diff options
| -rw-r--r-- | llvm/lib/MC/WasmObjectWriter.cpp | 56 | ||||
| -rw-r--r-- | llvm/test/MC/WebAssembly/weak-alias.ll | 8 |
2 files changed, 29 insertions, 35 deletions
diff --git a/llvm/lib/MC/WasmObjectWriter.cpp b/llvm/lib/MC/WasmObjectWriter.cpp index 4a824b2cae0..cac4aa17a5d 100644 --- a/llvm/lib/MC/WasmObjectWriter.cpp +++ b/llvm/lib/MC/WasmObjectWriter.cpp @@ -208,7 +208,7 @@ class WasmObjectWriter : public MCObjectWriter { DenseMap<const MCSymbolWasm *, uint32_t> TypeIndices; // Maps function symbols to the table element index space. Used // for TABLE_INDEX relocation types (i.e. address taken functions). - DenseMap<const MCSymbolWasm *, uint32_t> IndirectSymbolIndices; + DenseMap<const MCSymbolWasm *, uint32_t> TableIndices; // Maps function/global symbols to the function/global index space. DenseMap<const MCSymbolWasm *, uint32_t> SymbolIndices; @@ -243,7 +243,7 @@ private: DataRelocations.clear(); TypeIndices.clear(); SymbolIndices.clear(); - IndirectSymbolIndices.clear(); + TableIndices.clear(); FunctionTypeIndices.clear(); FunctionTypes.clear(); Globals.clear(); @@ -493,24 +493,23 @@ static const MCSymbolWasm* ResolveSymbol(const MCSymbolWasm& Symbol) { // useable. uint32_t WasmObjectWriter::getProvisionalValue(const WasmRelocationEntry &RelEntry) { - switch (RelEntry.Type) { case wasm::R_WEBASSEMBLY_TABLE_INDEX_SLEB: - case wasm::R_WEBASSEMBLY_TABLE_INDEX_I32: - // Provitional value is the indirect symbol index - if (!IndirectSymbolIndices.count(RelEntry.Symbol)) - report_fatal_error("symbol not found in table index space: " + - RelEntry.Symbol->getName()); - return IndirectSymbolIndices[RelEntry.Symbol]; + case wasm::R_WEBASSEMBLY_TABLE_INDEX_I32: { + // Provisional value is table address of the resolved symbol itself + const MCSymbolWasm *Sym = ResolveSymbol(*RelEntry.Symbol); + assert(Sym->isFunction()); + return TableIndices[Sym]; + } case wasm::R_WEBASSEMBLY_FUNCTION_INDEX_LEB: case wasm::R_WEBASSEMBLY_TYPE_INDEX_LEB: case wasm::R_WEBASSEMBLY_GLOBAL_INDEX_LEB: - // Provitional value is function/type/global index itself + // Provisional value is function/type/global index itself return getRelocationIndexValue(RelEntry); case wasm::R_WEBASSEMBLY_MEMORY_ADDR_LEB: case wasm::R_WEBASSEMBLY_MEMORY_ADDR_I32: case wasm::R_WEBASSEMBLY_MEMORY_ADDR_SLEB: { - // Provitional value is address of the global + // Provisional value is address of the global const MCSymbolWasm *Sym = ResolveSymbol(*RelEntry.Symbol); // For undefined symbols, use zero if (!Sym->isDefined()) @@ -1274,26 +1273,21 @@ void WasmObjectWriter::writeObject(MCAssembler &Asm, { auto HandleReloc = [&](const WasmRelocationEntry &Rel) { - // Functions referenced by a relocation need to prepared to be called - // indirectly. - const MCSymbolWasm& WS = *Rel.Symbol; - if (WS.isFunction() && IndirectSymbolIndices.count(&WS) == 0) { - switch (Rel.Type) { - case wasm::R_WEBASSEMBLY_TABLE_INDEX_I32: - case wasm::R_WEBASSEMBLY_TABLE_INDEX_SLEB: - case wasm::R_WEBASSEMBLY_MEMORY_ADDR_I32: - case wasm::R_WEBASSEMBLY_MEMORY_ADDR_SLEB: { - uint32_t Index = SymbolIndices.find(&WS)->second; - IndirectSymbolIndices[&WS] = TableElems.size() + kInitialTableOffset; - DEBUG(dbgs() << " -> adding " << WS.getName() - << " to table: " << TableElems.size() << "\n"); - TableElems.push_back(Index); - registerFunctionType(WS); - break; - } - default: - break; - } + // Functions referenced by a relocation need to put in the table. This is + // purely to make the object file's provisional values readable, and is + // ignored by the linker, which re-calculates the relocations itself. + if (Rel.Type != wasm::R_WEBASSEMBLY_TABLE_INDEX_I32 && + Rel.Type != wasm::R_WEBASSEMBLY_TABLE_INDEX_SLEB) + return; + assert(Rel.Symbol->isFunction()); + const MCSymbolWasm &WS = *ResolveSymbol(*Rel.Symbol); + uint32_t SymbolIndex = SymbolIndices.find(&WS)->second; + uint32_t TableIndex = TableElems.size() + kInitialTableOffset; + if (TableIndices.try_emplace(&WS, TableIndex).second) { + DEBUG(dbgs() << " -> adding " << WS.getName() + << " to table: " << TableIndex << "\n"); + TableElems.push_back(SymbolIndex); + registerFunctionType(WS); } }; diff --git a/llvm/test/MC/WebAssembly/weak-alias.ll b/llvm/test/MC/WebAssembly/weak-alias.ll index 2d2415991a0..7655211ec75 100644 --- a/llvm/test/MC/WebAssembly/weak-alias.ll +++ b/llvm/test/MC/WebAssembly/weak-alias.ll @@ -64,7 +64,7 @@ entry: ; CHECK-NEXT: Table: ; CHECK-NEXT: ElemType: ANYFUNC ; CHECK-NEXT: Limits: -; CHECK-NEXT: Initial: 0x00000002 +; CHECK-NEXT: Initial: 0x00000001 ; CHECK-NEXT: - Module: env ; CHECK-NEXT: Field: foo_alias ; CHECK-NEXT: Kind: FUNCTION @@ -133,7 +133,7 @@ entry: ; CHECK-NEXT: - Offset: ; CHECK-NEXT: Opcode: I32_CONST ; CHECK-NEXT: Value: 1 -; CHECK-NEXT: Functions: [ 1, 0 ] +; CHECK-NEXT: Functions: [ 1 ] ; CHECK-NEXT: - Type: CODE ; CHECK-NEXT: Relocations: ; CHECK-NEXT: - Type: R_WEBASSEMBLY_FUNCTION_INDEX_LEB @@ -193,10 +193,10 @@ entry: ; CHECK-NEXT: Content: '01000000' ; CHECK-NEXT: - SectionOffset: 24 ; CHECK-NEXT: MemoryIndex: 0 -; CHECK-NEXT: Offset: +; CHECK-NEXT: Offset: ; CHECK-NEXT: Opcode: I32_CONST ; CHECK-NEXT: Value: 16 -; CHECK-NEXT: Content: '02000000' +; CHECK-NEXT: Content: '01000000' ; CHECK-NEXT: - Type: CUSTOM ; CHECK-NEXT: Name: linking ; CHECK-NEXT: DataSize: 20 |
