*, 16> Elts;
922 if (fillC && fillC->isNullValue())
923 Elts.reserve(NumInitableElts + 1);
924 else
925 Elts.reserve(NumElements);
926
927 llvm::Type *CommonElementType = nullptr;
928 for (unsigned i = 0; i < NumInitableElts; ++i) {
8
Assuming 'i' is >= 'NumInitableElts'
9
Loop condition is false. Execution continues on line 940
929 Expr *Init = ILE->getInit(i);
930 llvm::Constant *C = Emitter.tryEmitPrivateForMemory(Init, EltType);
931 if (!C)
932 return nullptr;
933 if (i == 0)
934 CommonElementType = C->getType();
935 else if (C->getType() != CommonElementType)
936 CommonElementType = nullptr;
937 Elts.push_back(C);
938 }
939
940 return EmitArrayConstant(CGM, CAT, CommonElementType, NumElements, Elts,
11
Calling 'EmitArrayConstant'
941 fillC);
10
Passing null pointer value via 6th parameter 'Filler'
942 }
943
944 llvm::Constant *EmitRecordInitialization(InitListExpr *ILE, QualType T) {
945 return ConstStructBuilder::BuildStruct(Emitter, ILE, T);
946 }
947
948 llvm::Constant *VisitImplicitValueInitExpr(ImplicitValueInitExpr* E,
949 QualType T) {
950 return CGM.EmitNullConstant(T);
951 }
952
953 llvm::Constant *VisitInitListExpr(InitListExpr *ILE, QualType T) {
954 if (ILE->isTransparent())
1
Assuming the condition is false
2
Taking false branch
955 return Visit(ILE->getInit(0), T);
956
957 if (ILE->getType()->isArrayType())
3
Taking true branch
958 return EmitArrayInitialization(ILE, T);
4
Calling 'ConstExprEmitter::EmitArrayInitialization'
959
960 if (ILE->getType()->isRecordType())
961 return EmitRecordInitialization(ILE, T);
962
963 return nullptr;
964 }
965
966 llvm::Constant *EmitDesignatedInitUpdater(llvm::Constant *Base,
967 InitListExpr *Updater,
968 QualType destType) {
969 if (auto destAT = CGM.getContext().getAsArrayType(destType)) {
970 llvm::ArrayType *AType = cast<llvm::ArrayType>(ConvertType(destType));
971 llvm::Type *ElemType = AType->getElementType();
972
973 unsigned NumInitElements = Updater->getNumInits();
974 unsigned NumElements = AType->getNumElements();
975
976 std::vector<llvm::Constant *> Elts;
977 Elts.reserve(NumElements);
978
979 QualType destElemType = destAT->getElementType();
980
981 if (auto DataArray = dyn_cast<llvm::ConstantDataArray>(Base))
982 for (unsigned i = 0; i != NumElements; ++i)
983 Elts.push_back(DataArray->getElementAsConstant(i));
984 else if (auto Array = dyn_cast<llvm::ConstantArray>(Base))
985 for (unsigned i = 0; i != NumElements; ++i)
986 Elts.push_back(Array->getOperand(i));
987 else
988 return nullptr; // FIXME: other array types not implemented
989
990 llvm::Constant *fillC = nullptr;
991 if (Expr *filler = Updater->getArrayFiller())
992 if (!isa<NoInitExpr>(filler))
993 fillC = Emitter.tryEmitAbstractForMemory(filler, destElemType);
994 bool RewriteType = (fillC && fillC->getType() != ElemType);
995
996 for (unsigned i = 0; i != NumElements; ++i) {
997 Expr *Init = nullptr;
998 if (i < NumInitElements)
999 Init = Updater->getInit(i);
1000
1001 if (!Init && fillC)
1002 Elts[i] = fillC;
1003 else if (!Init || isa<NoInitExpr>(Init))
1004 ; // Do nothing.
1005 else if (InitListExpr *ChildILE = dyn_cast<InitListExpr>(Init))
1006 Elts[i] = EmitDesignatedInitUpdater(Elts[i], ChildILE, destElemType);
1007 else
1008 Elts[i] = Emitter.tryEmitPrivateForMemory(Init, destElemType);
1009
1010 if (!Elts[i])
1011 return nullptr;
1012 RewriteType |= (Elts[i]->getType() != ElemType);
1013 }
1014
1015 if (RewriteType) {
1016 std::vector<llvm::Type *> Types;
1017 Types.reserve(NumElements);
1018 for (unsigned i = 0; i != NumElements; ++i)
1019 Types.push_back(Elts[i]->getType());
1020 llvm::StructType *SType = llvm::StructType::get(AType->getContext(),
1021 Types, true);
1022 return llvm::ConstantStruct::get(SType, Elts);
1023 }
1024
1025 return llvm::ConstantArray::get(AType, Elts);
1026 }
1027
1028 if (destType->isRecordType())
1029 return ConstStructBuilder::BuildStruct(Emitter, this,
1030 dyn_cast<llvm::ConstantStruct>(Base), Updater, destType);
1031
1032 return nullptr;
1033 }
1034
1035 llvm::Constant *VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E,
1036 QualType destType) {
1037 auto C = Visit(E->getBase(), destType);
1038 if (!C) return nullptr;
1039 return EmitDesignatedInitUpdater(C, E->getUpdater(), destType);
1040 }
1041
1042 llvm::Constant *VisitCXXConstructExpr(CXXConstructExpr *E, QualType Ty) {
1043 if (!E->getConstructor()->isTrivial())
1044 return nullptr;
1045
1046 // FIXME: We should not have to call getBaseElementType here.
1047 const RecordType *RT =
1048 CGM.getContext().getBaseElementType(Ty)->getAs<RecordType>();
1049 const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1050
1051 // If the class doesn't have a trivial destructor, we can't emit it as a
1052 // constant expr.
1053 if (!RD->hasTrivialDestructor())
1054 return nullptr;
1055
1056 // Only copy and default constructors can be trivial.
1057
1058
1059 if (E->getNumArgs()) {
1060 assert(E->getNumArgs() == 1 && "trivial ctor with > 1 argument")(static_cast <bool> (E->getNumArgs() == 1 &&
"trivial ctor with > 1 argument") ? void (0) : __assert_fail
("E->getNumArgs() == 1 && \"trivial ctor with > 1 argument\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1060, __extension__ __PRETTY_FUNCTION__))
;
1061 assert(E->getConstructor()->isCopyOrMoveConstructor() &&(static_cast <bool> (E->getConstructor()->isCopyOrMoveConstructor
() && "trivial ctor has argument but isn't a copy/move ctor"
) ? void (0) : __assert_fail ("E->getConstructor()->isCopyOrMoveConstructor() && \"trivial ctor has argument but isn't a copy/move ctor\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1062, __extension__ __PRETTY_FUNCTION__))
1062 "trivial ctor has argument but isn't a copy/move ctor")(static_cast <bool> (E->getConstructor()->isCopyOrMoveConstructor
() && "trivial ctor has argument but isn't a copy/move ctor"
) ? void (0) : __assert_fail ("E->getConstructor()->isCopyOrMoveConstructor() && \"trivial ctor has argument but isn't a copy/move ctor\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1062, __extension__ __PRETTY_FUNCTION__))
;
1063
1064 Expr *Arg = E->getArg(0);
1065 assert(CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) &&(static_cast <bool> (CGM.getContext().hasSameUnqualifiedType
(Ty, Arg->getType()) && "argument to copy ctor is of wrong type"
) ? void (0) : __assert_fail ("CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) && \"argument to copy ctor is of wrong type\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1066, __extension__ __PRETTY_FUNCTION__))
1066 "argument to copy ctor is of wrong type")(static_cast <bool> (CGM.getContext().hasSameUnqualifiedType
(Ty, Arg->getType()) && "argument to copy ctor is of wrong type"
) ? void (0) : __assert_fail ("CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) && \"argument to copy ctor is of wrong type\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1066, __extension__ __PRETTY_FUNCTION__))
;
1067
1068 return Visit(Arg, Ty);
1069 }
1070
1071 return CGM.EmitNullConstant(Ty);
1072 }
1073
1074 llvm::Constant *VisitStringLiteral(StringLiteral *E, QualType T) {
1075 return CGM.GetConstantArrayFromStringLiteral(E);
1076 }
1077
1078 llvm::Constant *VisitObjCEncodeExpr(ObjCEncodeExpr *E, QualType T) {
1079 // This must be an @encode initializing an array in a static initializer.
