Store an optional section start label in MCSection.

This makes code that uses section relative expressions (debug info) simpler and
less brittle.

This is still a bit awkward as the symbol is created late and has to be
stored in a mutable field.

I will move the symbol creation earlier in the next patch.

llvm-svn: 231802

1 files changed, 2 insertions, 9 deletions

diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp
index 155aade65e1..9de36da51a0 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinterDwarf.cpp
@@ -163,20 +163,13 @@ void AsmPrinter::EmitTTypeReference(const GlobalValue *GV,
 ///
 /// SectionLabel is a temporary label emitted at the start of the section that
 /// Label lives in.
-void AsmPrinter::EmitSectionOffset(const MCSymbol *Label,
-                                   const MCSymbol *SectionLabel) const {
+void AsmPrinter::emitSectionOffset(const MCSymbol *Label) const {
   // On COFF targets, we have to emit the special .secrel32 directive.
   if (MAI->needsDwarfSectionOffsetDirective()) {
     OutStreamer.EmitCOFFSecRel32(Label);
     return;
   }
 
-  // If Label has already been emitted, verify that it is in the same section as
-  // section label for sanity.
-  assert((!Label->isInSection() ||
-          &Label->getSection() == &SectionLabel->getSection()) &&
-         "Section offset using wrong section base for label");
-
   // If the format uses relocations with dwarf, refer to the symbol directly.
   if (MAI->doesDwarfUseRelocationsAcrossSections()) {
     OutStreamer.EmitSymbolValue(Label, 4);
@@ -184,7 +177,7 @@ void AsmPrinter::EmitSectionOffset(const MCSymbol *Label,
   }
 
   // Otherwise, emit it as a label difference from the start of the section.
-  EmitLabelDifference(Label, SectionLabel, 4);
+  EmitLabelDifference(Label, Label->getSection().getBeginSymbol(), 4);
 }
 
 /// EmitDwarfRegOp - Emit dwarf register operation.