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Anders Carlsson3b1d57b2008-01-26 01:36:00 +00001//===--- CGExprConstant.cpp - Emit LLVM Code from Constant Expressions ----===//
2//
3// The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This contains code to emit Constant Expr nodes as LLVM code.
11//
12//===----------------------------------------------------------------------===//
13
14#include "CodeGenFunction.h"
15#include "CodeGenModule.h"
John McCall4c40d982010-08-31 07:33:07 +000016#include "CGCXXABI.h"
Daniel Dunbaraf2f62c2008-08-13 00:59:25 +000017#include "CGObjCRuntime.h"
Daniel Dunbar2924ade2010-03-30 22:26:10 +000018#include "CGRecordLayout.h"
Chris Lattnerf6b24ea2008-10-06 05:59:01 +000019#include "clang/AST/APValue.h"
Daniel Dunbarde7fb842008-08-11 05:00:27 +000020#include "clang/AST/ASTContext.h"
Anders Carlsson4c98efd2009-07-24 15:20:52 +000021#include "clang/AST/RecordLayout.h"
Daniel Dunbarde7fb842008-08-11 05:00:27 +000022#include "clang/AST/StmtVisitor.h"
Chris Lattner1b63e4f2009-06-14 01:54:56 +000023#include "clang/Basic/Builtins.h"
Anders Carlsson3b1d57b2008-01-26 01:36:00 +000024#include "llvm/Constants.h"
25#include "llvm/Function.h"
26#include "llvm/GlobalVariable.h"
Eli Friedmana8234002008-05-30 10:24:46 +000027#include "llvm/Target/TargetData.h"
Anders Carlsson3b1d57b2008-01-26 01:36:00 +000028using namespace clang;
29using namespace CodeGen;
30
Chris Lattnereba3e5a2010-04-13 17:45:57 +000031//===----------------------------------------------------------------------===//
32// ConstStructBuilder
33//===----------------------------------------------------------------------===//
34
35namespace {
Benjamin Kramer85b45212009-11-28 19:45:26 +000036class ConstStructBuilder {
Anders Carlsson4c98efd2009-07-24 15:20:52 +000037 CodeGenModule &CGM;
38 CodeGenFunction *CGF;
39
Mike Stump1eb44332009-09-09 15:08:12 +000040 bool Packed;
Ken Dyckdc496392011-03-17 01:33:18 +000041 CharUnits NextFieldOffsetInChars;
Ken Dyck7d2f9d52011-03-18 01:26:17 +000042 CharUnits LLVMStructAlignment;
Anders Carlsson4c98efd2009-07-24 15:20:52 +000043 std::vector<llvm::Constant *> Elements;
Chris Lattnereba3e5a2010-04-13 17:45:57 +000044public:
45 static llvm::Constant *BuildStruct(CodeGenModule &CGM, CodeGenFunction *CGF,
46 InitListExpr *ILE);
47
48private:
Anders Carlsson4c98efd2009-07-24 15:20:52 +000049 ConstStructBuilder(CodeGenModule &CGM, CodeGenFunction *CGF)
Ken Dyckdc496392011-03-17 01:33:18 +000050 : CGM(CGM), CGF(CGF), Packed(false),
51 NextFieldOffsetInChars(CharUnits::Zero()),
Ken Dyck7d2f9d52011-03-18 01:26:17 +000052 LLVMStructAlignment(CharUnits::One()) { }
Anders Carlsson4c98efd2009-07-24 15:20:52 +000053
Mike Stump1eb44332009-09-09 15:08:12 +000054 bool AppendField(const FieldDecl *Field, uint64_t FieldOffset,
Chris Lattner8ce9e452010-04-13 18:16:19 +000055 llvm::Constant *InitExpr);
Mike Stump1eb44332009-09-09 15:08:12 +000056
Chris Lattner18806662010-07-05 17:04:23 +000057 void AppendBitField(const FieldDecl *Field, uint64_t FieldOffset,
58 llvm::ConstantInt *InitExpr);
Mike Stump1eb44332009-09-09 15:08:12 +000059
Ken Dyckc29ea8f2011-03-11 23:42:54 +000060 void AppendPadding(CharUnits PadSize);
Mike Stump1eb44332009-09-09 15:08:12 +000061
Ken Dyck106ca042011-03-11 02:17:05 +000062 void AppendTailPadding(CharUnits RecordSize);
Anders Carlssond24393b2009-07-27 01:23:51 +000063
Chris Lattnereba3e5a2010-04-13 17:45:57 +000064 void ConvertStructToPacked();
Anders Carlsson31f2f9c2009-10-02 02:15:20 +000065
Chris Lattnereba3e5a2010-04-13 17:45:57 +000066 bool Build(InitListExpr *ILE);
Mike Stump1eb44332009-09-09 15:08:12 +000067
Ken Dyck7d2f9d52011-03-18 01:26:17 +000068 CharUnits getAlignment(const llvm::Constant *C) const {
69 if (Packed) return CharUnits::One();
70 return CharUnits::fromQuantity(
71 CGM.getTargetData().getABITypeAlignment(C->getType()));
Anders Carlsson4c98efd2009-07-24 15:20:52 +000072 }
Mike Stump1eb44332009-09-09 15:08:12 +000073
Ken Dyck15c152e2011-03-18 01:12:13 +000074 CharUnits getSizeInChars(const llvm::Constant *C) const {
75 return CharUnits::fromQuantity(
76 CGM.getTargetData().getTypeAllocSize(C->getType()));
Anders Carlsson4c98efd2009-07-24 15:20:52 +000077 }
Anders Carlsson4c98efd2009-07-24 15:20:52 +000078};
Mike Stump1eb44332009-09-09 15:08:12 +000079
Chris Lattnereba3e5a2010-04-13 17:45:57 +000080bool ConstStructBuilder::
Chris Lattner8ce9e452010-04-13 18:16:19 +000081AppendField(const FieldDecl *Field, uint64_t FieldOffset,
82 llvm::Constant *InitCst) {
Ken Dyck6925cc42011-03-15 01:09:02 +000083
84 const ASTContext &Context = CGM.getContext();
85
86 CharUnits FieldOffsetInChars = Context.toCharUnitsFromBits(FieldOffset);
Chris Lattnereba3e5a2010-04-13 17:45:57 +000087
Ken Dyckdc496392011-03-17 01:33:18 +000088 assert(NextFieldOffsetInChars <= FieldOffsetInChars
Chris Lattnereba3e5a2010-04-13 17:45:57 +000089 && "Field offset mismatch!");
90
Ken Dyck7d2f9d52011-03-18 01:26:17 +000091 CharUnits FieldAlignment = getAlignment(InitCst);
Chris Lattnereba3e5a2010-04-13 17:45:57 +000092
93 // Round up the field offset to the alignment of the field type.
Ken Dyckdc496392011-03-17 01:33:18 +000094 CharUnits AlignedNextFieldOffsetInChars =
Ken Dyck7d2f9d52011-03-18 01:26:17 +000095 NextFieldOffsetInChars.RoundUpToAlignment(FieldAlignment);
Chris Lattnereba3e5a2010-04-13 17:45:57 +000096
Ken Dyckdc496392011-03-17 01:33:18 +000097 if (AlignedNextFieldOffsetInChars > FieldOffsetInChars) {
Chris Lattnereba3e5a2010-04-13 17:45:57 +000098 assert(!Packed && "Alignment is wrong even with a packed struct!");
99
100 // Convert the struct to a packed struct.
101 ConvertStructToPacked();
102
Ken Dyckdc496392011-03-17 01:33:18 +0000103 AlignedNextFieldOffsetInChars = NextFieldOffsetInChars;
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000104 }
105
Ken Dyckdc496392011-03-17 01:33:18 +0000106 if (AlignedNextFieldOffsetInChars < FieldOffsetInChars) {
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000107 // We need to append padding.
Ken Dyckc29ea8f2011-03-11 23:42:54 +0000108 AppendPadding(
Ken Dyckdc496392011-03-17 01:33:18 +0000109 FieldOffsetInChars - NextFieldOffsetInChars);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000110
Ken Dyckdc496392011-03-17 01:33:18 +0000111 assert(NextFieldOffsetInChars == FieldOffsetInChars &&
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000112 "Did not add enough padding!");
113
Ken Dyckdc496392011-03-17 01:33:18 +0000114 AlignedNextFieldOffsetInChars = NextFieldOffsetInChars;
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000115 }
116
117 // Add the field.
Chris Lattner8ce9e452010-04-13 18:16:19 +0000118 Elements.push_back(InitCst);
Ken Dyckdc496392011-03-17 01:33:18 +0000119 NextFieldOffsetInChars = AlignedNextFieldOffsetInChars +
Ken Dyck15c152e2011-03-18 01:12:13 +0000120 getSizeInChars(InitCst);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000121
122 if (Packed)
Ken Dyck7d2f9d52011-03-18 01:26:17 +0000123 assert(LLVMStructAlignment == CharUnits::One() &&
124 "Packed struct not byte-aligned!");
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000125 else
126 LLVMStructAlignment = std::max(LLVMStructAlignment, FieldAlignment);
127
128 return true;
129}
130
Chris Lattner18806662010-07-05 17:04:23 +0000131void ConstStructBuilder::AppendBitField(const FieldDecl *Field,
132 uint64_t FieldOffset,
133 llvm::ConstantInt *CI) {
Ken Dyckf004da42011-03-12 12:03:11 +0000134 const ASTContext &Context = CGM.getContext();
Ken Dyck4f318c02011-03-19 00:57:28 +0000135 const uint64_t CharWidth = Context.getCharWidth();
Ken Dyckdc496392011-03-17 01:33:18 +0000136 uint64_t NextFieldOffsetInBits = Context.toBits(NextFieldOffsetInChars);
137 if (FieldOffset > NextFieldOffsetInBits) {
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000138 // We need to add padding.
Ken Dyckf004da42011-03-12 12:03:11 +0000139 CharUnits PadSize = Context.toCharUnitsFromBits(
Ken Dyckdc496392011-03-17 01:33:18 +0000140 llvm::RoundUpToAlignment(FieldOffset - NextFieldOffsetInBits,
Ken Dyckf004da42011-03-12 12:03:11 +0000141 Context.Target.getCharAlign()));
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000142
Ken Dyckf004da42011-03-12 12:03:11 +0000143 AppendPadding(PadSize);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000144 }
145
146 uint64_t FieldSize =
Ken Dyckf004da42011-03-12 12:03:11 +0000147 Field->getBitWidth()->EvaluateAsInt(Context).getZExtValue();
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000148
149 llvm::APInt FieldValue = CI->getValue();
150
151 // Promote the size of FieldValue if necessary
152 // FIXME: This should never occur, but currently it can because initializer
153 // constants are cast to bool, and because clang is not enforcing bitfield
154 // width limits.
155 if (FieldSize > FieldValue.getBitWidth())
Jay Foad9f71a8f2010-12-07 08:25:34 +0000156 FieldValue = FieldValue.zext(FieldSize);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000157
158 // Truncate the size of FieldValue to the bit field size.