1080 // Don't emit it as the address of the string, emit the string data itself
1081 // as an inline array.
1082 std::string Str;
1083 CGM.getContext().getObjCEncodingForType(E->getEncodedType(), Str);
1084 const ConstantArrayType *CAT = CGM.getContext().getAsConstantArrayType(T);
1085
1086 // Resize the string to the right size, adding zeros at the end, or
1087 // truncating as needed.
1088 Str.resize(CAT->getSize().getZExtValue(), '\0');
1089 return llvm::ConstantDataArray::getString(VMContext, Str, false);
1090 }
1091
1092 llvm::Constant *VisitUnaryExtension(const UnaryOperator *E, QualType T) {
1093 return Visit(E->getSubExpr(), T);
1094 }
1095
1096 // Utility methods
1097 llvm::Type *ConvertType(QualType T) {
1098 return CGM.getTypes().ConvertType(T);
1099 }
1100};
1101
1102} // end anonymous namespace.
1103
1104bool ConstStructBuilder::Build(ConstExprEmitter *ExprEmitter,
1105 llvm::ConstantStruct *Base,
1106 InitListExpr *Updater) {
1107 assert(Base && "base expression should not be empty")(static_cast <bool> (Base && "base expression should not be empty"
) ? void (0) : __assert_fail ("Base && \"base expression should not be empty\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1107, __extension__ __PRETTY_FUNCTION__))
;
1108
1109 QualType ExprType = Updater->getType();
1110 RecordDecl *RD = ExprType->getAs<RecordType>()->getDecl();
1111 const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
1112 const llvm::StructLayout *BaseLayout = CGM.getDataLayout().getStructLayout(
1113 Base->getType());
1114 unsigned FieldNo = -1;
1115 unsigned ElementNo = 0;
1116
1117 // Bail out if we have base classes. We could support these, but they only
1118 // arise in C++1z where we will have already constant folded most interesting
1119 // cases. FIXME: There are still a few more cases we can handle this way.
1120 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
1121 if (CXXRD->getNumBases())
1122 return false;
1123
1124 for (FieldDecl *Field : RD->fields()) {
1125 ++FieldNo;
1126
1127 if (RD->isUnion() && Updater->getInitializedFieldInUnion() != Field)
1128 continue;
1129
1130 // Skip anonymous bitfields.
1131 if (Field->isUnnamedBitfield())
1132 continue;
1133
1134 llvm::Constant *EltInit = Base->getOperand(ElementNo);
1135
1136 // Bail out if the type of the ConstantStruct does not have the same layout
1137 // as the type of the InitListExpr.
1138 if (CGM.getTypes().ConvertType(Field->getType()) != EltInit->getType() ||
1139 Layout.getFieldOffset(ElementNo) !=
1140 BaseLayout->getElementOffsetInBits(ElementNo))
1141 return false;
1142
1143 // Get the initializer. If we encounter an empty field or a NoInitExpr,
1144 // we use values from the base expression.
1145 Expr *Init = nullptr;
1146 if (ElementNo < Updater->getNumInits())
1147 Init = Updater->getInit(ElementNo);
1148
1149 if (!Init || isa<NoInitExpr>(Init))
1150 ; // Do nothing.
1151 else if (InitListExpr *ChildILE = dyn_cast<InitListExpr>(Init))
1152 EltInit = ExprEmitter->EmitDesignatedInitUpdater(EltInit, ChildILE,
1153 Field->getType());
1154 else
1155 EltInit = Emitter.tryEmitPrivateForMemory(Init, Field->getType());
1156
1157 ++ElementNo;
1158
1159 if (!EltInit)
1160 return false;
1161
1162 if (!Field->isBitField())
1163 AppendField(Field, Layout.getFieldOffset(FieldNo), EltInit);
1164 else if (llvm::ConstantInt *CI = dyn_cast<llvm::ConstantInt>(EltInit))
1165 AppendBitField(Field, Layout.getFieldOffset(FieldNo), CI);
1166 else
1167 // Initializing a bitfield with a non-trivial constant?
1168 return false;
1169 }
1170
1171 return true;
1172}
1173
1174llvm::Constant *ConstantEmitter::validateAndPopAbstract(llvm::Constant *C,
1175 AbstractState saved) {
1176 Abstract = saved.OldValue;
1177
1178 assert(saved.OldPlaceholdersSize == PlaceholderAddresses.size() &&(static_cast <bool> (saved.OldPlaceholdersSize == PlaceholderAddresses
.size() && "created a placeholder while doing an abstract emission?"
) ? void (0) : __assert_fail ("saved.OldPlaceholdersSize == PlaceholderAddresses.size() && \"created a placeholder while doing an abstract emission?\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1179, __extension__ __PRETTY_FUNCTION__))
1179 "created a placeholder while doing an abstract emission?")(static_cast <bool> (saved.OldPlaceholdersSize == PlaceholderAddresses
.size() && "created a placeholder while doing an abstract emission?"
) ? void (0) : __assert_fail ("saved.OldPlaceholdersSize == PlaceholderAddresses.size() && \"created a placeholder while doing an abstract emission?\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1179, __extension__ __PRETTY_FUNCTION__))
;
1180
1181 // No validation necessary for now.
1182 // No cleanup to do for now.
1183 return C;
1184}
1185
1186llvm::Constant *
1187ConstantEmitter::tryEmitAbstractForInitializer(const VarDecl &D) {
1188 auto state = pushAbstract();
1189 auto C = tryEmitPrivateForVarInit(D);
1190 return validateAndPopAbstract(C, state);
1191}
1192
1193llvm::Constant *
1194ConstantEmitter::tryEmitAbstract(const Expr *E, QualType destType) {
1195 auto state = pushAbstract();
1196 auto C = tryEmitPrivate(E, destType);
1197 return validateAndPopAbstract(C, state);
1198}
1199
1200llvm::Constant *
1201ConstantEmitter::tryEmitAbstract(const APValue &value, QualType destType) {
1202 auto state = pushAbstract();
1203 auto C = tryEmitPrivate(value, destType);
1204 return validateAndPopAbstract(C, state);
1205}
1206
1207llvm::Constant *
1208ConstantEmitter::emitAbstract(const Expr *E, QualType destType) {
1209 auto state = pushAbstract();
1210 auto C = tryEmitPrivate(E, destType);
1211 C = validateAndPopAbstract(C, state);
1212 if (!C) {
1213 CGM.Error(E->getExprLoc(),
1214 "internal error: could not emit constant value \"abstractly\"");
1215 C = CGM.EmitNullConstant(destType);
1216 }
1217 return C;
1218}
1219
1220llvm::Constant *
1221ConstantEmitter::emitAbstract(SourceLocation loc, const APValue &value,
1222 QualType destType) {
1223 auto state = pushAbstract();
1224 auto C = tryEmitPrivate(value, destType);
1225 C = validateAndPopAbstract(C, state);
1226 if (!C) {
1227 CGM.Error(loc,
1228 "internal error: could not emit constant value \"abstractly\"");
1229 C = CGM.EmitNullConstant(destType);
1230 }
1231 return C;
1232}
1233
1234llvm::Constant *ConstantEmitter::tryEmitForInitializer(const VarDecl &D) {
1235 initializeNonAbstract(D.getType().getAddressSpace());
1236 return markIfFailed(tryEmitPrivateForVarInit(D));
1237}
1238
1239llvm::Constant *ConstantEmitter::tryEmitForInitializer(const Expr *E,
1240 LangAS destAddrSpace,
1241 QualType destType) {
1242 initializeNonAbstract(destAddrSpace);
1243 return markIfFailed(tryEmitPrivateForMemory(E, destType));
1244}
1245
1246llvm::Constant *ConstantEmitter::emitForInitializer(const APValue &value,
1247 LangAS destAddrSpace,
1248 QualType destType) {
1249 initializeNonAbstract(destAddrSpace);
1250 auto C = tryEmitPrivateForMemory(value, destType);
1251 assert(C && "couldn't emit constant value non-abstractly?")(static_cast <bool> (C && "couldn't emit constant value non-abstractly?"
