Bug Summary

File:clang/lib/CodeGen/CGExprConstant.cpp
Warning:line 970, column 9
Called C++ object pointer is null

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -disable-llvm-verifier -discard-value-names -main-file-name CGExprConstant.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -fhalf-no-semantic-interposition -mframe-pointer=none -relaxed-aliasing -fmath-errno -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/build-llvm/tools/clang/lib/CodeGen -resource-dir /usr/lib/llvm-13/lib/clang/13.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/build-llvm/tools/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/include -I /build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/build-llvm/include -I /build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/llvm/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-13/lib/clang/13.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/build-llvm/tools/clang/lib/CodeGen -fdebug-prefix-map=/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c=. -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2021-03-08-182450-10039-1 -x c++ /build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp
1//===--- CGExprConstant.cpp - Emit LLVM Code from Constant Expressions ----===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// This contains code to emit Constant Expr nodes as LLVM code.
10//
11//===----------------------------------------------------------------------===//
12
13#include "CGCXXABI.h"
14#include "CGObjCRuntime.h"
15#include "CGRecordLayout.h"
16#include "CodeGenFunction.h"
17#include "CodeGenModule.h"
18#include "ConstantEmitter.h"
19#include "TargetInfo.h"
20#include "clang/AST/APValue.h"
21#include "clang/AST/ASTContext.h"
22#include "clang/AST/Attr.h"
23#include "clang/AST/RecordLayout.h"
24#include "clang/AST/StmtVisitor.h"
25#include "clang/Basic/Builtins.h"
26#include "llvm/ADT/STLExtras.h"
27#include "llvm/ADT/Sequence.h"
28#include "llvm/IR/Constants.h"
29#include "llvm/IR/DataLayout.h"
30#include "llvm/IR/Function.h"
31#include "llvm/IR/GlobalVariable.h"
32using namespace clang;
33using namespace CodeGen;
34
35//===----------------------------------------------------------------------===//
36// ConstantAggregateBuilder
37//===----------------------------------------------------------------------===//
38
39namespace {
40class ConstExprEmitter;
41
42struct ConstantAggregateBuilderUtils {
43 CodeGenModule &CGM;
44
45 ConstantAggregateBuilderUtils(CodeGenModule &CGM) : CGM(CGM) {}
46
47 CharUnits getAlignment(const llvm::Constant *C) const {
48 return CharUnits::fromQuantity(
49 CGM.getDataLayout().getABITypeAlignment(C->getType()));
50 }
51
52 CharUnits getSize(llvm::Type *Ty) const {
53 return CharUnits::fromQuantity(CGM.getDataLayout().getTypeAllocSize(Ty));
54 }
55
56 CharUnits getSize(const llvm::Constant *C) const {
57 return getSize(C->getType());
58 }
59
60 llvm::Constant *getPadding(CharUnits PadSize) const {
61 llvm::Type *Ty = CGM.CharTy;
62 if (PadSize > CharUnits::One())
63 Ty = llvm::ArrayType::get(Ty, PadSize.getQuantity());
64 return llvm::UndefValue::get(Ty);
65 }
66
67 llvm::Constant *getZeroes(CharUnits ZeroSize) const {
68 llvm::Type *Ty = llvm::ArrayType::get(CGM.CharTy, ZeroSize.getQuantity());
69 return llvm::ConstantAggregateZero::get(Ty);
70 }
71};
72
73/// Incremental builder for an llvm::Constant* holding a struct or array
74/// constant.
75class ConstantAggregateBuilder : private ConstantAggregateBuilderUtils {
76 /// The elements of the constant. These two arrays must have the same size;
77 /// Offsets[i] describes the offset of Elems[i] within the constant. The
78 /// elements are kept in increasing offset order, and we ensure that there
79 /// is no overlap: Offsets[i+1] >= Offsets[i] + getSize(Elemes[i]).
80 ///
81 /// This may contain explicit padding elements (in order to create a
82 /// natural layout), but need not. Gaps between elements are implicitly
83 /// considered to be filled with undef.
84 llvm::SmallVector<llvm::Constant*, 32> Elems;
85 llvm::SmallVector<CharUnits, 32> Offsets;
86
87 /// The size of the constant (the maximum end offset of any added element).
88 /// May be larger than the end of Elems.back() if we split the last element
89 /// and removed some trailing undefs.
90 CharUnits Size = CharUnits::Zero();
91
92 /// This is true only if laying out Elems in order as the elements of a
93 /// non-packed LLVM struct will give the correct layout.
94 bool NaturalLayout = true;
95
96 bool split(size_t Index, CharUnits Hint);
97 Optional<size_t> splitAt(CharUnits Pos);
98
99 static llvm::Constant *buildFrom(CodeGenModule &CGM,
100 ArrayRef<llvm::Constant *> Elems,
101 ArrayRef<CharUnits> Offsets,
102 CharUnits StartOffset, CharUnits Size,
103 bool NaturalLayout, llvm::Type *DesiredTy,
104 bool AllowOversized);
105
106public:
107 ConstantAggregateBuilder(CodeGenModule &CGM)
108 : ConstantAggregateBuilderUtils(CGM) {}
109
110 /// Update or overwrite the value starting at \p Offset with \c C.
111 ///
112 /// \param AllowOverwrite If \c true, this constant might overwrite (part of)
113 /// a constant that has already been added. This flag is only used to
114 /// detect bugs.
115 bool add(llvm::Constant *C, CharUnits Offset, bool AllowOverwrite);
116
117 /// Update or overwrite the bits starting at \p OffsetInBits with \p Bits.
118 bool addBits(llvm::APInt Bits, uint64_t OffsetInBits, bool AllowOverwrite);
119
120 /// Attempt to condense the value starting at \p Offset to a constant of type
121 /// \p DesiredTy.
122 void condense(CharUnits Offset, llvm::Type *DesiredTy);
123
124 /// Produce a constant representing the entire accumulated value, ideally of
125 /// the specified type. If \p AllowOversized, the constant might be larger
126 /// than implied by \p DesiredTy (eg, if there is a flexible array member).
127 /// Otherwise, the constant will be of exactly the same size as \p DesiredTy
128 /// even if we can't represent it as that type.
129 llvm::Constant *build(llvm::Type *DesiredTy, bool AllowOversized) const {
130 return buildFrom(CGM, Elems, Offsets, CharUnits::Zero(), Size,
131 NaturalLayout, DesiredTy, AllowOversized);
132 }
133};
134
135template<typename Container, typename Range = std::initializer_list<
136 typename Container::value_type>>
137static void replace(Container &C, size_t BeginOff, size_t EndOff, Range Vals) {
138 assert(BeginOff <= EndOff && "invalid replacement range")((BeginOff <= EndOff && "invalid replacement range"
) ? static_cast<void> (0) : __assert_fail ("BeginOff <= EndOff && \"invalid replacement range\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 138, __PRETTY_FUNCTION__))
;
139 llvm::replace(C, C.begin() + BeginOff, C.begin() + EndOff, Vals);
140}
141
142bool ConstantAggregateBuilder::add(llvm::Constant *C, CharUnits Offset,
143 bool AllowOverwrite) {
144 // Common case: appending to a layout.
145 if (Offset >= Size) {
146 CharUnits Align = getAlignment(C);
147 CharUnits AlignedSize = Size.alignTo(Align);
148 if (AlignedSize > Offset || Offset.alignTo(Align) != Offset)
149 NaturalLayout = false;
150 else if (AlignedSize < Offset) {
151 Elems.push_back(getPadding(Offset - Size));
152 Offsets.push_back(Size);
153 }
154 Elems.push_back(C);
155 Offsets.push_back(Offset);
156 Size = Offset + getSize(C);
157 return true;
158 }
159
160 // Uncommon case: constant overlaps what we've already created.
161 llvm::Optional<size_t> FirstElemToReplace = splitAt(Offset);
162 if (!FirstElemToReplace)
163 return false;
164
165 CharUnits CSize = getSize(C);
166 llvm::Optional<size_t> LastElemToReplace = splitAt(Offset + CSize);
167 if (!LastElemToReplace)
168 return false;
169
170 assert((FirstElemToReplace == LastElemToReplace || AllowOverwrite) &&(((FirstElemToReplace == LastElemToReplace || AllowOverwrite)
&& "unexpectedly overwriting field") ? static_cast<
void> (0) : __assert_fail ("(FirstElemToReplace == LastElemToReplace || AllowOverwrite) && \"unexpectedly overwriting field\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 171, __PRETTY_FUNCTION__))
171 "unexpectedly overwriting field")(((FirstElemToReplace == LastElemToReplace || AllowOverwrite)
&& "unexpectedly overwriting field") ? static_cast<
void> (0) : __assert_fail ("(FirstElemToReplace == LastElemToReplace || AllowOverwrite) && \"unexpectedly overwriting field\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 171, __PRETTY_FUNCTION__))
;
172
173 replace(Elems, *FirstElemToReplace, *LastElemToReplace, {C});
174 replace(Offsets, *FirstElemToReplace, *LastElemToReplace, {Offset});
175 Size = std::max(Size, Offset + CSize);
176 NaturalLayout = false;
177 return true;
178}
179
180bool ConstantAggregateBuilder::addBits(llvm::APInt Bits, uint64_t OffsetInBits,
181 bool AllowOverwrite) {
182 const ASTContext &Context = CGM.getContext();
183 const uint64_t CharWidth = CGM.getContext().getCharWidth();
184
185 // Offset of where we want the first bit to go within the bits of the
186 // current char.
187 unsigned OffsetWithinChar = OffsetInBits % CharWidth;
188
189 // We split bit-fields up into individual bytes. Walk over the bytes and
190 // update them.
191 for (CharUnits OffsetInChars =
192 Context.toCharUnitsFromBits(OffsetInBits - OffsetWithinChar);
193 /**/; ++OffsetInChars) {
194 // Number of bits we want to fill in this char.
195 unsigned WantedBits =
196 std::min((uint64_t)Bits.getBitWidth(), CharWidth - OffsetWithinChar);
197
198 // Get a char containing the bits we want in the right places. The other
199 // bits have unspecified values.
200 llvm::APInt BitsThisChar = Bits;
201 if (BitsThisChar.getBitWidth() < CharWidth)
202 BitsThisChar = BitsThisChar.zext(CharWidth);
203 if (CGM.getDataLayout().isBigEndian()) {
204 // Figure out how much to shift by. We may need to left-shift if we have
205 // less than one byte of Bits left.
206 int Shift = Bits.getBitWidth() - CharWidth + OffsetWithinChar;
207 if (Shift > 0)
208 BitsThisChar.lshrInPlace(Shift);
209 else if (Shift < 0)
210 BitsThisChar = BitsThisChar.shl(-Shift);
211 } else {
212 BitsThisChar = BitsThisChar.shl(OffsetWithinChar);
213 }
214 if (BitsThisChar.getBitWidth() > CharWidth)
215 BitsThisChar = BitsThisChar.trunc(CharWidth);
216
217 if (WantedBits == CharWidth) {
218 // Got a full byte: just add it directly.
219 add(llvm::ConstantInt::get(CGM.getLLVMContext(), BitsThisChar),
220 OffsetInChars, AllowOverwrite);
221 } else {
222 // Partial byte: update the existing integer if there is one. If we
223 // can't split out a 1-CharUnit range to update, then we can't add
224 // these bits and fail the entire constant emission.
225 llvm::Optional<size_t> FirstElemToUpdate = splitAt(OffsetInChars);
226 if (!FirstElemToUpdate)
227 return false;
228 llvm::Optional<size_t> LastElemToUpdate =
229 splitAt(OffsetInChars + CharUnits::One());
230 if (!LastElemToUpdate)
231 return false;
232 assert(*LastElemToUpdate - *FirstElemToUpdate < 2 &&((*LastElemToUpdate - *FirstElemToUpdate < 2 && "should have at most one element covering one byte"
) ? static_cast<void> (0) : __assert_fail ("*LastElemToUpdate - *FirstElemToUpdate < 2 && \"should have at most one element covering one byte\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 233, __PRETTY_FUNCTION__))
233 "should have at most one element covering one byte")((*LastElemToUpdate - *FirstElemToUpdate < 2 && "should have at most one element covering one byte"
) ? static_cast<void> (0) : __assert_fail ("*LastElemToUpdate - *FirstElemToUpdate < 2 && \"should have at most one element covering one byte\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 233, __PRETTY_FUNCTION__))
;
234
235 // Figure out which bits we want and discard the rest.
236 llvm::APInt UpdateMask(CharWidth, 0);
237 if (CGM.getDataLayout().isBigEndian())
238 UpdateMask.setBits(CharWidth - OffsetWithinChar - WantedBits,
239 CharWidth - OffsetWithinChar);
240 else
241 UpdateMask.setBits(OffsetWithinChar, OffsetWithinChar + WantedBits);
242 BitsThisChar &= UpdateMask;
243
244 if (*FirstElemToUpdate == *LastElemToUpdate ||
245 Elems[*FirstElemToUpdate]->isNullValue() ||
246 isa<llvm::UndefValue>(Elems[*FirstElemToUpdate])) {
247 // All existing bits are either zero or undef.
248 add(llvm::ConstantInt::get(CGM.getLLVMContext(), BitsThisChar),
249 OffsetInChars, /*AllowOverwrite*/ true);
250 } else {
251 llvm::Constant *&ToUpdate = Elems[*FirstElemToUpdate];
252 // In order to perform a partial update, we need the existing bitwise
253 // value, which we can only extract for a constant int.
254 auto *CI = dyn_cast<llvm::ConstantInt>(ToUpdate);
255 if (!CI)
256 return false;
257 // Because this is a 1-CharUnit range, the constant occupying it must
258 // be exactly one CharUnit wide.
259 assert(CI->getBitWidth() == CharWidth && "splitAt failed")((CI->getBitWidth() == CharWidth && "splitAt failed"
) ? static_cast<void> (0) : __assert_fail ("CI->getBitWidth() == CharWidth && \"splitAt failed\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 259, __PRETTY_FUNCTION__))
;
260 assert((!(CI->getValue() & UpdateMask) || AllowOverwrite) &&(((!(CI->getValue() & UpdateMask) || AllowOverwrite) &&
"unexpectedly overwriting bitfield") ? static_cast<void>
(0) : __assert_fail ("(!(CI->getValue() & UpdateMask) || AllowOverwrite) && \"unexpectedly overwriting bitfield\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 261, __PRETTY_FUNCTION__))
261 "unexpectedly overwriting bitfield")(((!(CI->getValue() & UpdateMask) || AllowOverwrite) &&
"unexpectedly overwriting bitfield") ? static_cast<void>
(0) : __assert_fail ("(!(CI->getValue() & UpdateMask) || AllowOverwrite) && \"unexpectedly overwriting bitfield\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 261, __PRETTY_FUNCTION__))
;
262 BitsThisChar |= (CI->getValue() & ~UpdateMask);
263 ToUpdate = llvm::ConstantInt::get(CGM.getLLVMContext(), BitsThisChar);
264 }
265 }
266
267 // Stop if we've added all the bits.
268 if (WantedBits == Bits.getBitWidth())
269 break;
270
271 // Remove the consumed bits from Bits.
