[WebAssembly] Reorder symbol table to match MC order
This removes a TODO introduced in rL325860
Differential Revision: https://reviews.llvm.org/D43685
llvm-svn: 326334
diff --git a/llvm/lib/MC/WasmObjectWriter.cpp b/llvm/lib/MC/WasmObjectWriter.cpp
index b1ce2c3..93bab05 100644
--- a/llvm/lib/MC/WasmObjectWriter.cpp
+++ b/llvm/lib/MC/WasmObjectWriter.cpp
@@ -974,32 +974,8 @@
SmallVector<wasm::WasmSymbolInfo, 4> SymbolInfos;
SmallVector<std::pair<uint16_t, uint32_t>, 2> InitFuncs;
std::map<StringRef, std::vector<WasmComdatEntry>> Comdats;
- unsigned NumSymbols = 0;
uint32_t DataSize = 0;
- auto AddSymbol = [&](const MCSymbolWasm &WS) {
- uint32_t Flags = 0;
- if (WS.isWeak())
- Flags |= wasm::WASM_SYMBOL_BINDING_WEAK;
- if (WS.isHidden())
- Flags |= wasm::WASM_SYMBOL_VISIBILITY_HIDDEN;
- if (!WS.isExternal() && WS.isDefined())
- Flags |= wasm::WASM_SYMBOL_BINDING_LOCAL;
- if (WS.isUndefined())
- Flags |= wasm::WASM_SYMBOL_UNDEFINED;
-
- wasm::WasmSymbolInfo Info;
- Info.Name = WS.getName();
- Info.Kind = WS.getType();
- Info.Flags = Flags;
- if (!WS.isData())
- Info.ElementIndex = WasmIndices[&WS];
- else if (WS.isDefined())
- Info.DataRef = DataLocations[&WS];
- SymbolInfos.emplace_back(Info);
- SymbolIndices[&WS] = NumSymbols++;
- };
-
// For now, always emit the memory import, since loads and stores are not
// valid without it. In the future, we could perhaps be more clever and omit
// it if there are no loads or stores.
@@ -1023,7 +999,9 @@
TableImport.Table.ElemType = wasm::WASM_TYPE_ANYFUNC;
Imports.push_back(TableImport);
- // Populate FunctionTypeIndices and Imports.
+ // Populate FunctionTypeIndices, and Imports and WasmIndices for undefined
+ // symbols. This must be done before populating WasmIndices for defined
+ // symbols.
for (const MCSymbol &S : Asm.symbols()) {
const auto &WS = static_cast<const MCSymbolWasm &>(S);
@@ -1054,17 +1032,10 @@
Imports.push_back(Import);
WasmIndices[&WS] = NumGlobalImports++;
}
-
- // TODO(ncw) We shouldn't be adding the symbol to the symbol table here!
- // Instead it should be done by removing the "if (WS.isDefined())" block
- // in the big loop below (line ~1284). However - that would reorder all
- // the symbols and thus require all the tests to be updated. I think it's
- // better to make that change therefore in a future commit, to isolate
- // each test update from the change that caused it.
- AddSymbol(WS);
}
}
+ // Populate DataSegments, which must be done before populating DataLocations.
for (MCSection &Sec : Asm) {
auto &Section = static_cast<MCSectionWasm &>(Sec);
if (!Section.isWasmData())
@@ -1093,7 +1064,7 @@
}
}
- // Handle regular defined and undefined symbols.
+ // Populate WasmIndices and DataLocations for defined symbols.
for (const MCSymbol &S : Asm.symbols()) {
// Ignore unnamed temporary symbols, which aren't ever exported, imported,
// or used in relocations.
@@ -1182,14 +1153,12 @@
DEBUG(dbgs() << " -> global index: " << WasmIndices.find(&WS)->second
<< "\n");
}
-
- if (WS.isDefined())
- AddSymbol(WS);
}
- // Handle weak aliases. We need to process these in a separate pass because
- // we need to have processed the target of the alias before the alias itself
- // and the symbols are not necessarily ordered in this way.
+ // Populate WasmIndices and DataLocations for aliased symbols. We need to
+ // process these in a separate pass because we need to have processed the
+ // target of the alias before the alias itself and the symbols are not
+ // necessarily ordered in this way.
for (const MCSymbol &S : Asm.symbols()) {
if (!S.isVariable())
continue;
@@ -1215,8 +1184,38 @@
} else {
report_fatal_error("don't yet support global aliases");
}
+ }
- AddSymbol(WS);
+ // Finally, populate the symbol table itself, in its "natural" order.
+ for (const MCSymbol &S : Asm.symbols()) {
+ const auto &WS = static_cast<const MCSymbolWasm &>(S);
+ if (WS.isTemporary() && WS.getName().empty())
+ continue;
+ if (WS.isComdat() && !WS.isDefined())
+ continue;
+ if (WS.isTemporary() && WS.isData() && !WS.getSize())
+ continue;
+
+ uint32_t Flags = 0;
+ if (WS.isWeak())
+ Flags |= wasm::WASM_SYMBOL_BINDING_WEAK;
+ if (WS.isHidden())
+ Flags |= wasm::WASM_SYMBOL_VISIBILITY_HIDDEN;
+ if (!WS.isExternal() && WS.isDefined())
+ Flags |= wasm::WASM_SYMBOL_BINDING_LOCAL;
+ if (WS.isUndefined())
+ Flags |= wasm::WASM_SYMBOL_UNDEFINED;
+
+ wasm::WasmSymbolInfo Info;
+ Info.Name = WS.getName();
+ Info.Kind = WS.getType();
+ Info.Flags = Flags;
+ if (!WS.isData())
+ Info.ElementIndex = WasmIndices.find(&WS)->second;
+ else if (WS.isDefined())
+ Info.DataRef = DataLocations.find(&WS)->second;
+ SymbolIndices[&WS] = SymbolInfos.size();
+ SymbolInfos.emplace_back(Info);
}
{