) ? void (0) : __assert_fail ("C && \"couldn't emit constant value non-abstractly?\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1251, __extension__ __PRETTY_FUNCTION__))
;
1252 return C;
1253}
1254
1255llvm::GlobalValue *ConstantEmitter::getCurrentAddrPrivate() {
1256 assert(!Abstract && "cannot get current address for abstract constant")(static_cast <bool> (!Abstract && "cannot get current address for abstract constant"
) ? void (0) : __assert_fail ("!Abstract && \"cannot get current address for abstract constant\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1256, __extension__ __PRETTY_FUNCTION__))
;
1257
1258
1259
1260 // Make an obviously ill-formed global that should blow up compilation
1261 // if it survives.
1262 auto global = new llvm::GlobalVariable(CGM.getModule(), CGM.Int8Ty, true,
1263 llvm::GlobalValue::PrivateLinkage,
1264 /*init*/ nullptr,
1265 /*name*/ "",
1266 /*before*/ nullptr,
1267 llvm::GlobalVariable::NotThreadLocal,
1268 CGM.getContext().getTargetAddressSpace(DestAddressSpace));
1269
1270 PlaceholderAddresses.push_back(std::make_pair(nullptr, global));
1271
1272 return global;
1273}
1274
1275void ConstantEmitter::registerCurrentAddrPrivate(llvm::Constant *signal,
1276 llvm::GlobalValue *placeholder) {
1277 assert(!PlaceholderAddresses.empty())(static_cast <bool> (!PlaceholderAddresses.empty()) ? void
(0) : __assert_fail ("!PlaceholderAddresses.empty()", "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1277, __extension__ __PRETTY_FUNCTION__))
;
1278 assert(PlaceholderAddresses.back().first == nullptr)(static_cast <bool> (PlaceholderAddresses.back().first ==
nullptr) ? void (0) : __assert_fail ("PlaceholderAddresses.back().first == nullptr"
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1278, __extension__ __PRETTY_FUNCTION__))
;
1279 assert(PlaceholderAddresses.back().second == placeholder)(static_cast <bool> (PlaceholderAddresses.back().second
== placeholder) ? void (0) : __assert_fail ("PlaceholderAddresses.back().second == placeholder"
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1279, __extension__ __PRETTY_FUNCTION__))
;
1280 PlaceholderAddresses.back().first = signal;
1281}
1282
1283namespace {
1284 struct ReplacePlaceholders {
1285 CodeGenModule &CGM;
1286
1287 /// The base address of the global.
1288 llvm::Constant *Base;
1289 llvm::Type *BaseValueTy = nullptr;
1290
1291 /// The placeholder addresses that were registered during emission.
1292 llvm::DenseMap<llvm::Constant*, llvm::GlobalVariable*> PlaceholderAddresses;
1293
1294 /// The locations of the placeholder signals.
1295 llvm::DenseMap<llvm::GlobalVariable*, llvm::Constant*> Locations;
1296
1297 /// The current index stack. We use a simple unsigned stack because
1298 /// we assume that placeholders will be relatively sparse in the
1299 /// initializer, but we cache the index values we find just in case.
1300 llvm::SmallVector<unsigned, 8> Indices;
1301 llvm::SmallVector<llvm::Constant*, 8> IndexValues;
1302
1303 ReplacePlaceholders(CodeGenModule &CGM, llvm::Constant *base,
1304 ArrayRef<std::pair<llvm::Constant*,
1305 llvm::GlobalVariable*>> addresses)
1306 : CGM(CGM), Base(base),
1307 PlaceholderAddresses(addresses.begin(), addresses.end()) {
1308 }
1309
1310 void replaceInInitializer(llvm::Constant *init) {
1311 // Remember the type of the top-most initializer.
1312 BaseValueTy = init->getType();
1313
1314 // Initialize the stack.
1315 Indices.push_back(0);
1316 IndexValues.push_back(nullptr);
1317
1318 // Recurse into the initializer.
1319 findLocations(init);
1320
1321 // Check invariants.
1322 assert(IndexValues.size() == Indices.size() && "mismatch")(static_cast <bool> (IndexValues.size() == Indices.size
() && "mismatch") ? void (0) : __assert_fail ("IndexValues.size() == Indices.size() && \"mismatch\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1322, __extension__ __PRETTY_FUNCTION__))
;
1323 assert(Indices.size() == 1 && "didn't pop all indices")(static_cast <bool> (Indices.size() == 1 && "didn't pop all indices"
) ? void (0) : __assert_fail ("Indices.size() == 1 && \"didn't pop all indices\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1323, __extension__ __PRETTY_FUNCTION__))
;
1324
1325 // Do the replacement; this basically invalidates 'init'.
1326 assert(Locations.size() == PlaceholderAddresses.size() &&(static_cast <bool> (Locations.size() == PlaceholderAddresses
.size() && "missed a placeholder?") ? void (0) : __assert_fail
("Locations.size() == PlaceholderAddresses.size() && \"missed a placeholder?\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1327, __extension__ __PRETTY_FUNCTION__))
1327 "missed a placeholder?")(static_cast <bool> (Locations.size() == PlaceholderAddresses
.size() && "missed a placeholder?") ? void (0) : __assert_fail
("Locations.size() == PlaceholderAddresses.size() && \"missed a placeholder?\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1327, __extension__ __PRETTY_FUNCTION__))
;
1328
1329 // We're iterating over a hashtable, so this would be a source of
1330 // non-determinism in compiler output *except* that we're just
1331 // messing around with llvm::Constant structures, which never itself
1332 // does anything that should be visible in compiler output.
1333 for (auto &entry : Locations) {
1334 assert(entry.first->getParent() == nullptr && "not a placeholder!")(static_cast <bool> (entry.first->getParent() == nullptr
&& "not a placeholder!") ? void (0) : __assert_fail (
"entry.first->getParent() == nullptr && \"not a placeholder!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1334, __extension__ __PRETTY_FUNCTION__))
;
1335 entry.first->replaceAllUsesWith(entry.second);
1336 entry.first->eraseFromParent();
1337 }
1338 }
1339
1340 private:
1341 void findLocations(llvm::Constant *init) {
1342 // Recurse into aggregates.
1343 if (auto agg = dyn_cast<llvm::ConstantAggregate>(init)) {
1344 for (unsigned i = 0, e = agg->getNumOperands(); i != e; ++i) {
1345 Indices.push_back(i);
1346 IndexValues.push_back(nullptr);
1347
1348 findLocations(agg->getOperand(i));
1349
1350 IndexValues.pop_back();
1351 Indices.pop_back();
1352 }
1353 return;
1354 }
1355
1356 // Otherwise, check for registered constants.
1357 while (true) {
1358 auto it = PlaceholderAddresses.find(init);
1359 if (it != PlaceholderAddresses.end()) {
1360 setLocation(it->second);
1361 break;
1362 }
1363
1364 // Look through bitcasts or other expressions.
1365 if (auto expr = dyn_cast<llvm::ConstantExpr>(init)) {
1366 init = expr->getOperand(0);
1367 } else {
1368 break;
1369 }
1370 }
1371 }
1372
1373 void setLocation(llvm::GlobalVariable *placeholder) {
1374 assert(Locations.find(placeholder) == Locations.end() &&(static_cast <bool> (Locations.find(placeholder) == Locations
.end() && "already found location for placeholder!") ?
void (0) : __assert_fail ("Locations.find(placeholder) == Locations.end() && \"already found location for placeholder!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1375, __extension__ __PRETTY_FUNCTION__))
1375 "already found location for placeholder!")(static_cast <bool> (Locations.find(placeholder) == Locations
.end() && "already found location for placeholder!") ?
void (0) : __assert_fail ("Locations.find(placeholder) == Locations.end() && \"already found location for placeholder!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1375, __extension__ __PRETTY_FUNCTION__))
;
1376
1377 // Lazily fill in IndexValues with the values from Indices.
1378 // We do this in reverse because we should always have a strict
1379 // prefix of indices from the start.
