Bug Summary

File:clang/lib/CodeGen/CGExprConstant.cpp
Warning:line 934, column 42
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~++20210506100649+6304c0836a4d/build-llvm/tools/clang/lib/CodeGen -resource-dir /usr/lib/llvm-13/lib/clang/13.0.0 -D CLANG_ROUND_TRIP_CC1_ARGS=ON -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/build-llvm/tools/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen -I /build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/include -I /build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/build-llvm/include -I /build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/llvm/include -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-13/lib/clang/13.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/build-llvm/tools/clang/lib/CodeGen -fdebug-prefix-map=/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d=. -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 -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2021-05-07-005843-9350-1 -x c++ /build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/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")(static_cast <bool> (BeginOff <= EndOff && "invalid replacement range"
) ? void (0) : __assert_fail ("BeginOff <= EndOff && \"invalid replacement range\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 138, __extension__ __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) &&(static_cast <bool> ((FirstElemToReplace == LastElemToReplace
|| AllowOverwrite) && "unexpectedly overwriting field"
) ? void (0) : __assert_fail ("(FirstElemToReplace == LastElemToReplace || AllowOverwrite) && \"unexpectedly overwriting field\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 171, __extension__ __PRETTY_FUNCTION__))
171 "unexpectedly overwriting field")(static_cast <bool> ((FirstElemToReplace == LastElemToReplace
|| AllowOverwrite) && "unexpectedly overwriting field"
) ? void (0) : __assert_fail ("(FirstElemToReplace == LastElemToReplace || AllowOverwrite) && \"unexpectedly overwriting field\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 171, __extension__ __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 &&(static_cast <bool> (*LastElemToUpdate - *FirstElemToUpdate
< 2 && "should have at most one element covering one byte"
) ? void (0) : __assert_fail ("*LastElemToUpdate - *FirstElemToUpdate < 2 && \"should have at most one element covering one byte\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 233, __extension__ __PRETTY_FUNCTION__))
233 "should have at most one element covering one byte")(static_cast <bool> (*LastElemToUpdate - *FirstElemToUpdate
< 2 && "should have at most one element covering one byte"
) ? void (0) : __assert_fail ("*LastElemToUpdate - *FirstElemToUpdate < 2 && \"should have at most one element covering one byte\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 233, __extension__ __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")(static_cast <bool> (CI->getBitWidth() == CharWidth &&
"splitAt failed") ? void (0) : __assert_fail ("CI->getBitWidth() == CharWidth && \"splitAt failed\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 259, __extension__ __PRETTY_FUNCTION__))
;
260 assert((!(CI->getValue() & UpdateMask) || AllowOverwrite) &&(static_cast <bool> ((!(CI->getValue() & UpdateMask
) || AllowOverwrite) && "unexpectedly overwriting bitfield"
) ? void (0) : __assert_fail ("(!(CI->getValue() & UpdateMask) || AllowOverwrite) && \"unexpectedly overwriting bitfield\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 261, __extension__ __PRETTY_FUNCTION__))
261 "unexpectedly overwriting bitfield")(static_cast <bool> ((!(CI->getValue() & UpdateMask
) || AllowOverwrite) && "unexpectedly overwriting bitfield"
) ? void (0) : __assert_fail ("(!(CI->getValue() & UpdateMask) || AllowOverwrite) && \"unexpectedly overwriting bitfield\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 261, __extension__ __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")(static_cast <bool> (Hint > Offset && Hint <
Offset + ElemSize && "nothing to split") ? void (0) :
__assert_fail ("Hint > Offset && Hint < Offset + ElemSize && \"nothing to split\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 371, __extension__ __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")(static_cast <bool> (!AllowOversized && "oversized array emission not supported"
) ? void (0) : __assert_fail ("!AllowOversized && \"oversized array emission not supported\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 412, __extension__ __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")(static_cast <bool> (DesiredOffset >= SizeSoFar &&
"elements out of order") ? void (0) : __assert_fail ("DesiredOffset >= SizeSoFar && \"elements out of order\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 473, __extension__ __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) &&(static_cast <bool> ((SizeSoFar <= DesiredSize || AllowOversized
) && "requested size is too small for contents") ? void
(0) : __assert_fail ("(SizeSoFar <= DesiredSize || AllowOversized) && \"requested size is too small for contents\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 486, __extension__ __PRETTY_FUNCTION__))
486 "requested size is too small for contents")(static_cast <bool> ((SizeSoFar <= DesiredSize || AllowOversized
) && "requested size is too small for contents") ? void
(0) : __assert_fail ("(SizeSoFar <= DesiredSize || AllowOversized) && \"requested size is too small for contents\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 486, __extension__ __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")(static_cast <bool> (!Base->isVirtual() && "should not have virtual bases here"
) ? void (0) : __assert_fail ("!Base->isVirtual() && \"should not have virtual bases here\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 795, __extension__ __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() &&(static_cast <bool> (!E->isFileScope() && "file-scope compound literal did not have constant initializer!"
) ? void (0) : __assert_fail ("!E->isFileScope() && \"file-scope compound literal did not have constant initializer!\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 911, __extension__ __PRETTY_FUNCTION__))
911 "file-scope compound literal did not have constant initializer!")(static_cast <bool> (!E->isFileScope() && "file-scope compound literal did not have constant initializer!"
) ? void (0) : __assert_fail ("!E->isFileScope() && \"file-scope compound literal did not have constant initializer!\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 911, __extension__ __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 true
15
Called C++ object pointer is null
935 NonzeroLength = Elements.size();
936 if (NonzeroLength == Elements.size()) {
937 while (NonzeroLength > 0 && Elements[NonzeroLength - 1]->isNullValue())
938 --NonzeroLength;
939 }
940
941 if (NonzeroLength == 0)
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 >= 8) {
947 assert(Elements.size() >= NonzeroLength &&(static_cast <bool> (Elements.size() >= NonzeroLength
&& "missing initializer for non-zero element") ? void
(0) : __assert_fail ("Elements.size() >= NonzeroLength && \"missing initializer for non-zero element\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 948, __extension__ __PRETTY_FUNCTION__))
948 "missing initializer for non-zero element")(static_cast <bool> (Elements.size() >= NonzeroLength
&& "missing initializer for non-zero element") ? void
(0) : __assert_fail ("Elements.size() >= NonzeroLength && \"missing initializer for non-zero element\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 948, __extension__ __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) {
968 // Otherwise pad to the right size with the filler if necessary.
969 Elements.resize(ArrayBound, Filler);
970 if (Filler->getType() != CommonElementType)
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() &&(static_cast <bool> (E->getType()->isUnionType() &&
"Destination type is not union type!") ? void (0) : __assert_fail
("E->getType()->isUnionType() && \"Destination type is not union type!\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1051, __extension__ __PRETTY_FUNCTION__))
1051 "Destination type is not union type!")(static_cast <bool> (E->getType()->isUnionType() &&
"Destination type is not union type!") ? void (0) : __assert_fail
("E->getType()->isUnionType() && \"Destination type is not union type!\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1051, __extension__ __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!")(static_cast <bool> (CurSize <= TotalSize &&
"Union size mismatch!") ? void (0) : __assert_fail ("CurSize <= TotalSize && \"Union size mismatch!\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1070, __extension__ __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~++20210506100649+6304c0836a4d/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~++20210506100649+6304c0836a4d/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~++20210506100649+6304c0836a4d/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 case CK_MatrixCast:
1174 return nullptr;
1175 }
1176 llvm_unreachable("Invalid CastKind")::llvm::llvm_unreachable_internal("Invalid CastKind", "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1176)
;
1177 }
1178
1179 llvm::Constant *VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE, QualType T) {
1180 // No need for a DefaultInitExprScope: we don't handle 'this' in a
1181 // constant expression.
1182 return Visit(DIE->getExpr(), T);
1183 }
1184
1185 llvm::Constant *VisitExprWithCleanups(ExprWithCleanups *E, QualType T) {
1186 return Visit(E->getSubExpr(), T);
1187 }
1188
1189 llvm::Constant *VisitMaterializeTemporaryExpr(MaterializeTemporaryExpr *E,
1190 QualType T) {
1191 return Visit(E->getSubExpr(), T);
1192 }
1193
1194 llvm::Constant *EmitArrayInitialization(InitListExpr *ILE, QualType T) {
1195 auto *CAT = CGM.getContext().getAsConstantArrayType(ILE->getType());
1196 assert(CAT && "can't emit array init for non-constant-bound array")(static_cast <bool> (CAT && "can't emit array init for non-constant-bound array"
) ? void (0) : __assert_fail ("CAT && \"can't emit array init for non-constant-bound array\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1196, __extension__ __PRETTY_FUNCTION__))
;
5
'?' condition is true
1197 unsigned NumInitElements = ILE->getNumInits();
1198 unsigned NumElements = CAT->getSize().getZExtValue();
1199
1200 // Initialising an array requires us to automatically
1201 // initialise any elements that have not been initialised explicitly
1202 unsigned NumInitableElts = std::min(NumInitElements, NumElements);
1203
1204 QualType EltType = CAT->getElementType();
1205
1206 // Initialize remaining array elements.
