commit 285da41e2202f37dcec2ad4e409d9d7297166178
author Sam Clegg <sbc@chromium.org> Thu Feb 21 17:05:19 2019 +0000
committer Sam Clegg <sbc@chromium.org> Thu Feb 21 17:05:19 2019 +0000
tree eabf58baaf315d6f2836a401ab1ee16daf4ff079
parent ede8818b21c578c2ecc6665ac04d7a15d90f6f2a

[WebAssembly] Don't create MSSymbolWasm object for non-symbols

`__linear_memory` and `__indirect_function_table` are both generated
as imports in wasm object files but are actually symbols and don't
appear in any symbols table or relocation entry.  Indeed we
don't have any symbol type to meaningfully represent either of them.

Differential Revision: https://reviews.llvm.org/D58487

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354599 91177308-0d34-0410-b5e6-96231b3b80d8

lib/MC/WasmObjectWriter.cpp

diff --git a/lib/MC/WasmObjectWriter.cpp b/lib/MC/WasmObjectWriter.cpp
index 10f16ba..d8dfc57 100644
--- a/lib/MC/WasmObjectWriter.cpp
+++ b/lib/MC/WasmObjectWriter.cpp
@@ -1148,7 +1148,6 @@
   uint64_t StartOffset = W.OS.tell();
 
   LLVM_DEBUG(dbgs() << "WasmObjectWriter::writeObject\n");
-  MCContext &Ctx = Asm.getContext();
 
   // Collect information from the available symbols.
   SmallVector<WasmFunction, 4> Functions;
@@ -1164,22 +1163,18 @@
   // 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.
-  auto *MemorySym =
-      cast<MCSymbolWasm>(Ctx.getOrCreateSymbol("__linear_memory"));
   wasm::WasmImport MemImport;
-  MemImport.Module = MemorySym->getImportModule();
-  MemImport.Field = MemorySym->getImportName();
+  MemImport.Module = "env";
+  MemImport.Field = "__linear_memory";
   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.
-  auto *TableSym =
-      cast<MCSymbolWasm>(Ctx.getOrCreateSymbol("__indirect_function_table"));
   wasm::WasmImport TableImport;
-  TableImport.Module = TableSym->getImportModule();
-  TableImport.Field = TableSym->getImportName();
+  TableImport.Module = "env";
+  TableImport.Field = "__indirect_function_table";
   TableImport.Kind = wasm::WASM_EXTERNAL_TABLE;
   TableImport.Table.ElemType = wasm::WASM_TYPE_FUNCREF;
   Imports.push_back(TableImport);