Correctly handle references to section symbols.

When processing assembly like

.long .text

we were creating a new undefined symbol .text. GAS on the other hand would
handle that as a reference to the .text section.

This patch implements that by creating the section symbols earlier so that
they are visible during asm parsing.

The patch also updates llvm-readobj to print the symbol number in the relocation
dump so that the test can differentiate between two sections with the same name.

llvm-svn: 219829

1 files changed, 17 insertions, 0 deletions

diff --git a/llvm/lib/MC/MCContext.cpp b/llvm/lib/MC/MCContext.cpp
index 9d8a57e55f6..3ac8d658873 100644
--- a/llvm/lib/MC/MCContext.cpp
+++ b/llvm/lib/MC/MCContext.cpp
@@ -113,6 +113,23 @@ MCSymbol *MCContext::GetOrCreateSymbol(StringRef Name) {
   return Sym;
 }
 
+MCSymbol *MCContext::getOrCreateSectionSymbol(const MCSectionELF &Section) {
+  MCSymbol *&Sym = SectionSymbols[&Section];
+  if (Sym)
+    return Sym;
+
+  StringRef Name = Section.getSectionName();
+  StringMapEntry<bool> *NameEntry = &UsedNames.GetOrCreateValue(Name);
+  NameEntry->setValue(true);
+  Sym = new (*this) MCSymbol(NameEntry->getKey(), /*isTemporary*/ false);
+
+  StringMapEntry<MCSymbol*> &Entry = Symbols.GetOrCreateValue(Name);
+  if (!Entry.getValue())
+    Entry.setValue(Sym);
+
+  return Sym;
+}
+
 MCSymbol *MCContext::CreateSymbol(StringRef Name) {
   // Determine whether this is an assembler temporary or normal label, if used.
   bool isTemporary = false;