1380 assert(Indices.size() == IndexValues.size())(static_cast <bool> (Indices.size() == IndexValues.size
()) ? void (0) : __assert_fail ("Indices.size() == IndexValues.size()"
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1380, __extension__ __PRETTY_FUNCTION__))
;
1381 for (size_t i = Indices.size() - 1; i != size_t(-1); --i) {
1382 if (IndexValues[i]) {
1383#ifndef NDEBUG
1384 for (size_t j = 0; j != i + 1; ++j) {
1385 assert(IndexValues[j] &&(static_cast <bool> (IndexValues[j] && isa<llvm
::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt
>(IndexValues[j])->getZExtValue() == Indices[j]) ? void
(0) : __assert_fail ("IndexValues[j] && isa<llvm::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue() == Indices[j]"
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1388, __extension__ __PRETTY_FUNCTION__))
1386 isa<llvm::ConstantInt>(IndexValues[j]) &&(static_cast <bool> (IndexValues[j] && isa<llvm
::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt
>(IndexValues[j])->getZExtValue() == Indices[j]) ? void
(0) : __assert_fail ("IndexValues[j] && isa<llvm::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue() == Indices[j]"
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1388, __extension__ __PRETTY_FUNCTION__))
1387 cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue()(static_cast <bool> (IndexValues[j] && isa<llvm
::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt
>(IndexValues[j])->getZExtValue() == Indices[j]) ? void
(0) : __assert_fail ("IndexValues[j] && isa<llvm::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue() == Indices[j]"
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1388, __extension__ __PRETTY_FUNCTION__))
1388 == Indices[j])(static_cast <bool> (IndexValues[j] && isa<llvm
::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt
>(IndexValues[j])->getZExtValue() == Indices[j]) ? void
(0) : __assert_fail ("IndexValues[j] && isa<llvm::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue() == Indices[j]"
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1388, __extension__ __PRETTY_FUNCTION__))
;
1389 }
1390#endif
1391 break;
1392 }
1393
1394 IndexValues[i] = llvm::ConstantInt::get(CGM.Int32Ty, Indices[i]);
1395 }
1396
1397 // Form a GEP and then bitcast to the placeholder type so that the
1398 // replacement will succeed.
1399 llvm::Constant *location =
1400 llvm::ConstantExpr::getInBoundsGetElementPtr(BaseValueTy,
1401 Base, IndexValues);
1402 location = llvm::ConstantExpr::getBitCast(location,
1403 placeholder->getType());
1404
1405 Locations.insert({placeholder, location});
1406 }
1407 };
1408}
1409
1410void ConstantEmitter::finalize(llvm::GlobalVariable *global) {
1411 assert(InitializedNonAbstract &&(static_cast <bool> (InitializedNonAbstract && "finalizing emitter that was used for abstract emission?"
) ? void (0) : __assert_fail ("InitializedNonAbstract && \"finalizing emitter that was used for abstract emission?\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1412, __extension__ __PRETTY_FUNCTION__))
1412 "finalizing emitter that was used for abstract emission?")(static_cast <bool> (InitializedNonAbstract && "finalizing emitter that was used for abstract emission?"
) ? void (0) : __assert_fail ("InitializedNonAbstract && \"finalizing emitter that was used for abstract emission?\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1412, __extension__ __PRETTY_FUNCTION__))
;
1413 assert(!Finalized && "finalizing emitter multiple times")(static_cast <bool> (!Finalized && "finalizing emitter multiple times"
) ? void (0) : __assert_fail ("!Finalized && \"finalizing emitter multiple times\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1413, __extension__ __PRETTY_FUNCTION__))
;
1414 assert(global->getInitializer())(static_cast <bool> (global->getInitializer()) ? void
(0) : __assert_fail ("global->getInitializer()", "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1414, __extension__ __PRETTY_FUNCTION__))
;
1415
1416 // Note that we might also be Failed.
1417 Finalized = true;
1418
1419 if (!PlaceholderAddresses.empty()) {
1420 ReplacePlaceholders(CGM, global, PlaceholderAddresses)
1421 .replaceInInitializer(global->getInitializer());
1422 PlaceholderAddresses.clear(); // satisfy
1423 }
1424}
1425
1426ConstantEmitter::~ConstantEmitter() {
1427 assert((!InitializedNonAbstract || Finalized || Failed) &&(static_cast <bool> ((!InitializedNonAbstract || Finalized
|| Failed) && "not finalized after being initialized for non-abstract emission"
) ? void (0) : __assert_fail ("(!InitializedNonAbstract || Finalized || Failed) && \"not finalized after being initialized for non-abstract emission\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1428, __extension__ __PRETTY_FUNCTION__))
1428 "not finalized after being initialized for non-abstract emission")(static_cast <bool> ((!InitializedNonAbstract || Finalized
|| Failed) && "not finalized after being initialized for non-abstract emission"
) ? void (0) : __assert_fail ("(!InitializedNonAbstract || Finalized || Failed) && \"not finalized after being initialized for non-abstract emission\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1428, __extension__ __PRETTY_FUNCTION__))
;
1429 assert(PlaceholderAddresses.empty() && "unhandled placeholders")(static_cast <bool> (PlaceholderAddresses.empty() &&
"unhandled placeholders") ? void (0) : __assert_fail ("PlaceholderAddresses.empty() && \"unhandled placeholders\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1429, __extension__ __PRETTY_FUNCTION__))
;
1430}
1431
1432static QualType getNonMemoryType(CodeGenModule &CGM, QualType type) {
1433 if (auto AT = type->getAs<AtomicType>()) {
1434 return CGM.getContext().getQualifiedType(AT->getValueType(),
1435 type.getQualifiers());
1436 }
1437 return type;
1438}
1439
1440llvm::Constant *ConstantEmitter::tryEmitPrivateForVarInit(const VarDecl &D) {
1441 // Make a quick check if variable can be default NULL initialized
1442 // and avoid going through rest of code which may do, for c++11,
1443 // initialization of memory to all NULLs.
1444 if (!D.hasLocalStorage()) {
1445 QualType Ty = CGM.getContext().getBaseElementType(D.getType());
1446 if (Ty->isRecordType())
1447 if (const CXXConstructExpr *E =
1448 dyn_cast_or_null<CXXConstructExpr>(D.getInit())) {
1449 const CXXConstructorDecl *CD = E->getConstructor();
1450 if (CD->isTrivial() && CD->isDefaultConstructor())
1451 return CGM.EmitNullConstant(D.getType());
1452 }
1453 }
1454
1455 QualType destType = D.getType();
1456
1457 // Try to emit the initializer. Note that this can allow some things that
1458 // are not allowed by tryEmitPrivateForMemory alone.
1459 if (auto value = D.evaluateValue()) {
1460 return tryEmitPrivateForMemory(*value, destType);
1461 }
1462
1463 // FIXME: Implement C++11 [basic.start.init]p2: if the initializer of a
1464 // reference is a constant expression, and the reference binds to a temporary,
1465 // then constant initialization is performed. ConstExprEmitter will
1466 // incorrectly emit a prvalue constant in this case, and the calling code
1467 // interprets that as the (pointer) value of the reference, rather than the
1468 // desired value of the referee.
