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
diff --git a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index ded4b3f..47c58d0 100644
--- a/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -408,7 +408,13 @@
/// 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");
}