272 if (!CGM.getDataLayout().isBigEndian())
273 Bits.lshrInPlace(WantedBits);
274 Bits = Bits.trunc(Bits.getBitWidth() - WantedBits);
275
276 // The remanining bits go at the start of the following bytes.
277 OffsetWithinChar = 0;
278 }
279
280 return true;
281}
282
283/// Returns a position within Elems and Offsets such that all elements
284/// before the returned index end before Pos and all elements at or after
285/// the returned index begin at or after Pos. Splits elements as necessary
286/// to ensure this. Returns None if we find something we can't split.
287Optional<size_t> ConstantAggregateBuilder::splitAt(CharUnits Pos) {
288 if (Pos >= Size)
289 return Offsets.size();
290
291 while (true) {
292 auto FirstAfterPos = llvm::upper_bound(Offsets, Pos);
293 if (FirstAfterPos == Offsets.begin())
294 return 0;
295
296 // If we already have an element starting at Pos, we're done.
297 size_t LastAtOrBeforePosIndex = FirstAfterPos - Offsets.begin() - 1;
298 if (Offsets[LastAtOrBeforePosIndex] == Pos)
299 return LastAtOrBeforePosIndex;
300
301 // We found an element starting before Pos. Check for overlap.
302 if (Offsets[LastAtOrBeforePosIndex] +
303 getSize(Elems[LastAtOrBeforePosIndex]) <= Pos)
304 return LastAtOrBeforePosIndex + 1;
305
306 // Try to decompose it into smaller constants.
307 if (!split(LastAtOrBeforePosIndex, Pos))
308 return None;
309 }
310}
311
312/// Split the constant at index Index, if possible. Return true if we did.
313/// Hint indicates the location at which we'd like to split, but may be
314/// ignored.
315bool ConstantAggregateBuilder::split(size_t Index, CharUnits Hint) {
316 NaturalLayout = false;
317 llvm::Constant *C = Elems[Index];
318 CharUnits Offset = Offsets[Index];
319
320 if (auto *CA = dyn_cast<llvm::ConstantAggregate>(C)) {
321 // Expand the sequence into its contained elements.
322 // FIXME: This assumes vector elements are byte-sized.
323 replace(Elems, Index, Index + 1,
324 llvm::map_range(llvm::seq(0u, CA->getNumOperands()),
325 [&](unsigned Op) { return CA->getOperand(Op); }));
326 if (isa<llvm::ArrayType>(CA->getType()) ||
327 isa<llvm::VectorType>(CA->getType())) {
328 // Array or vector.
329 llvm::Type *ElemTy =
330 llvm::GetElementPtrInst::getTypeAtIndex(CA->getType(), (uint64_t)0);
331 CharUnits ElemSize = getSize(ElemTy);
332 replace(
333 Offsets, Index, Index + 1,
334 llvm::map_range(llvm::seq(0u, CA->getNumOperands()),
335 [&](unsigned Op) { return Offset + Op * ElemSize; }));
336 } else {
337 // Must be a struct.
338 auto *ST = cast<llvm::StructType>(CA->getType());
339 const llvm::StructLayout *Layout =
340 CGM.getDataLayout().getStructLayout(ST);
341 replace(Offsets, Index, Index + 1,
342 llvm::map_range(
343 llvm::seq(0u, CA->getNumOperands()), [&](unsigned Op) {
344 return Offset + CharUnits::fromQuantity(
345 Layout->getElementOffset(Op));
346 }));
347 }
348 return true;
349 }
350
351 if (auto *CDS = dyn_cast<llvm::ConstantDataSequential>(C)) {
352 // Expand the sequence into its contained elements.
353 // FIXME: This assumes vector elements are byte-sized.
354 // FIXME: If possible, split into two ConstantDataSequentials at Hint.
355 CharUnits ElemSize = getSize(CDS->getElementType());
356 replace(Elems, Index, Index + 1,
357 llvm::map_range(llvm::seq(0u, CDS->getNumElements()),
358 [&](unsigned Elem) {
359 return CDS->getElementAsConstant(Elem);
360 }));
361 replace(Offsets, Index, Index + 1,
362 llvm::map_range(
363 llvm::seq(0u, CDS->getNumElements()),
364 [&](unsigned Elem) { return Offset + Elem * ElemSize; }));
365 return true;
366 }
367
368 if (isa<llvm::ConstantAggregateZero>(C)) {
369 // Split into two zeros at the hinted offset.
370 CharUnits ElemSize = getSize(C);
371 assert(Hint > Offset && Hint < Offset + ElemSize && "nothing to split")((Hint > Offset && Hint < Offset + ElemSize &&
"nothing to split") ? static_cast<void> (0) : __assert_fail
("Hint > Offset && Hint < Offset + ElemSize && \"nothing to split\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 371, __PRETTY_FUNCTION__))
;
372 replace(Elems, Index, Index + 1,
373 {getZeroes(Hint - Offset), getZeroes(Offset + ElemSize - Hint)});
374 replace(Offsets, Index, Index + 1, {Offset, Hint});
375 return true;
376 }
377
378 if (isa<llvm::UndefValue>(C)) {
379 // Drop undef; it doesn't contribute to the final layout.
380 replace(Elems, Index, Index + 1, {});
381 replace(Offsets, Index, Index + 1, {});
382 return true;
383 }
384
385 // FIXME: We could split a ConstantInt if the need ever arose.
386 // We don't need to do this to handle bit-fields because we always eagerly
387 // split them into 1-byte chunks.
388
389 return false;
390}
391
392static llvm::Constant *
393EmitArrayConstant(CodeGenModule &CGM, llvm::ArrayType *DesiredType,
394 llvm::Type *CommonElementType, unsigned ArrayBound,
395 SmallVectorImpl<llvm::Constant *> &Elements,
396 llvm::Constant *Filler);
397
398llvm::Constant *ConstantAggregateBuilder::buildFrom(
399 CodeGenModule &CGM, ArrayRef<llvm::Constant *> Elems,
400 ArrayRef<CharUnits> Offsets, CharUnits StartOffset, CharUnits Size,
401 bool NaturalLayout, llvm::Type *DesiredTy, bool AllowOversized) {
402 ConstantAggregateBuilderUtils Utils(CGM);
403
404 if (Elems.empty())
405 return llvm::UndefValue::get(DesiredTy);
406
407 auto Offset = [&](size_t I) { return Offsets[I] - StartOffset; };
408
409 // If we want an array type, see if all the elements are the same type and
410 // appropriately spaced.
411 if (llvm::ArrayType *ATy = dyn_cast<llvm::ArrayType>(DesiredTy)) {
412 assert(!AllowOversized && "oversized array emission not supported")((!AllowOversized && "oversized array emission not supported"
) ? static_cast<void> (0) : __assert_fail ("!AllowOversized && \"oversized array emission not supported\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 412, __PRETTY_FUNCTION__))
;
413
414 bool CanEmitArray = true;
415 llvm::Type *CommonType = Elems[0]->getType();
416 llvm::Constant *Filler = llvm::Constant::getNullValue(CommonType);
417 CharUnits ElemSize = Utils.getSize(ATy->getElementType());
418 SmallVector<llvm::Constant*, 32> ArrayElements;
419 for (size_t I = 0; I != Elems.size(); ++I) {
420 // Skip zeroes; we'll use a zero value as our array filler.
421 if (Elems[I]->isNullValue())
422 continue;
423
424 // All remaining elements must be the same type.
425 if (Elems[I]->getType() != CommonType ||
426 Offset(I) % ElemSize != 0) {
427 CanEmitArray = false;
428 break;
429 }
430 ArrayElements.resize(Offset(I) / ElemSize + 1, Filler);
431 ArrayElements.back() = Elems[I];
432 }
433
434 if (CanEmitArray) {
435 return EmitArrayConstant(CGM, ATy, CommonType, ATy->getNumElements(),
436 ArrayElements, Filler);
437 }
438
439 // Can't emit as an array, carry on to emit as a struct.
440 }
441
442 CharUnits DesiredSize = Utils.getSize(DesiredTy);
443 CharUnits Align = CharUnits::One();
444 for (llvm::Constant *C : Elems)
445 Align = std::max(Align, Utils.getAlignment(C));
446 CharUnits AlignedSize = Size.alignTo(Align);
447
448 bool Packed = false;
449 ArrayRef<llvm::Constant*> UnpackedElems = Elems;
450 llvm::SmallVector<llvm::Constant*, 32> UnpackedElemStorage;
451 if ((DesiredSize < AlignedSize && !AllowOversized) ||
452 DesiredSize.alignTo(Align) != DesiredSize) {
453 // The natural layout would be the wrong size; force use of a packed layout.
454 NaturalLayout = false;
455 Packed = true;
456 } else if (DesiredSize > AlignedSize) {
457 // The constant would be too small. Add padding to fix it.
458 UnpackedElemStorage.assign(Elems.begin(), Elems.end());
459 UnpackedElemStorage.push_back(Utils.getPadding(DesiredSize - Size));
460 UnpackedElems = UnpackedElemStorage;
461 }
462
463 // If we don't have a natural layout, insert padding as necessary.
464 // As we go, double-check to see if we can actually just emit Elems
465 // as a non-packed struct and do so opportunistically if possible.
466 llvm::SmallVector<llvm::Constant*, 32> PackedElems;
467 if (!NaturalLayout) {
468 CharUnits SizeSoFar = CharUnits::Zero();
469 for (size_t I = 0; I != Elems.size(); ++I) {
470 CharUnits Align = Utils.getAlignment(Elems[I]);
471 CharUnits NaturalOffset = SizeSoFar.alignTo(Align);
472 CharUnits DesiredOffset = Offset(I);
473 assert(DesiredOffset >= SizeSoFar && "elements out of order")((DesiredOffset >= SizeSoFar && "elements out of order"
) ? static_cast<void> (0) : __assert_fail ("DesiredOffset >= SizeSoFar && \"elements out of order\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 473, __PRETTY_FUNCTION__))
;
474
475 if (DesiredOffset != NaturalOffset)
476 Packed = true;
477 if (DesiredOffset != SizeSoFar)
478 PackedElems.push_back(Utils.getPadding(DesiredOffset - SizeSoFar));
479 PackedElems.push_back(Elems[I]);
480 SizeSoFar = DesiredOffset + Utils.getSize(Elems[I]);
481 }
482 // If we're using the packed layout, pad it out to the desired size if
483 // necessary.
484 if (Packed) {
485 assert((SizeSoFar <= DesiredSize || AllowOversized) &&(((SizeSoFar <= DesiredSize || AllowOversized) && "requested size is too small for contents"
) ? static_cast<void> (0) : __assert_fail ("(SizeSoFar <= DesiredSize || AllowOversized) && \"requested size is too small for contents\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 486, __PRETTY_FUNCTION__))
486 "requested size is too small for contents")(((SizeSoFar <= DesiredSize || AllowOversized) && "requested size is too small for contents"
) ? static_cast<void> (0) : __assert_fail ("(SizeSoFar <= DesiredSize || AllowOversized) && \"requested size is too small for contents\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 486, __PRETTY_FUNCTION__))
;
487 if (SizeSoFar < DesiredSize)
488 PackedElems.push_back(Utils.getPadding(DesiredSize - SizeSoFar));
489 }
490 }
491
492 llvm::StructType *STy = llvm::ConstantStruct::getTypeForElements(
493 CGM.getLLVMContext(), Packed ? PackedElems : UnpackedElems, Packed);
494
495 // Pick the type to use. If the type is layout identical to the desired
496 // type then use it, otherwise use whatever the builder produced for us.
497 if (llvm::StructType *DesiredSTy = dyn_cast<llvm::StructType>(DesiredTy)) {
498 if (DesiredSTy->isLayoutIdentical(STy))
499 STy = DesiredSTy;
500 }
501
502 return llvm::ConstantStruct::get(STy, Packed ? PackedElems : UnpackedElems);
503}
504
505void ConstantAggregateBuilder::condense(CharUnits Offset,
506 llvm::Type *DesiredTy) {
507 CharUnits Size = getSize(DesiredTy);
508
509 llvm::Optional<size_t> FirstElemToReplace = splitAt(Offset);
510 if (!FirstElemToReplace)
511 return;
512 size_t First = *FirstElemToReplace;
513
514 llvm::Optional<size_t> LastElemToReplace = splitAt(Offset + Size);
515 if (!LastElemToReplace)
516 return;
517 size_t Last = *LastElemToReplace;
518
519 size_t Length = Last - First;
520 if (Length == 0)
521 return;
522
523 if (Length == 1 && Offsets[First] == Offset &&
524 getSize(Elems[First]) == Size) {
525 // Re-wrap single element structs if necessary. Otherwise, leave any single
526 // element constant of the right size alone even if it has the wrong type.
527 auto *STy = dyn_cast<llvm::StructType>(DesiredTy);
528 if (STy && STy->getNumElements() == 1 &&
529 STy->getElementType(0) == Elems[First]->getType())
530 Elems[First] = llvm::ConstantStruct::get(STy, Elems[First]);
531 return;
532 }
533
534 llvm::Constant *Replacement = buildFrom(
535 CGM, makeArrayRef(Elems).slice(First, Length),
536 makeArrayRef(Offsets).slice(First, Length), Offset, getSize(DesiredTy),
537 /*known to have natural layout=*/false, DesiredTy, false);
538 replace(Elems, First, Last, {Replacement});
539 replace(Offsets, First, Last, {Offset});
540}
541
542//===----------------------------------------------------------------------===//
543// ConstStructBuilder
544//===----------------------------------------------------------------------===//
545
546class ConstStructBuilder {
547 CodeGenModule &CGM;
548 ConstantEmitter &Emitter;
549 ConstantAggregateBuilder &Builder;
550 CharUnits StartOffset;
551
552public:
553 static llvm::Constant *BuildStruct(ConstantEmitter &Emitter,
554 InitListExpr *ILE, QualType StructTy);
555 static llvm::Constant *BuildStruct(ConstantEmitter &Emitter,
556 const APValue &Value, QualType ValTy);
557 static bool UpdateStruct(ConstantEmitter &Emitter,
558 ConstantAggregateBuilder &Const, CharUnits Offset,
559 InitListExpr *Updater);
560
561private:
562 ConstStructBuilder(ConstantEmitter &Emitter,
563 ConstantAggregateBuilder &Builder, CharUnits StartOffset)
564 : CGM(Emitter.CGM), Emitter(Emitter), Builder(Builder),
565 StartOffset(StartOffset) {}
566
567 bool AppendField(const FieldDecl *Field, uint64_t FieldOffset,
568 llvm::Constant *InitExpr, bool AllowOverwrite = false);
569
570 bool AppendBytes(CharUnits FieldOffsetInChars, llvm::Constant *InitCst,
571 bool AllowOverwrite = false);
572
573 bool AppendBitField(const FieldDecl *Field, uint64_t FieldOffset,
574 llvm::ConstantInt *InitExpr, bool AllowOverwrite = false);
575
576 bool Build(InitListExpr *ILE, bool AllowOverwrite);
577 bool Build(const APValue &Val, const RecordDecl *RD, bool IsPrimaryBase,
578 const CXXRecordDecl *VTableClass, CharUnits BaseOffset);
579 llvm::Constant *Finalize(QualType Ty);
580};
581
582bool ConstStructBuilder::AppendField(
583 const FieldDecl *Field, uint64_t FieldOffset, llvm::Constant *InitCst,
584 bool AllowOverwrite) {
585 const ASTContext &Context = CGM.getContext();
586
587 CharUnits FieldOffsetInChars = Context.toCharUnitsFromBits(FieldOffset);
588
589 return AppendBytes(FieldOffsetInChars, InitCst, AllowOverwrite);
590}
591
592bool ConstStructBuilder::AppendBytes(CharUnits FieldOffsetInChars,
593 llvm::Constant *InitCst,
594 bool AllowOverwrite) {
595 return Builder.add(InitCst, StartOffset + FieldOffsetInChars, AllowOverwrite);
596}
597
598bool ConstStructBuilder::AppendBitField(
599 const FieldDecl *Field, uint64_t FieldOffset, llvm::ConstantInt *CI,
600 bool AllowOverwrite) {
601 const CGRecordLayout &RL =
602 CGM.getTypes().getCGRecordLayout(Field->getParent());
603 const CGBitFieldInfo &Info = RL.getBitFieldInfo(Field);
604 llvm::APInt FieldValue = CI->getValue();
605
606 // Promote the size of FieldValue if necessary
607 // FIXME: This should never occur, but currently it can because initializer
608 // constants are cast to bool, and because clang is not enforcing bitfield
609 // width limits.