1469 if (destType->isReferenceType())
1470 return nullptr;
1471
1472 const Expr *E = D.getInit();
1473 assert(E && "No initializer to emit")(static_cast <bool> (E && "No initializer to emit"
) ? void (0) : __assert_fail ("E && \"No initializer to emit\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1473, __extension__ __PRETTY_FUNCTION__))
;
1474
1475 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1476 auto C =
1477 ConstExprEmitter(*this).Visit(const_cast<Expr*>(E), nonMemoryDestType);
1478 return (C ? emitForMemory(C, destType) : nullptr);
1479}
1480
1481llvm::Constant *
1482ConstantEmitter::tryEmitAbstractForMemory(const Expr *E, QualType destType) {
1483 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1484 auto C = tryEmitAbstract(E, nonMemoryDestType);
1485 return (C ? emitForMemory(C, destType) : nullptr);
1486}
1487
1488llvm::Constant *
1489ConstantEmitter::tryEmitAbstractForMemory(const APValue &value,
1490 QualType destType) {
1491 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1492 auto C = tryEmitAbstract(value, nonMemoryDestType);
1493 return (C ? emitForMemory(C, destType) : nullptr);
1494}
1495
1496llvm::Constant *ConstantEmitter::tryEmitPrivateForMemory(const Expr *E,
1497 QualType destType) {
1498 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1499 llvm::Constant *C = tryEmitPrivate(E, nonMemoryDestType);
1500 return (C ? emitForMemory(C, destType) : nullptr);
1501}
1502
1503llvm::Constant *ConstantEmitter::tryEmitPrivateForMemory(const APValue &value,
1504 QualType destType) {
1505 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1506 auto C = tryEmitPrivate(value, nonMemoryDestType);
1507 return (C ? emitForMemory(C, destType) : nullptr);
1508}
1509
1510llvm::Constant *ConstantEmitter::emitForMemory(CodeGenModule &CGM,
1511 llvm::Constant *C,
1512 QualType destType) {
1513 // For an _Atomic-qualified constant, we may need to add tail padding.
1514 if (auto AT = destType->getAs<AtomicType>()) {
1515 QualType destValueType = AT->getValueType();
1516 C = emitForMemory(CGM, C, destValueType);
1517
1518 uint64_t innerSize = CGM.getContext().getTypeSize(destValueType);
1519 uint64_t outerSize = CGM.getContext().getTypeSize(destType);
1520 if (innerSize == outerSize)
1521 return C;
1522
1523 assert(innerSize < outerSize && "emitted over-large constant for atomic")(static_cast <bool> (innerSize < outerSize &&
"emitted over-large constant for atomic") ? void (0) : __assert_fail
("innerSize < outerSize && \"emitted over-large constant for atomic\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1523, __extension__ __PRETTY_FUNCTION__))
;
1524 llvm::Constant *elts[] = {
1525 C,
1526 llvm::ConstantAggregateZero::get(
1527 llvm::ArrayType::get(CGM.Int8Ty, (outerSize - innerSize) / 8))
1528 };
1529 return llvm::ConstantStruct::getAnon(elts);
1530 }
1531
1532 // Zero-extend bool.
1533 if (C->getType()->isIntegerTy(1)) {
1534 llvm::Type *boolTy = CGM.getTypes().ConvertTypeForMem(destType);
1535 return llvm::ConstantExpr::getZExt(C, boolTy);
1536 }
1537
1538 return C;
1539}
1540
1541llvm::Constant *ConstantEmitter::tryEmitPrivate(const Expr *E,
1542 QualType destType) {
1543 Expr::EvalResult Result;
1544
1545 bool Success = false;
1546
1547 if (destType->isReferenceType())
1548 Success = E->EvaluateAsLValue(Result, CGM.getContext());
1549 else
1550 Success = E->EvaluateAsRValue(Result, CGM.getContext());
1551
1552 llvm::Constant *C;
1553 if (Success && !Result.HasSideEffects)
1554 C = tryEmitPrivate(Result.Val, destType);
1555 else
1556 C = ConstExprEmitter(*this).Visit(const_cast<Expr*>(E), destType);
1557
1558 return C;
1559}
1560
1561llvm::Constant *CodeGenModule::getNullPointer(llvm::PointerType *T, QualType QT) {
1562 return getTargetCodeGenInfo().getNullPointer(*this, T, QT);
1563}
1564
1565namespace {
1566/// A struct which can be used to peephole certain kinds of finalization
1567/// that normally happen during l-value emission.
1568struct ConstantLValue {
1569 llvm::Constant *Value;
1570 bool HasOffsetApplied;
1571
1572 /*implicit*/ ConstantLValue(llvm::Constant *value,
1573 bool hasOffsetApplied = false)
1574 : Value(value), HasOffsetApplied(false) {}
1575
1576 /*implicit*/ ConstantLValue(ConstantAddress address)
1577 : ConstantLValue(address.getPointer()) {}
1578};
1579
1580/// A helper class for emitting constant l-values.
1581class ConstantLValueEmitter : public ConstStmtVisitor<ConstantLValueEmitter,
1582 ConstantLValue> {
1583 CodeGenModule &CGM;
1584 ConstantEmitter &Emitter;
1585 const APValue &Value;
1586 QualType DestType;
1587
1588 // Befriend StmtVisitorBase so that we don't have to expose Visit*.
1589 friend StmtVisitorBase;
1590
1591public:
1592 ConstantLValueEmitter(ConstantEmitter &emitter, const APValue &value,
1593 QualType destType)
1594 : CGM(emitter.CGM), Emitter(emitter), Value(value), DestType(destType) {}
1595
1596 llvm::Constant *tryEmit();
1597
1598private:
1599 llvm::Constant *tryEmitAbsolute(llvm::Type *destTy);
1600 ConstantLValue tryEmitBase(const APValue::LValueBase &base);
1601
1602 ConstantLValue VisitStmt(const Stmt *S) { return nullptr; }
1603 ConstantLValue VisitCompoundLiteralExpr(const CompoundLiteralExpr *E);
1604 ConstantLValue VisitStringLiteral(const StringLiteral *E);
1605 ConstantLValue VisitObjCEncodeExpr(const ObjCEncodeExpr *E);
1606 ConstantLValue VisitObjCStringLiteral(const ObjCStringLiteral *E);
1607 ConstantLValue VisitPredefinedExpr(const PredefinedExpr *E);
1608 ConstantLValue VisitAddrLabelExpr(const AddrLabelExpr *E);
1609 ConstantLValue VisitCallExpr(const CallExpr *E);
1610 ConstantLValue VisitBlockExpr(const BlockExpr *E);
1611 ConstantLValue VisitCXXTypeidExpr(const CXXTypeidExpr *E);
1612 ConstantLValue VisitCXXUuidofExpr(const CXXUuidofExpr *E);
1613 ConstantLValue VisitMaterializeTemporaryExpr(
1614 const MaterializeTemporaryExpr *E);
1615
1616 bool hasNonZeroOffset() const {
1617 return !Value.getLValueOffset().isZero();
1618 }
1619
1620 /// Return the value offset.
1621 llvm::Constant *getOffset() {
1622 return llvm::ConstantInt::get(CGM.Int64Ty,
1623 Value.getLValueOffset().getQuantity());
1624 }
1625
1626 /// Apply the value offset to the given constant.
1627 llvm::Constant *applyOffset(llvm::Constant *C) {
1628 if (!hasNonZeroOffset())
1629 return C;
1630
1631 llvm::Type *origPtrTy = C->getType();
1632 unsigned AS = origPtrTy->getPointerAddressSpace();
1633 llvm::Type *charPtrTy = CGM.Int8Ty->getPointerTo(AS);
1634 C = llvm::ConstantExpr::getBitCast(C, charPtrTy);
1635 C = llvm::ConstantExpr::getGetElementPtr(CGM.Int8Ty, C, getOffset());
1636 C = llvm::ConstantExpr::getPointerCast(C, origPtrTy);
1637 return C;
1638 }
1639};
1640
1641}
1642
1643llvm::Constant *ConstantLValueEmitter::tryEmit() {
1644 const APValue::LValueBase &base = Value.getLValueBase();
1645
1646 // Certain special array initializers are represented in APValue
1647 // as l-values referring to the base expression which generates the
1648 // array. This happens with e.g. string literals. These should
1649 // probably just get their own representation kind in APValue.
1650 if (DestType->isArrayType()) {
1651 assert(!hasNonZeroOffset() && "offset on array initializer")(static_cast <bool> (!hasNonZeroOffset() && "offset on array initializer"
) ? void (0) : __assert_fail ("!hasNonZeroOffset() && \"offset on array initializer\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1651, __extension__ __PRETTY_FUNCTION__))
;
1652 auto expr = const_cast<Expr*>(base.get<const Expr*>());
1653 return ConstExprEmitter(Emitter).Visit(expr, DestType);
1654 }
1655
1656 // Otherwise, the destination type should be a pointer or reference
1657 // type, but it might also be a cast thereof.
1658 //
1659 // FIXME: the chain of casts required should be reflected in the APValue.
