[lld] r322383 - [WebAssembly] Don't allow functions to be named more than once
Sam Clegg via llvm-commits
llvm-commits at lists.llvm.org
Fri Jan 12 09:56:15 PST 2018
Author: sbc
Date: Fri Jan 12 09:56:15 2018
New Revision: 322383
URL: http://llvm.org/viewvc/llvm-project?rev=322383&view=rev
Log:
[WebAssembly] Don't allow functions to be named more than once
Even though a function can have multiple names in the
linking standards (i.e. due to aliases), there can only
be one name for a given function in the NAME section.
Differential Revision: https://reviews.llvm.org/D41975
Added:
lld/trunk/test/wasm/alias.ll
Modified:
lld/trunk/wasm/InputChunks.h
lld/trunk/wasm/Symbols.cpp
lld/trunk/wasm/Symbols.h
lld/trunk/wasm/Writer.cpp
Added: lld/trunk/test/wasm/alias.ll
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/test/wasm/alias.ll?rev=322383&view=auto
==============================================================================
--- lld/trunk/test/wasm/alias.ll (added)
+++ lld/trunk/test/wasm/alias.ll Fri Jan 12 09:56:15 2018
@@ -0,0 +1,66 @@
+; RUN: llc -mtriple=wasm32-unknown-unknown-wasm -filetype=obj -o %t.o %s
+; RUN: lld -flavor wasm %t.o -o %t.wasm
+; RUN: obj2yaml %t.wasm | FileCheck %s
+
+ at start_alias = alias i32 (), i32 ()* @_start
+
+; Function Attrs: nounwind uwtable
+define i32 @_start() local_unnamed_addr #1 {
+entry:
+ ret i32 0
+}
+
+; CHECK: --- !WASM
+; CHECK-NEXT: FileHeader:
+; CHECK-NEXT: Version: 0x00000001
+; CHECK-NEXT: Sections:
+; CHECK-NEXT: - Type: TYPE
+; CHECK-NEXT: Signatures:
+; CHECK-NEXT: - Index: 0
+; CHECK-NEXT: ReturnType: I32
+; CHECK-NEXT: ParamTypes:
+; CHECK-NEXT: - Type: FUNCTION
+; CHECK-NEXT: FunctionTypes: [ 0 ]
+; CHECK-NEXT: - Type: TABLE
+; CHECK-NEXT: Tables:
+; CHECK-NEXT: - ElemType: ANYFUNC
+; CHECK-NEXT: Limits:
+; CHECK-NEXT: Flags: [ HAS_MAX ]
+; CHECK-NEXT: Initial: 0x00000001
+; CHECK-NEXT: Maximum: 0x00000001
+; CHECK-NEXT: - Type: MEMORY
+; CHECK-NEXT: Memories:
+; CHECK-NEXT: - Initial: 0x00000002
+; CHECK-NEXT: - Type: GLOBAL
+; CHECK-NEXT: Globals:
+; CHECK-NEXT: - Index: 0
+; CHECK-NEXT: Type: I32
+; CHECK-NEXT: Mutable: true
+; CHECK-NEXT: InitExpr:
+; CHECK-NEXT: Opcode: I32_CONST
+; CHECK-NEXT: Value: 66560
+; CHECK-NEXT: - Type: EXPORT
+; CHECK-NEXT: Exports:
+; CHECK-NEXT: - Name: memory
+; CHECK-NEXT: Kind: MEMORY
+; CHECK-NEXT: Index: 0
+; CHECK-NEXT: - Name: _start
+; CHECK-NEXT: Kind: FUNCTION
+; CHECK-NEXT: Index: 0
+; CHECK-NEXT: - Name: start_alias
+; CHECK-NEXT: Kind: FUNCTION
+; CHECK-NEXT: Index: 0
+; CHECK-NEXT: - Type: CODE
+; CHECK-NEXT: Functions:
+; CHECK-NEXT: - Index: 0
+; CHECK-NEXT: Locals:
+; CHECK-NEXT: Body: 41000B
+; CHECK-NEXT: - Type: CUSTOM
+; CHECK-NEXT: Name: linking
+; CHECK-NEXT: DataSize: 0
+; CHECK-NEXT: - Type: CUSTOM
+; CHECK-NEXT: Name: name
+; CHECK-NEXT: FunctionNames:
+; CHECK-NEXT: - Index: 0
+; CHECK-NEXT: Name: start_alias
+; CHECK-NEXT: ...