159 if (FieldSize < FieldValue.getBitWidth())
Jay Foad9f71a8f2010-12-07 08:25:34 +0000160 FieldValue = FieldValue.trunc(FieldSize);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000161
Ken Dyckdc496392011-03-17 01:33:18 +0000162 NextFieldOffsetInBits = Context.toBits(NextFieldOffsetInChars);
163 if (FieldOffset < NextFieldOffsetInBits) {
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000164 // Either part of the field or the entire field can go into the previous
165 // byte.
166 assert(!Elements.empty() && "Elements can't be empty!");
167
Ken Dyckdc496392011-03-17 01:33:18 +0000168 unsigned BitsInPreviousByte = NextFieldOffsetInBits - FieldOffset;
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000169
170 bool FitsCompletelyInPreviousByte =
171 BitsInPreviousByte >= FieldValue.getBitWidth();
172
173 llvm::APInt Tmp = FieldValue;
174
175 if (!FitsCompletelyInPreviousByte) {
176 unsigned NewFieldWidth = FieldSize - BitsInPreviousByte;
177
178 if (CGM.getTargetData().isBigEndian()) {
179 Tmp = Tmp.lshr(NewFieldWidth);
Jay Foad9f71a8f2010-12-07 08:25:34 +0000180 Tmp = Tmp.trunc(BitsInPreviousByte);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000181
182 // We want the remaining high bits.
Jay Foad9f71a8f2010-12-07 08:25:34 +0000183 FieldValue = FieldValue.trunc(NewFieldWidth);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000184 } else {
Jay Foad9f71a8f2010-12-07 08:25:34 +0000185 Tmp = Tmp.trunc(BitsInPreviousByte);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000186
187 // We want the remaining low bits.
188 FieldValue = FieldValue.lshr(BitsInPreviousByte);
Jay Foad9f71a8f2010-12-07 08:25:34 +0000189 FieldValue = FieldValue.trunc(NewFieldWidth);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000190 }
191 }
192
Ken Dyck4f318c02011-03-19 00:57:28 +0000193 Tmp = Tmp.zext(CharWidth);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000194 if (CGM.getTargetData().isBigEndian()) {
195 if (FitsCompletelyInPreviousByte)
196 Tmp = Tmp.shl(BitsInPreviousByte - FieldValue.getBitWidth());
197 } else {
Ken Dyck4f318c02011-03-19 00:57:28 +0000198 Tmp = Tmp.shl(CharWidth - BitsInPreviousByte);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000199 }
200
Chris Lattner2bc00252010-07-05 18:03:30 +0000201 // 'or' in the bits that go into the previous byte.
202 llvm::Value *LastElt = Elements.back();
203 if (llvm::ConstantInt *Val = dyn_cast<llvm::ConstantInt>(LastElt))
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000204 Tmp |= Val->getValue();
Chris Lattner2bc00252010-07-05 18:03:30 +0000205 else {
206 assert(isa<llvm::UndefValue>(LastElt));
207 // If there is an undef field that we're adding to, it can either be a
208 // scalar undef (in which case, we just replace it with our field) or it
209 // is an array. If it is an array, we have to pull one byte off the
210 // array so that the other undef bytes stay around.
211 if (!isa<llvm::IntegerType>(LastElt->getType())) {
212 // The undef padding will be a multibyte array, create a new smaller
213 // padding and then an hole for our i8 to get plopped into.
214 assert(isa<llvm::ArrayType>(LastElt->getType()) &&
215 "Expected array padding of undefs");
216 const llvm::ArrayType *AT = cast<llvm::ArrayType>(LastElt->getType());
Ken Dyck4f318c02011-03-19 00:57:28 +0000217 assert(AT->getElementType()->isIntegerTy(CharWidth) &&
Chris Lattner2bc00252010-07-05 18:03:30 +0000218 AT->getNumElements() != 0 &&
219 "Expected non-empty array padding of undefs");
220
221 // Remove the padding array.
Ken Dyckdc496392011-03-17 01:33:18 +0000222 NextFieldOffsetInChars -= CharUnits::fromQuantity(AT->getNumElements());
Chris Lattner2bc00252010-07-05 18:03:30 +0000223 Elements.pop_back();
224
225 // Add the padding back in two chunks.
Ken Dyckc29ea8f2011-03-11 23:42:54 +0000226 AppendPadding(CharUnits::fromQuantity(AT->getNumElements()-1));
227 AppendPadding(CharUnits::One());
Chris Lattner2bc00252010-07-05 18:03:30 +0000228 assert(isa<llvm::UndefValue>(Elements.back()) &&
Ken Dyck4f318c02011-03-19 00:57:28 +0000229 Elements.back()->getType()->isIntegerTy(CharWidth) &&
Chris Lattner2bc00252010-07-05 18:03:30 +0000230 "Padding addition didn't work right");
231 }
232 }
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000233
234 Elements.back() = llvm::ConstantInt::get(CGM.getLLVMContext(), Tmp);
235
236 if (FitsCompletelyInPreviousByte)
Chris Lattner18806662010-07-05 17:04:23 +0000237 return;
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000238 }
239
Ken Dyck4f318c02011-03-19 00:57:28 +0000240 while (FieldValue.getBitWidth() > CharWidth) {
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000241 llvm::APInt Tmp;
242
243 if (CGM.getTargetData().isBigEndian()) {
244 // We want the high bits.
Ken Dyck4f318c02011-03-19 00:57:28 +0000245 Tmp =
246 FieldValue.lshr(FieldValue.getBitWidth() - CharWidth).trunc(CharWidth);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000247 } else {
248 // We want the low bits.
Ken Dyck4f318c02011-03-19 00:57:28 +0000249 Tmp = FieldValue.trunc(CharWidth);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000250
Ken Dyck4f318c02011-03-19 00:57:28 +0000251 FieldValue = FieldValue.lshr(CharWidth);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000252 }
253
254 Elements.push_back(llvm::ConstantInt::get(CGM.getLLVMContext(), Tmp));
Ken Dyck199c1892011-03-19 01:28:06 +0000255 ++NextFieldOffsetInChars;
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000256
Ken Dyck4f318c02011-03-19 00:57:28 +0000257 FieldValue = FieldValue.trunc(FieldValue.getBitWidth() - CharWidth);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000258 }
259
260 assert(FieldValue.getBitWidth() > 0 &&
261 "Should have at least one bit left!");
Ken Dyck4f318c02011-03-19 00:57:28 +0000262 assert(FieldValue.getBitWidth() <= CharWidth &&
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000263 "Should not have more than a byte left!");
264
Ken Dyck4f318c02011-03-19 00:57:28 +0000265 if (FieldValue.getBitWidth() < CharWidth) {
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000266 if (CGM.getTargetData().isBigEndian()) {
267 unsigned BitWidth = FieldValue.getBitWidth();
268
Ken Dyck4f318c02011-03-19 00:57:28 +0000269 FieldValue = FieldValue.zext(CharWidth) << (CharWidth - BitWidth);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000270 } else
Ken Dyck4f318c02011-03-19 00:57:28 +0000271 FieldValue = FieldValue.zext(CharWidth);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000272 }
273
274 // Append the last element.
275 Elements.push_back(llvm::ConstantInt::get(CGM.getLLVMContext(),
276 FieldValue));
Ken Dyck199c1892011-03-19 01:28:06 +0000277 ++NextFieldOffsetInChars;
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000278}
279
Ken Dyckc29ea8f2011-03-11 23:42:54 +0000280void ConstStructBuilder::AppendPadding(CharUnits PadSize) {
281 if (PadSize.isZero())
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000282 return;
283
284 const llvm::Type *Ty = llvm::Type::getInt8Ty(CGM.getLLVMContext());
Ken Dyckc29ea8f2011-03-11 23:42:54 +0000285 if (PadSize > CharUnits::One())
286 Ty = llvm::ArrayType::get(Ty, PadSize.getQuantity());
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000287
Nuno Lopescdb30b42010-04-16 20:56:35 +0000288 llvm::Constant *C = llvm::UndefValue::get(Ty);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000289 Elements.push_back(C);
Ken Dyck7d2f9d52011-03-18 01:26:17 +0000290 assert(getAlignment(C) == CharUnits::One() &&
291 "Padding must have 1 byte alignment!");
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000292
Ken Dyck15c152e2011-03-18 01:12:13 +0000293 NextFieldOffsetInChars += getSizeInChars(C);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000294}
295
Ken Dyck106ca042011-03-11 02:17:05 +0000296void ConstStructBuilder::AppendTailPadding(CharUnits RecordSize) {
Ken Dyckdc496392011-03-17 01:33:18 +0000297 assert(NextFieldOffsetInChars <= RecordSize &&
Ken Dyck106ca042011-03-11 02:17:05 +0000298 "Size mismatch!");
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000299
Ken Dyckdc496392011-03-17 01:33:18 +0000300 AppendPadding(RecordSize - NextFieldOffsetInChars);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000301}
302
303void ConstStructBuilder::ConvertStructToPacked() {
304 std::vector<llvm::Constant *> PackedElements;
Ken Dyck4a5c87e2011-03-18 00:55:06 +0000305 CharUnits ElementOffsetInChars = CharUnits::Zero();
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000306
307 for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
308 llvm::Constant *C = Elements[i];
309
Ken Dyck7d2f9d52011-03-18 01:26:17 +0000310 CharUnits ElementAlign = CharUnits::fromQuantity(
311 CGM.getTargetData().getABITypeAlignment(C->getType()));
Ken Dyck4a5c87e2011-03-18 00:55:06 +0000312 CharUnits AlignedElementOffsetInChars =
Ken Dyck7d2f9d52011-03-18 01:26:17 +0000313 ElementOffsetInChars.RoundUpToAlignment(ElementAlign);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000314
Ken Dyck4a5c87e2011-03-18 00:55:06 +0000315 if (AlignedElementOffsetInChars > ElementOffsetInChars) {
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000316 // We need some padding.