1660 // We need this in order to correctly handle things like a ptrtoint of a
1661 // non-zero null pointer and addrspace casts that aren't trivially
1662 // represented in LLVM IR.
1663 auto destTy = CGM.getTypes().ConvertTypeForMem(DestType);
1664 assert(isa<llvm::IntegerType>(destTy) || isa<llvm::PointerType>(destTy))(static_cast <bool> (isa<llvm::IntegerType>(destTy
) || isa<llvm::PointerType>(destTy)) ? void (0) : __assert_fail
("isa<llvm::IntegerType>(destTy) || isa<llvm::PointerType>(destTy)"
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1664, __extension__ __PRETTY_FUNCTION__))
;
1665
1666 // If there's no base at all, this is a null or absolute pointer,
1667 // possibly cast back to an integer type.
1668 if (!base) {
1669 return tryEmitAbsolute(destTy);
1670 }
1671
1672 // Otherwise, try to emit the base.
1673 ConstantLValue result = tryEmitBase(base);
1674
1675 // If that failed, we're done.
1676 llvm::Constant *value = result.Value;
1677 if (!value) return nullptr;
1678
1679 // Apply the offset if necessary and not already done.
1680 if (!result.HasOffsetApplied) {
1681 value = applyOffset(value);
1682 }
1683
1684 // Convert to the appropriate type; this could be an lvalue for
1685 // an integer. FIXME: performAddrSpaceCast
1686 if (isa<llvm::PointerType>(destTy))
1687 return llvm::ConstantExpr::getPointerCast(value, destTy);
1688
1689 return llvm::ConstantExpr::getPtrToInt(value, destTy);
1690}
1691
1692/// Try to emit an absolute l-value, such as a null pointer or an integer
1693/// bitcast to pointer type.
1694llvm::Constant *
1695ConstantLValueEmitter::tryEmitAbsolute(llvm::Type *destTy) {
1696 auto offset = getOffset();
1697
1698 // If we're producing a pointer, this is easy.
1699 if (auto destPtrTy = cast<llvm::PointerType>(destTy)) {
1700 if (Value.isNullPointer()) {
1701 // FIXME: integer offsets from non-zero null pointers.
1702 return CGM.getNullPointer(destPtrTy, DestType);
1703 }
1704
1705 // Convert the integer to a pointer-sized integer before converting it
1706 // to a pointer.
1707 // FIXME: signedness depends on the original integer type.
1708 auto intptrTy = CGM.getDataLayout().getIntPtrType(destPtrTy);
1709 llvm::Constant *C = offset;
1710 C = llvm::ConstantExpr::getIntegerCast(getOffset(), intptrTy,
1711 /*isSigned*/ false);
1712 C = llvm::ConstantExpr::getIntToPtr(C, destPtrTy);
1713 return C;
1714 }
1715
1716 // Otherwise, we're basically returning an integer constant.
1717
1718 // FIXME: this does the wrong thing with ptrtoint of a null pointer,
1719 // but since we don't know the original pointer type, there's not much
1720 // we can do about it.
1721
1722 auto C = getOffset();
1723 C = llvm::ConstantExpr::getIntegerCast(C, destTy, /*isSigned*/ false);
1724 return C;
1725}
1726
1727ConstantLValue
1728ConstantLValueEmitter::tryEmitBase(const APValue::LValueBase &base) {
1729 // Handle values.
1730 if (const ValueDecl *D = base.dyn_cast<const ValueDecl*>()) {
1731 if (D->hasAttr<WeakRefAttr>())
1732 return CGM.GetWeakRefReference(D).getPointer();
1733
1734 if (auto FD = dyn_cast<FunctionDecl>(D))
1735 return CGM.GetAddrOfFunction(FD);
1736
1737 if (auto VD = dyn_cast<VarDecl>(D)) {
1738 // We can never refer to a variable with local storage.
1739 if (!VD->hasLocalStorage()) {
1740 if (VD->isFileVarDecl() || VD->hasExternalStorage())
1741 return CGM.GetAddrOfGlobalVar(VD);
1742
1743 if (VD->isLocalVarDecl()) {
1744 return CGM.getOrCreateStaticVarDecl(
1745 *VD, CGM.getLLVMLinkageVarDefinition(VD, /*isConstant=*/false));
1746 }
1747 }
1748 }
1749
1750 return nullptr;
1751 }
1752
1753 // Otherwise, it must be an expression.
1754 return Visit(base.get<const Expr*>());
1755}
1756
1757ConstantLValue
1758ConstantLValueEmitter::VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
1759 return tryEmitGlobalCompoundLiteral(CGM, Emitter.CGF, E);
1760}
1761
1762ConstantLValue
1763ConstantLValueEmitter::VisitStringLiteral(const StringLiteral *E) {
1764 return CGM.GetAddrOfConstantStringFromLiteral(E);
1765}
1766
1767ConstantLValue
1768ConstantLValueEmitter::VisitObjCEncodeExpr(const ObjCEncodeExpr *E) {
1769 return CGM.GetAddrOfConstantStringFromObjCEncode(E);
1770}
1771
1772ConstantLValue
1773ConstantLValueEmitter::VisitObjCStringLiteral(const ObjCStringLiteral *E) {
1774 auto C = CGM.getObjCRuntime().GenerateConstantString(E->getString());
1775 return C.getElementBitCast(CGM.getTypes().ConvertTypeForMem(E->getType()));
1776}
1777
1778ConstantLValue
1779ConstantLValueEmitter::VisitPredefinedExpr(const PredefinedExpr *E) {
1780 if (auto CGF = Emitter.CGF) {
1781 LValue Res = CGF->EmitPredefinedLValue(E);
1782 return cast<ConstantAddress>(Res.getAddress());
1783 }
1784
1785 auto kind = E->getIdentType();
1786 if (kind == PredefinedExpr::PrettyFunction) {
1787 return CGM.GetAddrOfConstantCString("top level", ".tmp");
1788 }
1789
1790 return CGM.GetAddrOfConstantCString("", ".tmp");
1791}
1792
1793ConstantLValue
1794ConstantLValueEmitter::VisitAddrLabelExpr(const AddrLabelExpr *E) {
1795 assert(Emitter.CGF && "Invalid address of label expression outside function")(static_cast <bool> (Emitter.CGF && "Invalid address of label expression outside function"
) ? void (0) : __assert_fail ("Emitter.CGF && \"Invalid address of label expression outside function\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1795, __extension__ __PRETTY_FUNCTION__))
;
1796 llvm::Constant *Ptr = Emitter.CGF->GetAddrOfLabel(E->getLabel());
1797 Ptr = llvm::ConstantExpr::getBitCast(Ptr,
1798 CGM.getTypes().ConvertType(E->getType()));
1799 return Ptr;
1800}
1801
1802ConstantLValue
1803ConstantLValueEmitter::VisitCallExpr(const CallExpr *E) {
1804 unsigned builtin = E->getBuiltinCallee();
1805 if (builtin != Builtin::BI__builtin___CFStringMakeConstantString &&
1806 builtin != Builtin::BI__builtin___NSStringMakeConstantString)
1807 return nullptr;
1808
1809 auto literal = cast<StringLiteral>(E->getArg(0)->IgnoreParenCasts());
1810 if (builtin == Builtin::BI__builtin___NSStringMakeConstantString) {
1811 return CGM.getObjCRuntime().GenerateConstantString(literal);
1812 } else {
1813 // FIXME: need to deal with UCN conversion issues.
