/Users/buildslave/jenkins/workspace/clang-stage2-coverage-R/llvm/lib/Target/WebAssembly/MCTargetDesc/WebAssemblyWasmObjectWriter.cpp
Line | Count | Source (jump to first uncovered line) |
1 | | //===-- WebAssemblyWasmObjectWriter.cpp - WebAssembly Wasm Writer ---------===// |
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 | | /// \file |
10 | | /// This file handles Wasm-specific object emission, converting LLVM's |
11 | | /// internal fixups into the appropriate relocations. |
12 | | /// |
13 | | //===----------------------------------------------------------------------===// |
14 | | |
15 | | #include "MCTargetDesc/WebAssemblyFixupKinds.h" |
16 | | #include "MCTargetDesc/WebAssemblyMCTargetDesc.h" |
17 | | #include "llvm/BinaryFormat/Wasm.h" |
18 | | #include "llvm/MC/MCAsmBackend.h" |
19 | | #include "llvm/MC/MCFixup.h" |
20 | | #include "llvm/MC/MCFixupKindInfo.h" |
21 | | #include "llvm/MC/MCObjectWriter.h" |
22 | | #include "llvm/MC/MCSectionWasm.h" |
23 | | #include "llvm/MC/MCSymbolWasm.h" |
24 | | #include "llvm/MC/MCValue.h" |
25 | | #include "llvm/MC/MCWasmObjectWriter.h" |
26 | | #include "llvm/Support/Casting.h" |
27 | | #include "llvm/Support/ErrorHandling.h" |
28 | | |
29 | | using namespace llvm; |
30 | | |
31 | | namespace { |
32 | | class WebAssemblyWasmObjectWriter final : public MCWasmObjectTargetWriter { |
33 | | public: |
34 | | explicit WebAssemblyWasmObjectWriter(bool Is64Bit); |
35 | | |
36 | | private: |
37 | | unsigned getRelocType(const MCValue &Target, |
38 | | const MCFixup &Fixup) const override; |
39 | | }; |
40 | | } // end anonymous namespace |
41 | | |
42 | | WebAssemblyWasmObjectWriter::WebAssemblyWasmObjectWriter(bool Is64Bit) |
43 | 443 | : MCWasmObjectTargetWriter(Is64Bit) {} |
44 | | |
45 | 120 | static const MCSection *getFixupSection(const MCExpr *Expr) { |
46 | 120 | if (auto SyExp = dyn_cast<MCSymbolRefExpr>(Expr)) { |
47 | 110 | if (SyExp->getSymbol().isInSection()) |
48 | 97 | return &SyExp->getSymbol().getSection(); |
49 | 13 | return nullptr; |
50 | 13 | } |
51 | 10 | |
52 | 10 | if (auto BinOp = dyn_cast<MCBinaryExpr>(Expr)) { |
53 | 5 | auto SectionLHS = getFixupSection(BinOp->getLHS()); |
54 | 5 | auto SectionRHS = getFixupSection(BinOp->getRHS()); |
55 | 5 | return SectionLHS == SectionRHS ? nullptr2 : SectionLHS3 ; |
56 | 5 | } |
57 | 5 | |
58 | 5 | if (auto UnOp = dyn_cast<MCUnaryExpr>(Expr)) |
59 | 0 | return getFixupSection(UnOp->getSubExpr()); |
60 | 5 | |
61 | 5 | return nullptr; |
62 | 5 | } |
63 | | |
64 | | unsigned WebAssemblyWasmObjectWriter::getRelocType(const MCValue &Target, |
65 | 532 | const MCFixup &Fixup) const { |
66 | 532 | const MCSymbolRefExpr *RefA = Target.getSymA(); |
67 | 532 | assert(RefA); |
68 | 532 | auto& SymA = cast<MCSymbolWasm>(RefA->getSymbol()); |
69 | 532 | |
70 | 532 | MCSymbolRefExpr::VariantKind Modifier = Target.getAccessVariant(); |
71 | 532 | |
72 | 532 | switch (Modifier) { |
73 | 532 | case MCSymbolRefExpr::VK_GOT: |
74 | 8 | return wasm::R_WASM_GLOBAL_INDEX_LEB; |
75 | 532 | case MCSymbolRefExpr::VK_WASM_TBREL: |
76 | 2 | assert(SymA.isFunction()); |
77 | 2 | return wasm::R_WASM_TABLE_INDEX_REL_SLEB; |
78 | 532 | case MCSymbolRefExpr::VK_WASM_MBREL: |
79 | 3 | assert(SymA.isData()); |
80 | 3 | return wasm::R_WASM_MEMORY_ADDR_REL_SLEB; |
81 | 532 | case MCSymbolRefExpr::VK_WASM_TYPEINDEX: |
82 | 16 | return wasm::R_WASM_TYPE_INDEX_LEB; |
83 | 532 | default: |
84 | 503 | break; |
85 | 503 | } |
86 | 503 | |
87 | 503 | switch (unsigned(Fixup.getKind())) { |
88 | 503 | case WebAssembly::fixup_sleb128_i32: |
89 | 61 | if (SymA.isFunction()) |
90 | 29 | return wasm::R_WASM_TABLE_INDEX_SLEB; |
91 | 32 | return wasm::R_WASM_MEMORY_ADDR_SLEB; |
92 | 32 | case WebAssembly::fixup_sleb128_i64: |
93 | 0 | llvm_unreachable("fixup_sleb128_i64 not implemented yet"); |
94 | 310 | case WebAssembly::fixup_uleb128_i32: |
95 | 310 | if (SymA.isGlobal()) |
96 | 34 | return wasm::R_WASM_GLOBAL_INDEX_LEB; |
97 | 276 | if (SymA.isFunction()) |
98 | 115 | return wasm::R_WASM_FUNCTION_INDEX_LEB; |
99 | 161 | if (SymA.isEvent()) |
100 | 7 | return wasm::R_WASM_EVENT_INDEX_LEB; |
101 | 154 | return wasm::R_WASM_MEMORY_ADDR_LEB; |
102 | 154 | case FK_Data_4: |
103 | 132 | if (SymA.isFunction()) |
104 | 22 | return wasm::R_WASM_TABLE_INDEX_I32; |
105 | 110 | if (auto Section = static_cast<const MCSectionWasm *>( |
106 | 97 | getFixupSection(Fixup.getValue()))) { |
107 | 97 | if (Section->getKind().isText()) |
108 | 26 | return wasm::R_WASM_FUNCTION_OFFSET_I32; |
109 | 71 | else if (!Section->isWasmData()) |
110 | 58 | return wasm::R_WASM_SECTION_OFFSET_I32; |
111 | 26 | } |
112 | 26 | return wasm::R_WASM_MEMORY_ADDR_I32; |
113 | 26 | default: |
114 | 0 | llvm_unreachable("unimplemented fixup kind"); |
115 | 503 | } |
116 | 503 | } |
117 | | |
118 | | std::unique_ptr<MCObjectTargetWriter> |
119 | 443 | llvm::createWebAssemblyWasmObjectWriter(bool Is64Bit) { |
120 | 443 | return llvm::make_unique<WebAssemblyWasmObjectWriter>(Is64Bit); |
121 | 443 | } |