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-rw-r--r--llvm/lib/MC/WasmObjectWriter.cpp64
1 files changed, 36 insertions, 28 deletions
diff --git a/llvm/lib/MC/WasmObjectWriter.cpp b/llvm/lib/MC/WasmObjectWriter.cpp
index 0014b695b90..adf0aef1202 100644
--- a/llvm/lib/MC/WasmObjectWriter.cpp
+++ b/llvm/lib/MC/WasmObjectWriter.cpp
@@ -243,6 +243,7 @@ class WasmObjectWriter : public MCObjectWriter {
// Maps function/global symbols to the function/global/event/section index
// space.
DenseMap<const MCSymbolWasm *, uint32_t> WasmIndices;
+ DenseMap<const MCSymbolWasm *, uint32_t> GOTIndices;
// Maps data symbols to the Wasm segment and offset/size with the segment.
DenseMap<const MCSymbolWasm *, wasm::WasmDataReference> DataLocations;
@@ -260,7 +261,6 @@ class WasmObjectWriter : public MCObjectWriter {
DenseMap<WasmSignature, uint32_t, WasmSignatureDenseMapInfo> SignatureIndices;
SmallVector<WasmSignature, 4> Signatures;
- SmallVector<WasmGlobal, 4> Globals;
SmallVector<WasmDataSegment, 4> DataSegments;
unsigned NumFunctionImports = 0;
unsigned NumGlobalImports = 0;
@@ -288,6 +288,7 @@ private:
DataRelocations.clear();
TypeIndices.clear();
WasmIndices.clear();
+ GOTIndices.clear();
TableIndices.clear();
DataLocations.clear();
CustomSections.clear();
@@ -296,7 +297,6 @@ private:
CustomSectionsRelocations.clear();
SignatureIndices.clear();
Signatures.clear();
- Globals.clear();
DataSegments.clear();
SectionFunctions.clear();
NumFunctionImports = 0;
@@ -326,7 +326,6 @@ private:
void writeImportSection(ArrayRef<wasm::WasmImport> Imports, uint32_t DataSize,
uint32_t NumElements);
void writeFunctionSection(ArrayRef<WasmFunction> Functions);
- void writeGlobalSection();
void writeExportSection(ArrayRef<wasm::WasmExport> Exports);
void writeElemSection(ArrayRef<uint32_t> TableElems);
void writeCodeSection(const MCAssembler &Asm, const MCAsmLayout &Layout,
@@ -545,6 +544,9 @@ void WasmObjectWriter::recordRelocation(MCAssembler &Asm,
SymA->setUsedInReloc();
}
+ if (RefA->getKind() == MCSymbolRefExpr::VK_GOT)
+ SymA->setUsedInGOT();
+
WasmRelocationEntry Rec(FixupOffset, SymA, C, Type, &FixupSection);
LLVM_DEBUG(dbgs() << "WasmReloc: " << Rec << "\n");
@@ -575,6 +577,11 @@ static const MCSymbolWasm *resolveSymbol(const MCSymbolWasm &Symbol) {
// useable.
uint32_t
WasmObjectWriter::getProvisionalValue(const WasmRelocationEntry &RelEntry) {
+ if (RelEntry.Type == wasm::R_WASM_GLOBAL_INDEX_LEB && !RelEntry.Symbol->isGlobal()) {
+ assert(GOTIndices.count(RelEntry.Symbol) > 0 && "symbol not found in GOT index space");
+ return GOTIndices[RelEntry.Symbol];
+ }
+
switch (RelEntry.Type) {
case wasm::R_WASM_TABLE_INDEX_SLEB:
case wasm::R_WASM_TABLE_INDEX_I32: {
@@ -590,9 +597,7 @@ WasmObjectWriter::getProvisionalValue(const WasmRelocationEntry &RelEntry) {
case wasm::R_WASM_GLOBAL_INDEX_LEB:
case wasm::R_WASM_EVENT_INDEX_LEB:
// Provisional value is function/global/event Wasm index
- if (!WasmIndices.count(RelEntry.Symbol))
- report_fatal_error("symbol not found in wasm index space: " +
- RelEntry.Symbol->getName());
+ assert(WasmIndices.count(RelEntry.Symbol) > 0 && "symbol not found in wasm index space");
return WasmIndices[RelEntry.Symbol];
case wasm::R_WASM_FUNCTION_OFFSET_I32:
case wasm::R_WASM_SECTION_OFFSET_I32: {
@@ -787,26 +792,6 @@ void WasmObjectWriter::writeFunctionSection(ArrayRef<WasmFunction> Functions) {
endSection(Section);
}
-void WasmObjectWriter::writeGlobalSection() {
- if (Globals.empty())
- return;
-
