[binutils-gdb] [SFrame-V3] include: libsframe: remove SFRAME_F_FRAME_POINTER flag

[Indu Bhagat]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=2a99ed634043c71882f9c07ebd3dc0bb81aded28

commit 2a99ed634043c71882f9c07ebd3dc0bb81aded28
Author: Indu Bhagat <indu.bhagat@oracle.com>
Date:   Thu Jan 15 16:43:49 2026 -0800

    [SFrame-V3] include: libsframe: remove SFRAME_F_FRAME_POINTER flag
    
    SFrame V3 has 8 precious flag bits, two of which are being used.  More
    flag byte (s) can be added to the auxiliary header when it comes to
    that.  But for now, it may be worthwhile to use the 8-bits frugally.
    
    SFRAME_F_FRAME_POINTER flag bit was added with the intention of marking
    binaries built with frame-pointer preserved.  A stack tracer could then
    use this information, to unambiguously ascertain whether frame-pointer
    based stack traces will be precise.  But such a marking of binary will
    ideally be done by the linker, and at the moment adding such a framework
    is not justified for such small gain.  The outcome of this is that
    SFRAME_F_FRAME_POINTER is never set in SFrame V2 binaries.
    
    Remove the definition SFRAME_F_FRAME_POINTER for SFrame V3.  The
    relinquished bit can be used (in future format incarnations) when
    reading/dumping SFrame V2 sections are no longer supported by consumers.
    Changing the values of existing flags, e.g.,
    SFRAME_F_FDE_FUNC_START_PCREL, is not being done for V3, to avoid
    version-specific flag bit reading (albeit doable) in consumers.
    
    Related changes to the specification are done in a subsequent commit.
    
    include/
            * sframe.h (SFRAME_V3_F_ALL_FLAGS): Remove
            SFRAME_F_FRAME_POINTER from the set of V3 flags.
    libsframe/
            * sframe-dump.c (dump_sframe_header_flags): Add a comment for
            clarity.

Diff:
---
 include/sframe.h        | 3 +--
 libsframe/sframe-dump.c | 9 ++++++---
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/include/sframe.h b/include/sframe.h
index f1409d36263..1c026d51472 100644
--- a/include/sframe.h
+++ b/include/sframe.h
@@ -100,8 +100,7 @@ extern "C"
 
 /* Set of all defined flags in SFrame V3.  */
 #define SFRAME_V3_F_ALL_FLAGS \
-  (SFRAME_F_FDE_SORTED | SFRAME_F_FRAME_POINTER \
-   | SFRAME_F_FDE_FUNC_START_PCREL)
+  (SFRAME_F_FDE_SORTED | SFRAME_F_FDE_FUNC_START_PCREL)
 
 #define SFRAME_CFA_FIXED_FP_INVALID 0
 #define SFRAME_CFA_FIXED_RA_INVALID 0
diff --git a/libsframe/sframe-dump.c b/libsframe/sframe-dump.c
index 9f7c6cfa898..742b60b6f4f 100644
--- a/libsframe/sframe-dump.c
+++ b/libsframe/sframe-dump.c
@@ -119,10 +119,11 @@ is_sframe_abi_arch_s390x (const sframe_decoder_ctx *sfd_ctx)
 static void
 dump_sframe_header_flags (const sframe_decoder_ctx *sfd_ctx)
 {
-  uint8_t flags;
   const char *prefix = "Flags: ";
 
-  flags = sframe_decoder_get_flags (sfd_ctx);
+  uint8_t ver = sframe_decoder_get_version (sfd_ctx);
+  uint8_t flags = sframe_decoder_get_flags (sfd_ctx);
+
   if (!flags)
     {
       printf ("%11sNONE\n", prefix);
@@ -137,7 +138,9 @@ dump_sframe_header_flags (const sframe_decoder_ctx *sfd_ctx)
     }
 
   PRINT_FLAG (SFRAME_F_FDE_SORTED);
-  PRINT_FLAG (SFRAME_F_FRAME_POINTER);
+  /* SFRAME_F_FRAME_POINTER has been removed from SFrame V3 and beyond.  */
+  if (ver == SFRAME_VERSION_2)
+    PRINT_FLAG (SFRAME_F_FRAME_POINTER);
   PRINT_FLAG (SFRAME_F_FDE_FUNC_START_PCREL);
 #undef PRINT_FLAG