1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
|
//===--- CodeGenFunction.cpp - Emit LLVM Code from ASTs for a Function ----===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Chris Lattner and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This coordinates the per-function state used while generating code.
//
//===----------------------------------------------------------------------===//
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "clang/Basic/TargetInfo.h"
#include "clang/AST/AST.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/Analysis/Verifier.h"
using namespace llvm;
using namespace clang;
using namespace CodeGen;
CodeGenFunction::CodeGenFunction(CodeGenModule &cgm)
: CGM(cgm), Target(CGM.getContext().Target) {}
ASTContext &CodeGenFunction::getContext() const {
return CGM.getContext();
}
llvm::BasicBlock *CodeGenFunction::getBasicBlockForLabel(const LabelStmt *S) {
BasicBlock *&BB = LabelMap[S];
if (BB) return BB;
// Create, but don't insert, the new block.
return BB = new BasicBlock(S->getName());
}
/// ConvertType - Convert the specified type to its LLVM form.
const llvm::Type *CodeGenFunction::ConvertType(QualType T, SourceLocation Loc) {
// FIXME: Cache these, move the CodeGenModule, expand, etc.
const clang::Type &Ty = *T.getCanonicalType();
switch (Ty.getTypeClass()) {
case Type::Builtin: {
switch (cast<BuiltinType>(Ty).getKind()) {
case BuiltinType::Void:
// LLVM void type can only be used as the result of a function call. Just
// map to the same as char.
case BuiltinType::Char_S:
case BuiltinType::Char_U:
case BuiltinType::SChar:
case BuiltinType::UChar:
return IntegerType::get(Target.getCharWidth(Loc));
case BuiltinType::Bool:
// FIXME: This is very strange. We want scalars to be i1, but in memory
// they can be i1 or i32. Should the codegen handle this issue?
return llvm::Type::Int1Ty;
case BuiltinType::Short:
case BuiltinType::UShort:
return IntegerType::get(Target.getShortWidth(Loc));
case BuiltinType::Int:
case BuiltinType::UInt:
return IntegerType::get(Target.getIntWidth(Loc));
case BuiltinType::Long:
case BuiltinType::ULong:
return IntegerType::get(Target.getLongWidth(Loc));
case BuiltinType::LongLong:
case BuiltinType::ULongLong:
return IntegerType::get(Target.getLongLongWidth(Loc));
case BuiltinType::Float: return llvm::Type::FloatTy;
case BuiltinType::Double: return llvm::Type::DoubleTy;
case BuiltinType::LongDouble:
case BuiltinType::FloatComplex:
case BuiltinType::DoubleComplex:
case BuiltinType::LongDoubleComplex:
;
}
break;
}
case Type::Pointer: {
const PointerType &P = cast<PointerType>(Ty);
return llvm::PointerType::get(ConvertType(P.getPointeeType(), Loc));
}
case Type::Reference: {
const ReferenceType &R = cast<ReferenceType>(Ty);
return llvm::PointerType::get(ConvertType(R.getReferenceeType(), Loc));
}
case Type::Array: {
const ArrayType &A = cast<ArrayType>(Ty);
assert(A.getSizeModifier() == ArrayType::Normal &&
A.getIndexTypeQualifier() == 0 &&
"FIXME: We only handle trivial array types so far!");
// FIXME: are there any promotions etc here?
RValue Size = EmitExpr(A.getSize());
assert(Size.isScalar() && isa<llvm::ConstantInt>(Size.getVal()) &&
"FIXME: Only handle fixed-size arrays so far");
const llvm::Type *EltTy = ConvertType(A.getElementType(), Loc);
return llvm::ArrayType::get(EltTy,
cast<llvm::ConstantInt>(Size.getVal())->getZExtValue());
}
case Type::FunctionNoProto:
case Type::FunctionProto: {
const FunctionType &FP = cast<FunctionType>(Ty);
const llvm::Type *ResultType;
if (FP.getResultType()->isVoidType())
ResultType = llvm::Type::VoidTy; // Result of function uses llvm void.
else
ResultType = ConvertType(FP.getResultType(), Loc);
// FIXME: Convert argument types.
bool isVarArg;
std::vector<const llvm::Type*> ArgTys;
if (const FunctionTypeProto *FTP = dyn_cast<FunctionTypeProto>(&FP)) {
DecodeArgumentTypes(*FTP, ArgTys, Loc);
isVarArg = FTP->isVariadic();
} else {
isVarArg = true;
}
return llvm::FunctionType::get(ResultType, ArgTys, isVarArg, 0);
}
case Type::TypeName:
case Type::Tagged:
break;
}
// FIXME: implement.
return OpaqueType::get();
}
void CodeGenFunction::DecodeArgumentTypes(const FunctionTypeProto &FTP,
std::vector<const llvm::Type*> &
ArgTys, SourceLocation Loc) {
for (unsigned i = 0, e = FTP.getNumArgs(); i != e; ++i)
ArgTys.push_back(ConvertType(FTP.getArgType(i), Loc));
}
void CodeGenFunction::GenerateCode(const FunctionDecl *FD) {
LLVMIntTy = ConvertType(getContext().IntTy, FD->getLocation());
LLVMPointerWidth = Target.getPointerWidth(FD->getLocation());
const llvm::FunctionType *Ty =
cast<llvm::FunctionType>(ConvertType(FD->getType(), FD->getLocation()));
CurFuncDecl = FD;
CurFn = new Function(Ty, Function::ExternalLinkage,
FD->getName(), &CGM.getModule());
BasicBlock *EntryBB = new BasicBlock("entry", CurFn);
// TODO: Walk the decls, creating allocas etc.
Builder.SetInsertPoint(EntryBB);
// Create a marker to make it easy to insert allocas into the entryblock
// later.
AllocaInsertPt = Builder.CreateBitCast(UndefValue::get(llvm::Type::Int32Ty),
llvm::Type::Int32Ty, "allocapt");
// TODO: handle params.
// Emit the function body.
EmitStmt(FD->getBody());
// Emit a return for code that falls off the end.
// FIXME: if this is C++ main, this should return 0.
if (Ty->getReturnType() == llvm::Type::VoidTy)
Builder.CreateRetVoid();
else
Builder.CreateRet(UndefValue::get(Ty->getReturnType()));
// Verify that the function is well formed.
assert(!verifyFunction(*CurFn));
}
|
