[binutils-gdb] binutils: factorize handling of arch-specific DWARF augmentations

[Jose E. Marchesi]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=11d33617e04dc6c54274ce69640218efd26519f5

commit 11d33617e04dc6c54274ce69640218efd26519f5
Author: Jose E. Marchesi <jose.marchesi@oracle.com>
Date:   Sat Jul 12 10:56:45 2025 +0200

    binutils: factorize handling of arch-specific DWARF augmentations
    
    This patch factorizes the handling of architecture/machine specific
    augmentation characters in CIEs.
    
    Based on an idea proposed by Richard Earnshaw.
    
    binutils/ChangeLog:
    
            * dwarf.c (is_mach_augmentation_ftype): New type.
            (is_mach_augmentation): New variable.
            (is_nomach_augmentation): New function.
            (is_aarch64_augmentation): Likewise.
            (init_dwarf_by_elf_machine_code): Set is_mach_augmentation as
            appropriate.
            (init_dwarf_by_bfd_arch_and_mach): Likewise.
            (read_cie): Handle architecture-specific augmentation characters
            in a generic way.

Diff:
---
 binutils/dwarf.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/binutils/dwarf.c b/binutils/dwarf.c
index 89594b5f5f2..8540b28aa90 100644
--- a/binutils/dwarf.c
+++ b/binutils/dwarf.c
@@ -8582,6 +8582,8 @@ typedef struct Frame_Chunk
 }
 Frame_Chunk;
 
+typedef bool (*is_mach_augmentation_ftype) (char c);
+static is_mach_augmentation_ftype is_mach_augmentation;
 typedef const char *(*dwarf_regname_lookup_ftype) (unsigned int);
 static dwarf_regname_lookup_ftype dwarf_regnames_lookup_func;
 static const char *const *dwarf_regnames;
@@ -8894,9 +8896,22 @@ init_dwarf_regnames_loongarch (void)
   dwarf_regnames_lookup_func = regname_internal_by_table_only;
 }
 
+static bool
+is_nomach_augmentation (char c ATTRIBUTE_UNUSED)
+{
+  return false;
+}
+
+static bool
+is_aarch64_augmentation (char c)
+{
+  return (c == 'B');
+}
+
 void
 init_dwarf_by_elf_machine_code (unsigned int e_machine)
 {
+  is_mach_augmentation = is_nomach_augmentation;
   dwarf_regnames_lookup_func = NULL;
   is_aarch64 = false;
 
@@ -8918,6 +8933,7 @@ init_dwarf_by_elf_machine_code (unsigned int e_machine)
 
     case EM_AARCH64:
       init_dwarf_regnames_aarch64 ();
+      is_mach_augmentation = is_aarch64_augmentation;
       break;
 
     case EM_S390:
@@ -8944,6 +8960,7 @@ void
 init_dwarf_by_bfd_arch_and_mach (enum bfd_architecture arch,
 				 unsigned long mach)
 {
+  is_mach_augmentation = is_nomach_augmentation;
   dwarf_regnames_lookup_func = NULL;
   is_aarch64 = false;
 
@@ -8971,6 +8988,7 @@ init_dwarf_by_bfd_arch_and_mach (enum bfd_architecture arch,
 
     case bfd_arch_aarch64:
       init_dwarf_regnames_aarch64();
+      is_mach_augmentation = is_aarch64_augmentation;
       break;
 
     case bfd_arch_s390:
@@ -9216,7 +9234,7 @@ read_cie (unsigned char *start, unsigned char *end,
 	    fc->fde_encoding = *q++;
 	  else if (*p == 'S')
 	    ;
-	  else if (*p == 'B')
+	  else if (is_mach_augmentation (*p))
 	    ;
 	  else
 	    break;