1207 llvm::Constant *fillC = nullptr;
6
'fillC' initialized to a null pointer value
1208 if (Expr *filler = ILE->getArrayFiller()) {
7
Assuming 'filler' is null
8
Taking false branch
1209 fillC = Emitter.tryEmitAbstractForMemory(filler, EltType);
1210 if (!fillC)
1211 return nullptr;
1212 }
1213
1214 // Copy initializer elements.
1215 SmallVector<llvm::Constant*, 16> Elts;
1216 if (fillC
8.1
'fillC' is null
&& fillC->isNullValue())
1217 Elts.reserve(NumInitableElts + 1);
1218 else
1219 Elts.reserve(NumElements);
1220
1221 llvm::Type *CommonElementType = nullptr;
1222 for (unsigned i = 0; i < NumInitableElts; ++i) {
9
Assuming 'i' is >= 'NumInitableElts'
10
Loop condition is false. Execution continues on line 1235
1223 Expr *Init = ILE->getInit(i);
1224 llvm::Constant *C = Emitter.tryEmitPrivateForMemory(Init, EltType);
1225 if (!C)
1226 return nullptr;
1227 if (i == 0)
1228 CommonElementType = C->getType();
1229 else if (C->getType() != CommonElementType)
1230 CommonElementType = nullptr;
1231 Elts.push_back(C);
1232 }
1233
1234 llvm::ArrayType *Desired =
1235 cast<llvm::ArrayType>(CGM.getTypes().ConvertType(ILE->getType()));
11
The object is a 'ArrayType'
1236 return EmitArrayConstant(CGM, Desired, CommonElementType, NumElements, Elts,
13
Calling 'EmitArrayConstant'
1237 fillC);
12
Passing null pointer value via 6th parameter 'Filler'
1238 }
1239
1240 llvm::Constant *EmitRecordInitialization(InitListExpr *ILE, QualType T) {
1241 return ConstStructBuilder::BuildStruct(Emitter, ILE, T);
1242 }
1243
1244 llvm::Constant *VisitImplicitValueInitExpr(ImplicitValueInitExpr* E,
1245 QualType T) {
1246 return CGM.EmitNullConstant(T);
1247 }
1248
1249 llvm::Constant *VisitInitListExpr(InitListExpr *ILE, QualType T) {
1250 if (ILE->isTransparent())
1
Assuming the condition is false
2
Taking false branch
1251 return Visit(ILE->getInit(0), T);
1252
1253 if (ILE->getType()->isArrayType())
3
Taking true branch
1254 return EmitArrayInitialization(ILE, T);
4
Calling 'ConstExprEmitter::EmitArrayInitialization'
1255
1256 if (ILE->getType()->isRecordType())
1257 return EmitRecordInitialization(ILE, T);
1258
1259 return nullptr;
1260 }
1261
1262 llvm::Constant *VisitDesignatedInitUpdateExpr(DesignatedInitUpdateExpr *E,
1263 QualType destType) {
1264 auto C = Visit(E->getBase(), destType);
1265 if (!C)
1266 return nullptr;
1267
1268 ConstantAggregateBuilder Const(CGM);
1269 Const.add(C, CharUnits::Zero(), false);
1270
1271 if (!EmitDesignatedInitUpdater(Emitter, Const, CharUnits::Zero(), destType,
1272 E->getUpdater()))
1273 return nullptr;
1274
1275 llvm::Type *ValTy = CGM.getTypes().ConvertType(destType);
1276 bool HasFlexibleArray = false;
1277 if (auto *RT = destType->getAs<RecordType>())
1278 HasFlexibleArray = RT->getDecl()->hasFlexibleArrayMember();
1279 return Const.build(ValTy, HasFlexibleArray);
1280 }
1281
1282 llvm::Constant *VisitCXXConstructExpr(CXXConstructExpr *E, QualType Ty) {
1283 if (!E->getConstructor()->isTrivial())
1284 return nullptr;
1285
1286 // Only default and copy/move constructors can be trivial.
1287 if (E->getNumArgs()) {
1288 assert(E->getNumArgs() == 1 && "trivial ctor with > 1 argument")(static_cast <bool> (E->getNumArgs() == 1 &&
"trivial ctor with > 1 argument") ? void (0) : __assert_fail
("E->getNumArgs() == 1 && \"trivial ctor with > 1 argument\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1288, __extension__ __PRETTY_FUNCTION__))
;
1289 assert(E->getConstructor()->isCopyOrMoveConstructor() &&(static_cast <bool> (E->getConstructor()->isCopyOrMoveConstructor
() && "trivial ctor has argument but isn't a copy/move ctor"
) ? void (0) : __assert_fail ("E->getConstructor()->isCopyOrMoveConstructor() && \"trivial ctor has argument but isn't a copy/move ctor\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1290, __extension__ __PRETTY_FUNCTION__))
1290 "trivial ctor has argument but isn't a copy/move ctor")(static_cast <bool> (E->getConstructor()->isCopyOrMoveConstructor
() && "trivial ctor has argument but isn't a copy/move ctor"
) ? void (0) : __assert_fail ("E->getConstructor()->isCopyOrMoveConstructor() && \"trivial ctor has argument but isn't a copy/move ctor\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1290, __extension__ __PRETTY_FUNCTION__))
;
1291
1292 Expr *Arg = E->getArg(0);
1293 assert(CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) &&(static_cast <bool> (CGM.getContext().hasSameUnqualifiedType
(Ty, Arg->getType()) && "argument to copy ctor is of wrong type"
) ? void (0) : __assert_fail ("CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) && \"argument to copy ctor is of wrong type\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1294, __extension__ __PRETTY_FUNCTION__))
1294 "argument to copy ctor is of wrong type")(static_cast <bool> (CGM.getContext().hasSameUnqualifiedType
(Ty, Arg->getType()) && "argument to copy ctor is of wrong type"
) ? void (0) : __assert_fail ("CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) && \"argument to copy ctor is of wrong type\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1294, __extension__ __PRETTY_FUNCTION__))
;
1295
1296 return Visit(Arg, Ty);
1297 }
1298
1299 return CGM.EmitNullConstant(Ty);
1300 }
1301
1302 llvm::Constant *VisitStringLiteral(StringLiteral *E, QualType T) {
1303 // This is a string literal initializing an array in an initializer.
1304 return CGM.GetConstantArrayFromStringLiteral(E);
1305 }
1306
1307 llvm::Constant *VisitObjCEncodeExpr(ObjCEncodeExpr *E, QualType T) {
1308 // This must be an @encode initializing an array in a static initializer.
1309 // Don't emit it as the address of the string, emit the string data itself
1310 // as an inline array.
1311 std::string Str;
1312 CGM.getContext().getObjCEncodingForType(E->getEncodedType(), Str);
1313 const ConstantArrayType *CAT = CGM.getContext().getAsConstantArrayType(T);
1314
1315 // Resize the string to the right size, adding zeros at the end, or
1316 // truncating as needed.
1317 Str.resize(CAT->getSize().getZExtValue(), '\0');
1318 return llvm::ConstantDataArray::getString(VMContext, Str, false);
1319 }
1320
1321 llvm::Constant *VisitUnaryExtension(const UnaryOperator *E, QualType T) {
1322 return Visit(E->getSubExpr(), T);
1323 }
1324
1325 // Utility methods
1326 llvm::Type *ConvertType(QualType T) {
1327 return CGM.getTypes().ConvertType(T);
1328 }
1329};
1330
1331} // end anonymous namespace.
1332
1333llvm::Constant *ConstantEmitter::validateAndPopAbstract(llvm::Constant *C,
1334 AbstractState saved) {
1335 Abstract = saved.OldValue;
1336
1337 assert(saved.OldPlaceholdersSize == PlaceholderAddresses.size() &&(static_cast <bool> (saved.OldPlaceholdersSize == PlaceholderAddresses
.size() && "created a placeholder while doing an abstract emission?"
) ? void (0) : __assert_fail ("saved.OldPlaceholdersSize == PlaceholderAddresses.size() && \"created a placeholder while doing an abstract emission?\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1338, __extension__ __PRETTY_FUNCTION__))
1338 "created a placeholder while doing an abstract emission?")(static_cast <bool> (saved.OldPlaceholdersSize == PlaceholderAddresses
.size() && "created a placeholder while doing an abstract emission?"
) ? void (0) : __assert_fail ("saved.OldPlaceholdersSize == PlaceholderAddresses.size() && \"created a placeholder while doing an abstract emission?\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1338, __extension__ __PRETTY_FUNCTION__))
;
1339
1340 // No validation necessary for now.
1341 // No cleanup to do for now.