Ken Dyck4a5c87e2011-03-18 00:55:06 +0000317 CharUnits NumChars =
318 AlignedElementOffsetInChars - ElementOffsetInChars;
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000319
320 const llvm::Type *Ty = llvm::Type::getInt8Ty(CGM.getLLVMContext());
Ken Dyck4a5c87e2011-03-18 00:55:06 +0000321 if (NumChars > CharUnits::One())
322 Ty = llvm::ArrayType::get(Ty, NumChars.getQuantity());
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000323
Nuno Lopescdb30b42010-04-16 20:56:35 +0000324 llvm::Constant *Padding = llvm::UndefValue::get(Ty);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000325 PackedElements.push_back(Padding);
Ken Dyck15c152e2011-03-18 01:12:13 +0000326 ElementOffsetInChars += getSizeInChars(Padding);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000327 }
328
329 PackedElements.push_back(C);
Ken Dyck15c152e2011-03-18 01:12:13 +0000330 ElementOffsetInChars += getSizeInChars(C);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000331 }
332
Ken Dyck4a5c87e2011-03-18 00:55:06 +0000333 assert(ElementOffsetInChars == NextFieldOffsetInChars &&
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000334 "Packing the struct changed its size!");
335
336 Elements = PackedElements;
Ken Dyck7d2f9d52011-03-18 01:26:17 +0000337 LLVMStructAlignment = CharUnits::One();
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000338 Packed = true;
339}
340
341bool ConstStructBuilder::Build(InitListExpr *ILE) {
342 RecordDecl *RD = ILE->getType()->getAs<RecordType>()->getDecl();
343 const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
344
345 unsigned FieldNo = 0;
346 unsigned ElementNo = 0;
347 for (RecordDecl::field_iterator Field = RD->field_begin(),
Chris Lattner8ce9e452010-04-13 18:16:19 +0000348 FieldEnd = RD->field_end(); Field != FieldEnd; ++Field, ++FieldNo) {
349
350 // If this is a union, skip all the fields that aren't being initialized.
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000351 if (RD->isUnion() && ILE->getInitializedFieldInUnion() != *Field)
352 continue;
353
Chris Lattner8ce9e452010-04-13 18:16:19 +0000354 // Don't emit anonymous bitfields, they just affect layout.
355 if (Field->isBitField() && !Field->getIdentifier())
356 continue;
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000357
Chris Lattner8ce9e452010-04-13 18:16:19 +0000358 // Get the initializer. A struct can include fields without initializers,
359 // we just use explicit null values for them.
360 llvm::Constant *EltInit;
361 if (ElementNo < ILE->getNumInits())
362 EltInit = CGM.EmitConstantExpr(ILE->getInit(ElementNo++),
363 Field->getType(), CGF);
364 else
365 EltInit = CGM.EmitNullConstant(Field->getType());
Eli Friedmanf0ca0ee2010-07-17 23:55:01 +0000366
367 if (!EltInit)
368 return false;
Chris Lattner8ce9e452010-04-13 18:16:19 +0000369
370 if (!Field->isBitField()) {
371 // Handle non-bitfield members.
372 if (!AppendField(*Field, Layout.getFieldOffset(FieldNo), EltInit))
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000373 return false;
374 } else {
Chris Lattner8ce9e452010-04-13 18:16:19 +0000375 // Otherwise we have a bitfield.
Chris Lattner18806662010-07-05 17:04:23 +0000376 AppendBitField(*Field, Layout.getFieldOffset(FieldNo),
377 cast<llvm::ConstantInt>(EltInit));
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000378 }
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000379 }
380
Ken Dyckdc496392011-03-17 01:33:18 +0000381 CharUnits LayoutSizeInChars = Layout.getSize();
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000382
Ken Dyckdc496392011-03-17 01:33:18 +0000383 if (NextFieldOffsetInChars > LayoutSizeInChars) {
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000384 // If the struct is bigger than the size of the record type,
385 // we must have a flexible array member at the end.
386 assert(RD->hasFlexibleArrayMember() &&
387 "Must have flexible array member if struct is bigger than type!");
388
389 // No tail padding is necessary.
390 return true;
391 }
392
Ken Dyckdc496392011-03-17 01:33:18 +0000393 CharUnits LLVMSizeInChars =
Ken Dyck7d2f9d52011-03-18 01:26:17 +0000394 NextFieldOffsetInChars.RoundUpToAlignment(LLVMStructAlignment);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000395
396 // Check if we need to convert the struct to a packed struct.
Ken Dyckdc496392011-03-17 01:33:18 +0000397 if (NextFieldOffsetInChars <= LayoutSizeInChars &&
398 LLVMSizeInChars > LayoutSizeInChars) {
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000399 assert(!Packed && "Size mismatch!");
400
401 ConvertStructToPacked();
Ken Dyckdc496392011-03-17 01:33:18 +0000402 assert(NextFieldOffsetInChars <= LayoutSizeInChars &&
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000403 "Converting to packed did not help!");
404 }
405
406 // Append tail padding if necessary.
Ken Dyckdc496392011-03-17 01:33:18 +0000407 AppendTailPadding(LayoutSizeInChars);
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000408
Ken Dyckdc496392011-03-17 01:33:18 +0000409 assert(LayoutSizeInChars == NextFieldOffsetInChars &&
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000410 "Tail padding mismatch!");
411
412 return true;
413}
414
415llvm::Constant *ConstStructBuilder::
416 BuildStruct(CodeGenModule &CGM, CodeGenFunction *CGF, InitListExpr *ILE) {
417 ConstStructBuilder Builder(CGM, CGF);
418
419 if (!Builder.Build(ILE))
420 return 0;
421
422 llvm::Constant *Result =
423 llvm::ConstantStruct::get(CGM.getLLVMContext(),
424 Builder.Elements, Builder.Packed);
425
Ken Dyck15c152e2011-03-18 01:12:13 +0000426 assert(Builder.NextFieldOffsetInChars.RoundUpToAlignment(
Ken Dyck7d2f9d52011-03-18 01:26:17 +0000427 Builder.getAlignment(Result)) ==
Ken Dyck15c152e2011-03-18 01:12:13 +0000428 Builder.getSizeInChars(Result) && "Size mismatch!");
Chris Lattnereba3e5a2010-04-13 17:45:57 +0000429
430 return Result;
431}
432
433
434//===----------------------------------------------------------------------===//
435// ConstExprEmitter
436//===----------------------------------------------------------------------===//
437
Benjamin Kramer85b45212009-11-28 19:45:26 +0000438class ConstExprEmitter :
Anders Carlsson84005b42008-01-26 04:30:23 +0000439 public StmtVisitor<ConstExprEmitter, llvm::Constant*> {
Anders Carlsson3b1d57b2008-01-26 01:36:00 +0000440 CodeGenModule &CGM;
Lauro Ramos Venancio81373352008-02-26 21:41:45 +0000441 CodeGenFunction *CGF;
Owen Andersona1cf15f2009-07-14 23:10:40 +0000442 llvm::LLVMContext &VMContext;
Anders Carlsson3b1d57b2008-01-26 01:36:00 +0000443public:
Lauro Ramos Venancio81373352008-02-26 21:41:45 +0000444 ConstExprEmitter(CodeGenModule &cgm, CodeGenFunction *cgf)
Owen Andersona1cf15f2009-07-14 23:10:40 +0000445 : CGM(cgm), CGF(cgf), VMContext(cgm.getLLVMContext()) {
Anders Carlsson3b1d57b2008-01-26 01:36:00 +0000446 }
Mike Stump1eb44332009-09-09 15:08:12 +0000447
Anders Carlsson3b1d57b2008-01-26 01:36:00 +0000448 //===--------------------------------------------------------------------===//
449 // Visitor Methods
450 //===--------------------------------------------------------------------===//
Mike Stump1eb44332009-09-09 15:08:12 +0000451
Anders Carlsson3b1d57b2008-01-26 01:36:00 +0000452 llvm::Constant *VisitStmt(Stmt *S) {
Anders Carlsson069880e2009-03-03 16:43:34 +0000453 return 0;
Anders Carlsson3b1d57b2008-01-26 01:36:00 +0000454 }
Mike Stump1eb44332009-09-09 15:08:12 +0000455
456 llvm::Constant *VisitParenExpr(ParenExpr *PE) {
457 return Visit(PE->getSubExpr());
Anders Carlsson3b1d57b2008-01-26 01:36:00 +0000458 }
Mike Stump1eb44332009-09-09 15:08:12 +0000459
Peter Collingbournef111d932011-04-15 00:35:48 +0000460 llvm::Constant *VisitGenericSelectionExpr(GenericSelectionExpr *GE) {
461 return Visit(GE->getResultExpr());
462 }
463
Anders Carlsson3b1d57b2008-01-26 01:36:00 +0000464 llvm::Constant *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
465 return Visit(E->getInitializer());
466 }
John McCall5808ce42011-02-03 08:15:49 +0000467
Anders Carlssonf57b4e42009-10-03 15:02:02 +0000468 llvm::Constant *VisitUnaryAddrOf(UnaryOperator *E) {
John McCall5808ce42011-02-03 08:15:49 +0000469 if (E->getType()->isMemberPointerType())
470 return CGM.getMemberPointerConstant(E);
Anders Carlsson45147d02010-02-02 03:37:46 +0000471
Anders Carlssonf57b4e42009-10-03 15:02:02 +0000472 return 0;
473 }
474
Chris Lattner3ae9f482009-10-13 07:14:16 +0000475 llvm::Constant *VisitBinSub(BinaryOperator *E) {
476 // This must be a pointer/pointer subtraction. This only happens for
477 // address of label.
478 if (!isa<AddrLabelExpr>(E->getLHS()->IgnoreParenNoopCasts(CGM.getContext())) ||
479 !isa<AddrLabelExpr>(E->getRHS()->IgnoreParenNoopCasts(CGM.getContext())))
480 return 0;
481
482 llvm::Constant *LHS = CGM.EmitConstantExpr(E->getLHS(),
483 E->getLHS()->getType(), CGF);
484 llvm::Constant *RHS = CGM.EmitConstantExpr(E->getRHS(),
485 E->getRHS()->getType(), CGF);
486
487 const llvm::Type *ResultType = ConvertType(E->getType());
488 LHS = llvm::ConstantExpr::getPtrToInt(LHS, ResultType);
489 RHS = llvm::ConstantExpr::getPtrToInt(RHS, ResultType);
490
491 // No need to divide by element size, since addr of label is always void*,
492 // which has size 1 in GNUish.