610 if (Info.Size > FieldValue.getBitWidth())
611 FieldValue = FieldValue.zext(Info.Size);
612
613 // Truncate the size of FieldValue to the bit field size.
614 if (Info.Size < FieldValue.getBitWidth())
615 FieldValue = FieldValue.trunc(Info.Size);
616
617 return Builder.addBits(FieldValue,
618 CGM.getContext().toBits(StartOffset) + FieldOffset,
619 AllowOverwrite);
620}
621
622static bool EmitDesignatedInitUpdater(ConstantEmitter &Emitter,
623 ConstantAggregateBuilder &Const,
624 CharUnits Offset, QualType Type,
625 InitListExpr *Updater) {
626 if (Type->isRecordType())
627 return ConstStructBuilder::UpdateStruct(Emitter, Const, Offset, Updater);
628
629 auto CAT = Emitter.CGM.getContext().getAsConstantArrayType(Type);
630 if (!CAT)
631 return false;
632 QualType ElemType = CAT->getElementType();
633 CharUnits ElemSize = Emitter.CGM.getContext().getTypeSizeInChars(ElemType);
634 llvm::Type *ElemTy = Emitter.CGM.getTypes().ConvertTypeForMem(ElemType);
635
636 llvm::Constant *FillC = nullptr;
637 if (Expr *Filler = Updater->getArrayFiller()) {
638 if (!isa<NoInitExpr>(Filler)) {
639 FillC = Emitter.tryEmitAbstractForMemory(Filler, ElemType);
640 if (!FillC)
641 return false;
642 }
643 }
644
645 unsigned NumElementsToUpdate =
646 FillC ? CAT->getSize().getZExtValue() : Updater->getNumInits();
647 for (unsigned I = 0; I != NumElementsToUpdate; ++I, Offset += ElemSize) {
648 Expr *Init = nullptr;
649 if (I < Updater->getNumInits())
650 Init = Updater->getInit(I);
651
652 if (!Init && FillC) {
653 if (!Const.add(FillC, Offset, true))
654 return false;
655 } else if (!Init || isa<NoInitExpr>(Init)) {
656 continue;
657 } else if (InitListExpr *ChildILE = dyn_cast<InitListExpr>(Init)) {
658 if (!EmitDesignatedInitUpdater(Emitter, Const, Offset, ElemType,
659 ChildILE))
660 return false;
661 // Attempt to reduce the array element to a single constant if necessary.
662 Const.condense(Offset, ElemTy);
663 } else {
664 llvm::Constant *Val = Emitter.tryEmitPrivateForMemory(Init, ElemType);
665 if (!Const.add(Val, Offset, true))
666 return false;
667 }
668 }
669
670 return true;
671}
672
673bool ConstStructBuilder::Build(InitListExpr *ILE, bool AllowOverwrite) {
674 RecordDecl *RD = ILE->getType()->castAs<RecordType>()->getDecl();
675 const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
676
677 unsigned FieldNo = -1;
678 unsigned ElementNo = 0;
679
680 // Bail out if we have base classes. We could support these, but they only
681 // arise in C++1z where we will have already constant folded most interesting
682 // cases. FIXME: There are still a few more cases we can handle this way.
683 if (auto *CXXRD = dyn_cast<CXXRecordDecl>(RD))
684 if (CXXRD->getNumBases())
685 return false;
686
687 for (FieldDecl *Field : RD->fields()) {
688 ++FieldNo;
689
690 // If this is a union, skip all the fields that aren't being initialized.
691 if (RD->isUnion() &&
692 !declaresSameEntity(ILE->getInitializedFieldInUnion(), Field))
693 continue;
694
695 // Don't emit anonymous bitfields or zero-sized fields.
696 if (Field->isUnnamedBitfield() || Field->isZeroSize(CGM.getContext()))
697 continue;
698
699 // Get the initializer. A struct can include fields without initializers,
700 // we just use explicit null values for them.
701 Expr *Init = nullptr;
702 if (ElementNo < ILE->getNumInits())
703 Init = ILE->getInit(ElementNo++);
704 if (Init && isa<NoInitExpr>(Init))
705 continue;
706
707 // When emitting a DesignatedInitUpdateExpr, a nested InitListExpr
708 // represents additional overwriting of our current constant value, and not
709 // a new constant to emit independently.
710 if (AllowOverwrite &&
711 (Field->getType()->isArrayType() || Field->getType()->isRecordType())) {
712 if (auto *SubILE = dyn_cast<InitListExpr>(Init)) {
713 CharUnits Offset = CGM.getContext().toCharUnitsFromBits(
714 Layout.getFieldOffset(FieldNo));
715 if (!EmitDesignatedInitUpdater(Emitter, Builder, StartOffset + Offset,
716 Field->getType(), SubILE))
717 return false;
718 // If we split apart the field's value, try to collapse it down to a
719 // single value now.
720 Builder.condense(StartOffset + Offset,
721 CGM.getTypes().ConvertTypeForMem(Field->getType()));
722 continue;
723 }
724 }
725
726 llvm::Constant *EltInit =
727 Init ? Emitter.tryEmitPrivateForMemory(Init, Field->getType())
728 : Emitter.emitNullForMemory(Field->getType());
729 if (!EltInit)
730 return false;
731
732 if (!Field->isBitField()) {
733 // Handle non-bitfield members.
734 if (!AppendField(Field, Layout.getFieldOffset(FieldNo), EltInit,
735 AllowOverwrite))
736 return false;
737 // After emitting a non-empty field with [[no_unique_address]], we may
738 // need to overwrite its tail padding.
739 if (Field->hasAttr<NoUniqueAddressAttr>())
740 AllowOverwrite = true;
741 } else {
742 // Otherwise we have a bitfield.
743 if (auto *CI = dyn_cast<llvm::ConstantInt>(EltInit)) {
744 if (!AppendBitField(Field, Layout.getFieldOffset(FieldNo), CI,
745 AllowOverwrite))
746 return false;
747 } else {
748 // We are trying to initialize a bitfield with a non-trivial constant,
749 // this must require run-time code.
750 return false;
751 }
752 }
753 }
754
755 return true;
756}
757
758namespace {
759struct BaseInfo {
760 BaseInfo(const CXXRecordDecl *Decl, CharUnits Offset, unsigned Index)
761 : Decl(Decl), Offset(Offset), Index(Index) {
762 }
763
764 const CXXRecordDecl *Decl;
765 CharUnits Offset;
766 unsigned Index;
767
768 bool operator<(const BaseInfo &O) const { return Offset < O.Offset; }
769};
770}
771
772bool ConstStructBuilder::Build(const APValue &Val, const RecordDecl *RD,
773 bool IsPrimaryBase,
774 const CXXRecordDecl *VTableClass,
775 CharUnits Offset) {
776 const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
777
778 if (const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD)) {
779 // Add a vtable pointer, if we need one and it hasn't already been added.
780 if (Layout.hasOwnVFPtr()) {
781 llvm::Constant *VTableAddressPoint =
782 CGM.getCXXABI().getVTableAddressPointForConstExpr(
783 BaseSubobject(CD, Offset), VTableClass);
784 if (!AppendBytes(Offset, VTableAddressPoint))
785 return false;
786 }
787
788 // Accumulate and sort bases, in order to visit them in address order, which
789 // may not be the same as declaration order.
790 SmallVector<BaseInfo, 8> Bases;
791 Bases.reserve(CD->getNumBases());
792 unsigned BaseNo = 0;
793 for (CXXRecordDecl::base_class_const_iterator Base = CD->bases_begin(),
794 BaseEnd = CD->bases_end(); Base != BaseEnd; ++Base, ++BaseNo) {
795 assert(!Base->isVirtual() && "should not have virtual bases here")((!Base->isVirtual() && "should not have virtual bases here"
) ? static_cast<void> (0) : __assert_fail ("!Base->isVirtual() && \"should not have virtual bases here\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 795, __PRETTY_FUNCTION__))
;
796 const CXXRecordDecl *BD = Base->getType()->getAsCXXRecordDecl();
797 CharUnits BaseOffset = Layout.getBaseClassOffset(BD);
798 Bases.push_back(BaseInfo(BD, BaseOffset, BaseNo));
799 }
800 llvm::stable_sort(Bases);
801
802 for (unsigned I = 0, N = Bases.size(); I != N; ++I) {
803 BaseInfo &Base = Bases[I];
804
805 bool IsPrimaryBase = Layout.getPrimaryBase() == Base.Decl;
806 Build(Val.getStructBase(Base.Index), Base.Decl, IsPrimaryBase,
807 VTableClass, Offset + Base.Offset);
808 }
809 }
810
811 unsigned FieldNo = 0;
812 uint64_t OffsetBits = CGM.getContext().toBits(Offset);
813
814 bool AllowOverwrite = false;
815 for (RecordDecl::field_iterator Field = RD->field_begin(),
816 FieldEnd = RD->field_end(); Field != FieldEnd; ++Field, ++FieldNo) {
817 // If this is a union, skip all the fields that aren't being initialized.
818 if (RD->isUnion() && !declaresSameEntity(Val.getUnionField(), *Field))
819 continue;
820
821 // Don't emit anonymous bitfields or zero-sized fields.
822 if (Field->isUnnamedBitfield() || Field->isZeroSize(CGM.getContext()))
823 continue;
824
825 // Emit the value of the initializer.
826 const APValue &FieldValue =
827 RD->isUnion() ? Val.getUnionValue() : Val.getStructField(FieldNo);
828 llvm::Constant *EltInit =
829 Emitter.tryEmitPrivateForMemory(FieldValue, Field->getType());
830 if (!EltInit)
831 return false;
832
833 if (!Field->isBitField()) {
834 // Handle non-bitfield members.
835 if (!AppendField(*Field, Layout.getFieldOffset(FieldNo) + OffsetBits,
836 EltInit, AllowOverwrite))
837 return false;
838 // After emitting a non-empty field with [[no_unique_address]], we may
839 // need to overwrite its tail padding.
840 if (Field->hasAttr<NoUniqueAddressAttr>())
841 AllowOverwrite = true;
842 } else {
843 // Otherwise we have a bitfield.
844 if (!AppendBitField(*Field, Layout.getFieldOffset(FieldNo) + OffsetBits,
845 cast<llvm::ConstantInt>(EltInit), AllowOverwrite))
846 return false;
847 }
848 }
849
850 return true;
851}
852
853llvm::Constant *ConstStructBuilder::Finalize(QualType Type) {
854 RecordDecl *RD = Type->castAs<RecordType>()->getDecl();
855 llvm::Type *ValTy = CGM.getTypes().ConvertType(Type);
856 return Builder.build(ValTy, RD->hasFlexibleArrayMember());
857}
858
859llvm::Constant *ConstStructBuilder::BuildStruct(ConstantEmitter &Emitter,
860 InitListExpr *ILE,
861 QualType ValTy) {
862 ConstantAggregateBuilder Const(Emitter.CGM);
863 ConstStructBuilder Builder(Emitter, Const, CharUnits::Zero());
864
865 if (!Builder.Build(ILE, /*AllowOverwrite*/false))
866 return nullptr;
867
868 return Builder.Finalize(ValTy);
869}
870
871llvm::Constant *ConstStructBuilder::BuildStruct(ConstantEmitter &Emitter,
872 const APValue &Val,
873 QualType ValTy) {
874 ConstantAggregateBuilder Const(Emitter.CGM);
875 ConstStructBuilder Builder(Emitter, Const, CharUnits::Zero());
876
877 const RecordDecl *RD = ValTy->castAs<RecordType>()->getDecl();
878 const CXXRecordDecl *CD = dyn_cast<CXXRecordDecl>(RD);
879 if (!Builder.Build(Val, RD, false, CD, CharUnits::Zero()))
880 return nullptr;
881
882 return Builder.Finalize(ValTy);
883}
884
885bool ConstStructBuilder::UpdateStruct(ConstantEmitter &Emitter,
886 ConstantAggregateBuilder &Const,
887 CharUnits Offset, InitListExpr *Updater) {
888 return ConstStructBuilder(Emitter, Const, Offset)
889 .Build(Updater, /*AllowOverwrite*/ true);
890}
891
892//===----------------------------------------------------------------------===//
893// ConstExprEmitter
894//===----------------------------------------------------------------------===//
895
896static ConstantAddress tryEmitGlobalCompoundLiteral(CodeGenModule &CGM,
897 CodeGenFunction *CGF,
898 const CompoundLiteralExpr *E) {
899 CharUnits Align = CGM.getContext().getTypeAlignInChars(E->getType());
900 if (llvm::GlobalVariable *Addr =
901 CGM.getAddrOfConstantCompoundLiteralIfEmitted(E))
902 return ConstantAddress(Addr, Align);
903
904 LangAS addressSpace = E->getType().getAddressSpace();
905
906 ConstantEmitter emitter(CGM, CGF);
907 llvm::Constant *C = emitter.tryEmitForInitializer(E->getInitializer(),
908 addressSpace, E->getType());
909 if (!C) {
910 assert(!E->isFileScope() &&((!E->isFileScope() && "file-scope compound literal did not have constant initializer!"
) ? static_cast<void> (0) : __assert_fail ("!E->isFileScope() && \"file-scope compound literal did not have constant initializer!\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 911, __PRETTY_FUNCTION__))
911 "file-scope compound literal did not have constant initializer!")((!E->isFileScope() && "file-scope compound literal did not have constant initializer!"