1342 return C;
1343}
1344
1345llvm::Constant *
1346ConstantEmitter::tryEmitAbstractForInitializer(const VarDecl &D) {
1347 auto state = pushAbstract();
1348 auto C = tryEmitPrivateForVarInit(D);
1349 return validateAndPopAbstract(C, state);
1350}
1351
1352llvm::Constant *
1353ConstantEmitter::tryEmitAbstract(const Expr *E, QualType destType) {
1354 auto state = pushAbstract();
1355 auto C = tryEmitPrivate(E, destType);
1356 return validateAndPopAbstract(C, state);
1357}
1358
1359llvm::Constant *
1360ConstantEmitter::tryEmitAbstract(const APValue &value, QualType destType) {
1361 auto state = pushAbstract();
1362 auto C = tryEmitPrivate(value, destType);
1363 return validateAndPopAbstract(C, state);
1364}
1365
1366llvm::Constant *ConstantEmitter::tryEmitConstantExpr(const ConstantExpr *CE) {
1367 if (!CE->hasAPValueResult())
1368 return nullptr;
1369 const Expr *Inner = CE->getSubExpr()->IgnoreImplicit();
1370 QualType RetType;
1371 if (auto *Call = dyn_cast<CallExpr>(Inner))
1372 RetType = Call->getCallReturnType(CGF->getContext());
1373 else if (auto *Ctor = dyn_cast<CXXConstructExpr>(Inner))
1374 RetType = Ctor->getType();
1375 llvm::Constant *Res =
1376 emitAbstract(CE->getBeginLoc(), CE->getAPValueResult(), RetType);
1377 return Res;
1378}
1379
1380llvm::Constant *
1381ConstantEmitter::emitAbstract(const Expr *E, QualType destType) {
1382 auto state = pushAbstract();
1383 auto C = tryEmitPrivate(E, destType);
1384 C = validateAndPopAbstract(C, state);
1385 if (!C) {
1386 CGM.Error(E->getExprLoc(),
1387 "internal error: could not emit constant value \"abstractly\"");
1388 C = CGM.EmitNullConstant(destType);
1389 }
1390 return C;
1391}
1392
1393llvm::Constant *
1394ConstantEmitter::emitAbstract(SourceLocation loc, const APValue &value,
1395 QualType destType) {
1396 auto state = pushAbstract();
1397 auto C = tryEmitPrivate(value, destType);
1398 C = validateAndPopAbstract(C, state);
1399 if (!C) {
1400 CGM.Error(loc,
1401 "internal error: could not emit constant value \"abstractly\"");
1402 C = CGM.EmitNullConstant(destType);
1403 }
1404 return C;
1405}
1406
1407llvm::Constant *ConstantEmitter::tryEmitForInitializer(const VarDecl &D) {
1408 initializeNonAbstract(D.getType().getAddressSpace());
1409 return markIfFailed(tryEmitPrivateForVarInit(D));
1410}
1411
1412llvm::Constant *ConstantEmitter::tryEmitForInitializer(const Expr *E,
1413 LangAS destAddrSpace,
1414 QualType destType) {
1415 initializeNonAbstract(destAddrSpace);
1416 return markIfFailed(tryEmitPrivateForMemory(E, destType));
1417}
1418
1419llvm::Constant *ConstantEmitter::emitForInitializer(const APValue &value,
1420 LangAS destAddrSpace,
1421 QualType destType) {
1422 initializeNonAbstract(destAddrSpace);
1423 auto C = tryEmitPrivateForMemory(value, destType);
1424 assert(C && "couldn't emit constant value non-abstractly?")(static_cast <bool> (C && "couldn't emit constant value non-abstractly?"
) ? void (0) : __assert_fail ("C && \"couldn't emit constant value non-abstractly?\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1424, __extension__ __PRETTY_FUNCTION__))
;
1425 return C;
1426}
1427
1428llvm::GlobalValue *ConstantEmitter::getCurrentAddrPrivate() {
1429 assert(!Abstract && "cannot get current address for abstract constant")(static_cast <bool> (!Abstract && "cannot get current address for abstract constant"
) ? void (0) : __assert_fail ("!Abstract && \"cannot get current address for abstract constant\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1429, __extension__ __PRETTY_FUNCTION__))
;
1430
1431
1432
1433 // Make an obviously ill-formed global that should blow up compilation
1434 // if it survives.
1435 auto global = new llvm::GlobalVariable(CGM.getModule(), CGM.Int8Ty, true,
1436 llvm::GlobalValue::PrivateLinkage,
1437 /*init*/ nullptr,
1438 /*name*/ "",
1439 /*before*/ nullptr,
1440 llvm::GlobalVariable::NotThreadLocal,
1441 CGM.getContext().getTargetAddressSpace(DestAddressSpace));
1442
1443 PlaceholderAddresses.push_back(std::make_pair(nullptr, global));
1444
1445 return global;
1446}
1447
1448void ConstantEmitter::registerCurrentAddrPrivate(llvm::Constant *signal,
1449 llvm::GlobalValue *placeholder) {
1450 assert(!PlaceholderAddresses.empty())(static_cast <bool> (!PlaceholderAddresses.empty()) ? void
(0) : __assert_fail ("!PlaceholderAddresses.empty()", "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1450, __extension__ __PRETTY_FUNCTION__))
;
1451 assert(PlaceholderAddresses.back().first == nullptr)(static_cast <bool> (PlaceholderAddresses.back().first ==
nullptr) ? void (0) : __assert_fail ("PlaceholderAddresses.back().first == nullptr"
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1451, __extension__ __PRETTY_FUNCTION__))
;
1452 assert(PlaceholderAddresses.back().second == placeholder)(static_cast <bool> (PlaceholderAddresses.back().second
== placeholder) ? void (0) : __assert_fail ("PlaceholderAddresses.back().second == placeholder"
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1452, __extension__ __PRETTY_FUNCTION__))
;
1453 PlaceholderAddresses.back().first = signal;
1454}
1455
1456namespace {
1457 struct ReplacePlaceholders {
1458 CodeGenModule &CGM;
1459
1460 /// The base address of the global.
1461 llvm::Constant *Base;
1462 llvm::Type *BaseValueTy = nullptr;
1463
1464 /// The placeholder addresses that were registered during emission.
1465 llvm::DenseMap<llvm::Constant*, llvm::GlobalVariable*> PlaceholderAddresses;
1466
1467 /// The locations of the placeholder signals.
1468 llvm::DenseMap<llvm::GlobalVariable*, llvm::Constant*> Locations;
1469
1470 /// The current index stack. We use a simple unsigned stack because
1471 /// we assume that placeholders will be relatively sparse in the
1472 /// initializer, but we cache the index values we find just in case.
1473 llvm::SmallVector<unsigned, 8> Indices;
1474 llvm::SmallVector<llvm::Constant*, 8> IndexValues;
1475
1476 ReplacePlaceholders(CodeGenModule &CGM, llvm::Constant *base,
1477 ArrayRef<std::pair<llvm::Constant*,
1478 llvm::GlobalVariable*>> addresses)
1479 : CGM(CGM), Base(base),
1480 PlaceholderAddresses(addresses.begin(), addresses.end()) {
1481 }
1482
1483 void replaceInInitializer(llvm::Constant *init) {
1484 // Remember the type of the top-most initializer.
1485 BaseValueTy = init->getType();
1486
1487 // Initialize the stack.
1488 Indices.push_back(0);
1489 IndexValues.push_back(nullptr);
1490
1491 // Recurse into the initializer.
1492 findLocations(init);
1493
1494 // Check invariants.
1495 assert(IndexValues.size() == Indices.size() && "mismatch")(static_cast <bool> (IndexValues.size() == Indices.size
() && "mismatch") ? void (0) : __assert_fail ("IndexValues.size() == Indices.size() && \"mismatch\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1495, __extension__ __PRETTY_FUNCTION__))
;
1496 assert(Indices.size() == 1 && "didn't pop all indices")(static_cast <bool> (Indices.size() == 1 && "didn't pop all indices"
) ? void (0) : __assert_fail ("Indices.size() == 1 && \"didn't pop all indices\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1496, __extension__ __PRETTY_FUNCTION__))
;
1497
1498 // Do the replacement; this basically invalidates 'init'.
1499 assert(Locations.size() == PlaceholderAddresses.size() &&(static_cast <bool> (Locations.size() == PlaceholderAddresses
.size() && "missed a placeholder?") ? void (0) : __assert_fail
("Locations.size() == PlaceholderAddresses.size() && \"missed a placeholder?\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1500, __extension__ __PRETTY_FUNCTION__))
1500 "missed a placeholder?")(static_cast <bool> (Locations.size() == PlaceholderAddresses
.size() && "missed a placeholder?") ? void (0) : __assert_fail
("Locations.size() == PlaceholderAddresses.size() && \"missed a placeholder?\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1500, __extension__ __PRETTY_FUNCTION__))
;
1501
1502 // We're iterating over a hashtable, so this would be a source of
1503 // non-determinism in compiler output *except* that we're just
1504 // messing around with llvm::Constant structures, which never itself
1505 // does anything that should be visible in compiler output.
