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
|
//===- WebAssembly.cpp ----------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "ABIInfoImpl.h"
#include "TargetInfo.h"
using namespace clang;
using namespace clang::CodeGen;
//===----------------------------------------------------------------------===//
// WebAssembly ABI Implementation
//
// This is a very simple ABI that relies a lot on DefaultABIInfo.
//===----------------------------------------------------------------------===//
class WebAssemblyABIInfo final : public ABIInfo {
DefaultABIInfo defaultInfo;
WebAssemblyABIKind Kind;
public:
explicit WebAssemblyABIInfo(CodeGen::CodeGenTypes &CGT,
WebAssemblyABIKind Kind)
: ABIInfo(CGT), defaultInfo(CGT), Kind(Kind) {}
private:
ABIArgInfo classifyReturnType(QualType RetTy) const;
ABIArgInfo classifyArgumentType(QualType Ty) const;
// DefaultABIInfo's classifyReturnType and classifyArgumentType are
// non-virtual, but computeInfo and EmitVAArg are virtual, so we
// overload them.
void computeInfo(CGFunctionInfo &FI) const override {
if (!getCXXABI().classifyReturnType(FI))
FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
for (auto &Arg : FI.arguments())
Arg.info = classifyArgumentType(Arg.type);
}
Address EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
QualType Ty) const override;
};
class WebAssemblyTargetCodeGenInfo final : public TargetCodeGenInfo {
public:
explicit WebAssemblyTargetCodeGenInfo(CodeGen::CodeGenTypes &CGT,
WebAssemblyABIKind K)
: TargetCodeGenInfo(std::make_unique<WebAssemblyABIInfo>(CGT, K)) {
SwiftInfo =
std::make_unique<SwiftABIInfo>(CGT, /*SwiftErrorInRegister=*/false);
}
void setTargetAttributes(const Decl *D, llvm::GlobalValue *GV,
CodeGen::CodeGenModule &CGM) const override {
TargetCodeGenInfo::setTargetAttributes(D, GV, CGM);
if (const auto *FD = dyn_cast_or_null<FunctionDecl>(D)) {
if (const auto *Attr = FD->getAttr<WebAssemblyImportModuleAttr>()) {
llvm::Function *Fn = cast<llvm::Function>(GV);
llvm::AttrBuilder B(GV->getContext());
B.addAttribute("wasm-import-module", Attr->getImportModule());
Fn->addFnAttrs(B);
}
if (const auto *Attr = FD->getAttr<WebAssemblyImportNameAttr>()) {
llvm::Function *Fn = cast<llvm::Function>(GV);
llvm::AttrBuilder B(GV->getContext());
B.addAttribute("wasm-import-name", Attr->getImportName());
Fn->addFnAttrs(B);
}
if (const auto *Attr = FD->getAttr<WebAssemblyExportNameAttr>()) {
llvm::Function *Fn = cast<llvm::Function>(GV);
llvm::AttrBuilder B(GV->getContext());
B.addAttribute("wasm-export-name", Attr->getExportName());
Fn->addFnAttrs(B);
}
}
if (auto *FD = dyn_cast_or_null<FunctionDecl>(D)) {
llvm::Function *Fn = cast<llvm::Function>(GV);
if (!FD->doesThisDeclarationHaveABody() && !FD->hasPrototype())
Fn->addFnAttr("no-prototype");
}
}
/// Return the WebAssembly externref reference type.
virtual llvm::Type *getWasmExternrefReferenceType() const override {
return llvm::Type::getWasm_ExternrefTy(getABIInfo().getVMContext());
}
/// Return the WebAssembly funcref reference type.
virtual llvm::Type *getWasmFuncrefReferenceType() const override {
return llvm::Type::getWasm_FuncrefTy(getABIInfo().getVMContext());
}
};
/// Classify argument of given type \p Ty.
ABIArgInfo WebAssemblyABIInfo::classifyArgumentType(QualType Ty) const {
Ty = useFirstFieldIfTransparentUnion(Ty);
if (isAggregateTypeForABI(Ty)) {
// Records with non-trivial destructors/copy-constructors should not be
// passed by value.
if (auto RAA = getRecordArgABI(Ty, getCXXABI()))
return getNaturalAlignIndirect(Ty, RAA == CGCXXABI::RAA_DirectInMemory);
// Ignore empty structs/unions.
if (isEmptyRecord(getContext(), Ty, true))
return ABIArgInfo::getIgnore();
// Lower single-element structs to just pass a regular value. TODO: We
// could do reasonable-size multiple-element structs too, using getExpand(),
// though watch out for things like bitfields.
if (const Type *SeltTy = isSingleElementStruct(Ty, getContext()))
return ABIArgInfo::getDirect(CGT.ConvertType(QualType(SeltTy, 0)));
// For the experimental multivalue ABI, fully expand all other aggregates
if (Kind == WebAssemblyABIKind::ExperimentalMV) {
const RecordType *RT = Ty->getAs<RecordType>();
assert(RT);
bool HasBitField = false;
for (auto *Field : RT->getDecl()->fields()) {
if (Field->isBitField()) {
HasBitField = true;
break;
}
}
if (!HasBitField)
return ABIArgInfo::getExpand();
}
}
// Otherwise just do the default thing.
return defaultInfo.classifyArgumentType(Ty);
}
ABIArgInfo WebAssemblyABIInfo::classifyReturnType(QualType RetTy) const {
if (isAggregateTypeForABI(RetTy)) {
// Records with non-trivial destructors/copy-constructors should not be
// returned by value.
if (!getRecordArgABI(RetTy, getCXXABI())) {
// Ignore empty structs/unions.
if (isEmptyRecord(getContext(), RetTy, true))
return ABIArgInfo::getIgnore();
// Lower single-element structs to just return a regular value. TODO: We
// could do reasonable-size multiple-element structs too, using
// ABIArgInfo::getDirect().
if (const Type *SeltTy = isSingleElementStruct(RetTy, getContext()))
return ABIArgInfo::getDirect(CGT.ConvertType(QualType(SeltTy, 0)));
// For the experimental multivalue ABI, return all other aggregates
if (Kind == WebAssemblyABIKind::ExperimentalMV)
return ABIArgInfo::getDirect();
}
}
// Otherwise just do the default thing.
return defaultInfo.classifyReturnType(RetTy);
}
Address WebAssemblyABIInfo::EmitVAArg(CodeGenFunction &CGF, Address VAListAddr,
QualType Ty) const {
bool IsIndirect = isAggregateTypeForABI(Ty) &&
!isEmptyRecord(getContext(), Ty, true) &&
!isSingleElementStruct(Ty, getContext());
return emitVoidPtrVAArg(CGF, VAListAddr, Ty, IsIndirect,
getContext().getTypeInfoInChars(Ty),
CharUnits::fromQuantity(4),
/*AllowHigherAlign=*/true);
}
std::unique_ptr<TargetCodeGenInfo>
CodeGen::createWebAssemblyTargetCodeGenInfo(CodeGenModule &CGM,
WebAssemblyABIKind K) {
return std::make_unique<WebAssemblyTargetCodeGenInfo>(CGM.getTypes(), K);
}
|
