[PATCH] D42306: [WebAssembly] Symbol changes #4d: export import flags, LLD only

[Nicholas Wilson via Phabricator via llvm-commits]

ncw created this revision.
ncw added a reviewer: sbc100.
Herald added subscribers: llvm-commits, sunfish, aheejin, jgravelle-google, dschuff, jfb.

This fixes an issue Sam identified in https://reviews.llvm.org/D42105.

https://reviews.llvm.org/D42105 was landed without the fix, and this is the followup patch to correct the omission.

Changes:

- Symbol flags should be written out for imports as well as exports. D'oh.


Repository:
  rLLD LLVM Linker

https://reviews.llvm.org/D42306

Files:
  test/wasm/init-fini.ll
  test/wasm/relocatable.ll
  wasm/Writer.cpp


Index: wasm/Writer.cpp
===================================================================
--- wasm/Writer.cpp
+++ wasm/Writer.cpp
@@ -386,14 +386,21 @@
     return;
 
   std::vector<std::pair<StringRef, uint32_t>> SymbolInfo;
-  for (const WasmExportEntry &E : ExportedSymbols) {
+  auto addSymInfo = [&](const Symbol *Sym, StringRef ExternalName) {
     uint32_t Flags =
-        (E.Sym->isLocal() ? WASM_SYMBOL_BINDING_LOCAL :
-         E.Sym->isWeak() ? WASM_SYMBOL_BINDING_WEAK : 0) |
-        (E.Sym->isHidden() ? WASM_SYMBOL_VISIBILITY_HIDDEN : 0);
+        (Sym->isLocal() ? WASM_SYMBOL_BINDING_LOCAL :
+         Sym->isWeak() ? WASM_SYMBOL_BINDING_WEAK : 0) |
+        (Sym->isHidden() ? WASM_SYMBOL_VISIBILITY_HIDDEN : 0);
     if (Flags)
-      SymbolInfo.emplace_back(E.FieldName, Flags);
-  }
+      SymbolInfo.emplace_back(ExternalName, Flags);
+  };
+  // (Imports can't have internal linkage, their names don't need to be budged.)
+  for (const Symbol *Sym : ImportedFunctions)
+    addSymInfo(Sym, Sym->getName());
+  for (const Symbol *Sym : ImportedGlobals)
+    addSymInfo(Sym, Sym->getName());
+  for (const WasmExportEntry &E : ExportedSymbols)
+    addSymInfo(E.Sym, E.FieldName);
   if (!SymbolInfo.empty()) {
     SubSection SubSection(WASM_SYMBOL_INFO);
     writeUleb128(SubSection.getStream(), SymbolInfo.size(), "num sym info");
Index: test/wasm/relocatable.ll
===================================================================
--- test/wasm/relocatable.ll
+++ test/wasm/relocatable.ll
@@ -229,6 +229,8 @@
 ; CHECK-NEXT:     Name:            linking
 ; CHECK-NEXT:     DataSize:        31
 ; CHECK-NEXT:     SymbolInfo:
+; CHECK-NEXT:       - Name:            bar_import
+; CHECK-NEXT:         Flags:           [ BINDING_WEAK ]
 ; CHECK-NEXT:       - Name:            hello
 ; CHECK-NEXT:         Flags:           [ VISIBILITY_HIDDEN ]
 ; CHECK-NEXT:       - Name:            my_func
Index: test/wasm/init-fini.ll
===================================================================
--- test/wasm/init-fini.ll
+++ test/wasm/init-fini.ll
@@ -108,6 +108,8 @@
 ; RELOC:          Name:            linking
 ; RELOC-NEXT:     DataSize:        0
 ; RELOC-NEXT:     SymbolInfo:      
+; RELOC-NEXT:       - Name:            __dso_handle
+; RELOC-NEXT:         Flags:           [ BINDING_WEAK, VISIBILITY_HIDDEN ]
 ; RELOC-NEXT:       - Name:            func1
 ; RELOC-NEXT:         Flags:           [ VISIBILITY_HIDDEN ]
 ; RELOC-NEXT:       - Name:            func2


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