1506 for (auto &entry : Locations) {
1507 assert(entry.first->getParent() == nullptr && "not a placeholder!")(static_cast <bool> (entry.first->getParent() == nullptr
&& "not a placeholder!") ? void (0) : __assert_fail (
"entry.first->getParent() == nullptr && \"not a placeholder!\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1507, __extension__ __PRETTY_FUNCTION__))
;
1508 entry.first->replaceAllUsesWith(entry.second);
1509 entry.first->eraseFromParent();
1510 }
1511 }
1512
1513 private:
1514 void findLocations(llvm::Constant *init) {
1515 // Recurse into aggregates.
1516 if (auto agg = dyn_cast<llvm::ConstantAggregate>(init)) {
1517 for (unsigned i = 0, e = agg->getNumOperands(); i != e; ++i) {
1518 Indices.push_back(i);
1519 IndexValues.push_back(nullptr);
1520
1521 findLocations(agg->getOperand(i));
1522
1523 IndexValues.pop_back();
1524 Indices.pop_back();
1525 }
1526 return;
1527 }
1528
1529 // Otherwise, check for registered constants.
1530 while (true) {
1531 auto it = PlaceholderAddresses.find(init);
1532 if (it != PlaceholderAddresses.end()) {
1533 setLocation(it->second);
1534 break;
1535 }
1536
1537 // Look through bitcasts or other expressions.
1538 if (auto expr = dyn_cast<llvm::ConstantExpr>(init)) {
1539 init = expr->getOperand(0);
1540 } else {
1541 break;
1542 }
1543 }
1544 }
1545
1546 void setLocation(llvm::GlobalVariable *placeholder) {
1547 assert(Locations.find(placeholder) == Locations.end() &&(static_cast <bool> (Locations.find(placeholder) == Locations
.end() && "already found location for placeholder!") ?
void (0) : __assert_fail ("Locations.find(placeholder) == Locations.end() && \"already found location for placeholder!\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1548, __extension__ __PRETTY_FUNCTION__))
1548 "already found location for placeholder!")(static_cast <bool> (Locations.find(placeholder) == Locations
.end() && "already found location for placeholder!") ?
void (0) : __assert_fail ("Locations.find(placeholder) == Locations.end() && \"already found location for placeholder!\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1548, __extension__ __PRETTY_FUNCTION__))
;
1549
1550 // Lazily fill in IndexValues with the values from Indices.
1551 // We do this in reverse because we should always have a strict
1552 // prefix of indices from the start.
1553 assert(Indices.size() == IndexValues.size())(static_cast <bool> (Indices.size() == IndexValues.size
()) ? void (0) : __assert_fail ("Indices.size() == IndexValues.size()"
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1553, __extension__ __PRETTY_FUNCTION__))
;
1554 for (size_t i = Indices.size() - 1; i != size_t(-1); --i) {
1555 if (IndexValues[i]) {
1556#ifndef NDEBUG
1557 for (size_t j = 0; j != i + 1; ++j) {
1558 assert(IndexValues[j] &&(static_cast <bool> (IndexValues[j] && isa<llvm
::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt
>(IndexValues[j])->getZExtValue() == Indices[j]) ? void
(0) : __assert_fail ("IndexValues[j] && isa<llvm::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue() == Indices[j]"
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1561, __extension__ __PRETTY_FUNCTION__))
1559 isa<llvm::ConstantInt>(IndexValues[j]) &&(static_cast <bool> (IndexValues[j] && isa<llvm
::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt
>(IndexValues[j])->getZExtValue() == Indices[j]) ? void
(0) : __assert_fail ("IndexValues[j] && isa<llvm::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue() == Indices[j]"
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1561, __extension__ __PRETTY_FUNCTION__))
1560 cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue()(static_cast <bool> (IndexValues[j] && isa<llvm
::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt
>(IndexValues[j])->getZExtValue() == Indices[j]) ? void
(0) : __assert_fail ("IndexValues[j] && isa<llvm::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue() == Indices[j]"
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1561, __extension__ __PRETTY_FUNCTION__))
1561 == Indices[j])(static_cast <bool> (IndexValues[j] && isa<llvm
::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt
>(IndexValues[j])->getZExtValue() == Indices[j]) ? void
(0) : __assert_fail ("IndexValues[j] && isa<llvm::ConstantInt>(IndexValues[j]) && cast<llvm::ConstantInt>(IndexValues[j])->getZExtValue() == Indices[j]"
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1561, __extension__ __PRETTY_FUNCTION__))
;
1562 }
1563#endif
1564 break;
1565 }
1566
1567 IndexValues[i] = llvm::ConstantInt::get(CGM.Int32Ty, Indices[i]);
1568 }
1569
1570 // Form a GEP and then bitcast to the placeholder type so that the
1571 // replacement will succeed.
1572 llvm::Constant *location =
1573 llvm::ConstantExpr::getInBoundsGetElementPtr(BaseValueTy,
1574 Base, IndexValues);
1575 location = llvm::ConstantExpr::getBitCast(location,
1576 placeholder->getType());
1577
1578 Locations.insert({placeholder, location});
1579 }
1580 };
1581}
1582
1583void ConstantEmitter::finalize(llvm::GlobalVariable *global) {
1584 assert(InitializedNonAbstract &&(static_cast <bool> (InitializedNonAbstract && "finalizing emitter that was used for abstract emission?"
) ? void (0) : __assert_fail ("InitializedNonAbstract && \"finalizing emitter that was used for abstract emission?\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1585, __extension__ __PRETTY_FUNCTION__))
1585 "finalizing emitter that was used for abstract emission?")(static_cast <bool> (InitializedNonAbstract && "finalizing emitter that was used for abstract emission?"
) ? void (0) : __assert_fail ("InitializedNonAbstract && \"finalizing emitter that was used for abstract emission?\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1585, __extension__ __PRETTY_FUNCTION__))
;
1586 assert(!Finalized && "finalizing emitter multiple times")(static_cast <bool> (!Finalized && "finalizing emitter multiple times"
) ? void (0) : __assert_fail ("!Finalized && \"finalizing emitter multiple times\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1586, __extension__ __PRETTY_FUNCTION__))
;
1587 assert(global->getInitializer())(static_cast <bool> (global->getInitializer()) ? void
(0) : __assert_fail ("global->getInitializer()", "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1587, __extension__ __PRETTY_FUNCTION__))
;
1588
1589 // Note that we might also be Failed.
1590 Finalized = true;
1591
1592 if (!PlaceholderAddresses.empty()) {
1593 ReplacePlaceholders(CGM, global, PlaceholderAddresses)
1594 .replaceInInitializer(global->getInitializer());
1595 PlaceholderAddresses.clear(); // satisfy
1596 }
1597}
1598
1599ConstantEmitter::~ConstantEmitter() {
1600 assert((!InitializedNonAbstract || Finalized || Failed) &&(static_cast <bool> ((!InitializedNonAbstract || Finalized
|| Failed) && "not finalized after being initialized for non-abstract emission"
) ? void (0) : __assert_fail ("(!InitializedNonAbstract || Finalized || Failed) && \"not finalized after being initialized for non-abstract emission\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1601, __extension__ __PRETTY_FUNCTION__))
1601 "not finalized after being initialized for non-abstract emission")(static_cast <bool> ((!InitializedNonAbstract || Finalized
|| Failed) && "not finalized after being initialized for non-abstract emission"
) ? void (0) : __assert_fail ("(!InitializedNonAbstract || Finalized || Failed) && \"not finalized after being initialized for non-abstract emission\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1601, __extension__ __PRETTY_FUNCTION__))
;
1602 assert(PlaceholderAddresses.empty() && "unhandled placeholders")(static_cast <bool> (PlaceholderAddresses.empty() &&
"unhandled placeholders") ? void (0) : __assert_fail ("PlaceholderAddresses.empty() && \"unhandled placeholders\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1602, __extension__ __PRETTY_FUNCTION__))
;
1603}
1604
1605static QualType getNonMemoryType(CodeGenModule &CGM, QualType type) {
1606 if (auto AT = type->getAs<AtomicType>()) {
1607 return CGM.getContext().getQualifiedType(AT->getValueType(),
1608 type.getQualifiers());
1609 }
1610 return type;
1611}
1612
1613llvm::Constant *ConstantEmitter::tryEmitPrivateForVarInit(const VarDecl &D) {
1614 // Make a quick check if variable can be default NULL initialized
1615 // and avoid going through rest of code which may do, for c++11,
1616 // initialization of memory to all NULLs.
1617 if (!D.hasLocalStorage()) {
1618 QualType Ty = CGM.getContext().getBaseElementType(D.getType());
1619 if (Ty->isRecordType())
1620 if (const CXXConstructExpr *E =
1621 dyn_cast_or_null<CXXConstructExpr>(D.getInit())) {
1622 const CXXConstructorDecl *CD = E->getConstructor();
1623 if (CD->isTrivial() && CD->isDefaultConstructor())
1624 return CGM.EmitNullConstant(D.getType());
1625 }
1626 }
1627 InConstantContext = D.hasConstantInitialization();
1628
1629 QualType destType = D.getType();
1630
1631 // Try to emit the initializer. Note that this can allow some things that
1632 // are not allowed by tryEmitPrivateForMemory alone.