493 return llvm::ConstantExpr::getSub(LHS, RHS);
494 }
495
Argyrios Kyrtzidis0835a3c2008-08-18 23:01:59 +0000496 llvm::Constant *VisitCastExpr(CastExpr* E) {
John McCall8bba1f42011-03-15 21:17:48 +0000497 Expr *subExpr = E->getSubExpr();
498 llvm::Constant *C = CGM.EmitConstantExpr(subExpr, subExpr->getType(), CGF);
499 if (!C) return 0;
500
501 const llvm::Type *destType = ConvertType(E->getType());
502
Anders Carlsson0086ccb2009-08-22 23:54:44 +0000503 switch (E->getCastKind()) {
John McCall2de56d12010-08-25 11:45:40 +0000504 case CK_ToUnion: {
Anders Carlsson0086ccb2009-08-22 23:54:44 +0000505 // GCC cast to union extension
506 assert(E->getType()->isUnionType() &&
507 "Destination type is not union type!");
Mike Stump1eb44332009-09-09 15:08:12 +0000508
Anders Carlssonaaed50d2009-07-31 21:38:39 +0000509 // Build a struct with the union sub-element as the first member,
510 // and padded to the appropriate size
511 std::vector<llvm::Constant*> Elts;
512 std::vector<const llvm::Type*> Types;
513 Elts.push_back(C);
514 Types.push_back(C->getType());
515 unsigned CurSize = CGM.getTargetData().getTypeAllocSize(C->getType());
John McCall8bba1f42011-03-15 21:17:48 +0000516 unsigned TotalSize = CGM.getTargetData().getTypeAllocSize(destType);
Mike Stump1eb44332009-09-09 15:08:12 +0000517
Anders Carlssonaaed50d2009-07-31 21:38:39 +0000518 assert(CurSize <= TotalSize && "Union size mismatch!");
519 if (unsigned NumPadBytes = TotalSize - CurSize) {
Owen Anderson0032b272009-08-13 21:57:51 +0000520 const llvm::Type *Ty = llvm::Type::getInt8Ty(VMContext);
Anders Carlssonaaed50d2009-07-31 21:38:39 +0000521 if (NumPadBytes > 1)
522 Ty = llvm::ArrayType::get(Ty, NumPadBytes);
Anders Carlsson0086ccb2009-08-22 23:54:44 +0000523
Nuno Lopescdb30b42010-04-16 20:56:35 +0000524 Elts.push_back(llvm::UndefValue::get(Ty));
Anders Carlssonaaed50d2009-07-31 21:38:39 +0000525 Types.push_back(Ty);
526 }
Mike Stump1eb44332009-09-09 15:08:12 +0000527
Anders Carlsson0086ccb2009-08-22 23:54:44 +0000528 llvm::StructType* STy =
529 llvm::StructType::get(C->getType()->getContext(), Types, false);
Anders Carlssonaaed50d2009-07-31 21:38:39 +0000530 return llvm::ConstantStruct::get(STy, Elts);
Nuno Lopes81e51e22009-01-17 00:48:48 +0000531 }
John McCall2de56d12010-08-25 11:45:40 +0000532 case CK_NullToMemberPointer: {
John McCalld608cdb2010-08-22 10:59:02 +0000533 const MemberPointerType *MPT = E->getType()->getAs<MemberPointerType>();
John McCall0bab0cd2010-08-23 01:21:21 +0000534 return CGM.getCXXABI().EmitNullMemberPointer(MPT);
John McCalld608cdb2010-08-22 10:59:02 +0000535 }
Anders Carlsson2c51f092009-10-03 15:13:22 +0000536
John McCall8bba1f42011-03-15 21:17:48 +0000537 case CK_DerivedToBaseMemberPointer:
538 case CK_BaseToDerivedMemberPointer:
John McCall0bab0cd2010-08-23 01:21:21 +0000539 return CGM.getCXXABI().EmitMemberPointerConversion(C, E);
Anders Carlssonbb378cb2009-10-18 20:31:03 +0000540
John McCall8bba1f42011-03-15 21:17:48 +0000541 case CK_LValueToRValue:
542 case CK_NoOp:
543 return C;
Anders Carlssonbb378cb2009-10-18 20:31:03 +0000544
John McCall8bba1f42011-03-15 21:17:48 +0000545 case CK_AnyPointerToObjCPointerCast:
546 case CK_AnyPointerToBlockPointerCast:
547 case CK_LValueBitCast:
548 case CK_BitCast:
549 if (C->getType() == destType) return C;
550 return llvm::ConstantExpr::getBitCast(C, destType);
Chris Lattner430656e2009-10-13 22:12:09 +0000551
John McCall8bba1f42011-03-15 21:17:48 +0000552 case CK_Dependent: llvm_unreachable("saw dependent cast!");
553
554 // These will never be supported.
555 case CK_ObjCObjectLValueCast:
556 case CK_GetObjCProperty:
557 case CK_ToVoid:
558 case CK_Dynamic:
Anders Carlsson0086ccb2009-08-22 23:54:44 +0000559 return 0;
John McCall8bba1f42011-03-15 21:17:48 +0000560
561 // These might need to be supported for constexpr.
562 case CK_UserDefinedConversion:
563 case CK_ConstructorConversion:
564 return 0;
565
566 // These should eventually be supported.
567 case CK_ArrayToPointerDecay:
568 case CK_FunctionToPointerDecay:
569 case CK_BaseToDerived:
570 case CK_DerivedToBase:
571 case CK_UncheckedDerivedToBase:
572 case CK_MemberPointerToBoolean:
573 case CK_VectorSplat:
574 case CK_FloatingRealToComplex:
575 case CK_FloatingComplexToReal:
576 case CK_FloatingComplexToBoolean:
577 case CK_FloatingComplexCast:
578 case CK_FloatingComplexToIntegralComplex:
579 case CK_IntegralRealToComplex:
580 case CK_IntegralComplexToReal:
581 case CK_IntegralComplexToBoolean:
582 case CK_IntegralComplexCast:
583 case CK_IntegralComplexToFloatingComplex:
584 return 0;
585
586 case CK_PointerToIntegral:
587 if (!E->getType()->isBooleanType())
588 return llvm::ConstantExpr::getPtrToInt(C, destType);
589 // fallthrough
590
591 case CK_PointerToBoolean:
592 return llvm::ConstantExpr::getICmp(llvm::CmpInst::ICMP_EQ, C,
593 llvm::ConstantPointerNull::get(cast<llvm::PointerType>(C->getType())));
594
595 case CK_NullToPointer:
596 return llvm::ConstantPointerNull::get(cast<llvm::PointerType>(destType));
597
598 case CK_IntegralCast: {
599 bool isSigned = subExpr->getType()->isSignedIntegerType();
600 return llvm::ConstantExpr::getIntegerCast(C, destType, isSigned);
Eli Friedmanddd2b6e2009-02-22 07:29:04 +0000601 }
John McCall8bba1f42011-03-15 21:17:48 +0000602
603 case CK_IntegralToPointer: {
604 bool isSigned = subExpr->getType()->isSignedIntegerType();
605 C = llvm::ConstantExpr::getIntegerCast(C, CGM.IntPtrTy, isSigned);
606 return llvm::ConstantExpr::getIntToPtr(C, destType);
607 }
608
609 case CK_IntegralToBoolean:
610 return llvm::ConstantExpr::getICmp(llvm::CmpInst::ICMP_EQ, C,
611 llvm::Constant::getNullValue(C->getType()));
612
613 case CK_IntegralToFloating:
614 if (subExpr->getType()->isSignedIntegerType())
615 return llvm::ConstantExpr::getSIToFP(C, destType);
616 else
617 return llvm::ConstantExpr::getUIToFP(C, destType);
618
619 case CK_FloatingToIntegral:
620 if (E->getType()->isSignedIntegerType())
621 return llvm::ConstantExpr::getFPToSI(C, destType);
622 else
623 return llvm::ConstantExpr::getFPToUI(C, destType);
624
625 case CK_FloatingToBoolean:
626 return llvm::ConstantExpr::getFCmp(llvm::CmpInst::FCMP_UNE, C,
627 llvm::Constant::getNullValue(C->getType()));
628
629 case CK_FloatingCast:
630 return llvm::ConstantExpr::getFPCast(C, destType);
Anders Carlsson0086ccb2009-08-22 23:54:44 +0000631 }
Matt Beaumont-Gay17d12fe2011-03-17 00:46:34 +0000632 llvm_unreachable("Invalid CastKind");
Anders Carlsson3b1d57b2008-01-26 01:36:00 +0000633 }
Devang Pateleae15602008-02-05 02:39:50 +0000634
Chris Lattner04421082008-04-08 04:40:51 +0000635 llvm::Constant *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
636 return Visit(DAE->getExpr());
637 }
638
Eli Friedmana8234002008-05-30 10:24:46 +0000639 llvm::Constant *EmitArrayInitialization(InitListExpr *ILE) {
Nuno Lopesa75b71f2010-04-18 19:06:43 +0000640 unsigned NumInitElements = ILE->getNumInits();
Benjamin Kramer0483a6f2011-03-02 21:27:44 +0000641 if (NumInitElements == 1 && ILE->getType() == ILE->getInit(0)->getType() &&
Nuno Lopesa75b71f2010-04-18 19:06:43 +0000642 (isa<StringLiteral>(ILE->getInit(0)) ||
643 isa<ObjCEncodeExpr>(ILE->getInit(0))))
644 return Visit(ILE->getInit(0));
645
Nuno Lopes67847042010-04-16 23:19:41 +0000646 std::vector<llvm::Constant*> Elts;
647 const llvm::ArrayType *AType =
648 cast<llvm::ArrayType>(ConvertType(ILE->getType()));
Devang Pateleae15602008-02-05 02:39:50 +0000649 const llvm::Type *ElemTy = AType->getElementType();
650 unsigned NumElements = AType->getNumElements();
651
Mike Stump1eb44332009-09-09 15:08:12 +0000652 // Initialising an array requires us to automatically
Devang Pateleae15602008-02-05 02:39:50 +0000653 // initialise any elements that have not been initialised explicitly
654 unsigned NumInitableElts = std::min(NumInitElements, NumElements);
655
656 // Copy initializer elements.
657 unsigned i = 0;
Eli Friedmana04a1532008-05-30 19:58:50 +0000658 bool RewriteType = false;
Devang Pateleae15602008-02-05 02:39:50 +0000659 for (; i < NumInitableElts; ++i) {
Anders Carlssone9352cc2009-04-08 04:48:15 +0000660 Expr *Init = ILE->getInit(i);
661 llvm::Constant *C = CGM.EmitConstantExpr(Init, Init->getType(), CGF);
Daniel Dunbard60f2fb2009-02-17 18:43:32 +0000662 if (!C)
663 return 0;
Eli Friedmana04a1532008-05-30 19:58:50 +0000664 RewriteType |= (C->getType() != ElemTy);
Devang Pateleae15602008-02-05 02:39:50 +0000665 Elts.push_back(C);
666 }
Eli Friedmana04a1532008-05-30 19:58:50 +0000667
Devang Pateleae15602008-02-05 02:39:50 +0000668 // Initialize remaining array elements.
Eli Friedman0f593122009-04-13 21:47:26 +0000669 // FIXME: This doesn't handle member pointers correctly!