) ? static_cast<void> (0) : __assert_fail ("!E->isFileScope() && \"file-scope compound literal did not have constant initializer!\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 911, __PRETTY_FUNCTION__))
;
912 return ConstantAddress::invalid();
913 }
914
915 auto GV = new llvm::GlobalVariable(CGM.getModule(), C->getType(),
916 CGM.isTypeConstant(E->getType(), true),
917 llvm::GlobalValue::InternalLinkage,
918 C, ".compoundliteral", nullptr,
919 llvm::GlobalVariable::NotThreadLocal,
920 CGM.getContext().getTargetAddressSpace(addressSpace));
921 emitter.finalize(GV);
922 GV->setAlignment(Align.getAsAlign());
923 CGM.setAddrOfConstantCompoundLiteral(E, GV);
924 return ConstantAddress(GV, Align);
925}
926
927static llvm::Constant *
928EmitArrayConstant(CodeGenModule &CGM, llvm::ArrayType *DesiredType,
929 llvm::Type *CommonElementType, unsigned ArrayBound,
930 SmallVectorImpl<llvm::Constant *> &Elements,
931 llvm::Constant *Filler) {
932 // Figure out how long the initial prefix of non-zero elements is.
933 unsigned NonzeroLength = ArrayBound;
934 if (Elements.size() < NonzeroLength && Filler->isNullValue())
14
Assuming the condition is false
935 NonzeroLength = Elements.size();
936 if (NonzeroLength == Elements.size()) {
15
Assuming the condition is false
16
Taking false branch
937 while (NonzeroLength > 0 && Elements[NonzeroLength - 1]->isNullValue())
938 --NonzeroLength;
939 }
940
941 if (NonzeroLength == 0)
17
Assuming 'NonzeroLength' is not equal to 0
18
Taking false branch
942 return llvm::ConstantAggregateZero::get(DesiredType);
943
944 // Add a zeroinitializer array filler if we have lots of trailing zeroes.
945 unsigned TrailingZeroes = ArrayBound - NonzeroLength;
946 if (TrailingZeroes
18.1
'TrailingZeroes' is < 8
>= 8) {
19
Taking false branch
947 assert(Elements.size() >= NonzeroLength &&((Elements.size() >= NonzeroLength && "missing initializer for non-zero element"
) ? static_cast<void> (0) : __assert_fail ("Elements.size() >= NonzeroLength && \"missing initializer for non-zero element\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 948, __PRETTY_FUNCTION__))
948 "missing initializer for non-zero element")((Elements.size() >= NonzeroLength && "missing initializer for non-zero element"
) ? static_cast<void> (0) : __assert_fail ("Elements.size() >= NonzeroLength && \"missing initializer for non-zero element\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 948, __PRETTY_FUNCTION__))
;
949
950 // If all the elements had the same type up to the trailing zeroes, emit a
951 // struct of two arrays (the nonzero data and the zeroinitializer).
952 if (CommonElementType && NonzeroLength >= 8) {
953 llvm::Constant *Initial = llvm::ConstantArray::get(
954 llvm::ArrayType::get(CommonElementType, NonzeroLength),
955 makeArrayRef(Elements).take_front(NonzeroLength));
956 Elements.resize(2);
957 Elements[0] = Initial;
958 } else {
959 Elements.resize(NonzeroLength + 1);
960 }
961
962 auto *FillerType =
963 CommonElementType ? CommonElementType : DesiredType->getElementType();
964 FillerType = llvm::ArrayType::get(FillerType, TrailingZeroes);
965 Elements.back() = llvm::ConstantAggregateZero::get(FillerType);
966 CommonElementType = nullptr;
967 } else if (Elements.size() != ArrayBound) {
20
Taking true branch
968 // Otherwise pad to the right size with the filler if necessary.
969 Elements.resize(ArrayBound, Filler);
970 if (Filler->getType() != CommonElementType)
21
Called C++ object pointer is null
971 CommonElementType = nullptr;
972 }
973
974 // If all elements have the same type, just emit an array constant.
975 if (CommonElementType)
976 return llvm::ConstantArray::get(
977 llvm::ArrayType::get(CommonElementType, ArrayBound), Elements);
978
979 // We have mixed types. Use a packed struct.
980 llvm::SmallVector<llvm::Type *, 16> Types;
981 Types.reserve(Elements.size());
982 for (llvm::Constant *Elt : Elements)
983 Types.push_back(Elt->getType());
984 llvm::StructType *SType =
985 llvm::StructType::get(CGM.getLLVMContext(), Types, true);
986 return llvm::ConstantStruct::get(SType, Elements);
987}
988
989// This class only needs to handle arrays, structs and unions. Outside C++11
990// mode, we don't currently constant fold those types. All other types are
991// handled by constant folding.
992//
993// Constant folding is currently missing support for a few features supported
994// here: CK_ToUnion, CK_ReinterpretMemberPointer, and DesignatedInitUpdateExpr.
995class ConstExprEmitter :
996 public StmtVisitor<ConstExprEmitter, llvm::Constant*, QualType> {
997 CodeGenModule &CGM;
998 ConstantEmitter &Emitter;
999 llvm::LLVMContext &VMContext;
1000public:
1001 ConstExprEmitter(ConstantEmitter &emitter)
1002 : CGM(emitter.CGM), Emitter(emitter), VMContext(CGM.getLLVMContext()) {
1003 }
1004
1005 //===--------------------------------------------------------------------===//
1006 // Visitor Methods
1007 //===--------------------------------------------------------------------===//
1008
1009 llvm::Constant *VisitStmt(Stmt *S, QualType T) {
1010 return nullptr;
1011 }
1012
1013 llvm::Constant *VisitConstantExpr(ConstantExpr *CE, QualType T) {
1014 if (llvm::Constant *Result = Emitter.tryEmitConstantExpr(CE))
1015 return Result;
1016 return Visit(CE->getSubExpr(), T);
1017 }
1018
1019 llvm::Constant *VisitParenExpr(ParenExpr *PE, QualType T) {
1020 return Visit(PE->getSubExpr(), T);
1021 }
1022
1023 llvm::Constant *
1024 VisitSubstNonTypeTemplateParmExpr(SubstNonTypeTemplateParmExpr *PE,
1025 QualType T) {
1026 return Visit(PE->getReplacement(), T);
1027 }
1028
1029 llvm::Constant *VisitGenericSelectionExpr(GenericSelectionExpr *GE,
1030 QualType T) {
1031 return Visit(GE->getResultExpr(), T);
1032 }
1033
1034 llvm::Constant *VisitChooseExpr(ChooseExpr *CE, QualType T) {
1035 return Visit(CE->getChosenSubExpr(), T);
1036 }
1037
1038 llvm::Constant *VisitCompoundLiteralExpr(CompoundLiteralExpr *E, QualType T) {
1039 return Visit(E->getInitializer(), T);
1040 }
1041
1042 llvm::Constant *VisitCastExpr(CastExpr *E, QualType destType) {
1043 if (const auto *ECE = dyn_cast<ExplicitCastExpr>(E))
1044 CGM.EmitExplicitCastExprType(ECE, Emitter.CGF);
1045 Expr *subExpr = E->getSubExpr();
1046
1047 switch (E->getCastKind()) {
1048 case CK_ToUnion: {
1049 // GCC cast to union extension
1050 assert(E->getType()->isUnionType() &&((E->getType()->isUnionType() && "Destination type is not union type!"
) ? static_cast<void> (0) : __assert_fail ("E->getType()->isUnionType() && \"Destination type is not union type!\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1051, __PRETTY_FUNCTION__))
1051 "Destination type is not union type!")((E->getType()->isUnionType() && "Destination type is not union type!"
) ? static_cast<void> (0) : __assert_fail ("E->getType()->isUnionType() && \"Destination type is not union type!\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1051, __PRETTY_FUNCTION__))
;
1052
1053 auto field = E->getTargetUnionField();
1054
1055 auto C = Emitter.tryEmitPrivateForMemory(subExpr, field->getType());
1056 if (!C) return nullptr;
1057
1058 auto destTy = ConvertType(destType);
1059 if (C->getType() == destTy) return C;
1060
1061 // Build a struct with the union sub-element as the first member,
1062 // and padded to the appropriate size.
1063 SmallVector<llvm::Constant*, 2> Elts;
1064 SmallVector<llvm::Type*, 2> Types;
1065 Elts.push_back(C);
1066 Types.push_back(C->getType());
1067 unsigned CurSize = CGM.getDataLayout().getTypeAllocSize(C->getType());
1068 unsigned TotalSize = CGM.getDataLayout().getTypeAllocSize(destTy);
1069
1070 assert(CurSize <= TotalSize && "Union size mismatch!")((CurSize <= TotalSize && "Union size mismatch!") ?
static_cast<void> (0) : __assert_fail ("CurSize <= TotalSize && \"Union size mismatch!\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1070, __PRETTY_FUNCTION__))
;
1071 if (unsigned NumPadBytes = TotalSize - CurSize) {
1072 llvm::Type *Ty = CGM.CharTy;
1073 if (NumPadBytes > 1)
1074 Ty = llvm::ArrayType::get(Ty, NumPadBytes);
1075
1076 Elts.push_back(llvm::UndefValue::get(Ty));
1077 Types.push_back(Ty);
1078 }
1079
1080 llvm::StructType *STy = llvm::StructType::get(VMContext, Types, false);
1081 return llvm::ConstantStruct::get(STy, Elts);
1082 }
1083
1084 case CK_AddressSpaceConversion: {
1085 auto C = Emitter.tryEmitPrivate(subExpr, subExpr->getType());
1086 if (!C) return nullptr;
1087 LangAS destAS = E->getType()->getPointeeType().getAddressSpace();
1088 LangAS srcAS = subExpr->getType()->getPointeeType().getAddressSpace();
1089 llvm::Type *destTy = ConvertType(E->getType());
1090 return CGM.getTargetCodeGenInfo().performAddrSpaceCast(CGM, C, srcAS,
1091 destAS, destTy);
1092 }
1093
1094 case CK_LValueToRValue:
1095 case CK_AtomicToNonAtomic:
1096 case CK_NonAtomicToAtomic:
1097 case CK_NoOp:
1098 case CK_ConstructorConversion:
1099 return Visit(subExpr, destType);
1100
1101 case CK_IntToOCLSampler:
1102 llvm_unreachable("global sampler variables are not generated")::llvm::llvm_unreachable_internal("global sampler variables are not generated"
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1102)
;
1103
1104 case CK_Dependent: llvm_unreachable("saw dependent cast!")::llvm::llvm_unreachable_internal("saw dependent cast!", "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1104)
;
1105
1106 case CK_BuiltinFnToFnPtr:
1107 llvm_unreachable("builtin functions are handled elsewhere")::llvm::llvm_unreachable_internal("builtin functions are handled elsewhere"
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1107)
;
1108
1109 case CK_ReinterpretMemberPointer:
1110 case CK_DerivedToBaseMemberPointer:
1111 case CK_BaseToDerivedMemberPointer: {
1112 auto C = Emitter.tryEmitPrivate(subExpr, subExpr->getType());
1113 if (!C) return nullptr;
1114 return CGM.getCXXABI().EmitMemberPointerConversion(E, C);
1115 }
1116
1117 // These will never be supported.
1118 case CK_ObjCObjectLValueCast:
1119 case CK_ARCProduceObject:
1120 case CK_ARCConsumeObject:
1121 case CK_ARCReclaimReturnedObject:
1122 case CK_ARCExtendBlockObject:
1123 case CK_CopyAndAutoreleaseBlockObject:
1124 return nullptr;
1125
1126 // These don't need to be handled here because Evaluate knows how to
1127 // evaluate them in the cases where they can be folded.
1128 case CK_BitCast:
1129 case CK_ToVoid:
1130 case CK_Dynamic:
1131 case CK_LValueBitCast:
1132 case CK_LValueToRValueBitCast:
1133 case CK_NullToMemberPointer:
1134 case CK_UserDefinedConversion:
1135 case CK_CPointerToObjCPointerCast:
1136 case CK_BlockPointerToObjCPointerCast:
1137 case CK_AnyPointerToBlockPointerCast:
1138 case CK_ArrayToPointerDecay:
1139 case CK_FunctionToPointerDecay:
1140 case CK_BaseToDerived:
1141 case CK_DerivedToBase:
1142 case CK_UncheckedDerivedToBase:
1143 case CK_MemberPointerToBoolean:
1144 case CK_VectorSplat:
1145 case CK_FloatingRealToComplex:
1146 case CK_FloatingComplexToReal:
1147 case CK_FloatingComplexToBoolean:
1148 case CK_FloatingComplexCast:
1149 case CK_FloatingComplexToIntegralComplex:
1150 case CK_IntegralRealToComplex:
1151 case CK_IntegralComplexToReal:
1152 case CK_IntegralComplexToBoolean:
1153 case CK_IntegralComplexCast:
1154 case CK_IntegralComplexToFloatingComplex:
1155 case CK_PointerToIntegral:
1156 case CK_PointerToBoolean:
1157 case CK_NullToPointer:
1158 case CK_IntegralCast:
1159 case CK_BooleanToSignedIntegral:
1160 case CK_IntegralToPointer:
1161 case CK_IntegralToBoolean:
1162 case CK_IntegralToFloating:
1163 case CK_FloatingToIntegral:
1164 case CK_FloatingToBoolean:
1165 case CK_FloatingCast:
1166 case CK_FloatingToFixedPoint:
1167 case CK_FixedPointToFloating:
1168 case CK_FixedPointCast:
1169 case CK_FixedPointToBoolean:
1170 case CK_FixedPointToIntegral:
1171 case CK_IntegralToFixedPoint:
1172 case CK_ZeroToOCLOpaqueType:
1173 return nullptr;
1174 }
1175 llvm_unreachable("Invalid CastKind")::llvm::llvm_unreachable_internal("Invalid CastKind", "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1175)
;
1176 }
1177
1178 llvm::Constant *VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE, QualType T) {
1179 // No need for a DefaultInitExprScope: we don't handle 'this' in a
1180 // constant expression.
1181 return Visit(DIE->getExpr(), T);
1182 }
1183
1184 llvm::Constant *VisitExprWithCleanups(ExprWithCleanups *E, QualType T) {
1185 return Visit(E->getSubExpr(), T);
1186 }
1187
1188 llvm::Constant *VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E,
1189 QualType T) {
1190 return Visit(E->getSubExpr(), T);
1191 }
1192
1193 llvm::Constant *EmitArrayInitialization(InitListExpr *ILE, QualType T) {
1194 auto *CAT = CGM.getContext().getAsConstantArrayType(ILE->getType());
1195 assert(CAT && "can't emit array init for non-constant-bound array")((CAT && "can't emit array init for non-constant-bound array"
) ? static_cast<void> (0) : __assert_fail ("CAT && \"can't emit array init for non-constant-bound array\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1195, __PRETTY_FUNCTION__))
;
5
'?' condition is true
1196 unsigned NumInitElements = ILE->getNumInits();
1197 unsigned NumElements = CAT->getSize().getZExtValue();
1198
1199 // Initialising an array requires us to automatically
1200 // initialise any elements that have not been initialised explicitly
1201 unsigned NumInitableElts = std::min(NumInitElements, NumElements);
1202
1203 QualType EltType = CAT->getElementType();
1204
1205 // Initialize remaining array elements.
1206 llvm::Constant *fillC = nullptr;
6
'fillC' initialized to a null pointer value
1207 if (Expr *filler = ILE->getArrayFiller()) {
7
Assuming 'filler' is null
8
Taking false branch
1208 fillC = Emitter.tryEmitAbstractForMemory(filler, EltType);
1209 if (!fillC)
1210 return nullptr;
1211 }
1212
1213 // Copy initializer elements.
