[WebAssembly][Object]Use file offset as function symbol address for linked files

llvm/lib/Object/WasmObjectFile.cpp

@@ -1662,10 +1662,18 @@ Expected<StringRef> WasmObjectFile::getSymbolName(DataRefImpl Symb) const {
 Expected<uint64_t> WasmObjectFile::getSymbolAddress(DataRefImpl Symb) const {
   auto &Sym = getWasmSymbol(Symb);
   if (Sym.Info.Kind == wasm::WASM_SYMBOL_TYPE_FUNCTION &&
-      isDefinedFunctionIndex(Sym.Info.ElementIndex))
-    return getDefinedFunction(Sym.Info.ElementIndex).CodeSectionOffset;
-  else
-    return getSymbolValue(Symb);
+      isDefinedFunctionIndex(Sym.Info.ElementIndex)) {
+    // For object files, use the section offset. The linker relies on this.
+    // For linked files, use the file offset. This behavior matches the way
+    // browsers print stack traces and is useful for binary size analysis.
+    // (see https://webassembly.github.io/spec/web-api/index.html#conventions)
+    uint32_t Adjustment = isRelocatableObject() || isSharedObject()
+                              ? 0
+                              : Sections[CodeSection].Offset;
+    return getDefinedFunction(Sym.Info.ElementIndex).CodeSectionOffset +
+           Adjustment;
+  }
+  return getSymbolValue(Symb);
 }
 
 uint64_t WasmObjectFile::getWasmSymbolValue(const WasmSymbol &Sym) const {

llvm/test/tools/llvm-nm/wasm/linked.yaml

@@ -0,0 +1,74 @@
+# RUN: yaml2obj %s -o %t.wasm
+# RUN: llvm-nm %t.wasm | FileCheck %s
+
+# CHECK: 0000009f T my_func_export
+# CHECK-NEXT: 0000002a D my_global_export
+# CHECK-NEXT: 00000000 D my_table_export
+
+--- !WASM
+FileHeader:
+  Version:         0x1
+Sections:
+  - Type:            TYPE
+    Signatures:
+      - Index:           0
+        ParamTypes:      []
+        ReturnTypes:     []
+  - Type:            IMPORT
+    Imports:
+      - Module:          env
+        Field:           foo
+        Kind:            FUNCTION
+        SigIndex:        0
+      - Module:          env
+        Field:           bar
+        Kind:            GLOBAL
+        GlobalType:      I32
+        GlobalMutable:   true
+      - Module:          env
+        Field:           memory
+        Kind:            MEMORY
+        Memory:
+          Minimum:         0x1
+  - Type:            FUNCTION
+    FunctionTypes:   [ 0 ]
+  - Type:            TABLE
+    Tables:
+      - Index:           0
+        ElemType:        FUNCREF
+        Limits:
+          Flags:           [ HAS_MAX ]
+          Minimum:         0x1
+          Maximum:         0x1
+  - Type:            GLOBAL
+    Globals:
+      - Index:           1
+        Mutable:         false
+        Type:            I32
+        InitExpr:
+          Opcode:          I32_CONST
+          Value:           42
+  - Type:            EXPORT
+    Exports:
+      - Name:            my_func_export
+        Kind:            FUNCTION
+        Index:           1
+      - Name:            my_global_export
+        Kind:            GLOBAL
+        Index:           1
+      - Name:            my_table_export
+        Kind:            TABLE
+        Index:           0
+  - Type:            CODE
+    Functions:
+      - Index:           1
+        Locals:
+        Body:            00
+  - Type:            DATA
+    Segments:
+      - SectionOffset:   0
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           0
+        Content:         ''

llvm/test/tools/llvm-objdump/wasm/linked-symbol-table.yaml

@@ -0,0 +1,75 @@
+# RUN: yaml2obj %s -o %t.wasm
+# RUN: llvm-objdump -t %t.wasm | FileCheck %s
+#
+# CHECK:      SYMBOL TABLE:
+# CHECK-NEXT: 0000009f g F CODE my_func_export
+# CHECK-NEXT: 0000002a g O DATA my_global_export
+# CHECK-NEXT: 00000000 g   TABLE my_table_export
+
+--- !WASM
+FileHeader:
+  Version:         0x1
+Sections:
+  - Type:            TYPE
+    Signatures:
+      - Index:           0
+        ParamTypes:      []
+        ReturnTypes:     []
+  - Type:            IMPORT
+    Imports:
+      - Module:          env
+        Field:           foo
+        Kind:            FUNCTION
+        SigIndex:        0
+      - Module:          env
+        Field:           bar
+        Kind:            GLOBAL
+        GlobalType:      I32
+        GlobalMutable:   true
+      - Module:          env
+        Field:           memory
+        Kind:            MEMORY
+        Memory:
+          Minimum:         0x1
+  - Type:            FUNCTION
+    FunctionTypes:   [ 0 ]
+  - Type:            TABLE
+    Tables:
+      - Index:           0
+        ElemType:        FUNCREF
+        Limits:
+          Flags:           [ HAS_MAX ]
+          Minimum:         0x1
+          Maximum:         0x1
+  - Type:            GLOBAL
+    Globals:
+      - Index:           1
+        Mutable:         false
+        Type:            I32
+        InitExpr:
+          Opcode:          I32_CONST
+          Value:           42
+  - Type:            EXPORT
+    Exports:
+      - Name:            my_func_export
+        Kind:            FUNCTION
+        Index:           1
+      - Name:            my_global_export
+        Kind:            GLOBAL
+        Index:           1
+      - Name:            my_table_export
+        Kind:            TABLE
+        Index:           0
+  - Type:            CODE
+    Functions:
+      - Index:           1
+        Locals:
+        Body:            00
+  - Type:            DATA
+    Segments:
+      - SectionOffset:   0
+        InitFlags:       0
+        Offset:
+          Opcode:          I32_CONST
+          Value:           0
+        Content:         ''