Devang Pateleae15602008-02-05 02:39:50 +0000670 for (; i < NumElements; ++i)
Owen Andersonc9c88b42009-07-31 20:28:54 +0000671 Elts.push_back(llvm::Constant::getNullValue(ElemTy));
Devang Pateleae15602008-02-05 02:39:50 +0000672
Eli Friedmana04a1532008-05-30 19:58:50 +0000673 if (RewriteType) {
674 // FIXME: Try to avoid packing the array
675 std::vector<const llvm::Type*> Types;
676 for (unsigned i = 0; i < Elts.size(); ++i)
677 Types.push_back(Elts[i]->getType());
Mike Stump1eb44332009-09-09 15:08:12 +0000678 const llvm::StructType *SType = llvm::StructType::get(AType->getContext(),
Owen Anderson47a434f2009-08-05 23:18:46 +0000679 Types, true);
Owen Anderson08e25242009-07-27 22:29:56 +0000680 return llvm::ConstantStruct::get(SType, Elts);
Eli Friedmana04a1532008-05-30 19:58:50 +0000681 }
682
Mike Stump1eb44332009-09-09 15:08:12 +0000683 return llvm::ConstantArray::get(AType, Elts);
Devang Pateleae15602008-02-05 02:39:50 +0000684 }
685
Eli Friedmana8234002008-05-30 10:24:46 +0000686 llvm::Constant *EmitStructInitialization(InitListExpr *ILE) {
Anders Carlsson8dca3b32009-07-27 05:54:15 +0000687 return ConstStructBuilder::BuildStruct(CGM, CGF, ILE);
Devang Pateleae15602008-02-05 02:39:50 +0000688 }
Mike Stump1eb44332009-09-09 15:08:12 +0000689
Eli Friedmana8234002008-05-30 10:24:46 +0000690 llvm::Constant *EmitUnionInitialization(InitListExpr *ILE) {
Anders Carlssonf6c43962009-07-31 21:34:04 +0000691 return ConstStructBuilder::BuildStruct(CGM, CGF, ILE);
Eli Friedmana8234002008-05-30 10:24:46 +0000692 }
693
Anders Carlsson7d801ea2009-01-30 06:13:25 +0000694 llvm::Constant *VisitImplicitValueInitExpr(ImplicitValueInitExpr* E) {
Eli Friedman0f593122009-04-13 21:47:26 +0000695 return CGM.EmitNullConstant(E->getType());
Anders Carlsson7d801ea2009-01-30 06:13:25 +0000696 }
Mike Stump1eb44332009-09-09 15:08:12 +0000697
Anders Carlsson3b1d57b2008-01-26 01:36:00 +0000698 llvm::Constant *VisitInitListExpr(InitListExpr *ILE) {
Eli Friedmana8234002008-05-30 10:24:46 +0000699 if (ILE->getType()->isScalarType()) {
700 // We have a scalar in braces. Just use the first element.
Anders Carlssone9352cc2009-04-08 04:48:15 +0000701 if (ILE->getNumInits() > 0) {
702 Expr *Init = ILE->getInit(0);
703 return CGM.EmitConstantExpr(Init, Init->getType(), CGF);
704 }
Eli Friedman0f593122009-04-13 21:47:26 +0000705 return CGM.EmitNullConstant(ILE->getType());
Anders Carlsson3b1d57b2008-01-26 01:36:00 +0000706 }
Mike Stump1eb44332009-09-09 15:08:12 +0000707
Eli Friedmana8234002008-05-30 10:24:46 +0000708 if (ILE->getType()->isArrayType())
709 return EmitArrayInitialization(ILE);
Devang Patel47fb6972008-01-29 23:23:18 +0000710
Anders Carlsson01a79ac2009-11-21 23:56:04 +0000711 if (ILE->getType()->isRecordType())
Eli Friedmana8234002008-05-30 10:24:46 +0000712 return EmitStructInitialization(ILE);
713
714 if (ILE->getType()->isUnionType())
715 return EmitUnionInitialization(ILE);
716
Eli Friedman8ac55492010-01-02 23:43:59 +0000717 // If ILE was a constant vector, we would have handled it already.
Eli Friedmana8234002008-05-30 10:24:46 +0000718 if (ILE->getType()->isVectorType())
Eli Friedman8ac55492010-01-02 23:43:59 +0000719 return 0;
Eli Friedmana8234002008-05-30 10:24:46 +0000720
Devang Pateleae15602008-02-05 02:39:50 +0000721 assert(0 && "Unable to handle InitListExpr");
Chris Lattner2b94fe32008-03-01 08:45:05 +0000722 // Get rid of control reaches end of void function warning.
723 // Not reached.
724 return 0;
Anders Carlsson3b1d57b2008-01-26 01:36:00 +0000725 }
Eli Friedman3b707e72008-02-21 17:57:49 +0000726
John McCallfb8b69a2010-02-02 08:02:49 +0000727 llvm::Constant *VisitCXXConstructExpr(CXXConstructExpr *E) {
728 if (!E->getConstructor()->isTrivial())
729 return 0;
730
Anders Carlsson2ca4f632010-02-05 18:38:45 +0000731 QualType Ty = E->getType();
732
733 // FIXME: We should not have to call getBaseElementType here.
734 const RecordType *RT =
735 CGM.getContext().getBaseElementType(Ty)->getAs<RecordType>();
736 const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
737
738 // If the class doesn't have a trivial destructor, we can't emit it as a
739 // constant expr.
740 if (!RD->hasTrivialDestructor())
741 return 0;
742
John McCallfb8b69a2010-02-02 08:02:49 +0000743 // Only copy and default constructors can be trivial.
744
John McCallfb8b69a2010-02-02 08:02:49 +0000745
746 if (E->getNumArgs()) {
747 assert(E->getNumArgs() == 1 && "trivial ctor with > 1 argument");
748 assert(E->getConstructor()->isCopyConstructor() &&
749 "trivial ctor has argument but isn't a copy ctor");
750
751 Expr *Arg = E->getArg(0);
752 assert(CGM.getContext().hasSameUnqualifiedType(Ty, Arg->getType()) &&
753 "argument to copy ctor is of wrong type");
754
Chandler Carruth878b55c2010-02-02 12:15:55 +0000755 return Visit(Arg);
John McCallfb8b69a2010-02-02 08:02:49 +0000756 }
757
758 return CGM.EmitNullConstant(Ty);
759 }
760
Anders Carlsson3b1d57b2008-01-26 01:36:00 +0000761 llvm::Constant *VisitStringLiteral(StringLiteral *E) {
Chris Lattnera7ad98f2008-02-11 00:02:17 +0000762 assert(!E->getType()->isPointerType() && "Strings are always arrays");
Mike Stump1eb44332009-09-09 15:08:12 +0000763
Chris Lattnereaf2bb82009-02-24 22:18:39 +0000764 // This must be a string initializing an array in a static initializer.
765 // Don't emit it as the address of the string, emit the string data itself
766 // as an inline array.
Owen Anderson0032b272009-08-13 21:57:51 +0000767 return llvm::ConstantArray::get(VMContext,
768 CGM.GetStringForStringLiteral(E), false);
Anders Carlsson3b1d57b2008-01-26 01:36:00 +0000769 }
770
Chris Lattnereaf2bb82009-02-24 22:18:39 +0000771 llvm::Constant *VisitObjCEncodeExpr(ObjCEncodeExpr *E) {
772 // This must be an @encode initializing an array in a static initializer.
773 // Don't emit it as the address of the string, emit the string data itself
774 // as an inline array.
775 std::string Str;
776 CGM.getContext().getObjCEncodingForType(E->getEncodedType(), Str);
777 const ConstantArrayType *CAT = cast<ConstantArrayType>(E->getType());
Mike Stump1eb44332009-09-09 15:08:12 +0000778
Chris Lattnereaf2bb82009-02-24 22:18:39 +0000779 // Resize the string to the right size, adding zeros at the end, or
780 // truncating as needed.
781 Str.resize(CAT->getSize().getZExtValue(), '\0');
Owen Anderson0032b272009-08-13 21:57:51 +0000782 return llvm::ConstantArray::get(VMContext, Str, false);
Chris Lattnereaf2bb82009-02-24 22:18:39 +0000783 }
Mike Stump1eb44332009-09-09 15:08:12 +0000784
Eli Friedmanbc5ed6e2008-05-29 11:22:45 +0000785 llvm::Constant *VisitUnaryExtension(const UnaryOperator *E) {
786 return Visit(E->getSubExpr());
787 }
Mike Stumpb83d2872009-02-19 22:01:56 +0000788
Anders Carlsson3b1d57b2008-01-26 01:36:00 +0000789 // Utility methods
790 const llvm::Type *ConvertType(QualType T) {
791 return CGM.getTypes().ConvertType(T);
792 }
Anders Carlsson84005b42008-01-26 04:30:23 +0000793
Anders Carlsson5ea7d072008-11-16 06:23:45 +0000794public:
Anders Carlsson84005b42008-01-26 04:30:23 +0000795 llvm::Constant *EmitLValue(Expr *E) {
Anders Carlssone3d3b7d2008-01-26 02:08:50 +0000796 switch (E->getStmtClass()) {
Eli Friedman546d94c2008-02-11 00:23:10 +0000797 default: break;
Anders Carlssone3d3b7d2008-01-26 02:08:50 +0000798 case Expr::CompoundLiteralExprClass: {
799 // Note that due to the nature of compound literals, this is guaranteed
800 // to be the only use of the variable, so we just generate it here.
Anders Carlsson84005b42008-01-26 04:30:23 +0000801 CompoundLiteralExpr *CLE = cast<CompoundLiteralExpr>(E);
802 llvm::Constant* C = Visit(CLE->getInitializer());
Daniel Dunbard60f2fb2009-02-17 18:43:32 +0000803 // FIXME: "Leaked" on failure.
804 if (C)
Owen Anderson1c431b32009-07-08 19:05:04 +0000805 C = new llvm::GlobalVariable(CGM.getModule(), C->getType(),
Eli Friedmand15d8c62009-08-26 20:01:39 +0000806 E->getType().isConstant(CGM.getContext()),
Daniel Dunbard60f2fb2009-02-17 18:43:32 +0000807 llvm::GlobalValue::InternalLinkage,
Eli Friedmand15d8c62009-08-26 20:01:39 +0000808 C, ".compoundliteral", 0, false,
Peter Collingbourne207f4d82011-03-18 22:38:29 +0000809 CGM.getContext().getTargetAddressSpace(E->getType()));
Anders Carlssone3d3b7d2008-01-26 02:08:50 +0000810 return C;
Anders Carlsson84005b42008-01-26 04:30:23 +0000811 }
Douglas Gregora2813ce2009-10-23 18:54:35 +0000812 case Expr::DeclRefExprClass: {
Rafael Espindolada182612010-03-04 21:26:03 +0000813 ValueDecl *Decl = cast<DeclRefExpr>(E)->getDecl();
814 if (Decl->hasAttr<WeakRefAttr>())
Eli Friedmana7e68452010-08-22 01:00:03 +0000815 return CGM.GetWeakRefReference(Decl);
Anders Carlssone3d3b7d2008-01-26 02:08:50 +0000816 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Decl))
Anders Carlsson555b4bb2009-09-10 23:43:36 +0000817 return CGM.GetAddrOfFunction(FD);
Steve Naroff248a7532008-04-15 22:42:06 +0000818 if (const VarDecl* VD = dyn_cast<VarDecl>(Decl)) {
Daniel Dunbard01b6692009-02-24 18:41:57 +0000819 // We can never refer to a variable with local storage.