1814 return CGM.GetAddrOfConstantCFString(literal);
1815 }
1816}
1817
1818ConstantLValue
1819ConstantLValueEmitter::VisitBlockExpr(const BlockExpr *E) {
1820 StringRef functionName;
1821 if (auto CGF = Emitter.CGF)
1822 functionName = CGF->CurFn->getName();
1823 else
1824 functionName = "global";
1825
1826 return CGM.GetAddrOfGlobalBlock(E, functionName);
1827}
1828
1829ConstantLValue
1830ConstantLValueEmitter::VisitCXXTypeidExpr(const CXXTypeidExpr *E) {
1831 QualType T;
1832 if (E->isTypeOperand())
1833 T = E->getTypeOperand(CGM.getContext());
1834 else
1835 T = E->getExprOperand()->getType();
1836 return CGM.GetAddrOfRTTIDescriptor(T);
1837}
1838
1839ConstantLValue
1840ConstantLValueEmitter::VisitCXXUuidofExpr(const CXXUuidofExpr *E) {
1841 return CGM.GetAddrOfUuidDescriptor(E);
1842}
1843
1844ConstantLValue
1845ConstantLValueEmitter::VisitMaterializeTemporaryExpr(
1846 const MaterializeTemporaryExpr *E) {
1847 assert(E->getStorageDuration() == SD_Static)(static_cast <bool> (E->getStorageDuration() == SD_Static
) ? void (0) : __assert_fail ("E->getStorageDuration() == SD_Static"
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1847, __extension__ __PRETTY_FUNCTION__))
;
1848 SmallVector<const Expr *, 2> CommaLHSs;
1849 SmallVector<SubobjectAdjustment, 2> Adjustments;
1850 const Expr *Inner = E->GetTemporaryExpr()
1851 ->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
1852 return CGM.GetAddrOfGlobalTemporary(E, Inner);
1853}
1854
1855llvm::Constant *ConstantEmitter::tryEmitPrivate(const APValue &Value,
1856 QualType DestType) {
1857 switch (Value.getKind()) {
1858 case APValue::Uninitialized:
1859 llvm_unreachable("Constant expressions should be initialized.")::llvm::llvm_unreachable_internal("Constant expressions should be initialized."
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1859)
;
1860 case APValue::LValue:
1861 return ConstantLValueEmitter(*this, Value, DestType).tryEmit();
1862 case APValue::Int:
1863 return llvm::ConstantInt::get(CGM.getLLVMContext(), Value.getInt());
1864 case APValue::ComplexInt: {
1865 llvm::Constant *Complex[2];
1866
1867 Complex[0] = llvm::ConstantInt::get(CGM.getLLVMContext(),
1868 Value.getComplexIntReal());
1869 Complex[1] = llvm::ConstantInt::get(CGM.getLLVMContext(),
1870 Value.getComplexIntImag());
1871
1872 // FIXME: the target may want to specify that this is packed.
1873 llvm::StructType *STy =
1874 llvm::StructType::get(Complex[0]->getType(), Complex[1]->getType());
1875 return llvm::ConstantStruct::get(STy, Complex);
1876 }
1877 case APValue::Float: {
1878 const llvm::APFloat &Init = Value.getFloat();
1879 if (&Init.getSemantics() == &llvm::APFloat::IEEEhalf() &&
1880 !CGM.getContext().getLangOpts().NativeHalfType &&
1881 CGM.getContext().getTargetInfo().useFP16ConversionIntrinsics())
1882 return llvm::ConstantInt::get(CGM.getLLVMContext(),
1883 Init.bitcastToAPInt());
1884 else
1885 return llvm::ConstantFP::get(CGM.getLLVMContext(), Init);
1886 }
1887 case APValue::ComplexFloat: {
1888 llvm::Constant *Complex[2];
1889
1890 Complex[0] = llvm::ConstantFP::get(CGM.getLLVMContext(),
1891 Value.getComplexFloatReal());
1892 Complex[1] = llvm::ConstantFP::get(CGM.getLLVMContext(),
1893 Value.getComplexFloatImag());
1894
1895 // FIXME: the target may want to specify that this is packed.
1896 llvm::StructType *STy =
1897 llvm::StructType::get(Complex[0]->getType(), Complex[1]->getType());
1898 return llvm::ConstantStruct::get(STy, Complex);
1899 }
1900 case APValue::Vector: {
1901 unsigned NumElts = Value.getVectorLength();
1902 SmallVector<llvm::Constant *, 4> Inits(NumElts);
1903
1904 for (unsigned I = 0; I != NumElts; ++I) {
1905 const APValue &Elt = Value.getVectorElt(I);
1906 if (Elt.isInt())
1907 Inits[I] = llvm::ConstantInt::get(CGM.getLLVMContext(), Elt.getInt());
1908 else if (Elt.isFloat())
1909 Inits[I] = llvm::ConstantFP::get(CGM.getLLVMContext(), Elt.getFloat());
1910 else
1911 llvm_unreachable("unsupported vector element type")::llvm::llvm_unreachable_internal("unsupported vector element type"
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1911)
;
1912 }
1913 return llvm::ConstantVector::get(Inits);
1914 }
1915 case APValue::AddrLabelDiff: {
1916 const AddrLabelExpr *LHSExpr = Value.getAddrLabelDiffLHS();
1917 const AddrLabelExpr *RHSExpr = Value.getAddrLabelDiffRHS();
1918 llvm::Constant *LHS = tryEmitPrivate(LHSExpr, LHSExpr->getType());
1919 llvm::Constant *RHS = tryEmitPrivate(RHSExpr, RHSExpr->getType());
1920 if (!LHS || !RHS) return nullptr;
1921
1922 // Compute difference
1923 llvm::Type *ResultType = CGM.getTypes().ConvertType(DestType);
1924 LHS = llvm::ConstantExpr::getPtrToInt(LHS, CGM.IntPtrTy);
1925 RHS = llvm::ConstantExpr::getPtrToInt(RHS, CGM.IntPtrTy);
1926 llvm::Constant *AddrLabelDiff = llvm::ConstantExpr::getSub(LHS, RHS);
1927
1928 // LLVM is a bit sensitive about the exact format of the
1929 // address-of-label difference; make sure to truncate after
1930 // the subtraction.
1931 return llvm::ConstantExpr::getTruncOrBitCast(AddrLabelDiff, ResultType);
1932 }
1933 case APValue::Struct:
1934 case APValue::Union:
1935 return ConstStructBuilder::BuildStruct(*this, Value, DestType);
1936 case APValue::Array: {
1937 const ConstantArrayType *CAT =
1938 CGM.getContext().getAsConstantArrayType(DestType);
1939 unsigned NumElements = Value.getArraySize();
1940 unsigned NumInitElts = Value.getArrayInitializedElts();
1941
1942 // Emit array filler, if there is one.
1943 llvm::Constant *Filler = nullptr;
1944 if (Value.hasArrayFiller()) {
1945 Filler = tryEmitAbstractForMemory(Value.getArrayFiller(),
1946 CAT->getElementType());
1947 if (!Filler)
1948 return nullptr;
1949 }
1950
1951 // Emit initializer elements.
1952 SmallVector<llvm::Constant*, 16> Elts;
1953 if (Filler && Filler->isNullValue())
1954 Elts.reserve(NumInitElts + 1);
1955 else
1956 Elts.reserve(NumElements);
1957
1958 llvm::Type *CommonElementType = nullptr;
1959 for (unsigned I = 0; I < NumInitElts; ++I) {
1960 llvm::Constant *C = tryEmitPrivateForMemory(
1961 Value.getArrayInitializedElt(I), CAT->getElementType());
1962 if (!C) return nullptr;
1963
1964 if (I == 0)
1965 CommonElementType = C->getType();
1966 else if (C->getType() != CommonElementType)
1967 CommonElementType = nullptr;
1968 Elts.push_back(C);
1969 }
1970
1971 return EmitArrayConstant(CGM, CAT, CommonElementType, NumElements, Elts,
1972 Filler);
1973 }
1974 case APValue::MemberPointer:
1975 return CGM.getCXXABI().EmitMemberPointer(Value, DestType);
1976 }
1977 llvm_unreachable("Unknown APValue kind")::llvm::llvm_unreachable_internal("Unknown APValue kind", "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1977)
;
1978}
1979
1980llvm::GlobalVariable *CodeGenModule::getAddrOfConstantCompoundLiteralIfEmitted(
1981 const CompoundLiteralExpr *E) {
1982 return EmittedCompoundLiterals.lookup(E);
1983}
1984
1985void CodeGenModule::setAddrOfConstantCompoundLiteral(
1986 const CompoundLiteralExpr *CLE, llvm::GlobalVariable *GV) {
1987 bool Ok = EmittedCompoundLiterals.insert(std::make_pair(CLE, GV)).second;
1988 (void)Ok;
1989 assert(Ok && "CLE has already been emitted!")(static_cast <bool> (Ok && "CLE has already been emitted!"