1214 SmallVector<llvm::Constant*, 16> Elts;
1215 if (fillC
8.1
'fillC' is null
&& fillC->isNullValue())
1216 Elts.reserve(NumInitableElts + 1);
1217 else
1218 Elts.reserve(NumElements);
1219
1220 llvm::Type *CommonElementType = nullptr;
1221 for (unsigned i = 0; i < NumInitableElts; ++i) {
9
Assuming 'i' is >= 'NumInitableElts'
10
Loop condition is false. Execution continues on line 1234
1222 Expr *Init = ILE->getInit(i);
1223 llvm::Constant *C = Emitter.tryEmitPrivateForMemory(Init, EltType);
1224 if (!C)
1225 return nullptr;
1226 if (i == 0)
1227 CommonElementType = C->getType();
1228 else if (C->getType() != CommonElementType)
1229 CommonElementType = nullptr;
1230 Elts.push_back(C);
1231 }
1232
1233 llvm::ArrayType *Desired =
1234 cast<llvm::ArrayType>(CGM.getTypes().ConvertType(ILE->getType()));
11
The object is a 'ArrayType'
1235 return EmitArrayConstant(CGM, Desired, CommonElementType, NumElements, Elts,
13
Calling 'EmitArrayConstant'
1236 fillC);
12
Passing null pointer value via 6th parameter 'Filler'
1237 }
1238
1239 llvm::Constant *EmitRecordInitialization(InitListExpr *ILE, QualType T) {
1240 return ConstStructBuilder::BuildStruct(Emitter, ILE, T);
1241 }
1242
1243 llvm::Constant *VisitImplicitValueInitExpr(ImplicitValueInitExpr* E,
1244 QualType T) {
1245 return CGM.EmitNullConstant(T);
1246 }
1247
1248 llvm::Constant *VisitInitListExpr(InitListExpr *ILE, QualType T) {
1249 if (ILE->isTransparent())
1
Assuming the condition is false
2
Taking false branch
1250 return Visit(ILE->getInit(0), T);
1251
1252 if (ILE->getType()->isArrayType())
3
Taking true branch
1253 return EmitArrayInitialization(ILE, T);
4
Calling 'ConstExprEmitter::EmitArrayInitialization'
1254
1255 if (ILE->getType()->isRecordType())
1256 return EmitRecordInitialization(ILE, T);
1257
1258 return nullptr;
1259 }
1260
1261 llvm::Constant *VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E,
1262 QualType destType) {
1263 auto C = Visit(E->getBase(), destType);
1264 if (!C)
1265 return nullptr;
1266
1267 ConstantAggregateBuilder Const(CGM);
1268 Const.add(C, CharUnits::Zero(), false);
1269
1270 if (!EmitDesignatedInitUpdater(Emitter, Const, CharUnits::Zero(), destType,
1271 E->getUpdater()))
1272 return nullptr;
1273
1274 llvm::Type *ValTy = CGM.getTypes().ConvertType(destType);
1275 bool HasFlexibleArray = false;
1276 if (auto *RT = destType->getAs<RecordType>())
1277 HasFlexibleArray = RT->getDecl()->hasFlexibleArrayMember();
1278 return Const.build(ValTy, HasFlexibleArray);
1279 }
1280
1281 llvm::Constant *VisitCXXConstructExpr(CXXConstructExpr *E, QualType Ty) {
1282 if (!E->getConstructor()->isTrivial())
1283 return nullptr;
1284
1285 // Only default and copy/move constructors can be trivial.
1286 if (E->getNumArgs()) {
1287 assert(E->getNumArgs() == 1 && "trivial ctor with > 1 argument")((E->getNumArgs() == 1 && "trivial ctor with > 1 argument"
) ? static_cast<void> (0) : __assert_fail ("E->getNumArgs() == 1 && \"trivial ctor with > 1 argument\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1287, __PRETTY_FUNCTION__))
;
1288 assert(E->getConstructor()->isCopyOrMoveConstructor() &&((E->getConstructor()->isCopyOrMoveConstructor() &&
"trivial ctor has argument but isn't a copy/move ctor") ? static_cast
<void> (0) : __assert_fail ("E->getConstructor()->isCopyOrMoveConstructor() && \"trivial ctor has argument but isn't a copy/move ctor\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1289, __PRETTY_FUNCTION__))
1289 "trivial ctor has argument but isn't a copy/move ctor")((E->getConstructor()->isCopyOrMoveConstructor() &&
"trivial ctor has argument but isn't a copy/move ctor") ? static_cast
<void> (0) : __assert_fail ("E->getConstructor()->isCopyOrMoveConstructor() && \"trivial ctor has argument but isn't a copy/move ctor\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1289, __PRETTY_FUNCTION__))
;
1290
1291 Expr *Arg = E->getArg(0);
1292 assert(CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) &&((CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType
()) && "argument to copy ctor is of wrong type") ? static_cast
<void> (0) : __assert_fail ("CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) && \"argument to copy ctor is of wrong type\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1293, __PRETTY_FUNCTION__))
1293 "argument to copy ctor is of wrong type")((CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType
()) && "argument to copy ctor is of wrong type") ? static_cast
<void> (0) : __assert_fail ("CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) && \"argument to copy ctor is of wrong type\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1293, __PRETTY_FUNCTION__))
;
1294
1295 return Visit(Arg, Ty);
1296 }
1297
1298 return CGM.EmitNullConstant(Ty);
1299 }
1300
1301 llvm::Constant *VisitStringLiteral(StringLiteral *E, QualType T) {
1302 // This is a string literal initializing an array in an initializer.
1303 return CGM.GetConstantArrayFromStringLiteral(E);
1304 }
1305
1306 llvm::Constant *VisitObjCEncodeExpr(ObjCEncodeExpr *E, QualType T) {
1307 // This must be an @encode initializing an array in a static initializer.
1308 // Don't emit it as the address of the string, emit the string data itself
1309 // as an inline array.
1310 std::string Str;
1311 CGM.getContext().getObjCEncodingForType(E->getEncodedType(), Str);
1312 const ConstantArrayType *CAT = CGM.getContext().getAsConstantArrayType(T);
1313
1314 // Resize the string to the right size, adding zeros at the end, or
1315 // truncating as needed.
1316 Str.resize(CAT->getSize().getZExtValue(), '\0');
1317 return llvm::ConstantDataArray::getString(VMContext, Str, false);
1318 }
1319
1320 llvm::Constant *VisitUnaryExtension(const UnaryOperator *E, QualType T) {
1321 return Visit(E->getSubExpr(), T);
1322 }
1323
1324 // Utility methods
1325 llvm::Type *ConvertType(QualType T) {
1326 return CGM.getTypes().ConvertType(T);
1327 }
1328};
1329
1330} // end anonymous namespace.
1331
1332llvm::Constant *ConstantEmitter::validateAndPopAbstract(llvm::Constant *C,
1333 AbstractState saved) {
1334 Abstract = saved.OldValue;
1335
1336 assert(saved.OldPlaceholdersSize == PlaceholderAddresses.size() &&((saved.OldPlaceholdersSize == PlaceholderAddresses.size() &&
"created a placeholder while doing an abstract emission?") ?
static_cast<void> (0) : __assert_fail ("saved.OldPlaceholdersSize == PlaceholderAddresses.size() && \"created a placeholder while doing an abstract emission?\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1337, __PRETTY_FUNCTION__))
1337 "created a placeholder while doing an abstract emission?")((saved.OldPlaceholdersSize == PlaceholderAddresses.size() &&
"created a placeholder while doing an abstract emission?") ?
static_cast<void> (0) : __assert_fail ("saved.OldPlaceholdersSize == PlaceholderAddresses.size() && \"created a placeholder while doing an abstract emission?\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1337, __PRETTY_FUNCTION__))
;
1338
1339 // No validation necessary for now.
1340 // No cleanup to do for now.
1341 return C;
1342}
1343
1344llvm::Constant *
1345ConstantEmitter::tryEmitAbstractForInitializer(const VarDecl &D) {
1346 auto state = pushAbstract();
1347 auto C = tryEmitPrivateForVarInit(D);
1348 return validateAndPopAbstract(C, state);
1349}
1350
1351llvm::Constant *
1352ConstantEmitter::tryEmitAbstract(const Expr *E, QualType destType) {
1353 auto state = pushAbstract();
1354 auto C = tryEmitPrivate(E, destType);
1355 return validateAndPopAbstract(C, state);
1356}
1357
1358llvm::Constant *
1359ConstantEmitter::tryEmitAbstract(const APValue &value, QualType destType) {
1360 auto state = pushAbstract();
1361 auto C = tryEmitPrivate(value, destType);
1362 return validateAndPopAbstract(C, state);
1363}
1364
1365llvm::Constant *ConstantEmitter::tryEmitConstantExpr(const ConstantExpr *CE) {
1366 if (!CE->hasAPValueResult())
1367 return nullptr;
1368 const Expr *Inner = CE->getSubExpr()->IgnoreImplicit();
1369 QualType RetType;
1370 if (auto *Call = dyn_cast<CallExpr>(Inner))
1371 RetType = Call->getCallReturnType(CGF->getContext());
1372 else if (auto *Ctor = dyn_cast<CXXConstructExpr>(Inner))
1373 RetType = Ctor->getType();
1374 llvm::Constant *Res =
1375 emitAbstract(CE->getBeginLoc(), CE->getAPValueResult(), RetType);
1376 return Res;
1377}
1378
1379llvm::Constant *
1380ConstantEmitter::emitAbstract(const Expr *E, QualType destType) {
1381 auto state = pushAbstract();
1382 auto C = tryEmitPrivate(E, destType);
1383 C = validateAndPopAbstract(C, state);
1384 if (!C) {
1385 CGM.Error(E->getExprLoc(),
1386 "internal error: could not emit constant value \"abstractly\"");
1387 C = CGM.EmitNullConstant(destType);
1388 }
1389 return C;
1390}
1391
1392llvm::Constant *
1393ConstantEmitter::emitAbstract(SourceLocation loc, const APValue &value,
1394 QualType destType) {
1395 auto state = pushAbstract();
1396 auto C = tryEmitPrivate(value, destType);
1397 C = validateAndPopAbstract(C, state);
1398 if (!C) {
1399 CGM.Error(loc,
1400 "internal error: could not emit constant value \"abstractly\"");
1401 C = CGM.EmitNullConstant(destType);
1402 }
1403 return C;
1404}
1405
1406llvm::Constant *ConstantEmitter::tryEmitForInitializer(const VarDecl &D) {
1407 initializeNonAbstract(D.getType().getAddressSpace());
1408 return markIfFailed(tryEmitPrivateForVarInit(D));
1409}
1410
1411llvm::Constant *ConstantEmitter::tryEmitForInitializer(const Expr *E,
1412 LangAS destAddrSpace,
1413 QualType destType) {
1414 initializeNonAbstract(destAddrSpace);
1415 return markIfFailed(tryEmitPrivateForMemory(E, destType));
1416}
1417
1418llvm::Constant *ConstantEmitter::emitForInitializer(const APValue &value,
1419 LangAS destAddrSpace,
1420 QualType destType) {
1421 initializeNonAbstract(destAddrSpace);
1422 auto C = tryEmitPrivateForMemory(value, destType);
1423 assert(C && "couldn't emit constant value non-abstractly?")((C && "couldn't emit constant value non-abstractly?"
) ? static_cast<void> (0) : __assert_fail ("C && \"couldn't emit constant value non-abstractly?\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1423, __PRETTY_FUNCTION__))
;
1424 return C;
1425}
1426
1427llvm::GlobalValue *ConstantEmitter::getCurrentAddrPrivate() {
1428 assert(!Abstract && "cannot get current address for abstract constant")((!Abstract && "cannot get current address for abstract constant"
) ? static_cast<void> (0) : __assert_fail ("!Abstract && \"cannot get current address for abstract constant\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1428, __PRETTY_FUNCTION__))
;
1429
1430
1431
1432 // Make an obviously ill-formed global that should blow up compilation
1433 // if it survives.
1434 auto global = new llvm::GlobalVariable(CGM.getModule(), CGM.Int8Ty, true,
1435 llvm::GlobalValue::PrivateLinkage,
1436 /*init*/ nullptr,
1437 /*name*/ "",
1438 /*before*/ nullptr,
1439 llvm::GlobalVariable::NotThreadLocal,
1440 CGM.getContext().getTargetAddressSpace(DestAddressSpace));
1441
1442 PlaceholderAddresses.push_back(std::make_pair(nullptr, global));
1443
1444 return global;
1445}
1446
1447void ConstantEmitter::registerCurrentAddrPrivate(llvm::Constant *signal,
1448 llvm::GlobalValue *placeholder) {
1449 assert(!PlaceholderAddresses.empty())((!PlaceholderAddresses.empty()) ? static_cast<void> (0
) : __assert_fail ("!PlaceholderAddresses.empty()", "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1449, __PRETTY_FUNCTION__))
;
1450 assert(PlaceholderAddresses.back().first == nullptr)((PlaceholderAddresses.back().first == nullptr) ? static_cast
<void> (0) : __assert_fail ("PlaceholderAddresses.back().first == nullptr"
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1450, __PRETTY_FUNCTION__))
;
1451 assert(PlaceholderAddresses.back().second == placeholder)((PlaceholderAddresses.back().second == placeholder) ? static_cast
<void> (0) : __assert_fail ("PlaceholderAddresses.back().second == placeholder"
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1451, __PRETTY_FUNCTION__))
;
1452 PlaceholderAddresses.back().first = signal;
1453}
1454
1455namespace {
1456 struct ReplacePlaceholders {
1457 CodeGenModule &CGM;
1458
1459 /// The base address of the global.
1460 llvm::Constant *Base;
1461 llvm::Type *BaseValueTy = nullptr;
1462
1463 /// The placeholder addresses that were registered during emission.
1464 llvm::DenseMap<llvm::Constant*, llvm::GlobalVariable*> PlaceholderAddresses;
1465
1466 /// The locations of the placeholder signals.
1467 llvm::DenseMap<llvm::GlobalVariable*, llvm::Constant*> Locations;
1468
1469 /// The current index stack. We use a simple unsigned stack because
1470 /// we assume that placeholders will be relatively sparse in the
1471 /// initializer, but we cache the index values we find just in case.
1472 llvm::SmallVector<unsigned, 8> Indices;
1473 llvm::SmallVector<llvm::Constant*, 8> IndexValues;
1474
1475 ReplacePlaceholders(CodeGenModule &CGM, llvm::Constant *base,
1476 ArrayRef<std::pair<llvm::Constant*,
1477 llvm::GlobalVariable*>> addresses)
1478 : CGM(CGM), Base(base),
1479 PlaceholderAddresses(addresses.begin(), addresses.end()) {
1480 }
1481
1482 void replaceInInitializer(llvm::Constant *init) {
1483 // Remember the type of the top-most initializer.
1484 BaseValueTy = init->getType();
1485
1486 // Initialize the stack.
1487 Indices.push_back(0);
1488 IndexValues.push_back(nullptr);
1489
1490 // Recurse into the initializer.
1491 findLocations(init);
1492
1493 // Check invariants.