Mike Stump1eb44332009-09-09 15:08:12 +0000820 if (!VD->hasLocalStorage()) {
Daniel Dunbard01b6692009-02-24 18:41:57 +0000821 if (VD->isFileVarDecl() || VD->hasExternalStorage())
822 return CGM.GetAddrOfGlobalVar(VD);
John McCallb6bbcc92010-10-15 04:57:14 +0000823 else if (VD->isLocalVarDecl()) {
Daniel Dunbard01b6692009-02-24 18:41:57 +0000824 assert(CGF && "Can't access static local vars without CGF");
825 return CGF->GetAddrOfStaticLocalVar(VD);
826 }
Steve Naroff248a7532008-04-15 22:42:06 +0000827 }
Lauro Ramos Venancio81373352008-02-26 21:41:45 +0000828 }
Eli Friedman546d94c2008-02-11 00:23:10 +0000829 break;
Anders Carlssone3d3b7d2008-01-26 02:08:50 +0000830 }
Daniel Dunbar61432932008-08-13 23:20:05 +0000831 case Expr::StringLiteralClass:
832 return CGM.GetAddrOfConstantStringFromLiteral(cast<StringLiteral>(E));
Chris Lattnereaf2bb82009-02-24 22:18:39 +0000833 case Expr::ObjCEncodeExprClass:
834 return CGM.GetAddrOfConstantStringFromObjCEncode(cast<ObjCEncodeExpr>(E));
Anders Carlsson5ea7d072008-11-16 06:23:45 +0000835 case Expr::ObjCStringLiteralClass: {
836 ObjCStringLiteral* SL = cast<ObjCStringLiteral>(E);
David Chisnall0d13f6f2010-01-23 02:40:42 +0000837 llvm::Constant *C =
838 CGM.getObjCRuntime().GenerateConstantString(SL->getString());
Owen Anderson3c4972d2009-07-29 18:54:39 +0000839 return llvm::ConstantExpr::getBitCast(C, ConvertType(E->getType()));
Anders Carlsson5ea7d072008-11-16 06:23:45 +0000840 }
Chris Lattner35345642008-12-12 05:18:02 +0000841 case Expr::PredefinedExprClass: {
Eli Friedmanf70b24e2009-11-14 08:37:13 +0000842 unsigned Type = cast<PredefinedExpr>(E)->getIdentType();
843 if (CGF) {
Daniel Dunbar3ec0baf2010-08-21 03:01:12 +0000844 LValue Res = CGF->EmitPredefinedLValue(cast<PredefinedExpr>(E));
Eli Friedmanf70b24e2009-11-14 08:37:13 +0000845 return cast<llvm::Constant>(Res.getAddress());
846 } else if (Type == PredefinedExpr::PrettyFunction) {
847 return CGM.GetAddrOfConstantCString("top level", ".tmp");
848 }
Mike Stump1eb44332009-09-09 15:08:12 +0000849
Eli Friedmanf70b24e2009-11-14 08:37:13 +0000850 return CGM.GetAddrOfConstantCString("", ".tmp");
Chris Lattner35345642008-12-12 05:18:02 +0000851 }
Eli Friedmanf0115892009-01-25 01:21:06 +0000852 case Expr::AddrLabelExprClass: {
853 assert(CGF && "Invalid address of label expression outside function.");
Chris Lattnerd9becd12009-10-28 23:59:40 +0000854 llvm::Constant *Ptr =
855 CGF->GetAddrOfLabel(cast<AddrLabelExpr>(E)->getLabel());
856 return llvm::ConstantExpr::getBitCast(Ptr, ConvertType(E->getType()));
Eli Friedmanf0115892009-01-25 01:21:06 +0000857 }
Eli Friedman3941b182009-01-25 01:54:01 +0000858 case Expr::CallExprClass: {
859 CallExpr* CE = cast<CallExpr>(E);
David Chisnall0d13f6f2010-01-23 02:40:42 +0000860 unsigned builtin = CE->isBuiltinCall(CGM.getContext());
861 if (builtin !=
862 Builtin::BI__builtin___CFStringMakeConstantString &&
863 builtin !=
864 Builtin::BI__builtin___NSStringMakeConstantString)
Eli Friedman3941b182009-01-25 01:54:01 +0000865 break;
866 const Expr *Arg = CE->getArg(0)->IgnoreParenCasts();
867 const StringLiteral *Literal = cast<StringLiteral>(Arg);
David Chisnall0d13f6f2010-01-23 02:40:42 +0000868 if (builtin ==
869 Builtin::BI__builtin___NSStringMakeConstantString) {
870 return CGM.getObjCRuntime().GenerateConstantString(Literal);
871 }
Steve Naroff33fdb732009-03-31 16:53:37 +0000872 // FIXME: need to deal with UCN conversion issues.
Steve Naroff8d4141f2009-04-01 13:55:36 +0000873 return CGM.GetAddrOfConstantCFString(Literal);
Eli Friedman3941b182009-01-25 01:54:01 +0000874 }
Mike Stumpbd65cac2009-02-19 01:01:04 +0000875 case Expr::BlockExprClass: {
Anders Carlsson4de9fce2009-03-01 01:09:12 +0000876 std::string FunctionName;
877 if (CGF)
878 FunctionName = CGF->CurFn->getName();
879 else
880 FunctionName = "global";
881
882 return CGM.GetAddrOfGlobalBlock(cast<BlockExpr>(E), FunctionName.c_str());
Mike Stumpbd65cac2009-02-19 01:01:04 +0000883 }
Eli Friedman546d94c2008-02-11 00:23:10 +0000884 }
Daniel Dunbard60f2fb2009-02-17 18:43:32 +0000885
886 return 0;
Anders Carlssone3d3b7d2008-01-26 02:08:50 +0000887 }
Anders Carlssone3d3b7d2008-01-26 02:08:50 +0000888};
Mike Stump1eb44332009-09-09 15:08:12 +0000889
Anders Carlsson3b1d57b2008-01-26 01:36:00 +0000890} // end anonymous namespace.
891
Lauro Ramos Venancio81373352008-02-26 21:41:45 +0000892llvm::Constant *CodeGenModule::EmitConstantExpr(const Expr *E,
Anders Carlssone9352cc2009-04-08 04:48:15 +0000893 QualType DestType,
Chris Lattner96196622008-07-26 22:37:01 +0000894 CodeGenFunction *CGF) {
Anders Carlsson4b3f9c02008-12-01 02:42:14 +0000895 Expr::EvalResult Result;
Mike Stump1eb44332009-09-09 15:08:12 +0000896
Anders Carlsson1e5dc6e2009-04-11 01:08:03 +0000897 bool Success = false;
Mike Stump1eb44332009-09-09 15:08:12 +0000898
Eli Friedman50c39ea2009-05-27 06:04:58 +0000899 if (DestType->isReferenceType())
900 Success = E->EvaluateAsLValue(Result, Context);
Mike Stump1eb44332009-09-09 15:08:12 +0000901 else
Anders Carlsson1e5dc6e2009-04-11 01:08:03 +0000902 Success = E->Evaluate(Result, Context);
Mike Stump1eb44332009-09-09 15:08:12 +0000903
Eli Friedman55f9bdd2009-11-14 08:51:33 +0000904 if (Success && !Result.HasSideEffects) {
Anders Carlsson4b3f9c02008-12-01 02:42:14 +0000905 switch (Result.Val.getKind()) {
Daniel Dunbara5fd07b2009-01-28 22:24:07 +0000906 case APValue::Uninitialized:
Daniel Dunbard60f2fb2009-02-17 18:43:32 +0000907 assert(0 && "Constant expressions should be initialized.");
908 return 0;
Anders Carlsson5a9a4572008-11-15 20:45:50 +0000909 case APValue::LValue: {
Anders Carlsson1e5dc6e2009-04-11 01:08:03 +0000910 const llvm::Type *DestTy = getTypes().ConvertTypeForMem(DestType);
Mike Stump1eb44332009-09-09 15:08:12 +0000911 llvm::Constant *Offset =
912 llvm::ConstantInt::get(llvm::Type::getInt64Ty(VMContext),
Ken Dycka7305832010-01-15 12:37:54 +0000913 Result.Val.getLValueOffset().getQuantity());
Mike Stump1eb44332009-09-09 15:08:12 +0000914
Daniel Dunbare20de512009-02-19 21:44:24 +0000915 llvm::Constant *C;
Anders Carlsson4b3f9c02008-12-01 02:42:14 +0000916 if (const Expr *LVBase = Result.Val.getLValueBase()) {
Daniel Dunbare20de512009-02-19 21:44:24 +0000917 C = ConstExprEmitter(*this, CGF).EmitLValue(const_cast<Expr*>(LVBase));
Anders Carlsson5ea7d072008-11-16 06:23:45 +0000918
Daniel Dunbare20de512009-02-19 21:44:24 +0000919 // Apply offset if necessary.
920 if (!Offset->isNullValue()) {
Benjamin Kramer3c0ef8c2009-10-13 10:07:13 +0000921 const llvm::Type *Type = llvm::Type::getInt8PtrTy(VMContext);
Owen Anderson3c4972d2009-07-29 18:54:39 +0000922 llvm::Constant *Casted = llvm::ConstantExpr::getBitCast(C, Type);
923 Casted = llvm::ConstantExpr::getGetElementPtr(Casted, &Offset, 1);
924 C = llvm::ConstantExpr::getBitCast(Casted, C->getType());
Daniel Dunbare20de512009-02-19 21:44:24 +0000925 }
926
927 // Convert to the appropriate type; this could be an lvalue for
928 // an integer.
Anders Carlsson12e330c2009-04-10 04:59:59 +0000929 if (isa<llvm::PointerType>(DestTy))
Owen Anderson3c4972d2009-07-29 18:54:39 +0000930 return llvm::ConstantExpr::getBitCast(C, DestTy);
Daniel Dunbare20de512009-02-19 21:44:24 +0000931
Owen Anderson3c4972d2009-07-29 18:54:39 +0000932 return llvm::ConstantExpr::getPtrToInt(C, DestTy);
Daniel Dunbare20de512009-02-19 21:44:24 +0000933 } else {
934 C = Offset;
935
936 // Convert to the appropriate type; this could be an lvalue for
937 // an integer.
Anders Carlsson12e330c2009-04-10 04:59:59 +0000938 if (isa<llvm::PointerType>(DestTy))
Owen Anderson3c4972d2009-07-29 18:54:39 +0000939 return llvm::ConstantExpr::getIntToPtr(C, DestTy);
Daniel Dunbare20de512009-02-19 21:44:24 +0000940
941 // If the types don't match this should only be a truncate.