1633 if (auto value = D.evaluateValue()) {
1634 return tryEmitPrivateForMemory(*value, destType);
1635 }
1636
1637 // FIXME: Implement C++11 [basic.start.init]p2: if the initializer of a
1638 // reference is a constant expression, and the reference binds to a temporary,
1639 // then constant initialization is performed. ConstExprEmitter will
1640 // incorrectly emit a prvalue constant in this case, and the calling code
1641 // interprets that as the (pointer) value of the reference, rather than the
1642 // desired value of the referee.
1643 if (destType->isReferenceType())
1644 return nullptr;
1645
1646 const Expr *E = D.getInit();
1647 assert(E && "No initializer to emit")(static_cast <bool> (E && "No initializer to emit"
) ? void (0) : __assert_fail ("E && \"No initializer to emit\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1647, __extension__ __PRETTY_FUNCTION__))
;
1648
1649 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1650 auto C =
1651 ConstExprEmitter(*this).Visit(const_cast<Expr*>(E), nonMemoryDestType);
1652 return (C ? emitForMemory(C, destType) : nullptr);
1653}
1654
1655llvm::Constant *
1656ConstantEmitter::tryEmitAbstractForMemory(const Expr *E, QualType destType) {
1657 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1658 auto C = tryEmitAbstract(E, nonMemoryDestType);
1659 return (C ? emitForMemory(C, destType) : nullptr);
1660}
1661
1662llvm::Constant *
1663ConstantEmitter::tryEmitAbstractForMemory(const APValue &value,
1664 QualType destType) {
1665 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1666 auto C = tryEmitAbstract(value, nonMemoryDestType);
1667 return (C ? emitForMemory(C, destType) : nullptr);
1668}
1669
1670llvm::Constant *ConstantEmitter::tryEmitPrivateForMemory(const Expr *E,
1671 QualType destType) {
1672 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1673 llvm::Constant *C = tryEmitPrivate(E, nonMemoryDestType);
1674 return (C ? emitForMemory(C, destType) : nullptr);
1675}
1676
1677llvm::Constant *ConstantEmitter::tryEmitPrivateForMemory(const APValue &value,
1678 QualType destType) {
1679 auto nonMemoryDestType = getNonMemoryType(CGM, destType);
1680 auto C = tryEmitPrivate(value, nonMemoryDestType);
1681 return (C ? emitForMemory(C, destType) : nullptr);
1682}
1683
1684llvm::Constant *ConstantEmitter::emitForMemory(CodeGenModule &CGM,
1685 llvm::Constant *C,
1686 QualType destType) {
1687 // For an _Atomic-qualified constant, we may need to add tail padding.
1688 if (auto AT = destType->getAs<AtomicType>()) {
1689 QualType destValueType = AT->getValueType();
1690 C = emitForMemory(CGM, C, destValueType);
1691
1692 uint64_t innerSize = CGM.getContext().getTypeSize(destValueType);
1693 uint64_t outerSize = CGM.getContext().getTypeSize(destType);
1694 if (innerSize == outerSize)
1695 return C;
1696
1697 assert(innerSize < outerSize && "emitted over-large constant for atomic")(static_cast <bool> (innerSize < outerSize &&
"emitted over-large constant for atomic") ? void (0) : __assert_fail
("innerSize < outerSize && \"emitted over-large constant for atomic\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1697, __extension__ __PRETTY_FUNCTION__))
;
1698 llvm::Constant *elts[] = {
1699 C,
1700 llvm::ConstantAggregateZero::get(
1701 llvm::ArrayType::get(CGM.Int8Ty, (outerSize - innerSize) / 8))
1702 };
1703 return llvm::ConstantStruct::getAnon(elts);
1704 }
1705
1706 // Zero-extend bool.
1707 if (C->getType()->isIntegerTy(1)) {
1708 llvm::Type *boolTy = CGM.getTypes().ConvertTypeForMem(destType);
1709 return llvm::ConstantExpr::getZExt(C, boolTy);
1710 }
1711
1712 return C;
1713}
1714
1715llvm::Constant *ConstantEmitter::tryEmitPrivate(const Expr *E,
1716 QualType destType) {
1717 Expr::EvalResult Result;
1718
1719 bool Success = false;
1720
1721 if (destType->isReferenceType())
1722 Success = E->EvaluateAsLValue(Result, CGM.getContext());
1723 else
1724 Success = E->EvaluateAsRValue(Result, CGM.getContext(), InConstantContext);
1725
1726 llvm::Constant *C;
1727 if (Success && !Result.HasSideEffects)
1728 C = tryEmitPrivate(Result.Val, destType);
1729 else
1730 C = ConstExprEmitter(*this).Visit(const_cast<Expr*>(E), destType);
1731
1732 return C;
1733}
1734
1735llvm::Constant *CodeGenModule::getNullPointer(llvm::PointerType *T, QualType QT) {
1736 return getTargetCodeGenInfo().getNullPointer(*this, T, QT);
1737}
1738
1739namespace {
1740/// A struct which can be used to peephole certain kinds of finalization
1741/// that normally happen during l-value emission.
1742struct ConstantLValue {
1743 llvm::Constant *Value;
1744 bool HasOffsetApplied;
1745
1746 /*implicit*/ ConstantLValue(llvm::Constant *value,
1747 bool hasOffsetApplied = false)
1748 : Value(value), HasOffsetApplied(hasOffsetApplied) {}
1749
1750 /*implicit*/ ConstantLValue(ConstantAddress address)
1751 : ConstantLValue(address.getPointer()) {}
1752};
1753
1754/// A helper class for emitting constant l-values.
1755class ConstantLValueEmitter : public ConstStmtVisitor<ConstantLValueEmitter,
1756 ConstantLValue> {
1757 CodeGenModule &CGM;
1758 ConstantEmitter &Emitter;
1759 const APValue &Value;
1760 QualType DestType;
1761
1762 // Befriend StmtVisitorBase so that we don't have to expose Visit*.
1763 friend StmtVisitorBase;
1764
1765public:
1766 ConstantLValueEmitter(ConstantEmitter &emitter, const APValue &value,
1767 QualType destType)
1768 : CGM(emitter.CGM), Emitter(emitter), Value(value), DestType(destType) {}
1769
1770 llvm::Constant *tryEmit();
1771
1772private:
1773 llvm::Constant *tryEmitAbsolute(llvm::Type *destTy);
1774 ConstantLValue tryEmitBase(const APValue::LValueBase &base);
1775
1776 ConstantLValue VisitStmt(const Stmt *S) { return nullptr; }
1777 ConstantLValue VisitConstantExpr(const ConstantExpr *E);
1778 ConstantLValue VisitCompoundLiteralExpr(const CompoundLiteralExpr *E);
1779 ConstantLValue VisitStringLiteral(const StringLiteral *E);
1780 ConstantLValue VisitObjCBoxedExpr(const ObjCBoxedExpr *E);
1781 ConstantLValue VisitObjCEncodeExpr(const ObjCEncodeExpr *E);
1782 ConstantLValue VisitObjCStringLiteral(const ObjCStringLiteral *E);
1783 ConstantLValue VisitPredefinedExpr(const PredefinedExpr *E);
1784 ConstantLValue VisitAddrLabelExpr(const AddrLabelExpr *E);
1785 ConstantLValue VisitCallExpr(const CallExpr *E);
1786 ConstantLValue VisitBlockExpr(const BlockExpr *E);
1787 ConstantLValue VisitCXXTypeidExpr(const CXXTypeidExpr *E);
1788 ConstantLValue VisitMaterializeTemporaryExpr(
1789 const MaterializeTemporaryExpr *E);
1790
1791 bool hasNonZeroOffset() const {
1792 return !Value.getLValueOffset().isZero();
1793 }
1794
1795 /// Return the value offset.
1796 llvm::Constant *getOffset() {
1797 return llvm::ConstantInt::get(CGM.Int64Ty,
1798 Value.getLValueOffset().getQuantity());
1799 }
1800
1801 /// Apply the value offset to the given constant.
1802 llvm::Constant *applyOffset(llvm::Constant *C) {
1803 if (!hasNonZeroOffset())
1804 return C;
1805
1806 llvm::Type *origPtrTy = C->getType();
1807 unsigned AS = origPtrTy->getPointerAddressSpace();
1808 llvm::Type *charPtrTy = CGM.Int8Ty->getPointerTo(AS);
1809 C = llvm::ConstantExpr::getBitCast(C, charPtrTy);
1810 C = llvm::ConstantExpr::getGetElementPtr(CGM.Int8Ty, C, getOffset());
1811 C = llvm::ConstantExpr::getPointerCast(C, origPtrTy);
1812 return C;
1813 }
1814};
1815
1816}
1817
1818llvm::Constant *ConstantLValueEmitter::tryEmit() {
1819 const APValue::LValueBase &base = Value.getLValueBase();
1820
1821 // The destination type should be a pointer or reference
1822 // type, but it might also be a cast thereof.