1494 assert(IndexValues.size() == Indices.size() && "mismatch")((IndexValues.size() == Indices.size() && "mismatch")
? static_cast<void> (0) : __assert_fail ("IndexValues.size() == Indices.size() && \"mismatch\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1494, __PRETTY_FUNCTION__))
;
1495 assert(Indices.size() == 1 && "didn't pop all indices")((Indices.size() == 1 && "didn't pop all indices") ? static_cast
<void> (0) : __assert_fail ("Indices.size() == 1 && \"didn't pop all indices\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1495, __PRETTY_FUNCTION__))
;
1496
1497 // Do the replacement; this basically invalidates 'init'.
1498 assert(Locations.size() == PlaceholderAddresses.size() &&((Locations.size() == PlaceholderAddresses.size() && "missed a placeholder?"
) ? static_cast<void> (0) : __assert_fail ("Locations.size() == PlaceholderAddresses.size() && \"missed a placeholder?\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1499, __PRETTY_FUNCTION__))
1499 "missed a placeholder?")((Locations.size() == PlaceholderAddresses.size() && "missed a placeholder?"
) ? static_cast<void> (0) : __assert_fail ("Locations.size() == PlaceholderAddresses.size() && \"missed a placeholder?\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1499, __PRETTY_FUNCTION__))
;
1500
1501 // We're iterating over a hashtable, so this would be a source of
1502 // non-determinism in compiler output *except* that we're just
1503 // messing around with llvm::Constant structures, which never itself
1504 // does anything that should be visible in compiler output.
1505 for (auto &entry : Locations) {
1506 assert(entry.first->getParent() == nullptr && "not a placeholder!")((entry.first->getParent() == nullptr && "not a placeholder!"
) ? static_cast<void> (0) : __assert_fail ("entry.first->getParent() == nullptr && \"not a placeholder!\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1506, __PRETTY_FUNCTION__))
;
1507 entry.first->replaceAllUsesWith(entry.second);
1508 entry.first->eraseFromParent();
1509 }
1510 }
1511
1512 private:
1513 void findLocations(llvm::Constant *init) {
1514 // Recurse into aggregates.
1515 if (auto agg = dyn_cast<llvm::ConstantAggregate>(init)) {
1516 for (unsigned i = 0, e = agg->getNumOperands(); i != e; ++i) {
1517 Indices.push_back(i);
1518 IndexValues.push_back(nullptr);
1519
1520 findLocations(agg->getOperand(i));
1521
1522 IndexValues.pop_back();
1523 Indices.pop_back();
1524 }
1525 return;
1526 }
1527
1528 // Otherwise, check for registered constants.
1529 while (true) {
1530 auto it = PlaceholderAddresses.find(init);
1531 if (it != PlaceholderAddresses.end()) {
1532 setLocation(it->second);
1533 break;
1534 }
1535
1536 // Look through bitcasts or other expressions.
1537 if (auto expr = dyn_cast<llvm::ConstantExpr>(init)) {
1538 init = expr->getOperand(0);
1539 } else {
1540 break;
1541 }
1542 }
1543 }
1544
1545 void setLocation(llvm::GlobalVariable *placeholder) {
1546 assert(Locations.find(placeholder) == Locations.end() &&((Locations.find(placeholder) == Locations.end() && "already found location for placeholder!"
) ? static_cast<void> (0) : __assert_fail ("Locations.find(placeholder) == Locations.end() && \"already found location for placeholder!\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1547, __PRETTY_FUNCTION__))
1547 "already found location for placeholder!")((Locations.find(placeholder) == Locations.end() && "already found location for placeholder!"
) ? static_cast<void> (0) : __assert_fail ("Locations.find(placeholder) == Locations.end() && \"already found location for placeholder!\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1547, __PRETTY_FUNCTION__))
;
1548
1549 // Lazily fill in IndexValues with the values from Indices.
1550 // We do this in reverse because we should always have a strict
1551 // prefix of indices from the start.
1552 assert(Indices.size() == IndexValues.size())((Indices.size() == IndexValues.size()) ? static_cast<void
> (0) : __assert_fail ("Indices.size() == IndexValues.size()"
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1552, __PRETTY_FUNCTION__))
;
1553 for (size_t i = Indices.size() - 1; i != size_t(-1); --i) {
1554 if (IndexValues[i]) {
1555#ifndef NDEBUG
1556 for (size_t j = 0; j != i + 1; ++j) {
1557 assert(IndexValues[j] &&((IndexValues[j] && isa<llvm::ConstantInt>(IndexValues
[j]) && cast<llvm::ConstantInt>(IndexValues[j])
->getZExtValue() == Indices[j]) ? static_cast<void> (
0) : __assert_fail ("IndexValues[j] && isa<llvm::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue() == Indices[j]"
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1560, __PRETTY_FUNCTION__))
1558 isa<llvm::ConstantInt>(IndexValues[j]) &&((IndexValues[j] && isa<llvm::ConstantInt>(IndexValues
[j]) && cast<llvm::ConstantInt>(IndexValues[j])
->getZExtValue() == Indices[j]) ? static_cast<void> (
0) : __assert_fail ("IndexValues[j] && isa<llvm::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue() == Indices[j]"
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1560, __PRETTY_FUNCTION__))
1559 cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue()((IndexValues[j] && isa<llvm::ConstantInt>(IndexValues
[j]) && cast<llvm::ConstantInt>(IndexValues[j])
->getZExtValue() == Indices[j]) ? static_cast<void> (
0) : __assert_fail ("IndexValues[j] && isa<llvm::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue() == Indices[j]"
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1560, __PRETTY_FUNCTION__))
1560 == Indices[j])((IndexValues[j] && isa<llvm::ConstantInt>(IndexValues
[j]) && cast<llvm::ConstantInt>(IndexValues[j])
->getZExtValue() == Indices[j]) ? static_cast<void> (
0) : __assert_fail ("IndexValues[j] && isa<llvm::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue() == Indices[j]"
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1560, __PRETTY_FUNCTION__))
;
1561 }
1562#endif
1563 break;
1564 }
1565
1566 IndexValues[i] = llvm::ConstantInt::get(CGM.Int32Ty, Indices[i]);
1567 }
1568
1569 // Form a GEP and then bitcast to the placeholder type so that the
1570 // replacement will succeed.
1571 llvm::Constant *location =
1572 llvm::ConstantExpr::getInBoundsGetElementPtr(BaseValueTy,
1573 Base, IndexValues);
1574 location = llvm::ConstantExpr::getBitCast(location,
1575 placeholder->getType());
1576
1577 Locations.insert({placeholder, location});
1578 }
1579 };
1580}
1581
1582void ConstantEmitter::finalize(llvm::GlobalVariable *global) {
1583 assert(InitializedNonAbstract &&((InitializedNonAbstract && "finalizing emitter that was used for abstract emission?"
) ? static_cast<void> (0) : __assert_fail ("InitializedNonAbstract && \"finalizing emitter that was used for abstract emission?\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1584, __PRETTY_FUNCTION__))
1584 "finalizing emitter that was used for abstract emission?")((InitializedNonAbstract && "finalizing emitter that was used for abstract emission?"
) ? static_cast<void> (0) : __assert_fail ("InitializedNonAbstract && \"finalizing emitter that was used for abstract emission?\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1584, __PRETTY_FUNCTION__))
;
1585 assert(!Finalized && "finalizing emitter multiple times")((!Finalized && "finalizing emitter multiple times") ?
static_cast<void> (0) : __assert_fail ("!Finalized && \"finalizing emitter multiple times\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1585, __PRETTY_FUNCTION__))
;
1586 assert(global->getInitializer())((global->getInitializer()) ? static_cast<void> (0) :
__assert_fail ("global->getInitializer()", "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1586, __PRETTY_FUNCTION__))
;
1587
1588 // Note that we might also be Failed.
1589 Finalized = true;
1590
1591 if (!PlaceholderAddresses.empty()) {
1592 ReplacePlaceholders(CGM, global, PlaceholderAddresses)
1593 .replaceInInitializer(global->getInitializer());
1594 PlaceholderAddresses.clear(); // satisfy
1595 }
1596}
1597
1598ConstantEmitter::~ConstantEmitter() {
1599 assert((!InitializedNonAbstract || Finalized || Failed) &&(((!InitializedNonAbstract || Finalized || Failed) &&
"not finalized after being initialized for non-abstract emission"
) ? static_cast<void> (0) : __assert_fail ("(!InitializedNonAbstract || Finalized || Failed) && \"not finalized after being initialized for non-abstract emission\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1600, __PRETTY_FUNCTION__))
1600 "not finalized after being initialized for non-abstract emission")(((!InitializedNonAbstract || Finalized || Failed) &&
"not finalized after being initialized for non-abstract emission"
) ? static_cast<void> (0) : __assert_fail ("(!InitializedNonAbstract || Finalized || Failed) && \"not finalized after being initialized for non-abstract emission\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1600, __PRETTY_FUNCTION__))
;
1601 assert(PlaceholderAddresses.empty() && "unhandled placeholders")((PlaceholderAddresses.empty() && "unhandled placeholders"
) ? static_cast<void> (0) : __assert_fail ("PlaceholderAddresses.empty() && \"unhandled placeholders\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1601, __PRETTY_FUNCTION__))
;
1602}
1603
1604static QualType getNonMemoryType(CodeGenModule &CGM, QualType type) {
1605 if (auto AT = type->getAs<AtomicType>()) {
1606 return CGM.getContext().getQualifiedType(AT->getValueType(),
1607 type.getQualifiers());
1608 }
1609 return type;
1610}
1611
1612llvm::Constant *ConstantEmitter::tryEmitPrivateForVarInit(const VarDecl &D) {
1613 // Make a quick check if variable can be default NULL initialized
1614 // and avoid going through rest of code which may do, for c++11,
1615 // initialization of memory to all NULLs.
1616 if (!D.hasLocalStorage()) {
1617 QualType Ty = CGM.getContext().getBaseElementType(D.getType());
1618 if (Ty->isRecordType())
1619 if (const CXXConstructExpr *E =
1620 dyn_cast_or_null<CXXConstructExpr>(D.getInit())) {
1621 const CXXConstructorDecl *CD = E->getConstructor();
1622 if (CD->isTrivial() && CD->isDefaultConstructor())
1623 return CGM.EmitNullConstant(D.getType());
1624 }
1625 }
1626 InConstantContext = D.hasConstantInitialization();
1627
1628 QualType destType = D.getType();
1629
1630 // Try to emit the initializer. Note that this can allow some things that
1631 // are not allowed by tryEmitPrivateForMemory alone.
1632 if (auto value = D.evaluateValue()) {
1633 return tryEmitPrivateForMemory(*value, destType);
1634 }
1635
1636 // FIXME: Implement C++11 [basic.start.init]p2: if the initializer of a
1637 // reference is a constant expression, and the reference binds to a temporary,
1638 // then constant initialization is performed. ConstExprEmitter will
1639 // incorrectly emit a prvalue constant in this case, and the calling code
1640 // interprets that as the (pointer) value of the reference, rather than the
1641 // desired value of the referee.
1642 if (destType->isReferenceType())
1643 return nullptr;
1644
1645 const Expr *E = D.getInit();
1646 assert(E && "No initializer to emit")((E && "No initializer to emit") ? static_cast<void
> (0) : __assert_fail ("E && \"No initializer to emit\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1646, __PRETTY_FUNCTION__))
;
1647
1648 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1649 auto C =
1650 ConstExprEmitter(*this).Visit(const_cast<Expr*>(E), nonMemoryDestType);
1651 return (C ? emitForMemory(C, destType) : nullptr);
1652}
1653
1654llvm::Constant *
1655ConstantEmitter::tryEmitAbstractForMemory(const Expr *E, QualType destType) {
1656 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1657 auto C = tryEmitAbstract(E, nonMemoryDestType);
1658 return (C ? emitForMemory(C, destType) : nullptr);
1659}
1660
1661llvm::Constant *
1662ConstantEmitter::tryEmitAbstractForMemory(const APValue &value,
1663 QualType destType) {
1664 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1665 auto C = tryEmitAbstract(value, nonMemoryDestType);
1666 return (C ? emitForMemory(C, destType) : nullptr);
1667}
1668
1669llvm::Constant *ConstantEmitter::tryEmitPrivateForMemory(const Expr *E,
1670 QualType destType) {
1671 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1672 llvm::Constant *C = tryEmitPrivate(E, nonMemoryDestType);
1673 return (C ? emitForMemory(C, destType) : nullptr);
1674}
1675
1676llvm::Constant *ConstantEmitter::tryEmitPrivateForMemory(const APValue &value,
1677 QualType destType) {
1678 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1679 auto C = tryEmitPrivate(value, nonMemoryDestType);
1680 return (C ? emitForMemory(C, destType) : nullptr);
1681}
1682
1683llvm::Constant *ConstantEmitter::emitForMemory(CodeGenModule &CGM,
1684 llvm::Constant *C,
1685 QualType destType) {
1686 // For an _Atomic-qualified constant, we may need to add tail padding.
1687 if (auto AT = destType->getAs<AtomicType>()) {
1688 QualType destValueType = AT->getValueType();
1689 C = emitForMemory(CGM, C, destValueType);
1690
1691 uint64_t innerSize = CGM.getContext().getTypeSize(destValueType);
1692 uint64_t outerSize = CGM.getContext().getTypeSize(destType);
1693 if (innerSize == outerSize)
1694 return C;
1695
1696 assert(innerSize < outerSize && "emitted over-large constant for atomic")((innerSize < outerSize && "emitted over-large constant for atomic"
) ? static_cast<void> (0) : __assert_fail ("innerSize < outerSize && \"emitted over-large constant for atomic\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1696, __PRETTY_FUNCTION__))
;
1697 llvm::Constant *elts[] = {
1698 C,
1699 llvm::ConstantAggregateZero::get(
1700 llvm::ArrayType::get(CGM.Int8Ty, (outerSize - innerSize) / 8))
1701 };
1702 return llvm::ConstantStruct::getAnon(elts);
1703 }
1704
1705 // Zero-extend bool.
1706 if (C->getType()->isIntegerTy(1)) {
1707 llvm::Type *boolTy = CGM.getTypes().ConvertTypeForMem(destType);
1708 return llvm::ConstantExpr::getZExt(C, boolTy);
1709 }
1710
1711 return C;
1712}
1713
1714llvm::Constant *ConstantEmitter::tryEmitPrivate(const Expr *E,
1715 QualType destType) {
1716 Expr::EvalResult Result;
1717
1718 bool Success = false;
1719
1720 if (destType->isReferenceType())
1721 Success = E->EvaluateAsLValue(Result, CGM.getContext());
1722 else
1723 Success = E->EvaluateAsRValue(Result, CGM.getContext(), InConstantContext);
1724
1725 llvm::Constant *C;
1726 if (Success && !Result.HasSideEffects)
1727 C = tryEmitPrivate(Result.Val, destType);
1728 else
1729 C = ConstExprEmitter(*this).Visit(const_cast<Expr*>(E), destType);
1730
1731 return C;
1732}
1733
1734llvm::Constant *CodeGenModule::getNullPointer(llvm::PointerType *T, QualType QT) {
1735 return getTargetCodeGenInfo().getNullPointer(*this, T, QT);
1736}
1737
1738namespace {
1739/// A struct which can be used to peephole certain kinds of finalization
1740/// that normally happen during l-value emission.