Modified: lld/trunk/wasm/InputChunks.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/wasm/InputChunks.h?rev=322383&r1=322382&r2=322383&view=diff
==============================================================================
--- lld/trunk/wasm/InputChunks.h (original)
+++ lld/trunk/wasm/InputChunks.h Fri Jan 12 09:56:15 2018
@@ -110,7 +110,7 @@ class InputFunction : public InputChunk
public:
InputFunction(const WasmSignature &S, const WasmFunction &Func,
const ObjFile &F)
- : InputChunk(F), Signature(S), Function(Func) {}
+ : InputChunk(F), Signature(S), WrittenToNameSec(false), Function(Func) {}
uint32_t getSize() const override { return Function.Size; }
const uint8_t *getData() const override {
@@ -126,6 +126,8 @@ public:
const WasmSignature &Signature;
+ unsigned WrittenToNameSec : 1;
+
protected:
uint32_t getInputSectionOffset() const override {
return Function.CodeSectionOffset;
Modified: lld/trunk/wasm/Symbols.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/wasm/Symbols.cpp?rev=322383&r1=322382&r2=322383&view=diff
==============================================================================
--- lld/trunk/wasm/Symbols.cpp (original)
+++ lld/trunk/wasm/Symbols.cpp Fri Jan 12 09:56:15 2018
@@ -74,7 +74,7 @@ void Symbol::setTableIndex(uint32_t Inde
}
void Symbol::update(Kind K, InputFile *F, uint32_t Flags_,
- const InputSegment *Seg, const InputFunction *Func,
+ const InputSegment *Seg, InputFunction *Func,
uint32_t Address) {
SymbolKind = K;
File = F;
Modified: lld/trunk/wasm/Symbols.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/wasm/Symbols.h?rev=322383&r1=322382&r2=322383&view=diff
==============================================================================
--- lld/trunk/wasm/Symbols.h (original)
+++ lld/trunk/wasm/Symbols.h Fri Jan 12 09:56:15 2018
@@ -93,11 +93,11 @@ public:
void update(Kind K, InputFile *F = nullptr, uint32_t Flags = 0,
const InputSegment *Segment = nullptr,
- const InputFunction *Function = nullptr,
- uint32_t Address = UINT32_MAX);
+ InputFunction *Function = nullptr, uint32_t Address = UINT32_MAX);
void setArchiveSymbol(const Archive::Symbol &Sym) { ArchiveSymbol = Sym; }
const Archive::Symbol &getArchiveSymbol() { return ArchiveSymbol; }
+ InputFunction *getFunction() { return Function; }
// This bit is used by Writer::writeNameSection() to prevent
// symbols from being written to the symbol table more than once.
@@ -113,7 +113,7 @@ protected:
Kind SymbolKind = InvalidKind;
InputFile *File = nullptr;
const InputSegment *Segment = nullptr;
- const InputFunction *Function = nullptr;
+ InputFunction *Function = nullptr;
llvm::Optional<uint32_t> OutputIndex;
llvm::Optional<uint32_t> TableIndex;
const WasmSignature *FunctionType = nullptr;
Modified: lld/trunk/wasm/Writer.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/wasm/Writer.cpp?rev=322383&r1=322382&r2=322383&view=diff
==============================================================================
--- lld/trunk/wasm/Writer.cpp (original)
+++ lld/trunk/wasm/Writer.cpp Fri Jan 12 09:56:15 2018
@@ -442,6 +442,15 @@ void Writer::createNameSection() {
for (Symbol *S : File->getSymbols()) {
if (!S->isFunction() || S->isWeak() || S->WrittenToNameSec)
continue;
+ // We also need to guard against two different symbols (two different
+ // names) for the same wasm function. While this is possible (aliases)
+ // it is not legal in the "name" section.
+ InputFunction *Function = S->getFunction();
+ if (Function) {
+ if (Function->WrittenToNameSec)
+ continue;
+ Function->WrittenToNameSec = true;
+ }
S->WrittenToNameSec = true;
Names.emplace_back(S);
}
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