1823 //
1824 // FIXME: the chain of casts required should be reflected in the APValue.
1825 // We need this in order to correctly handle things like a ptrtoint of a
1826 // non-zero null pointer and addrspace casts that aren't trivially
1827 // represented in LLVM IR.
1828 auto destTy = CGM.getTypes().ConvertTypeForMem(DestType);
1829 assert(isa<llvm::IntegerType>(destTy) || isa<llvm::PointerType>(destTy))(static_cast <bool> (isa<llvm::IntegerType>(destTy
) || isa<llvm::PointerType>(destTy)) ? void (0) : __assert_fail
("isa<llvm::IntegerType>(destTy) || isa<llvm::PointerType>(destTy)"
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1829, __extension__ __PRETTY_FUNCTION__))
;
1830
1831 // If there's no base at all, this is a null or absolute pointer,
1832 // possibly cast back to an integer type.
1833 if (!base) {
1834 return tryEmitAbsolute(destTy);
1835 }
1836
1837 // Otherwise, try to emit the base.
1838 ConstantLValue result = tryEmitBase(base);
1839
1840 // If that failed, we're done.
1841 llvm::Constant *value = result.Value;
1842 if (!value) return nullptr;
1843
1844 // Apply the offset if necessary and not already done.
1845 if (!result.HasOffsetApplied) {
1846 value = applyOffset(value);
1847 }
1848
1849 // Convert to the appropriate type; this could be an lvalue for
1850 // an integer. FIXME: performAddrSpaceCast
1851 if (isa<llvm::PointerType>(destTy))
1852 return llvm::ConstantExpr::getPointerCast(value, destTy);
1853
1854 return llvm::ConstantExpr::getPtrToInt(value, destTy);
1855}
1856
1857/// Try to emit an absolute l-value, such as a null pointer or an integer
1858/// bitcast to pointer type.
1859llvm::Constant *
1860ConstantLValueEmitter::tryEmitAbsolute(llvm::Type *destTy) {
1861 // If we're producing a pointer, this is easy.
1862 auto destPtrTy = cast<llvm::PointerType>(destTy);
1863 if (Value.isNullPointer()) {
1864 // FIXME: integer offsets from non-zero null pointers.
1865 return CGM.getNullPointer(destPtrTy, DestType);
1866 }
1867
1868 // Convert the integer to a pointer-sized integer before converting it
1869 // to a pointer.
1870 // FIXME: signedness depends on the original integer type.
1871 auto intptrTy = CGM.getDataLayout().getIntPtrType(destPtrTy);
1872 llvm::Constant *C;
1873 C = llvm::ConstantExpr::getIntegerCast(getOffset(), intptrTy,
1874 /*isSigned*/ false);
1875 C = llvm::ConstantExpr::getIntToPtr(C, destPtrTy);
1876 return C;
1877}
1878
1879ConstantLValue
1880ConstantLValueEmitter::tryEmitBase(const APValue::LValueBase &base) {
1881 // Handle values.
1882 if (const ValueDecl *D = base.dyn_cast<const ValueDecl*>()) {
1883 // The constant always points to the canonical declaration. We want to look
1884 // at properties of the most recent declaration at the point of emission.
1885 D = cast<ValueDecl>(D->getMostRecentDecl());
1886
1887 if (D->hasAttr<WeakRefAttr>())
1888 return CGM.GetWeakRefReference(D).getPointer();
1889
1890 if (auto FD = dyn_cast<FunctionDecl>(D))
1891 return CGM.GetAddrOfFunction(FD);
1892
1893 if (auto VD = dyn_cast<VarDecl>(D)) {
1894 // We can never refer to a variable with local storage.
1895 if (!VD->hasLocalStorage()) {
1896 if (VD->isFileVarDecl() || VD->hasExternalStorage())
1897 return CGM.GetAddrOfGlobalVar(VD);
1898
1899 if (VD->isLocalVarDecl()) {
1900 return CGM.getOrCreateStaticVarDecl(
1901 *VD, CGM.getLLVMLinkageVarDefinition(VD, /*IsConstant=*/false));
1902 }
1903 }
1904 }
1905
1906 if (auto *GD = dyn_cast<MSGuidDecl>(D))
1907 return CGM.GetAddrOfMSGuidDecl(GD);
1908
1909 if (auto *TPO = dyn_cast<TemplateParamObjectDecl>(D))
1910 return CGM.GetAddrOfTemplateParamObject(TPO);
1911
1912 return nullptr;
1913 }
1914
1915 // Handle typeid(T).
1916 if (TypeInfoLValue TI = base.dyn_cast<TypeInfoLValue>()) {
1917 llvm::Type *StdTypeInfoPtrTy =
1918 CGM.getTypes().ConvertType(base.getTypeInfoType())->getPointerTo();
1919 llvm::Constant *TypeInfo =
1920 CGM.GetAddrOfRTTIDescriptor(QualType(TI.getType(), 0));
1921 if (TypeInfo->getType() != StdTypeInfoPtrTy)
1922 TypeInfo = llvm::ConstantExpr::getBitCast(TypeInfo, StdTypeInfoPtrTy);
1923 return TypeInfo;
1924 }
1925
1926 // Otherwise, it must be an expression.
1927 return Visit(base.get<const Expr*>());
1928}
1929
1930ConstantLValue
1931ConstantLValueEmitter::VisitConstantExpr(const ConstantExpr *E) {
1932 if (llvm::Constant *Result = Emitter.tryEmitConstantExpr(E))
1933 return Result;
1934 return Visit(E->getSubExpr());
1935}
1936
1937ConstantLValue
1938ConstantLValueEmitter::VisitCompoundLiteralExpr(const CompoundLiteralExpr *E) {
1939 return tryEmitGlobalCompoundLiteral(CGM, Emitter.CGF, E);
1940}
1941
1942ConstantLValue
1943ConstantLValueEmitter::VisitStringLiteral(const StringLiteral *E) {
1944 return CGM.GetAddrOfConstantStringFromLiteral(E);
1945}
1946
1947ConstantLValue
1948ConstantLValueEmitter::VisitObjCEncodeExpr(const ObjCEncodeExpr *E) {
1949 return CGM.GetAddrOfConstantStringFromObjCEncode(E);
1950}
1951
1952static ConstantLValue emitConstantObjCStringLiteral(const StringLiteral *S,
1953 QualType T,
1954 CodeGenModule &CGM) {
1955 auto C = CGM.getObjCRuntime().GenerateConstantString(S);
1956 return C.getElementBitCast(CGM.getTypes().ConvertTypeForMem(T));
1957}
1958
1959ConstantLValue
1960ConstantLValueEmitter::VisitObjCStringLiteral(const ObjCStringLiteral *E) {
1961 return emitConstantObjCStringLiteral(E->getString(), E->getType(), CGM);
1962}
1963
1964ConstantLValue
1965ConstantLValueEmitter::VisitObjCBoxedExpr(const ObjCBoxedExpr *E) {
1966 assert(E->isExpressibleAsConstantInitializer() &&(static_cast <bool> (E->isExpressibleAsConstantInitializer
() && "this boxed expression can't be emitted as a compile-time constant"
) ? void (0) : __assert_fail ("E->isExpressibleAsConstantInitializer() && \"this boxed expression can't be emitted as a compile-time constant\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1967, __extension__ __PRETTY_FUNCTION__))
1967 "this boxed expression can't be emitted as a compile-time constant")(static_cast <bool> (E->isExpressibleAsConstantInitializer
() && "this boxed expression can't be emitted as a compile-time constant"
) ? void (0) : __assert_fail ("E->isExpressibleAsConstantInitializer() && \"this boxed expression can't be emitted as a compile-time constant\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1967, __extension__ __PRETTY_FUNCTION__))
;
1968 auto *SL = cast<StringLiteral>(E->getSubExpr()->IgnoreParenCasts());
1969 return emitConstantObjCStringLiteral(SL, E->getType(), CGM);
1970}
1971
1972ConstantLValue
1973ConstantLValueEmitter::VisitPredefinedExpr(const PredefinedExpr *E) {
1974 return CGM.GetAddrOfConstantStringFromLiteral(E->getFunctionName());
1975}
1976
1977ConstantLValue
1978ConstantLValueEmitter::VisitAddrLabelExpr(const AddrLabelExpr *E) {
1979 assert(Emitter.CGF && "Invalid address of label expression outside function")(static_cast <bool> (Emitter.CGF && "Invalid address of label expression outside function"
) ? void (0) : __assert_fail ("Emitter.CGF && \"Invalid address of label expression outside function\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 1979, __extension__ __PRETTY_FUNCTION__))
;
1980 llvm::Constant *Ptr = Emitter.CGF->GetAddrOfLabel(E->getLabel());
1981 Ptr = llvm::ConstantExpr::getBitCast(Ptr,
1982 CGM.getTypes().ConvertType(E->getType()));
1983 return Ptr;
1984}
1985
1986ConstantLValue
1987ConstantLValueEmitter::VisitCallExpr(const CallExpr *E) {
1988 unsigned builtin = E->getBuiltinCallee();
1989 if (builtin != Builtin::BI__builtin___CFStringMakeConstantString &&
1990 builtin != Builtin::BI__builtin___NSStringMakeConstantString)
1991 return nullptr;
1992
1993 auto literal = cast<StringLiteral>(E->getArg(0)->IgnoreParenCasts());
1994 if (builtin == Builtin::BI__builtin___NSStringMakeConstantString) {
1995 return CGM.getObjCRuntime().GenerateConstantString(literal);
1996 } else {
1997 // FIXME: need to deal with UCN conversion issues.