1741struct ConstantLValue {
1742 llvm::Constant *Value;
1743 bool HasOffsetApplied;
1744
1745 /*implicit*/ ConstantLValue(llvm::Constant *value,
1746 bool hasOffsetApplied = false)
1747 : Value(value), HasOffsetApplied(hasOffsetApplied) {}
1748
1749 /*implicit*/ ConstantLValue(ConstantAddress address)
1750 : ConstantLValue(address.getPointer()) {}
1751};
1752
1753/// A helper class for emitting constant l-values.
1754class ConstantLValueEmitter : public ConstStmtVisitor<ConstantLValueEmitter,
1755 ConstantLValue> {
1756 CodeGenModule &CGM;
1757 ConstantEmitter &Emitter;
1758 const APValue &Value;
1759 QualType DestType;
1760
1761 // Befriend StmtVisitorBase so that we don't have to expose Visit*.
1762 friend StmtVisitorBase;
1763
1764public:
1765 ConstantLValueEmitter(ConstantEmitter &emitter, const APValue &value,
1766 QualType destType)
1767 : CGM(emitter.CGM), Emitter(emitter), Value(value), DestType(destType) {}
1768
1769 llvm::Constant *tryEmit();
1770
1771private:
1772 llvm::Constant *tryEmitAbsolute(llvm::Type *destTy);
1773 ConstantLValue tryEmitBase(const APValue::LValueBase &base);
1774
1775 ConstantLValue VisitStmt(const Stmt *S) { return nullptr; }
1776 ConstantLValue VisitConstantExpr(const ConstantExpr *E);
1777 ConstantLValue VisitCompoundLiteralExpr(const CompoundLiteralExpr *E);
1778 ConstantLValue VisitStringLiteral(const StringLiteral *E);
1779 ConstantLValue VisitObjCBoxedExpr(const ObjCBoxedExpr *E);
1780 ConstantLValue VisitObjCEncodeExpr(const ObjCEncodeExpr *E);
1781 ConstantLValue VisitObjCStringLiteral(const ObjCStringLiteral *E);
1782 ConstantLValue VisitPredefinedExpr(const PredefinedExpr *E);
1783 ConstantLValue VisitAddrLabelExpr(const AddrLabelExpr *E);
1784 ConstantLValue VisitCallExpr(const CallExpr *E);
1785 ConstantLValue VisitBlockExpr(const BlockExpr *E);
1786 ConstantLValue VisitCXXTypeidExpr(const CXXTypeidExpr *E);
1787 ConstantLValue VisitMaterializeTemporaryExpr(
1788 const MaterializeTemporaryExpr *E);
1789
1790 bool hasNonZeroOffset() const {
1791 return !Value.getLValueOffset().isZero();
1792 }
1793
1794 /// Return the value offset.
1795 llvm::Constant *getOffset() {
1796 return llvm::ConstantInt::get(CGM.Int64Ty,
1797 Value.getLValueOffset().getQuantity());
1798 }
1799
1800 /// Apply the value offset to the given constant.
1801 llvm::Constant *applyOffset(llvm::Constant *C) {
1802 if (!hasNonZeroOffset())
1803 return C;
1804
1805 llvm::Type *origPtrTy = C->getType();
1806 unsigned AS = origPtrTy->getPointerAddressSpace();
1807 llvm::Type *charPtrTy = CGM.Int8Ty->getPointerTo(AS);
1808 C = llvm::ConstantExpr::getBitCast(C, charPtrTy);
1809 C = llvm::ConstantExpr::getGetElementPtr(CGM.Int8Ty, C, getOffset());
1810 C = llvm::ConstantExpr::getPointerCast(C, origPtrTy);
1811 return C;
1812 }
1813};
1814
1815}
1816
1817llvm::Constant *ConstantLValueEmitter::tryEmit() {
1818 const APValue::LValueBase &base = Value.getLValueBase();
1819
1820 // The destination type should be a pointer or reference
1821 // type, but it might also be a cast thereof.
1822 //
1823 // FIXME: the chain of casts required should be reflected in the APValue.
1824 // We need this in order to correctly handle things like a ptrtoint of a
1825 // non-zero null pointer and addrspace casts that aren't trivially
1826 // represented in LLVM IR.
1827 auto destTy = CGM.getTypes().ConvertTypeForMem(DestType);
1828 assert(isa<llvm::IntegerType>(destTy) || isa<llvm::PointerType>(destTy))((isa<llvm::IntegerType>(destTy) || isa<llvm::PointerType
>(destTy)) ? static_cast<void> (0) : __assert_fail (
"isa<llvm::IntegerType>(destTy) || isa<llvm::PointerType>(destTy)"
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1828, __PRETTY_FUNCTION__))
;
1829
1830 // If there's no base at all, this is a null or absolute pointer,
1831 // possibly cast back to an integer type.
1832 if (!base) {
1833 return tryEmitAbsolute(destTy);
1834 }
1835
1836 // Otherwise, try to emit the base.
1837 ConstantLValue result = tryEmitBase(base);
1838
1839 // If that failed, we're done.
1840 llvm::Constant *value = result.Value;
1841 if (!value) return nullptr;
1842
1843 // Apply the offset if necessary and not already done.
1844 if (!result.HasOffsetApplied) {
1845 value = applyOffset(value);
1846 }
1847
1848 // Convert to the appropriate type; this could be an lvalue for
1849 // an integer. FIXME: performAddrSpaceCast
1850 if (isa<llvm::PointerType>(destTy))
1851 return llvm::ConstantExpr::getPointerCast(value, destTy);
1852
1853 return llvm::ConstantExpr::getPtrToInt(value, destTy);
1854}
1855
1856/// Try to emit an absolute l-value, such as a null pointer or an integer
1857/// bitcast to pointer type.
1858llvm::Constant *
1859ConstantLValueEmitter::tryEmitAbsolute(llvm::Type *destTy) {
1860 // If we're producing a pointer, this is easy.
1861 auto destPtrTy = cast<llvm::PointerType>(destTy);
1862 if (Value.isNullPointer()) {
1863 // FIXME: integer offsets from non-zero null pointers.
1864 return CGM.getNullPointer(destPtrTy, DestType);
1865 }
1866
1867 // Convert the integer to a pointer-sized integer before converting it
1868 // to a pointer.
1869 // FIXME: signedness depends on the original integer type.
1870 auto intptrTy = CGM.getDataLayout().getIntPtrType(destPtrTy);
1871 llvm::Constant *C;
1872 C = llvm::ConstantExpr::getIntegerCast(getOffset(), intptrTy,
1873 /*isSigned*/ false);
1874 C = llvm::ConstantExpr::getIntToPtr(C, destPtrTy);
1875 return C;
1876}
1877
1878ConstantLValue
1879ConstantLValueEmitter::tryEmitBase(const APValue::LValueBase &base) {
1880 // Handle values.
1881 if (const ValueDecl *D = base.dyn_cast<const ValueDecl*>()) {
1882 // The constant always points to the canonical declaration. We want to look
1883 // at properties of the most recent declaration at the point of emission.
1884 D = cast<ValueDecl>(D->getMostRecentDecl());
1885
1886 if (D->hasAttr<WeakRefAttr>())
1887 return CGM.GetWeakRefReference(D).getPointer();
1888
1889 if (auto FD = dyn_cast<FunctionDecl>(D))
1890 return CGM.GetAddrOfFunction(FD);
1891
1892 if (auto VD = dyn_cast<VarDecl>(D)) {
1893 // We can never refer to a variable with local storage.
1894 if (!VD->hasLocalStorage()) {
1895 if (VD->isFileVarDecl() || VD->hasExternalStorage())
1896 return CGM.GetAddrOfGlobalVar(VD);
1897
1898 if (VD->isLocalVarDecl()) {
1899 return CGM.getOrCreateStaticVarDecl(
1900 *VD, CGM.getLLVMLinkageVarDefinition(VD, /*IsConstant=*/false));
1901 }
1902 }
1903 }
1904
1905 if (auto *GD = dyn_cast<MSGuidDecl>(D))
1906 return CGM.GetAddrOfMSGuidDecl(GD);
1907
1908 if (auto *TPO = dyn_cast<TemplateParamObjectDecl>(D))
1909 return CGM.GetAddrOfTemplateParamObject(TPO);
1910
1911 return nullptr;
1912 }
1913
1914 // Handle typeid(T).
1915 if (TypeInfoLValue TI = base.dyn_cast<TypeInfoLValue>()) {
1916 llvm::Type *StdTypeInfoPtrTy =
1917 CGM.getTypes().ConvertType(base.getTypeInfoType())->getPointerTo();
1918 llvm::Constant *TypeInfo =
1919 CGM.GetAddrOfRTTIDescriptor(QualType(TI.getType(), 0));
1920 if (TypeInfo->getType() != StdTypeInfoPtrTy)
1921 TypeInfo = llvm::ConstantExpr::getBitCast(TypeInfo, StdTypeInfoPtrTy);
1922 return TypeInfo;
1923 }
1924
1925 // Otherwise, it must be an expression.
1926 return Visit(base.get<const Expr*>());
1927}
1928
1929ConstantLValue
1930ConstantLValueEmitter::VisitConstantExpr(const ConstantExpr *E) {
1931 if (llvm::Constant *Result = Emitter.tryEmitConstantExpr(E))
1932 return Result;
1933 return Visit(E->getSubExpr());
1934}
1935
1936ConstantLValue
1937ConstantLValueEmitter::VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
1938 return tryEmitGlobalCompoundLiteral(CGM, Emitter.CGF, E);
1939}
1940
1941ConstantLValue
1942ConstantLValueEmitter::VisitStringLiteral(const StringLiteral *E) {
1943 return CGM.GetAddrOfConstantStringFromLiteral(E);
1944}
1945
1946ConstantLValue
1947ConstantLValueEmitter::VisitObjCEncodeExpr(const ObjCEncodeExpr *E) {
1948 return CGM.GetAddrOfConstantStringFromObjCEncode(E);
1949}
1950
1951static ConstantLValue emitConstantObjCStringLiteral(const StringLiteral *S,
1952 QualType T,
1953 CodeGenModule &CGM) {
1954 auto C = CGM.getObjCRuntime().GenerateConstantString(S);
1955 return C.getElementBitCast(CGM.getTypes().ConvertTypeForMem(T));
1956}
1957
1958ConstantLValue
1959ConstantLValueEmitter::VisitObjCStringLiteral(const ObjCStringLiteral *E) {
1960 return emitConstantObjCStringLiteral(E->getString(), E->getType(), CGM);
1961}
1962
1963ConstantLValue
1964ConstantLValueEmitter::VisitObjCBoxedExpr(const ObjCBoxedExpr *E) {
1965 assert(E->isExpressibleAsConstantInitializer() &&((E->isExpressibleAsConstantInitializer() && "this boxed expression can't be emitted as a compile-time constant"
) ? static_cast<void> (0) : __assert_fail ("E->isExpressibleAsConstantInitializer() && \"this boxed expression can't be emitted as a compile-time constant\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1966, __PRETTY_FUNCTION__))
1966 "this boxed expression can't be emitted as a compile-time constant")((E->isExpressibleAsConstantInitializer() && "this boxed expression can't be emitted as a compile-time constant"
) ? static_cast<void> (0) : __assert_fail ("E->isExpressibleAsConstantInitializer() && \"this boxed expression can't be emitted as a compile-time constant\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1966, __PRETTY_FUNCTION__))
;
1967 auto *SL = cast<StringLiteral>(E->getSubExpr()->IgnoreParenCasts());
1968 return emitConstantObjCStringLiteral(SL, E->getType(), CGM);
1969}
1970
1971ConstantLValue
1972ConstantLValueEmitter::VisitPredefinedExpr(const PredefinedExpr *E) {
1973 return CGM.GetAddrOfConstantStringFromLiteral(E->getFunctionName());
1974}
1975
1976ConstantLValue
1977ConstantLValueEmitter::VisitAddrLabelExpr(const AddrLabelExpr *E) {
1978 assert(Emitter.CGF && "Invalid address of label expression outside function")((Emitter.CGF && "Invalid address of label expression outside function"
) ? static_cast<void> (0) : __assert_fail ("Emitter.CGF && \"Invalid address of label expression outside function\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 1978, __PRETTY_FUNCTION__))
;
1979 llvm::Constant *Ptr = Emitter.CGF->GetAddrOfLabel(E->getLabel());
1980 Ptr = llvm::ConstantExpr::getBitCast(Ptr,
1981 CGM.getTypes().ConvertType(E->getType()));
1982 return Ptr;
1983}
1984
1985ConstantLValue
1986ConstantLValueEmitter::VisitCallExpr(const CallExpr *E) {
1987 unsigned builtin = E->getBuiltinCallee();
1988 if (builtin != Builtin::BI__builtin___CFStringMakeConstantString &&
1989 builtin != Builtin::BI__builtin___NSStringMakeConstantString)
1990 return nullptr;
1991
1992 auto literal = cast<StringLiteral>(E->getArg(0)->IgnoreParenCasts());
1993 if (builtin == Builtin::BI__builtin___NSStringMakeConstantString) {
1994 return CGM.getObjCRuntime().GenerateConstantString(literal);
1995 } else {
1996 // FIXME: need to deal with UCN conversion issues.
1997 return CGM.GetAddrOfConstantCFString(literal);
1998 }
1999}
2000
2001ConstantLValue
2002ConstantLValueEmitter::VisitBlockExpr(const BlockExpr *E) {
2003 StringRef functionName;
2004 if (auto CGF = Emitter.CGF)
2005 functionName = CGF->CurFn->getName();
2006 else
2007 functionName = "global";
2008
2009 return CGM.GetAddrOfGlobalBlock(E, functionName);
2010}
2011
2012ConstantLValue
2013ConstantLValueEmitter::VisitCXXTypeidExpr(const CXXTypeidExpr *E) {
2014 QualType T;
2015 if (E->isTypeOperand())
2016 T = E->getTypeOperand(CGM.getContext());
2017 else
2018 T = E->getExprOperand()->getType();
2019 return CGM.GetAddrOfRTTIDescriptor(T);
2020}
2021
2022ConstantLValue
2023ConstantLValueEmitter::VisitMaterializeTemporaryExpr(
2024 const MaterializeTemporaryExpr *E) {
2025 assert(E->getStorageDuration() == SD_Static)((E->getStorageDuration() == SD_Static) ? static_cast<void
> (0) : __assert_fail ("E->getStorageDuration() == SD_Static"
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 2025, __PRETTY_FUNCTION__))
;
2026 SmallVector<const Expr *, 2> CommaLHSs;
2027 SmallVector<SubobjectAdjustment, 2> Adjustments;
2028 const Expr *Inner =
2029 E->getSubExpr()->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
2030 return CGM.GetAddrOfGlobalTemporary(E, Inner);
2031}
2032
2033llvm::Constant *ConstantEmitter::tryEmitPrivate(const APValue &Value,
2034 QualType DestType) {
2035 switch (Value.getKind()) {
2036 case APValue::None:
2037 case APValue::Indeterminate:
2038 // Out-of-lifetime and indeterminate values can be modeled as 'undef'.
