[WebAssembly] Don't allow functions to be named twice

[sbc100]

Summary

The spec doesn't allow this.

[sbc100]

• rename

lib/Object/WasmObjectFile.cpp

 //===- WasmObjectFile.cpp - Wasm object file implementation ---------------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSet.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/BinaryFormat/Wasm.h"
 #include "llvm/MC/SubtargetFeature.h"
 #include "llvm/Object/Binary.h"
 #include "llvm/Object/Error.h"
case wasm::WASM_SEC_DATA:
     return parseDataSection(Start, End);
   default:
     return make_error<GenericBinaryError>("Bad section type",
                                           object_error::parse_failed);
   }
 }
 
 Error WasmObjectFile::parseNameSection(const uint8_t *Ptr, const uint8_t *End) {
+  llvm::DenseSet<uint64_t> Seen;
+
   while (Ptr < End) {
     uint8_t Type = readVarint7(Ptr);
     uint32_t Size = readVaruint32(Ptr);
     const uint8_t *SubSectionEnd = Ptr + Size;
     switch (Type) {
     case wasm::WASM_NAMES_FUNCTION: {
       uint32_t Count = readVaruint32(Ptr);
       while (Count--) {
         uint32_t Index = readVaruint32(Ptr);
+        if (!Seen.insert(Index).second)
+          return make_error<GenericBinaryError>("Function named more than once",
+                                                object_error::parse_failed);
         StringRef Name = readString(Ptr);
         if (!Name.empty())
           Symbols.emplace_back(Name,
                                WasmSymbol::SymbolType::DEBUG_FUNCTION_NAME,
                                Sections.size(), Index);
       }
       break;
     }
while (Ptr < End) {
     uint8_t Type = readVarint7(Ptr);
     uint32_t Size = readVaruint32(Ptr);
     const uint8_t *SubSectionEnd = Ptr + Size;
     switch (Type) {
     case wasm::WASM_SYMBOL_INFO: {
       uint32_t Count = readVaruint32(Ptr);
       while (Count--) {
         StringRef Symbol = readString(Ptr);
-        DEBUG(dbgs() << "reading syminfo: " << Symbol << "\n");
         uint32_t Flags = readVaruint32(Ptr);
         auto iter = SymbolMap.find(Symbol);
         if (iter == SymbolMap.end()) {
           return make_error<GenericBinaryError>(
               "Invalid symbol name in linking section: " + Symbol,
               object_error::parse_failed);
         }
         uint32_t SymIndex = iter->second;

test/Object/wasm-duplicate-name.test

+# RUN: yaml2obj %s | not llvm-objdump -h - 2>&1 | FileCheck %s
+
+--- !WASM
+FileHeader:
+  Version:         0x00000001
+Sections:
+  - Type:            TYPE
+    Signatures:
+      - Index:           0
+        ReturnType:      I32
+        ParamTypes:
+          - I32
+  - Type:            IMPORT
+    Imports:
+      - Module:          foo
+        Field:           a
+        Kind:            FUNCTION
+        SigIndex:        0
+  - Type:            CUSTOM
+    Name:            name
+    FunctionNames:
+      - Index:         0
+        Name:          a
+      - Index:         0
+        Name:          b
+...
+
+# CHECK: {{.*}}: Function named more than once