[WebAssembly] Include SYMBOL_INFO for imports as well as exports

Only effects --emit-relocs/--relocatable

Patch by Nicholas Wilson!

Differential Revision: https://reviews.llvm.org/D42306

llvm-svn: 322994

3 files changed, 17 insertions, 6 deletions

diff --git a/lld/test/wasm/init-fini.ll b/lld/test/wasm/init-fini.ll
index 0fa9b20a3f8..a83a5129c63 100644
--- a/lld/test/wasm/init-fini.ll
+++ b/lld/test/wasm/init-fini.ll
@@ -108,6 +108,8 @@ entry:
 ; 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
diff --git a/lld/test/wasm/relocatable.ll b/lld/test/wasm/relocatable.ll
index 6167353c6c0..8efb240ccfc 100644
--- a/lld/test/wasm/relocatable.ll
+++ b/lld/test/wasm/relocatable.ll
@@ -229,6 +229,8 @@ entry:
 ; 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
diff --git a/lld/wasm/Writer.cpp b/lld/wasm/Writer.cpp
index ab1ce2c683f..a6d21c10cc9 100644
--- a/lld/wasm/Writer.cpp
+++ b/lld/wasm/Writer.cpp
@@ -386,14 +386,21 @@ void Writer::createLinkingSection() {
     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");