2039 return llvm::UndefValue::get(CGM.getTypes().ConvertType(DestType));
2040 case APValue::LValue:
2041 return ConstantLValueEmitter(*this, Value, DestType).tryEmit();
2042 case APValue::Int:
2043 return llvm::ConstantInt::get(CGM.getLLVMContext(), Value.getInt());
2044 case APValue::FixedPoint:
2045 return llvm::ConstantInt::get(CGM.getLLVMContext(),
2046 Value.getFixedPoint().getValue());
2047 case APValue::ComplexInt: {
2048 llvm::Constant *Complex[2];
2049
2050 Complex[0] = llvm::ConstantInt::get(CGM.getLLVMContext(),
2051 Value.getComplexIntReal());
2052 Complex[1] = llvm::ConstantInt::get(CGM.getLLVMContext(),
2053 Value.getComplexIntImag());
2054
2055 // FIXME: the target may want to specify that this is packed.
2056 llvm::StructType *STy =
2057 llvm::StructType::get(Complex[0]->getType(), Complex[1]->getType());
2058 return llvm::ConstantStruct::get(STy, Complex);
2059 }
2060 case APValue::Float: {
2061 const llvm::APFloat &Init = Value.getFloat();
2062 if (&Init.getSemantics() == &llvm::APFloat::IEEEhalf() &&
2063 !CGM.getContext().getLangOpts().NativeHalfType &&
2064 CGM.getContext().getTargetInfo().useFP16ConversionIntrinsics())
2065 return llvm::ConstantInt::get(CGM.getLLVMContext(),
2066 Init.bitcastToAPInt());
2067 else
2068 return llvm::ConstantFP::get(CGM.getLLVMContext(), Init);
2069 }
2070 case APValue::ComplexFloat: {
2071 llvm::Constant *Complex[2];
2072
2073 Complex[0] = llvm::ConstantFP::get(CGM.getLLVMContext(),
2074 Value.getComplexFloatReal());
2075 Complex[1] = llvm::ConstantFP::get(CGM.getLLVMContext(),
2076 Value.getComplexFloatImag());
2077
2078 // FIXME: the target may want to specify that this is packed.
2079 llvm::StructType *STy =
2080 llvm::StructType::get(Complex[0]->getType(), Complex[1]->getType());
2081 return llvm::ConstantStruct::get(STy, Complex);
2082 }
2083 case APValue::Vector: {
2084 unsigned NumElts = Value.getVectorLength();
2085 SmallVector<llvm::Constant *, 4> Inits(NumElts);
2086
2087 for (unsigned I = 0; I != NumElts; ++I) {
2088 const APValue &Elt = Value.getVectorElt(I);
2089 if (Elt.isInt())
2090 Inits[I] = llvm::ConstantInt::get(CGM.getLLVMContext(), Elt.getInt());
2091 else if (Elt.isFloat())
2092 Inits[I] = llvm::ConstantFP::get(CGM.getLLVMContext(), Elt.getFloat());
2093 else
2094 llvm_unreachable("unsupported vector element type")::llvm::llvm_unreachable_internal("unsupported vector element type"
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 2094)
;
2095 }
2096 return llvm::ConstantVector::get(Inits);
2097 }
2098 case APValue::AddrLabelDiff: {
2099 const AddrLabelExpr *LHSExpr = Value.getAddrLabelDiffLHS();
2100 const AddrLabelExpr *RHSExpr = Value.getAddrLabelDiffRHS();
2101 llvm::Constant *LHS = tryEmitPrivate(LHSExpr, LHSExpr->getType());
2102 llvm::Constant *RHS = tryEmitPrivate(RHSExpr, RHSExpr->getType());
2103 if (!LHS || !RHS) return nullptr;
2104
2105 // Compute difference
2106 llvm::Type *ResultType = CGM.getTypes().ConvertType(DestType);
2107 LHS = llvm::ConstantExpr::getPtrToInt(LHS, CGM.IntPtrTy);
2108 RHS = llvm::ConstantExpr::getPtrToInt(RHS, CGM.IntPtrTy);
2109 llvm::Constant *AddrLabelDiff = llvm::ConstantExpr::getSub(LHS, RHS);
2110
2111 // LLVM is a bit sensitive about the exact format of the
2112 // address-of-label difference; make sure to truncate after
2113 // the subtraction.
2114 return llvm::ConstantExpr::getTruncOrBitCast(AddrLabelDiff, ResultType);
2115 }
2116 case APValue::Struct:
2117 case APValue::Union:
2118 return ConstStructBuilder::BuildStruct(*this, Value, DestType);
2119 case APValue::Array: {
2120 const ArrayType *ArrayTy = CGM.getContext().getAsArrayType(DestType);
2121 unsigned NumElements = Value.getArraySize();
2122 unsigned NumInitElts = Value.getArrayInitializedElts();
2123
2124 // Emit array filler, if there is one.
2125 llvm::Constant *Filler = nullptr;
2126 if (Value.hasArrayFiller()) {
2127 Filler = tryEmitAbstractForMemory(Value.getArrayFiller(),
2128 ArrayTy->getElementType());
2129 if (!Filler)
2130 return nullptr;
2131 }
2132
2133 // Emit initializer elements.
2134 SmallVector<llvm::Constant*, 16> Elts;
2135 if (Filler && Filler->isNullValue())
2136 Elts.reserve(NumInitElts + 1);
2137 else
2138 Elts.reserve(NumElements);
2139
2140 llvm::Type *CommonElementType = nullptr;
2141 for (unsigned I = 0; I < NumInitElts; ++I) {
2142 llvm::Constant *C = tryEmitPrivateForMemory(
2143 Value.getArrayInitializedElt(I), ArrayTy->getElementType());
2144 if (!C) return nullptr;
2145
2146 if (I == 0)
2147 CommonElementType = C->getType();
2148 else if (C->getType() != CommonElementType)
2149 CommonElementType = nullptr;
2150 Elts.push_back(C);
2151 }
2152
2153 llvm::ArrayType *Desired =
2154 cast<llvm::ArrayType>(CGM.getTypes().ConvertType(DestType));
2155 return EmitArrayConstant(CGM, Desired, CommonElementType, NumElements, Elts,
2156 Filler);
2157 }
2158 case APValue::MemberPointer:
2159 return CGM.getCXXABI().EmitMemberPointer(Value, DestType);
2160 }
2161 llvm_unreachable("Unknown APValue kind")::llvm::llvm_unreachable_internal("Unknown APValue kind", "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 2161)
;
2162}
2163
2164llvm::GlobalVariable *CodeGenModule::getAddrOfConstantCompoundLiteralIfEmitted(
2165 const CompoundLiteralExpr *E) {
2166 return EmittedCompoundLiterals.lookup(E);
2167}
2168
2169void CodeGenModule::setAddrOfConstantCompoundLiteral(
2170 const CompoundLiteralExpr *CLE, llvm::GlobalVariable *GV) {
2171 bool Ok = EmittedCompoundLiterals.insert(std::make_pair(CLE, GV)).second;
2172 (void)Ok;
2173 assert(Ok && "CLE has already been emitted!")((Ok && "CLE has already been emitted!") ? static_cast
<void> (0) : __assert_fail ("Ok && \"CLE has already been emitted!\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 2173, __PRETTY_FUNCTION__))
;
2174}
2175
2176ConstantAddress
2177CodeGenModule::GetAddrOfConstantCompoundLiteral(const CompoundLiteralExpr *E) {
2178 assert(E->isFileScope() && "not a file-scope compound literal expr")((E->isFileScope() && "not a file-scope compound literal expr"
) ? static_cast<void> (0) : __assert_fail ("E->isFileScope() && \"not a file-scope compound literal expr\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 2178, __PRETTY_FUNCTION__))
;
2179 return tryEmitGlobalCompoundLiteral(*this, nullptr, E);
2180}
2181
2182llvm::Constant *
2183CodeGenModule::getMemberPointerConstant(const UnaryOperator *uo) {
2184 // Member pointer constants always have a very particular form.
2185 const MemberPointerType *type = cast<MemberPointerType>(uo->getType());
2186 const ValueDecl *decl = cast<DeclRefExpr>(uo->getSubExpr())->getDecl();
2187
2188 // A member function pointer.
2189 if (const CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(decl))
2190 return getCXXABI().EmitMemberFunctionPointer(method);
2191
2192 // Otherwise, a member data pointer.
2193 uint64_t fieldOffset = getContext().getFieldOffset(decl);
2194 CharUnits chars = getContext().toCharUnitsFromBits((int64_t) fieldOffset);
2195 return getCXXABI().EmitMemberDataPointer(type, chars);
2196}
2197
2198static llvm::Constant *EmitNullConstantForBase(CodeGenModule &CGM,
2199 llvm::Type *baseType,
2200 const CXXRecordDecl *base);
2201
2202static llvm::Constant *EmitNullConstant(CodeGenModule &CGM,
2203 const RecordDecl *record,
2204 bool asCompleteObject) {
2205 const CGRecordLayout &layout = CGM.getTypes().getCGRecordLayout(record);
2206 llvm::StructType *structure =
2207 (asCompleteObject ? layout.getLLVMType()
2208 : layout.getBaseSubobjectLLVMType());
2209
2210 unsigned numElements = structure->getNumElements();
2211 std::vector<llvm::Constant *> elements(numElements);
2212
2213 auto CXXR = dyn_cast<CXXRecordDecl>(record);
2214 // Fill in all the bases.
2215 if (CXXR) {
2216 for (const auto &I : CXXR->bases()) {
2217 if (I.isVirtual()) {
2218 // Ignore virtual bases; if we're laying out for a complete
2219 // object, we'll lay these out later.
2220 continue;
2221 }
2222
2223 const CXXRecordDecl *base =
2224 cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
2225
2226 // Ignore empty bases.
2227 if (base->isEmpty() ||
2228 CGM.getContext().getASTRecordLayout(base).getNonVirtualSize()
2229 .isZero())
2230 continue;
2231
2232 unsigned fieldIndex = layout.getNonVirtualBaseLLVMFieldNo(base);
2233 llvm::Type *baseType = structure->getElementType(fieldIndex);
2234 elements[fieldIndex] = EmitNullConstantForBase(CGM, baseType, base);
2235 }
2236 }
2237
2238 // Fill in all the fields.
2239 for (const auto *Field : record->fields()) {
2240 // Fill in non-bitfields. (Bitfields always use a zero pattern, which we
2241 // will fill in later.)
2242 if (!Field->isBitField() && !Field->isZeroSize(CGM.getContext())) {
2243 unsigned fieldIndex = layout.getLLVMFieldNo(Field);
2244 elements[fieldIndex] = CGM.EmitNullConstant(Field->getType());
2245 }
2246
2247 // For unions, stop after the first named field.
2248 if (record->isUnion()) {
2249 if (Field->getIdentifier())
2250 break;
2251 if (const auto *FieldRD = Field->getType()->getAsRecordDecl())
2252 if (FieldRD->findFirstNamedDataMember())
2253 break;
2254 }
2255 }
2256
2257 // Fill in the virtual bases, if we're working with the complete object.
2258 if (CXXR && asCompleteObject) {
2259 for (const auto &I : CXXR->vbases()) {
2260 const CXXRecordDecl *base =
2261 cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
2262
2263 // Ignore empty bases.
2264 if (base->isEmpty())
2265 continue;
2266
2267 unsigned fieldIndex = layout.getVirtualBaseIndex(base);
2268
2269 // We might have already laid this field out.
2270 if (elements[fieldIndex]) continue;
2271
2272 llvm::Type *baseType = structure->getElementType(fieldIndex);
2273 elements[fieldIndex] = EmitNullConstantForBase(CGM, baseType, base);
2274 }
2275 }
2276
2277 // Now go through all other fields and zero them out.
2278 for (unsigned i = 0; i != numElements; ++i) {
2279 if (!elements[i])
2280 elements[i] = llvm::Constant::getNullValue(structure->getElementType(i));
2281 }
2282
2283 return llvm::ConstantStruct::get(structure, elements);
2284}
2285
2286/// Emit the null constant for a base subobject.
2287static llvm::Constant *EmitNullConstantForBase(CodeGenModule &CGM,
2288 llvm::Type *baseType,
2289 const CXXRecordDecl *base) {
2290 const CGRecordLayout &baseLayout = CGM.getTypes().getCGRecordLayout(base);
2291
2292 // Just zero out bases that don't have any pointer to data members.
2293 if (baseLayout.isZeroInitializableAsBase())
2294 return llvm::Constant::getNullValue(baseType);
2295
2296 // Otherwise, we can just use its null constant.
2297 return EmitNullConstant(CGM, base, /*asCompleteObject=*/false);
2298}
2299
2300llvm::Constant *ConstantEmitter::emitNullForMemory(CodeGenModule &CGM,
2301 QualType T) {
2302 return emitForMemory(CGM, CGM.EmitNullConstant(T), T);
2303}
2304
2305llvm::Constant *CodeGenModule::EmitNullConstant(QualType T) {
2306 if (T->getAs<PointerType>())
2307 return getNullPointer(
2308 cast<llvm::PointerType>(getTypes().ConvertTypeForMem(T)), T);
2309
2310 if (getTypes().isZeroInitializable(T))
2311 return llvm::Constant::getNullValue(getTypes().ConvertTypeForMem(T));
2312
2313 if (const ConstantArrayType *CAT = Context.getAsConstantArrayType(T)) {
2314 llvm::ArrayType *ATy =
2315 cast<llvm::ArrayType>(getTypes().ConvertTypeForMem(T));
2316
2317 QualType ElementTy = CAT->getElementType();
2318
2319 llvm::Constant *Element =
2320 ConstantEmitter::emitNullForMemory(*this, ElementTy);
2321 unsigned NumElements = CAT->getSize().getZExtValue();
2322 SmallVector<llvm::Constant *, 8> Array(NumElements, Element);
2323 return llvm::ConstantArray::get(ATy, Array);
2324 }
2325
2326 if (const RecordType *RT = T->getAs<RecordType>())
2327 return ::EmitNullConstant(*this, RT->getDecl(), /*complete object*/ true);
2328
2329 assert(T->isMemberDataPointerType() &&((T->isMemberDataPointerType() && "Should only see pointers to data members here!"
) ? static_cast<void> (0) : __assert_fail ("T->isMemberDataPointerType() && \"Should only see pointers to data members here!\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 2330, __PRETTY_FUNCTION__))
2330 "Should only see pointers to data members here!")((T->isMemberDataPointerType() && "Should only see pointers to data members here!"
) ? static_cast<void> (0) : __assert_fail ("T->isMemberDataPointerType() && \"Should only see pointers to data members here!\""
, "/build/llvm-toolchain-snapshot-13~++20210308111132+66e3a4abe99c/clang/lib/CodeGen/CGExprConstant.cpp"
, 2330, __PRETTY_FUNCTION__))
;
2331
2332 return getCXXABI().EmitNullMemberPointer(T->castAs<MemberPointerType>());
2333}
2334
2335llvm::Constant *
2336CodeGenModule::EmitNullConstantForBase(const CXXRecordDecl *Record) {
2337 return ::EmitNullConstant(*this, Record, false);
2338}