Anders Carlsson12e330c2009-04-10 04:59:59 +0000942 if (C->getType() != DestTy)
Owen Anderson3c4972d2009-07-29 18:54:39 +0000943 return llvm::ConstantExpr::getTrunc(C, DestTy);
Daniel Dunbare20de512009-02-19 21:44:24 +0000944
945 return C;
Anders Carlsson5ea7d072008-11-16 06:23:45 +0000946 }
Anders Carlsson5a9a4572008-11-15 20:45:50 +0000947 }
Eli Friedman7b30b1c2008-11-17 03:57:28 +0000948 case APValue::Int: {
Mike Stump1eb44332009-09-09 15:08:12 +0000949 llvm::Constant *C = llvm::ConstantInt::get(VMContext,
Owen Anderson4a28d5d2009-07-24 23:12:58 +0000950 Result.Val.getInt());
Mike Stump1eb44332009-09-09 15:08:12 +0000951
Chris Lattner7f215c12010-06-26 21:52:32 +0000952 if (C->getType()->isIntegerTy(1)) {
Anders Carlsson5a9a4572008-11-15 20:45:50 +0000953 const llvm::Type *BoolTy = getTypes().ConvertTypeForMem(E->getType());
Owen Anderson3c4972d2009-07-29 18:54:39 +0000954 C = llvm::ConstantExpr::getZExt(C, BoolTy);
Anders Carlsson5a9a4572008-11-15 20:45:50 +0000955 }
956 return C;
Eli Friedman7b30b1c2008-11-17 03:57:28 +0000957 }
Daniel Dunbara5fd07b2009-01-28 22:24:07 +0000958 case APValue::ComplexInt: {
959 llvm::Constant *Complex[2];
Mike Stump1eb44332009-09-09 15:08:12 +0000960
Owen Anderson4a28d5d2009-07-24 23:12:58 +0000961 Complex[0] = llvm::ConstantInt::get(VMContext,
962 Result.Val.getComplexIntReal());
Mike Stump1eb44332009-09-09 15:08:12 +0000963 Complex[1] = llvm::ConstantInt::get(VMContext,
Owen Anderson4a28d5d2009-07-24 23:12:58 +0000964 Result.Val.getComplexIntImag());
Mike Stump1eb44332009-09-09 15:08:12 +0000965
Nick Lewycky0d36dd22009-09-19 20:00:52 +0000966 // FIXME: the target may want to specify that this is packed.
967 return llvm::ConstantStruct::get(VMContext, Complex, 2, false);
Daniel Dunbara5fd07b2009-01-28 22:24:07 +0000968 }
Anders Carlsson5a9a4572008-11-15 20:45:50 +0000969 case APValue::Float:
Owen Andersonbc0a2222009-07-27 21:00:51 +0000970 return llvm::ConstantFP::get(VMContext, Result.Val.getFloat());
Anders Carlssonaa432562008-11-17 01:58:55 +0000971 case APValue::ComplexFloat: {
972 llvm::Constant *Complex[2];
Mike Stump1eb44332009-09-09 15:08:12 +0000973
974 Complex[0] = llvm::ConstantFP::get(VMContext,
Owen Andersonbc0a2222009-07-27 21:00:51 +0000975 Result.Val.getComplexFloatReal());
976 Complex[1] = llvm::ConstantFP::get(VMContext,
977 Result.Val.getComplexFloatImag());
Mike Stump1eb44332009-09-09 15:08:12 +0000978
Nick Lewycky0d36dd22009-09-19 20:00:52 +0000979 // FIXME: the target may want to specify that this is packed.
980 return llvm::ConstantStruct::get(VMContext, Complex, 2, false);
Anders Carlssonaa432562008-11-17 01:58:55 +0000981 }
Nate Begeman3d309f92009-01-18 01:01:34 +0000982 case APValue::Vector: {
983 llvm::SmallVector<llvm::Constant *, 4> Inits;
984 unsigned NumElts = Result.Val.getVectorLength();
Mike Stump1eb44332009-09-09 15:08:12 +0000985
Anton Yartsevd06fea82011-03-27 09:32:40 +0000986 if (Context.getLangOptions().AltiVec &&
987 isa<CastExpr>(E) &&
988 cast<CastExpr>(E)->getCastKind() == CK_VectorSplat) {
989 // AltiVec vector initialization with a single literal
990 APValue &Elt = Result.Val.getVectorElt(0);
991
992 llvm::Constant* InitValue = Elt.isInt()
993 ? cast<llvm::Constant>
994 (llvm::ConstantInt::get(VMContext, Elt.getInt()))
995 : cast<llvm::Constant>
996 (llvm::ConstantFP::get(VMContext, Elt.getFloat()));
997
998 for (unsigned i = 0; i != NumElts; ++i)
999 Inits.push_back(InitValue);
1000
1001 } else {
1002 for (unsigned i = 0; i != NumElts; ++i) {
1003 APValue &Elt = Result.Val.getVectorElt(i);
1004 if (Elt.isInt())
1005 Inits.push_back(llvm::ConstantInt::get(VMContext, Elt.getInt()));
1006 else
1007 Inits.push_back(llvm::ConstantFP::get(VMContext, Elt.getFloat()));
1008 }
Nate Begeman3d309f92009-01-18 01:01:34 +00001009 }
Chris Lattnerfb018d12011-02-15 00:14:06 +00001010 return llvm::ConstantVector::get(Inits);
Nate Begeman3d309f92009-01-18 01:01:34 +00001011 }
Anders Carlsson5a9a4572008-11-15 20:45:50 +00001012 }
1013 }
Eli Friedman7dfa6392008-06-01 15:31:44 +00001014
1015 llvm::Constant* C = ConstExprEmitter(*this, CGF).Visit(const_cast<Expr*>(E));
Chris Lattner7f215c12010-06-26 21:52:32 +00001016 if (C && C->getType()->isIntegerTy(1)) {
Eli Friedman7dfa6392008-06-01 15:31:44 +00001017 const llvm::Type *BoolTy = getTypes().ConvertTypeForMem(E->getType());
Owen Anderson3c4972d2009-07-29 18:54:39 +00001018 C = llvm::ConstantExpr::getZExt(C, BoolTy);
Eli Friedman7dfa6392008-06-01 15:31:44 +00001019 }
1020 return C;
Anders Carlsson3b1d57b2008-01-26 01:36:00 +00001021}
Eli Friedman0f593122009-04-13 21:47:26 +00001022
John McCall5808ce42011-02-03 08:15:49 +00001023static uint64_t getFieldOffset(ASTContext &C, const FieldDecl *field) {
1024 const ASTRecordLayout &layout = C.getASTRecordLayout(field->getParent());
1025 return layout.getFieldOffset(field->getFieldIndex());
1026}
1027
1028llvm::Constant *
1029CodeGenModule::getMemberPointerConstant(const UnaryOperator *uo) {
1030 // Member pointer constants always have a very particular form.
1031 const MemberPointerType *type = cast<MemberPointerType>(uo->getType());
1032 const ValueDecl *decl = cast<DeclRefExpr>(uo->getSubExpr())->getDecl();
1033
1034 // A member function pointer.
1035 if (const CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(decl))
1036 return getCXXABI().EmitMemberPointer(method);
1037
1038 // Otherwise, a member data pointer.
1039 uint64_t fieldOffset;
1040 if (const FieldDecl *field = dyn_cast<FieldDecl>(decl))
1041 fieldOffset = getFieldOffset(getContext(), field);
1042 else {
1043 const IndirectFieldDecl *ifield = cast<IndirectFieldDecl>(decl);
1044
1045 fieldOffset = 0;
1046 for (IndirectFieldDecl::chain_iterator ci = ifield->chain_begin(),
1047 ce = ifield->chain_end(); ci != ce; ++ci)
1048 fieldOffset += getFieldOffset(getContext(), cast<FieldDecl>(*ci));
1049 }
1050
1051 CharUnits chars = getContext().toCharUnitsFromBits((int64_t) fieldOffset);
1052 return getCXXABI().EmitMemberDataPointer(type, chars);
1053}
1054
Anders Carlssona83fb4b2010-05-18 16:51:41 +00001055static void
1056FillInNullDataMemberPointers(CodeGenModule &CGM, QualType T,
1057 std::vector<llvm::Constant *> &Elements,
1058 uint64_t StartOffset) {
Ken Dyckc4d68db2011-03-22 00:24:31 +00001059 assert(StartOffset % CGM.getContext().getCharWidth() == 0 &&
1060 "StartOffset not byte aligned!");
Anders Carlssona83fb4b2010-05-18 16:51:41 +00001061
John McCallf16aa102010-08-22 21:01:12 +00001062 if (CGM.getTypes().isZeroInitializable(T))
Anders Carlssona83fb4b2010-05-18 16:51:41 +00001063 return;
1064
1065 if (const ConstantArrayType *CAT =
1066 CGM.getContext().getAsConstantArrayType(T)) {
1067 QualType ElementTy = CAT->getElementType();
1068 uint64_t ElementSize = CGM.getContext().getTypeSize(ElementTy);
1069
1070 for (uint64_t I = 0, E = CAT->getSize().getZExtValue(); I != E; ++I) {
1071 FillInNullDataMemberPointers(CGM, ElementTy, Elements,
1072 StartOffset + I * ElementSize);
1073 }
1074 } else if (const RecordType *RT = T->getAs<RecordType>()) {
1075 const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
1076 const ASTRecordLayout &Layout = CGM.getContext().getASTRecordLayout(RD);
1077
1078 // Go through all bases and fill in any null pointer to data members.
1079 for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(),
1080 E = RD->bases_end(); I != E; ++I) {
Anders Carlsson0a87b372010-05-27 18:51:01 +00001081 if (I->isVirtual()) {
Anders Carlssonada4b322010-11-22 18:42:14 +00001082 // Ignore virtual bases.
Anders Carlsson0a87b372010-05-27 18:51:01 +00001083 continue;
1084 }
Anders Carlssona83fb4b2010-05-18 16:51:41 +00001085
1086 const CXXRecordDecl *BaseDecl =
1087 cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl());
1088
1089 // Ignore empty bases.
1090 if (BaseDecl->isEmpty())
1091 continue;
1092
1093 // Ignore bases that don't have any pointer to data members.
John McCallf16aa102010-08-22 21:01:12 +00001094 if (CGM.getTypes().isZeroInitializable(BaseDecl))
Anders Carlssona83fb4b2010-05-18 16:51:41 +00001095 continue;
1096
Anders Carlssona14f5972010-10-31 23:22:37 +00001097 uint64_t BaseOffset = Layout.getBaseClassOffsetInBits(BaseDecl);
Anders Carlssona83fb4b2010-05-18 16:51:41 +00001098 FillInNullDataMemberPointers(CGM, I->getType(),
1099 Elements, StartOffset + BaseOffset);
1100 }
1101
1102 // Visit all fields.
1103 unsigned FieldNo = 0;
1104 for (RecordDecl::field_iterator I = RD->field_begin(),
1105 E = RD->field_end(); I != E; ++I, ++FieldNo) {
1106 QualType FieldType = I->getType();
1107
John McCallf16aa102010-08-22 21:01:12 +00001108 if (CGM.getTypes().isZeroInitializable(FieldType))
Anders Carlssona83fb4b2010-05-18 16:51:41 +00001109 continue;
1110
1111 uint64_t FieldOffset = StartOffset + Layout.getFieldOffset(FieldNo);
1112 FillInNullDataMemberPointers(CGM, FieldType, Elements, FieldOffset);
1113 }
1114 } else {
1115 assert(T->isMemberPointerType() && "Should only see member pointers here!");
1116 assert(!T->getAs<MemberPointerType>()->getPointeeType()->isFunctionType() &&
1117 "Should only see pointers to data members here!");
1118
Ken Dyckc4d68db2011-03-22 00:24:31 +00001119 CharUnits StartIndex = CGM.getContext().toCharUnitsFromBits(StartOffset);
1120 CharUnits EndIndex = StartIndex + CGM.getContext().getTypeSizeInChars(T);
Anders Carlssona83fb4b2010-05-18 16:51:41 +00001121
John McCall5808ce42011-02-03 08:15:49 +00001122 // FIXME: hardcodes Itanium member pointer representation!