1998 return CGM.GetAddrOfConstantCFString(literal);
1999 }
2000}
2001
2002ConstantLValue
2003ConstantLValueEmitter::VisitBlockExpr(const BlockExpr *E) {
2004 StringRef functionName;
2005 if (auto CGF = Emitter.CGF)
2006 functionName = CGF->CurFn->getName();
2007 else
2008 functionName = "global";
2009
2010 return CGM.GetAddrOfGlobalBlock(E, functionName);
2011}
2012
2013ConstantLValue
2014ConstantLValueEmitter::VisitCXXTypeidExpr(const CXXTypeidExpr *E) {
2015 QualType T;
2016 if (E->isTypeOperand())
2017 T = E->getTypeOperand(CGM.getContext());
2018 else
2019 T = E->getExprOperand()->getType();
2020 return CGM.GetAddrOfRTTIDescriptor(T);
2021}
2022
2023ConstantLValue
2024ConstantLValueEmitter::VisitMaterializeTemporaryExpr(
2025 const MaterializeTemporaryExpr *E) {
2026 assert(E->getStorageDuration() == SD_Static)(static_cast <bool> (E->getStorageDuration() == SD_Static
) ? void (0) : __assert_fail ("E->getStorageDuration() == SD_Static"
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 2026, __extension__ __PRETTY_FUNCTION__))
;
2027 SmallVector<const Expr *, 2> CommaLHSs;
2028 SmallVector<SubobjectAdjustment, 2> Adjustments;
2029 const Expr *Inner =
2030 E->getSubExpr()->skipRValueSubobjectAdjustments(CommaLHSs, Adjustments);
2031 return CGM.GetAddrOfGlobalTemporary(E, Inner);
2032}
2033
2034llvm::Constant *ConstantEmitter::tryEmitPrivate(const APValue &Value,
2035 QualType DestType) {
2036 switch (Value.getKind()) {
2037 case APValue::None:
2038 case APValue::Indeterminate:
2039 // Out-of-lifetime and indeterminate values can be modeled as 'undef'.
2040 return llvm::UndefValue::get(CGM.getTypes().ConvertType(DestType));
2041 case APValue::LValue:
2042 return ConstantLValueEmitter(*this, Value, DestType).tryEmit();
2043 case APValue::Int:
2044 return llvm::ConstantInt::get(CGM.getLLVMContext(), Value.getInt());
2045 case APValue::FixedPoint:
2046 return llvm::ConstantInt::get(CGM.getLLVMContext(),
2047 Value.getFixedPoint().getValue());
2048 case APValue::ComplexInt: {
2049 llvm::Constant *Complex[2];
2050
2051 Complex[0] = llvm::ConstantInt::get(CGM.getLLVMContext(),
2052 Value.getComplexIntReal());
2053 Complex[1] = llvm::ConstantInt::get(CGM.getLLVMContext(),
2054 Value.getComplexIntImag());
2055
2056 // FIXME: the target may want to specify that this is packed.
2057 llvm::StructType *STy =
2058 llvm::StructType::get(Complex[0]->getType(), Complex[1]->getType());
2059 return llvm::ConstantStruct::get(STy, Complex);
2060 }
2061 case APValue::Float: {
2062 const llvm::APFloat &Init = Value.getFloat();
2063 if (&Init.getSemantics() == &llvm::APFloat::IEEEhalf() &&
2064 !CGM.getContext().getLangOpts().NativeHalfType &&
2065 CGM.getContext().getTargetInfo().useFP16ConversionIntrinsics())
2066 return llvm::ConstantInt::get(CGM.getLLVMContext(),
2067 Init.bitcastToAPInt());
2068 else
2069 return llvm::ConstantFP::get(CGM.getLLVMContext(), Init);
2070 }
2071 case APValue::ComplexFloat: {
2072 llvm::Constant *Complex[2];
2073
2074 Complex[0] = llvm::ConstantFP::get(CGM.getLLVMContext(),
2075 Value.getComplexFloatReal());
2076 Complex[1] = llvm::ConstantFP::get(CGM.getLLVMContext(),
2077 Value.getComplexFloatImag());
2078
2079 // FIXME: the target may want to specify that this is packed.
2080 llvm::StructType *STy =
2081 llvm::StructType::get(Complex[0]->getType(), Complex[1]->getType());
2082 return llvm::ConstantStruct::get(STy, Complex);
2083 }
2084 case APValue::Vector: {
2085 unsigned NumElts = Value.getVectorLength();
2086 SmallVector<llvm::Constant *, 4> Inits(NumElts);
2087
2088 for (unsigned I = 0; I != NumElts; ++I) {
2089 const APValue &Elt = Value.getVectorElt(I);
2090 if (Elt.isInt())
2091 Inits[I] = llvm::ConstantInt::get(CGM.getLLVMContext(), Elt.getInt());
2092 else if (Elt.isFloat())
2093 Inits[I] = llvm::ConstantFP::get(CGM.getLLVMContext(), Elt.getFloat());
2094 else
2095 llvm_unreachable("unsupported vector element type")::llvm::llvm_unreachable_internal("unsupported vector element type"
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 2095)
;
2096 }
2097 return llvm::ConstantVector::get(Inits);
2098 }
2099 case APValue::AddrLabelDiff: {
2100 const AddrLabelExpr *LHSExpr = Value.getAddrLabelDiffLHS();
2101 const AddrLabelExpr *RHSExpr = Value.getAddrLabelDiffRHS();
2102 llvm::Constant *LHS = tryEmitPrivate(LHSExpr, LHSExpr->getType());
2103 llvm::Constant *RHS = tryEmitPrivate(RHSExpr, RHSExpr->getType());
2104 if (!LHS || !RHS) return nullptr;
2105
2106 // Compute difference
2107 llvm::Type *ResultType = CGM.getTypes().ConvertType(DestType);
2108 LHS = llvm::ConstantExpr::getPtrToInt(LHS, CGM.IntPtrTy);
2109 RHS = llvm::ConstantExpr::getPtrToInt(RHS, CGM.IntPtrTy);
2110 llvm::Constant *AddrLabelDiff = llvm::ConstantExpr::getSub(LHS, RHS);
2111
2112 // LLVM is a bit sensitive about the exact format of the
2113 // address-of-label difference; make sure to truncate after
2114 // the subtraction.
2115 return llvm::ConstantExpr::getTruncOrBitCast(AddrLabelDiff, ResultType);
2116 }
2117 case APValue::Struct:
2118 case APValue::Union:
2119 return ConstStructBuilder::BuildStruct(*this, Value, DestType);
2120 case APValue::Array: {
2121 const ArrayType *ArrayTy = CGM.getContext().getAsArrayType(DestType);
2122 unsigned NumElements = Value.getArraySize();
2123 unsigned NumInitElts = Value.getArrayInitializedElts();
2124
2125 // Emit array filler, if there is one.
2126 llvm::Constant *Filler = nullptr;
2127 if (Value.hasArrayFiller()) {
2128 Filler = tryEmitAbstractForMemory(Value.getArrayFiller(),
2129 ArrayTy->getElementType());
2130 if (!Filler)
2131 return nullptr;
2132 }
2133
2134 // Emit initializer elements.
2135 SmallVector<llvm::Constant*, 16> Elts;
2136 if (Filler && Filler->isNullValue())
2137 Elts.reserve(NumInitElts + 1);
2138 else
2139 Elts.reserve(NumElements);
2140
2141 llvm::Type *CommonElementType = nullptr;
2142 for (unsigned I = 0; I < NumInitElts; ++I) {
2143 llvm::Constant *C = tryEmitPrivateForMemory(
2144 Value.getArrayInitializedElt(I), ArrayTy->getElementType());
2145 if (!C) return nullptr;
2146
2147 if (I == 0)
2148 CommonElementType = C->getType();
2149 else if (C->getType() != CommonElementType)
2150 CommonElementType = nullptr;
2151 Elts.push_back(C);
2152 }
2153
2154 llvm::ArrayType *Desired =
2155 cast<llvm::ArrayType>(CGM.getTypes().ConvertType(DestType));
2156 return EmitArrayConstant(CGM, Desired, CommonElementType, NumElements, Elts,
2157 Filler);
2158 }
2159 case APValue::MemberPointer:
2160 return CGM.getCXXABI().EmitMemberPointer(Value, DestType);
2161 }
2162 llvm_unreachable("Unknown APValue kind")::llvm::llvm_unreachable_internal("Unknown APValue kind", "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 2162)
;
2163}
2164
2165llvm::GlobalVariable *CodeGenModule::getAddrOfConstantCompoundLiteralIfEmitted(
2166 const CompoundLiteralExpr *E) {
2167 return EmittedCompoundLiterals.lookup(E);
2168}
2169
2170void CodeGenModule::setAddrOfConstantCompoundLiteral(
2171 const CompoundLiteralExpr *CLE, llvm::GlobalVariable *GV) {
2172 bool Ok = EmittedCompoundLiterals.insert(std::make_pair(CLE, GV)).second;
2173 (void)Ok;
2174 assert(Ok && "CLE has already been emitted!")(static_cast <bool> (Ok && "CLE has already been emitted!"
