[ELF] Support 'G' in .eh_frame

[eugenis]

LGTM

[fmayer]

test more

[MaskRay]

llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp code can be tested with llvm-objdump/llvm-dwarfdump but should have a test in test/DebugInfo.

lld doesn't use llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp code. It's inappropriate to rely on lld/test/ELF to provide the test coverage.

You should move llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp into another patch with a test/DebugInfo patch.

[fmayer]

remove DWARF parser

[fmayer]

remove dwarf test

[fmayer]

In D127148#3562065, @MaskRay wrote:

llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp code can be tested with llvm-objdump/llvm-dwarfdump but should have a test in test/DebugInfo.

lld doesn't use llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp code. It's inappropriate to rely on lld/test/ELF to provide the test coverage.

You should move llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp into another patch with a test/DebugInfo patch.

Done, moved DWARF change to D127171.

[MaskRay]

lld/test/ELF/stack-tagging-cfi.s

1

3

-s is not needed

20

Delete NoUnwind

[fmayer]

address comments

[fmayer]

rebase

[fmayer]

address comment

[fmayer]

remove comments

[fmayer]

Tests broke on windows.

[fmayer]

add requires aarch64

lld/ELF/EhFrame.cpp

for (char c : aug) {
     if (c == 'R')
       return readByte();
     if (c == 'z')
       skipLeb128();
     else if (c == 'L')
       readByte();
     else if (c == 'P')
       skipAugP();
-    else if (c != 'B' && c != 'S')
+    else if (c != 'B' && c != 'S' && c != 'G')
       failOn(aug.data(), "unknown .eh_frame augmentation string: " + aug);
   }
   return DW_EH_PE_absptr;
 }
 
 bool EhReader::hasLSDA() {
   StringRef aug = getAugmentation();
   for (char c : aug) {
     if (c == 'L')
       return true;
     if (c == 'z')
       skipLeb128();
     else if (c == 'P')
       skipAugP();
     else if (c == 'R')
       readByte();
-    else if (c != 'B' && c != 'S')
+    else if (c != 'B' && c != 'S' && c != 'G')
       failOn(aug.data(), "unknown .eh_frame augmentation string: " + aug);
   }
   return false;
 }

lld/test/ELF/stack-tagging-cfi.s

+# RUN: llvm-mc -filetype=obj -triple aarch64-generic-linux -mattr=+mte %s -o %t.o
+# RUN: ld.lld --eh-frame-hdr %t.o -o %t
+# RUN: llvm-objdump -s --dwarf=frames %t | FileCheck %s
+
+# CHECK: Augmentation:          "zRG"
+
+  .text
+  .globl  WithUnwind                      // -- Begin function WithUnwind
+  .p2align  2
+  .type WithUnwind,@function
+WithUnwind:                             // @WithUnwind
+  .cfi_startproc
+// %bb.0:                               // %entry
+  .cfi_mte_tagged_frame
+  ret
+.Lfunc_end0:
+  .size WithUnwind, .Lfunc_end0-WithUnwind
+  .cfi_endproc
+                                        // -- End function
+  .globl  NoUnwind                        // -- Begin function NoUnwind
+  .p2align  2
+  .type NoUnwind,@function