- SectionBookkeeping Section;
- startSection(Section, wasm::WASM_SEC_GLOBAL);
-
- encodeULEB128(Globals.size(), W.OS);
- for (const WasmGlobal &Global : Globals) {
- writeValueType(static_cast<wasm::ValType>(Global.Type.Type));
- W.OS << char(Global.Type.Mutable);
-
- W.OS << char(wasm::WASM_OPCODE_I32_CONST);
- encodeSLEB128(Global.InitialValue, W.OS);
- W.OS << char(wasm::WASM_OPCODE_END);
- }
-
- endSection(Section);
-}
-
void WasmObjectWriter::writeEventSection(ArrayRef<wasm::WasmEventType> Events) {
if (Events.empty())
return;
@@ -1208,17 +1193,19 @@ uint64_t WasmObjectWriter::writeObject(MCAssembler &Asm,
Import.Kind = wasm::WASM_EXTERNAL_FUNCTION;
Import.SigIndex = getFunctionType(WS);
Imports.push_back(Import);
+ assert(WasmIndices.count(&WS) == 0);
WasmIndices[&WS] = NumFunctionImports++;
} else if (WS.isGlobal()) {
if (WS.isWeak())
report_fatal_error("undefined global symbol cannot be weak");
wasm::WasmImport Import;
- Import.Module = WS.getImportModule();
Import.Field = WS.getImportName();
Import.Kind = wasm::WASM_EXTERNAL_GLOBAL;
+ Import.Module = WS.getImportModule();
Import.Global = WS.getGlobalType();
Imports.push_back(Import);
+ assert(WasmIndices.count(&WS) == 0);
WasmIndices[&WS] = NumGlobalImports++;
} else if (WS.isEvent()) {
if (WS.isWeak())
@@ -1231,11 +1218,30 @@ uint64_t WasmObjectWriter::writeObject(MCAssembler &Asm,
Import.Event.Attribute = wasm::WASM_EVENT_ATTRIBUTE_EXCEPTION;
Import.Event.SigIndex = getEventType(WS);
Imports.push_back(Import);
+ assert(WasmIndices.count(&WS) == 0);
WasmIndices[&WS] = NumEventImports++;
}
}
}
+ // Add imports for GOT globals
+ for (const MCSymbol &S : Asm.symbols()) {
+ const auto &WS = static_cast<const MCSymbolWasm &>(S);
+ if (WS.isUsedInGOT()) {
+ wasm::WasmImport Import;
+ if (WS.isFunction())
+ Import.Module = "GOT.func";
+ else
+ Import.Module = "GOT.mem";
+ Import.Field = WS.getName();
+ Import.Kind = wasm::WASM_EXTERNAL_GLOBAL;
+ Import.Global = {wasm::WASM_TYPE_I32, true};
+ Imports.push_back(Import);
+ assert(GOTIndices.count(&WS) == 0);
+ GOTIndices[&WS] = NumGlobalImports++;
+ }
+ }
+
// Populate DataSegments and CustomSections, which must be done before
// populating DataLocations.
for (MCSection &Sec : Asm) {
@@ -1401,10 +1407,12 @@ uint64_t WasmObjectWriter::writeObject(MCAssembler &Asm,
wasm::WasmEventType Event;
Event.SigIndex = getEventType(WS);
Event.Attribute = wasm::WASM_EVENT_ATTRIBUTE_EXCEPTION;
+ assert(WasmIndices.count(&WS) == 0);
WasmIndices[&WS] = Index;
Events.push_back(Event);
} else {
// An import; the index was assigned above.
+ assert(WasmIndices.count(&WS) > 0);
Index = WasmIndices.find(&WS)->second;
}
LLVM_DEBUG(dbgs() << " -> event index: " << WasmIndices.find(&WS)->second
@@ -1434,6 +1442,7 @@ uint64_t WasmObjectWriter::writeObject(MCAssembler &Asm,
if (ResolvedSym->isFunction()) {
assert(WasmIndices.count(ResolvedSym) > 0);
uint32_t WasmIndex = WasmIndices.find(ResolvedSym)->second;
+ assert(WasmIndices.count(&WS) == 0);
WasmIndices[&WS] = WasmIndex;
LLVM_DEBUG(dbgs() << " -> index:" << WasmIndex << "\n");
} else if (ResolvedSym->isData()) {
@@ -1586,7 +1595,6 @@ uint64_t WasmObjectWriter::writeObject(MCAssembler &Asm,
writeFunctionSection(Functions);
// Skip the "table" section; we import the table instead.
// Skip the "memory" section; we import the memory instead.
- writeGlobalSection();
writeEventSection(Events);
writeExportSection(Exports);
writeElemSection(TableElems);
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