[PATCH] D76151: [MC][X86] Allow SHT_PROGBITS for .eh_frame on x86-64

[Fangrui Song via Phabricator via llvm-commits]

MaskRay updated this revision to Diff 258089.
MaskRay edited the summary of this revision.
MaskRay added a comment.

Mention GNU as but drop mention of x86-64 psABI change (which hasn't happened yet and may not happen)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D76151/new/

https://reviews.llvm.org/D76151

Files:
  llvm/lib/MC/MCParser/ELFAsmParser.cpp
  llvm/test/MC/ELF/section-type-changed.s


Index: llvm/test/MC/ELF/section-type-changed.s
===================================================================
--- llvm/test/MC/ELF/section-type-changed.s
+++ llvm/test/MC/ELF/section-type-changed.s
@@ -9,3 +9,11 @@
 .pushsection .foo,"a", at nobits
 
 .pushsection .foo,"a", at progbits
+
+## GNU as emits SHT_PROGBITS .eh_frame for .cfi_* directives. Don't error.
+.section .eh_frame,"a", at progbits
+.section .eh_frame,"a", at unwind
+.pushsection .eh_frame,"a", at progbits
+
+# CHECK: {{.*}}.s:[[# @LINE+1]]:1: error: changed section type for .eh_frame, expected: 0x70000001
+.section .eh_frame,"a", at nobits
Index: llvm/lib/MC/MCParser/ELFAsmParser.cpp
===================================================================
--- llvm/lib/MC/MCParser/ELFAsmParser.cpp
+++ llvm/lib/MC/MCParser/ELFAsmParser.cpp
@@ -637,7 +637,11 @@
   MCSectionELF *Section = getContext().getELFSection(
       SectionName, Type, Flags, Size, GroupName, UniqueID, LinkedToSym);
   getStreamer().SwitchSection(Section, Subsection);
-  if (Section->getType() != Type)
+  // x86-64 psABI names SHT_X86_64_UNWIND as the canonical type for .eh_frame,
+  // but GNU as emits SHT_PROGBITS .eh_frame for .cfi_* directives. Don't error
+  // for SHT_PROGBITS .eh_frame
+  if (Section->getType() != Type &&
+      !(SectionName == ".eh_frame" && Type == ELF::SHT_PROGBITS))
     Error(loc, "changed section type for " + SectionName + ", expected: 0x" +
                    utohexstr(Section->getType()));
   if (Section->getFlags() != Flags)


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