) ? void (0) : __assert_fail ("Ok && \"CLE has already been emitted!\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 2174, __extension__ __PRETTY_FUNCTION__))
;
2175}
2176
2177ConstantAddress
2178CodeGenModule::GetAddrOfConstantCompoundLiteral(const CompoundLiteralExpr *E) {
2179 assert(E->isFileScope() && "not a file-scope compound literal expr")(static_cast <bool> (E->isFileScope() && "not a file-scope compound literal expr"
) ? void (0) : __assert_fail ("E->isFileScope() && \"not a file-scope compound literal expr\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 2179, __extension__ __PRETTY_FUNCTION__))
;
2180 return tryEmitGlobalCompoundLiteral(*this, nullptr, E);
2181}
2182
2183llvm::Constant *
2184CodeGenModule::getMemberPointerConstant(const UnaryOperator *uo) {
2185 // Member pointer constants always have a very particular form.
2186 const MemberPointerType *type = cast<MemberPointerType>(uo->getType());
2187 const ValueDecl *decl = cast<DeclRefExpr>(uo->getSubExpr())->getDecl();
2188
2189 // A member function pointer.
2190 if (const CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(decl))
2191 return getCXXABI().EmitMemberFunctionPointer(method);
2192
2193 // Otherwise, a member data pointer.
2194 uint64_t fieldOffset = getContext().getFieldOffset(decl);
2195 CharUnits chars = getContext().toCharUnitsFromBits((int64_t) fieldOffset);
2196 return getCXXABI().EmitMemberDataPointer(type, chars);
2197}
2198
2199static llvm::Constant *EmitNullConstantForBase(CodeGenModule &CGM,
2200 llvm::Type *baseType,
2201 const CXXRecordDecl *base);
2202
2203static llvm::Constant *EmitNullConstant(CodeGenModule &CGM,
2204 const RecordDecl *record,
2205 bool asCompleteObject) {
2206 const CGRecordLayout &layout = CGM.getTypes().getCGRecordLayout(record);
2207 llvm::StructType *structure =
2208 (asCompleteObject ? layout.getLLVMType()
2209 : layout.getBaseSubobjectLLVMType());
2210
2211 unsigned numElements = structure->getNumElements();
2212 std::vector<llvm::Constant *> elements(numElements);
2213
2214 auto CXXR = dyn_cast<CXXRecordDecl>(record);
2215 // Fill in all the bases.
2216 if (CXXR) {
2217 for (const auto &I : CXXR->bases()) {
2218 if (I.isVirtual()) {
2219 // Ignore virtual bases; if we're laying out for a complete
2220 // object, we'll lay these out later.
2221 continue;
2222 }
2223
2224 const CXXRecordDecl *base =
2225 cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
2226
2227 // Ignore empty bases.
2228 if (base->isEmpty() ||
2229 CGM.getContext().getASTRecordLayout(base).getNonVirtualSize()
2230 .isZero())
2231 continue;
2232
2233 unsigned fieldIndex = layout.getNonVirtualBaseLLVMFieldNo(base);
2234 llvm::Type *baseType = structure->getElementType(fieldIndex);
2235 elements[fieldIndex] = EmitNullConstantForBase(CGM, baseType, base);
2236 }
2237 }
2238
2239 // Fill in all the fields.
2240 for (const auto *Field : record->fields()) {
2241 // Fill in non-bitfields. (Bitfields always use a zero pattern, which we
2242 // will fill in later.)
2243 if (!Field->isBitField() && !Field->isZeroSize(CGM.getContext())) {
2244 unsigned fieldIndex = layout.getLLVMFieldNo(Field);
2245 elements[fieldIndex] = CGM.EmitNullConstant(Field->getType());
2246 }
2247
2248 // For unions, stop after the first named field.
2249 if (record->isUnion()) {
2250 if (Field->getIdentifier())
2251 break;
2252 if (const auto *FieldRD = Field->getType()->getAsRecordDecl())
2253 if (FieldRD->findFirstNamedDataMember())
2254 break;
2255 }
2256 }
2257
2258 // Fill in the virtual bases, if we're working with the complete object.
2259 if (CXXR && asCompleteObject) {
2260 for (const auto &I : CXXR->vbases()) {
2261 const CXXRecordDecl *base =
2262 cast<CXXRecordDecl>(I.getType()->castAs<RecordType>()->getDecl());
2263
2264 // Ignore empty bases.
2265 if (base->isEmpty())
2266 continue;
2267
2268 unsigned fieldIndex = layout.getVirtualBaseIndex(base);
2269
2270 // We might have already laid this field out.
2271 if (elements[fieldIndex]) continue;
2272
2273 llvm::Type *baseType = structure->getElementType(fieldIndex);
2274 elements[fieldIndex] = EmitNullConstantForBase(CGM, baseType, base);
2275 }
2276 }
2277
2278 // Now go through all other fields and zero them out.
2279 for (unsigned i = 0; i != numElements; ++i) {
2280 if (!elements[i])
2281 elements[i] = llvm::Constant::getNullValue(structure->getElementType(i));
2282 }
2283
2284 return llvm::ConstantStruct::get(structure, elements);
2285}
2286
2287/// Emit the null constant for a base subobject.
2288static llvm::Constant *EmitNullConstantForBase(CodeGenModule &CGM,
2289 llvm::Type *baseType,
2290 const CXXRecordDecl *base) {
2291 const CGRecordLayout &baseLayout = CGM.getTypes().getCGRecordLayout(base);
2292
2293 // Just zero out bases that don't have any pointer to data members.
2294 if (baseLayout.isZeroInitializableAsBase())
2295 return llvm::Constant::getNullValue(baseType);
2296
2297 // Otherwise, we can just use its null constant.
2298 return EmitNullConstant(CGM, base, /*asCompleteObject=*/false);
2299}
2300
2301llvm::Constant *ConstantEmitter::emitNullForMemory(CodeGenModule &CGM,
2302 QualType T) {
2303 return emitForMemory(CGM, CGM.EmitNullConstant(T), T);
2304}
2305
2306llvm::Constant *CodeGenModule::EmitNullConstant(QualType T) {
2307 if (T->getAs<PointerType>())
2308 return getNullPointer(
2309 cast<llvm::PointerType>(getTypes().ConvertTypeForMem(T)), T);
2310
2311 if (getTypes().isZeroInitializable(T))
2312 return llvm::Constant::getNullValue(getTypes().ConvertTypeForMem(T));
2313
2314 if (const ConstantArrayType *CAT = Context.getAsConstantArrayType(T)) {
2315 llvm::ArrayType *ATy =
2316 cast<llvm::ArrayType>(getTypes().ConvertTypeForMem(T));
2317
2318 QualType ElementTy = CAT->getElementType();
2319
2320 llvm::Constant *Element =
2321 ConstantEmitter::emitNullForMemory(*this, ElementTy);
2322 unsigned NumElements = CAT->getSize().getZExtValue();
2323 SmallVector<llvm::Constant *, 8> Array(NumElements, Element);
2324 return llvm::ConstantArray::get(ATy, Array);
2325 }
2326
2327 if (const RecordType *RT = T->getAs<RecordType>())
2328 return ::EmitNullConstant(*this, RT->getDecl(), /*complete object*/ true);
2329
2330 assert(T->isMemberDataPointerType() &&(static_cast <bool> (T->isMemberDataPointerType() &&
"Should only see pointers to data members here!") ? void (0)
: __assert_fail ("T->isMemberDataPointerType() && \"Should only see pointers to data members here!\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 2331, __extension__ __PRETTY_FUNCTION__))
2331 "Should only see pointers to data members here!")(static_cast <bool> (T->isMemberDataPointerType() &&
"Should only see pointers to data members here!") ? void (0)
: __assert_fail ("T->isMemberDataPointerType() && \"Should only see pointers to data members here!\""
, "/build/llvm-toolchain-snapshot-13~++20210506100649+6304c0836a4d/clang/lib/CodeGen/CGExprConstant.cpp"
, 2331, __extension__ __PRETTY_FUNCTION__))
;
2332
2333 return getCXXABI().EmitNullMemberPointer(T->castAs<MemberPointerType>());
2334}
2335
2336llvm::Constant *
2337CodeGenModule::EmitNullConstantForBase(const CXXRecordDecl *Record) {
2338 return ::EmitNullConstant(*this, Record, false);
2339}