Anders Carlssona83fb4b2010-05-18 16:51:41 +00001123 llvm::Constant *NegativeOne =
1124 llvm::ConstantInt::get(llvm::Type::getInt8Ty(CGM.getLLVMContext()),
John McCall5808ce42011-02-03 08:15:49 +00001125 -1ULL, /*isSigned*/true);
Anders Carlssona83fb4b2010-05-18 16:51:41 +00001126
1127 // Fill in the null data member pointer.
Ken Dyckc4d68db2011-03-22 00:24:31 +00001128 for (CharUnits I = StartIndex; I != EndIndex; ++I)
1129 Elements[I.getQuantity()] = NegativeOne;
Anders Carlssona83fb4b2010-05-18 16:51:41 +00001130 }
1131}
1132
John McCall9b7da1c2011-02-15 06:40:56 +00001133static llvm::Constant *EmitNullConstantForBase(CodeGenModule &CGM,
1134 const llvm::Type *baseType,
1135 const CXXRecordDecl *base);
1136
Anders Carlssonada4b322010-11-22 18:42:14 +00001137static llvm::Constant *EmitNullConstant(CodeGenModule &CGM,
John McCall9b7da1c2011-02-15 06:40:56 +00001138 const CXXRecordDecl *record,
1139 bool asCompleteObject) {
1140 const CGRecordLayout &layout = CGM.getTypes().getCGRecordLayout(record);
1141 const llvm::StructType *structure =
1142 (asCompleteObject ? layout.getLLVMType()
1143 : layout.getBaseSubobjectLLVMType());
Anders Carlssonada4b322010-11-22 18:42:14 +00001144
John McCall9b7da1c2011-02-15 06:40:56 +00001145 unsigned numElements = structure->getNumElements();
1146 std::vector<llvm::Constant *> elements(numElements);
Anders Carlssonada4b322010-11-22 18:42:14 +00001147
John McCall9b7da1c2011-02-15 06:40:56 +00001148 // Fill in all the bases.
1149 for (CXXRecordDecl::base_class_const_iterator
1150 I = record->bases_begin(), E = record->bases_end(); I != E; ++I) {
Anders Carlssonada4b322010-11-22 18:42:14 +00001151 if (I->isVirtual()) {
John McCall9b7da1c2011-02-15 06:40:56 +00001152 // Ignore virtual bases; if we're laying out for a complete
1153 // object, we'll lay these out later.
Anders Carlssonada4b322010-11-22 18:42:14 +00001154 continue;
1155 }
1156
John McCall9b7da1c2011-02-15 06:40:56 +00001157 const CXXRecordDecl *base =
1158 cast<CXXRecordDecl>(I->getType()->castAs<RecordType>()->getDecl());
Anders Carlssonada4b322010-11-22 18:42:14 +00001159
1160 // Ignore empty bases.
John McCall9b7da1c2011-02-15 06:40:56 +00001161 if (base->isEmpty())
Anders Carlssonada4b322010-11-22 18:42:14 +00001162 continue;
1163
John McCall9b7da1c2011-02-15 06:40:56 +00001164 unsigned fieldIndex = layout.getNonVirtualBaseLLVMFieldNo(base);
1165 const llvm::Type *baseType = structure->getElementType(fieldIndex);
1166 elements[fieldIndex] = EmitNullConstantForBase(CGM, baseType, base);
Anders Carlssonada4b322010-11-22 18:42:14 +00001167 }
1168
John McCall9b7da1c2011-02-15 06:40:56 +00001169 // Fill in all the fields.
1170 for (RecordDecl::field_iterator I = record->field_begin(),
1171 E = record->field_end(); I != E; ++I) {
1172 const FieldDecl *field = *I;
Anders Carlssonada4b322010-11-22 18:42:14 +00001173
1174 // Ignore bit fields.
John McCall9b7da1c2011-02-15 06:40:56 +00001175 if (field->isBitField())
Anders Carlssonada4b322010-11-22 18:42:14 +00001176 continue;
1177
John McCall9b7da1c2011-02-15 06:40:56 +00001178 unsigned fieldIndex = layout.getLLVMFieldNo(field);
1179 elements[fieldIndex] = CGM.EmitNullConstant(field->getType());
1180 }
1181
1182 // Fill in the virtual bases, if we're working with the complete object.
1183 if (asCompleteObject) {
1184 for (CXXRecordDecl::base_class_const_iterator
1185 I = record->vbases_begin(), E = record->vbases_end(); I != E; ++I) {
1186 const CXXRecordDecl *base =
1187 cast<CXXRecordDecl>(I->getType()->castAs<RecordType>()->getDecl());
1188
1189 // Ignore empty bases.
1190 if (base->isEmpty())
1191 continue;
1192
1193 unsigned fieldIndex = layout.getVirtualBaseIndex(base);
1194
1195 // We might have already laid this field out.
1196 if (elements[fieldIndex]) continue;
1197
1198 const llvm::Type *baseType = structure->getElementType(fieldIndex);
1199 elements[fieldIndex] = EmitNullConstantForBase(CGM, baseType, base);
1200 }
Anders Carlssonada4b322010-11-22 18:42:14 +00001201 }
1202
1203 // Now go through all other fields and zero them out.
John McCall9b7da1c2011-02-15 06:40:56 +00001204 for (unsigned i = 0; i != numElements; ++i) {
1205 if (!elements[i])
1206 elements[i] = llvm::Constant::getNullValue(structure->getElementType(i));
Anders Carlssonada4b322010-11-22 18:42:14 +00001207 }
1208
John McCall9b7da1c2011-02-15 06:40:56 +00001209 return llvm::ConstantStruct::get(structure, elements);
1210}
1211
1212/// Emit the null constant for a base subobject.
1213static llvm::Constant *EmitNullConstantForBase(CodeGenModule &CGM,
1214 const llvm::Type *baseType,
1215 const CXXRecordDecl *base) {
1216 const CGRecordLayout &baseLayout = CGM.getTypes().getCGRecordLayout(base);
1217
1218 // Just zero out bases that don't have any pointer to data members.
1219 if (baseLayout.isZeroInitializableAsBase())
1220 return llvm::Constant::getNullValue(baseType);
1221
1222 // If the base type is a struct, we can just use its null constant.
1223 if (isa<llvm::StructType>(baseType)) {
1224 return EmitNullConstant(CGM, base, /*complete*/ false);
1225 }
1226
1227 // Otherwise, some bases are represented as arrays of i8 if the size
1228 // of the base is smaller than its corresponding LLVM type. Figure
1229 // out how many elements this base array has.
1230 const llvm::ArrayType *baseArrayType = cast<llvm::ArrayType>(baseType);
1231 unsigned numBaseElements = baseArrayType->getNumElements();
1232
1233 // Fill in null data member pointers.
1234 std::vector<llvm::Constant *> baseElements(numBaseElements);
1235 FillInNullDataMemberPointers(CGM, CGM.getContext().getTypeDeclType(base),
1236 baseElements, 0);
1237
1238 // Now go through all other elements and zero them out.
1239 if (numBaseElements) {
1240 const llvm::Type *i8 = llvm::Type::getInt8Ty(CGM.getLLVMContext());
1241 llvm::Constant *i8_zero = llvm::Constant::getNullValue(i8);
1242 for (unsigned i = 0; i != numBaseElements; ++i) {
1243 if (!baseElements[i])
1244 baseElements[i] = i8_zero;
1245 }
1246 }
1247
1248 return llvm::ConstantArray::get(baseArrayType, baseElements);
Anders Carlssonada4b322010-11-22 18:42:14 +00001249}
1250
Eli Friedman0f593122009-04-13 21:47:26 +00001251llvm::Constant *CodeGenModule::EmitNullConstant(QualType T) {
John McCallf16aa102010-08-22 21:01:12 +00001252 if (getTypes().isZeroInitializable(T))
Anders Carlssonad3e7112009-08-24 17:16:23 +00001253 return llvm::Constant::getNullValue(getTypes().ConvertTypeForMem(T));
Anders Carlsson2c12d032010-02-02 05:17:25 +00001254
Anders Carlsson237957c2009-08-09 18:26:27 +00001255 if (const ConstantArrayType *CAT = Context.getAsConstantArrayType(T)) {
Mike Stump1eb44332009-09-09 15:08:12 +00001256
Anders Carlsson237957c2009-08-09 18:26:27 +00001257 QualType ElementTy = CAT->getElementType();
1258
Anders Carlsson2c12d032010-02-02 05:17:25 +00001259 llvm::Constant *Element = EmitNullConstant(ElementTy);
1260 unsigned NumElements = CAT->getSize().getZExtValue();
1261 std::vector<llvm::Constant *> Array(NumElements);
1262 for (unsigned i = 0; i != NumElements; ++i)
1263 Array[i] = Element;
Mike Stump1eb44332009-09-09 15:08:12 +00001264
Anders Carlsson2c12d032010-02-02 05:17:25 +00001265 const llvm::ArrayType *ATy =
1266 cast<llvm::ArrayType>(getTypes().ConvertTypeForMem(T));
1267 return llvm::ConstantArray::get(ATy, Array);
Anders Carlsson237957c2009-08-09 18:26:27 +00001268 }
Anders Carlssonfc3eaa42009-08-23 01:25:01 +00001269
1270 if (const RecordType *RT = T->getAs<RecordType>()) {
Anders Carlsson2c12d032010-02-02 05:17:25 +00001271 const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
John McCall9b7da1c2011-02-15 06:40:56 +00001272 return ::EmitNullConstant(*this, RD, /*complete object*/ true);
Anders Carlssonfc3eaa42009-08-23 01:25:01 +00001273 }
Mike Stump1eb44332009-09-09 15:08:12 +00001274
Anders Carlssona83fb4b2010-05-18 16:51:41 +00001275 assert(T->isMemberPointerType() && "Should only see member pointers here!");
Anders Carlsson2c12d032010-02-02 05:17:25 +00001276 assert(!T->getAs<MemberPointerType>()->getPointeeType()->isFunctionType() &&
1277 "Should only see pointers to data members here!");
1278
1279 // Itanium C++ ABI 2.3:
1280 // A NULL pointer is represented as -1.
John McCall5808ce42011-02-03 08:15:49 +00001281 return getCXXABI().EmitNullMemberPointer(T->castAs<MemberPointerType>());
Eli Friedman0f593122009-04-13 21:47:26 +00001282}