From b4202dbb36e9799c96890fc3aa0040c1aedb33c8 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Thu, 6 May 2010 00:05:37 +0000 Subject: [PATCH] Fix PR7054 - Assertion `Symbol->isUndefined() && "Cannot define a symbol twice!"' failed. Users can write broken code that emits the same label twice with asm renaming, detect this and emit a fatal backend error instead of aborting. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103140 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/AsmPrinter/AsmPrinter.cpp | 8 +++++++- test/CodeGen/X86/label-redefinition.ll | 15 +++++++++++++++ 2 files changed, 22 insertions(+), 1 deletion(-) create mode 100644 test/CodeGen/X86/label-redefinition.ll diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp index ded4b3f18bb..47c58d0f0fd 100644 --- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp +++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp @@ -408,7 +408,13 @@ void AsmPrinter::EmitFunctionHeader() { /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the /// function. This can be overridden by targets as required to do custom stuff. void AsmPrinter::EmitFunctionEntryLabel() { - OutStreamer.EmitLabel(CurrentFnSym); + // The function label could have already been emitted if two symbols end up + // conflicting due to asm renaming. Detect this and emit an error. + if (CurrentFnSym->isUndefined()) + return OutStreamer.EmitLabel(CurrentFnSym); + + report_fatal_error("'" + Twine(CurrentFnSym->getName()) + + "' label emitted multiple times to assembly file"); } diff --git a/test/CodeGen/X86/label-redefinition.ll b/test/CodeGen/X86/label-redefinition.ll new file mode 100644 index 00000000000..9ad33e02976 --- /dev/null +++ b/test/CodeGen/X86/label-redefinition.ll @@ -0,0 +1,15 @@ +; PR7054 +; RUN: not llc %s -o - |& grep {'_foo' label emitted multiple times to assembly} +target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-n8:16:32" +target triple = "i386-apple-darwin10.0.0" + +define i32 @"\01_foo"() { + unreachable +} + +define i32 @foo() { +entry: + unreachable +} + +declare i32 @xstat64(i32, i8*, i8*) -- 2.11.0