) ? void (0) : __assert_fail ("Ok && \"CLE has already been emitted!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1989, __extension__ __PRETTY_FUNCTION__))
;
1990}
1991
1992ConstantAddress
1993CodeGenModule::GetAddrOfConstantCompoundLiteral(const CompoundLiteralExpr *E) {
1994 assert(E->isFileScope() && "not a file-scope compound literal expr")(static_cast <bool> (E->isFileScope() && "not a file-scope compound literal expr"
) ? void (0) : __assert_fail ("E->isFileScope() && \"not a file-scope compound literal expr\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 1994, __extension__ __PRETTY_FUNCTION__))
;
1995 return tryEmitGlobalCompoundLiteral(*this, nullptr, E);
1996}
1997
1998llvm::Constant *
1999CodeGenModule::getMemberPointerConstant(const UnaryOperator *uo) {
2000 // Member pointer constants always have a very particular form.
2001 const MemberPointerType *type = cast<MemberPointerType>(uo->getType());
2002 const ValueDecl *decl = cast<DeclRefExpr>(uo->getSubExpr())->getDecl();
2003
2004 // A member function pointer.
2005 if (const CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(decl))
2006 return getCXXABI().EmitMemberFunctionPointer(method);
2007
2008 // Otherwise, a member data pointer.
2009 uint64_t fieldOffset = getContext().getFieldOffset(decl);
2010 CharUnits chars = getContext().toCharUnitsFromBits((int64_t) fieldOffset);
2011 return getCXXABI().EmitMemberDataPointer(type, chars);
2012}
2013
2014static llvm::Constant *EmitNullConstantForBase(CodeGenModule &CGM,
2015 llvm::Type *baseType,
2016 const CXXRecordDecl *base);
2017
2018static llvm::Constant *EmitNullConstant(CodeGenModule &CGM,
2019 const RecordDecl *record,
2020 bool asCompleteObject) {
2021 const CGRecordLayout &layout = CGM.getTypes().getCGRecordLayout(record);
2022 llvm::StructType *structure =
2023 (asCompleteObject ? layout.getLLVMType()
2024 : layout.getBaseSubobjectLLVMType());
2025
2026 unsigned numElements = structure->getNumElements();
2027 std::vector<llvm::Constant *> elements(numElements);
2028
2029 auto CXXR = dyn_cast<CXXRecordDecl>(record);
2030 // Fill in all the bases.
2031 if (CXXR) {
2032 for (const auto &I : CXXR->bases()) {
2033 if (I.isVirtual()) {
2034 // Ignore virtual bases; if we're laying out for a complete
2035 // object, we'll lay these out later.
2036 continue;
2037 }
2038
2039 const CXXRecordDecl *base =
2040 cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
2041
2042 // Ignore empty bases.
2043 if (base->isEmpty() ||
2044 CGM.getContext().getASTRecordLayout(base).getNonVirtualSize()
2045 .isZero())
2046 continue;
2047
2048 unsigned fieldIndex = layout.getNonVirtualBaseLLVMFieldNo(base);
2049 llvm::Type *baseType = structure->getElementType(fieldIndex);
2050 elements[fieldIndex] = EmitNullConstantForBase(CGM, baseType, base);
2051 }
2052 }
2053
2054 // Fill in all the fields.
2055 for (const auto *Field : record->fields()) {
2056 // Fill in non-bitfields. (Bitfields always use a zero pattern, which we
2057 // will fill in later.)
2058 if (!Field->isBitField()) {
2059 unsigned fieldIndex = layout.getLLVMFieldNo(Field);
2060 elements[fieldIndex] = CGM.EmitNullConstant(Field->getType());
2061 }
2062
2063 // For unions, stop after the first named field.
2064 if (record->isUnion()) {
2065 if (Field->getIdentifier())
2066 break;
2067 if (const auto *FieldRD = Field->getType()->getAsRecordDecl())
2068 if (FieldRD->findFirstNamedDataMember())
2069 break;
2070 }
2071 }
2072
2073 // Fill in the virtual bases, if we're working with the complete object.
2074 if (CXXR && asCompleteObject) {
2075 for (const auto &I : CXXR->vbases()) {
2076 const CXXRecordDecl *base =
2077 cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
2078
2079 // Ignore empty bases.
2080 if (base->isEmpty())
2081 continue;
2082
2083 unsigned fieldIndex = layout.getVirtualBaseIndex(base);
2084
2085 // We might have already laid this field out.
2086 if (elements[fieldIndex]) continue;
2087
2088 llvm::Type *baseType = structure->getElementType(fieldIndex);
2089 elements[fieldIndex] = EmitNullConstantForBase(CGM, baseType, base);
2090 }
2091 }
2092
2093 // Now go through all other fields and zero them out.
2094 for (unsigned i = 0; i != numElements; ++i) {
2095 if (!elements[i])
2096 elements[i] = llvm::Constant::getNullValue(structure->getElementType(i));
2097 }
2098
2099 return llvm::ConstantStruct::get(structure, elements);
2100}
2101
2102/// Emit the null constant for a base subobject.
2103static llvm::Constant *EmitNullConstantForBase(CodeGenModule &CGM,
2104 llvm::Type *baseType,
2105 const CXXRecordDecl *base) {
2106 const CGRecordLayout &baseLayout = CGM.getTypes().getCGRecordLayout(base);
2107
2108 // Just zero out bases that don't have any pointer to data members.
2109 if (baseLayout.isZeroInitializableAsBase())
2110 return llvm::Constant::getNullValue(baseType);
2111
2112 // Otherwise, we can just use its null constant.
2113 return EmitNullConstant(CGM, base, /*asCompleteObject=*/false);
2114}
2115
2116llvm::Constant *ConstantEmitter::emitNullForMemory(CodeGenModule &CGM,
2117 QualType T) {
2118 return emitForMemory(CGM, CGM.EmitNullConstant(T), T);
2119}
2120
2121llvm::Constant *CodeGenModule::EmitNullConstant(QualType T) {
2122 if (T->getAs<PointerType>())
2123 return getNullPointer(
2124 cast<llvm::PointerType>(getTypes().ConvertTypeForMem(T)), T);
2125
2126 if (getTypes().isZeroInitializable(T))
2127 return llvm::Constant::getNullValue(getTypes().ConvertTypeForMem(T));
2128
2129 if (const ConstantArrayType *CAT = Context.getAsConstantArrayType(T)) {
2130 llvm::ArrayType *ATy =
2131 cast<llvm::ArrayType>(getTypes().ConvertTypeForMem(T));
2132
2133 QualType ElementTy = CAT->getElementType();
2134
2135 llvm::Constant *Element =
2136 ConstantEmitter::emitNullForMemory(*this, ElementTy);
2137 unsigned NumElements = CAT->getSize().getZExtValue();
2138 SmallVector<llvm::Constant *, 8> Array(NumElements, Element);
2139 return llvm::ConstantArray::get(ATy, Array);
2140 }
2141
2142 if (const RecordType *RT = T->getAs<RecordType>())
2143 return ::EmitNullConstant(*this, RT->getDecl(), /*complete object*/ true);
2144
2145 assert(T->isMemberDataPointerType() &&(static_cast <bool> (T->isMemberDataPointerType() &&
"Should only see pointers to data members here!") ? void (0)
: __assert_fail ("T->isMemberDataPointerType() && \"Should only see pointers to data members here!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 2146, __extension__ __PRETTY_FUNCTION__))
2146 "Should only see pointers to data members here!")(static_cast <bool> (T->isMemberDataPointerType() &&
"Should only see pointers to data members here!") ? void (0)
: __assert_fail ("T->isMemberDataPointerType() && \"Should only see pointers to data members here!\""
, "/build/llvm-toolchain-snapshot-7~svn338205/tools/clang/lib/CodeGen/CGExprConstant.cpp"
, 2146, __extension__ __PRETTY_FUNCTION__))
;
2147
2148 return getCXXABI().EmitNullMemberPointer(T->castAs<MemberPointerType>());
2149}
2150
2151llvm::Constant *
2152CodeGenModule::EmitNullConstantForBase(const CXXRecordDecl *Record) {
2153 return ::EmitNullConstant(*this, Record, false);
2154}