Reland "[WebAssembly] Import the linear memory and function table."
Original change: https://reviews.llvm.org/D40875
llvm-svn: 320432
diff --git a/llvm/lib/MC/WasmObjectWriter.cpp b/llvm/lib/MC/WasmObjectWriter.cpp
index 351927d..7c50f43 100644
--- a/llvm/lib/MC/WasmObjectWriter.cpp
+++ b/llvm/lib/MC/WasmObjectWriter.cpp
@@ -270,10 +270,9 @@
}
void writeTypeSection(ArrayRef<WasmFunctionType> FunctionTypes);
- void writeImportSection(ArrayRef<WasmImport> Imports);
+ void writeImportSection(ArrayRef<WasmImport> Imports, uint32_t DataSize,
+ uint32_t NumElements);
void writeFunctionSection(ArrayRef<WasmFunction> Functions);
- void writeTableSection(uint32_t NumElements);
- void writeMemorySection(uint32_t DataSize);
void writeGlobalSection();
void writeExportSection(ArrayRef<WasmExport> Exports);
void writeElemSection(ArrayRef<uint32_t> TableElems);
@@ -661,10 +660,14 @@
endSection(Section);
}
-void WasmObjectWriter::writeImportSection(ArrayRef<WasmImport> Imports) {
+void WasmObjectWriter::writeImportSection(ArrayRef<WasmImport> Imports,
+ uint32_t DataSize,
+ uint32_t NumElements) {
if (Imports.empty())
return;
+ uint32_t NumPages = (DataSize + wasm::WasmPageSize - 1) / wasm::WasmPageSize;
+
SectionBookkeeping Section;
startSection(Section, wasm::WASM_SEC_IMPORT);
@@ -683,6 +686,15 @@
encodeSLEB128(int32_t(Import.Type), getStream());
encodeULEB128(int32_t(Import.IsMutable), getStream());
break;
+ case wasm::WASM_EXTERNAL_MEMORY:
+ encodeULEB128(0, getStream()); // flags
+ encodeULEB128(NumPages, getStream()); // initial
+ break;
+ case wasm::WASM_EXTERNAL_TABLE:
+ encodeSLEB128(int32_t(Import.Type), getStream());
+ encodeULEB128(0, getStream()); // flags
+ encodeULEB128(NumElements, getStream()); // initial
+ break;
default:
llvm_unreachable("unsupported import kind");
}
@@ -705,39 +717,6 @@
endSection(Section);
}
-void WasmObjectWriter::writeTableSection(uint32_t NumElements) {
- // For now, always emit the table section, since indirect calls are not
- // valid without it. In the future, we could perhaps be more clever and omit
- // it if there are no indirect calls.
-
- SectionBookkeeping Section;
- startSection(Section, wasm::WASM_SEC_TABLE);
-
- encodeULEB128(1, getStream()); // The number of tables.
- // Fixed to 1 for now.
- encodeSLEB128(wasm::WASM_TYPE_ANYFUNC, getStream()); // Type of table
- encodeULEB128(0, getStream()); // flags
- encodeULEB128(NumElements, getStream()); // initial
-
- endSection(Section);
-}
-
-void WasmObjectWriter::writeMemorySection(uint32_t DataSize) {
- // For now, always emit the memory section, 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.
- SectionBookkeeping Section;
- uint32_t NumPages = (DataSize + wasm::WasmPageSize - 1) / wasm::WasmPageSize;
-
- startSection(Section, wasm::WASM_SEC_MEMORY);
- encodeULEB128(1, getStream()); // number of memory spaces
-
- encodeULEB128(0, getStream()); // flags
- encodeULEB128(NumPages, getStream()); // initial
-
- endSection(Section);
-}
-
void WasmObjectWriter::writeGlobalSection() {
if (Globals.empty())
return;
@@ -1085,6 +1064,29 @@
}
}
+ // 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.
+ MCSymbolWasm *MemorySym =
+ cast<MCSymbolWasm>(Ctx.getOrCreateSymbol("__linear_memory"));
+ WasmImport MemImport;
+ MemImport.ModuleName = MemorySym->getModuleName();
+ MemImport.FieldName = MemorySym->getName();
+ MemImport.Kind = wasm::WASM_EXTERNAL_MEMORY;
+ Imports.push_back(MemImport);
+
+ // For now, always emit the table section, since indirect calls are not
+ // valid without it. In the future, we could perhaps be more clever and omit
+ // it if there are no indirect calls.
+ MCSymbolWasm *TableSym =
+ cast<MCSymbolWasm>(Ctx.getOrCreateSymbol("__indirect_function_table"));
+ WasmImport TableImport;
+ TableImport.ModuleName = TableSym->getModuleName();
+ TableImport.FieldName = TableSym->getName();
+ TableImport.Kind = wasm::WASM_EXTERNAL_TABLE;
+ TableImport.Type = wasm::WASM_TYPE_ANYFUNC;
+ Imports.push_back(TableImport);
+
// Populate FunctionTypeIndices and Imports.
for (const MCSymbol &S : Asm.symbols()) {
const auto &WS = static_cast<const MCSymbolWasm &>(S);
@@ -1295,10 +1297,10 @@
writeHeader(Asm);
writeTypeSection(FunctionTypes);
- writeImportSection(Imports);
+ writeImportSection(Imports, DataSize, TableElems.size());
writeFunctionSection(Functions);
- writeTableSection(TableElems.size());
- writeMemorySection(DataSize);
+ // Skip the "table" section; we import the table instead.
+ // Skip the "memory" section; we import the memory instead.
writeGlobalSection();
writeExportSection(Exports);
// TODO: Start Section