On 2/27/24 11:04, Cupertino Miranda wrote:
> BPF applications, when generating BTF information should always create a
> .BTF.ext section.
> Current implementation was only creating it when -mco-re option was used.
> This patch makes .BTF.ext always be generated for BPF target objects.
> The patch also adds conditions around btf_finalize function call
> such that BTF deallocation happens later for BPF target.
> For BPF, btf_finalize is only called after .BTF.ext is generated.
Thank you, this version makes it much more clear what the patch does.
>
> gcc/ChangeLog:
>
> * config/bpf/bpf.cc (bpf_option_override): Make .BTF.ext
> enabled by default for BPF.
> (bpf_file_end): Call BTF deallocation.
> * dwarf2ctf.cc (ctf_debug_finalize): Conditionally execute BTF
> deallocation.
You are missing ChangeLog entries for bpf_asm_init_sections and
ctf_debug_finish.
The script contrib/gcc-changelog/git_check_commit.py may help
to catch those.
The code changes LGTM, so OK with the ChangeLog fixed.
Thanks.
> ---
> gcc/config/bpf/bpf.cc | 20 +++++++++-----------
> gcc/dwarf2ctf.cc | 12 ++++++------
> 2 files changed, 15 insertions(+), 17 deletions(-)
>
> diff --git a/gcc/config/bpf/bpf.cc b/gcc/config/bpf/bpf.cc
> index d6ca47eeecbe..4318b26b9cda 100644
> --- a/gcc/config/bpf/bpf.cc
> +++ b/gcc/config/bpf/bpf.cc
> @@ -195,10 +195,8 @@ bpf_option_override (void)
> if (TARGET_BPF_CORE && !btf_debuginfo_p ())
> error ("BPF CO-RE requires BTF debugging information, use %<-gbtf%>");
>
> - /* To support the portability needs of BPF CO-RE approach, BTF debug
> - information includes the BPF CO-RE relocations. */
> - if (TARGET_BPF_CORE)
> - write_symbols |= BTF_WITH_CORE_DEBUG;
> + /* BPF applications always generate .BTF.ext. */
> + write_symbols |= BTF_WITH_CORE_DEBUG;
>
> /* Unlike much of the other BTF debug information, the information
> necessary
> for CO-RE relocations is added to the CTF container by the BPF backend.
> @@ -218,10 +216,7 @@ bpf_option_override (void)
> /* -gbtf implies -mcore when using the BPF backend, unless -mno-co-re
> is specified. */
> if (btf_debuginfo_p () && !(target_flags_explicit & MASK_BPF_CORE))
> - {
> - target_flags |= MASK_BPF_CORE;
> - write_symbols |= BTF_WITH_CORE_DEBUG;
> - }
> + target_flags |= MASK_BPF_CORE;
>
> /* Determine available features from ISA setting (-mcpu=). */
> if (bpf_has_jmpext == -1)
> @@ -267,7 +262,7 @@ bpf_option_override (void)
> static void
> bpf_asm_init_sections (void)
> {
> - if (TARGET_BPF_CORE)
> + if (btf_debuginfo_p () && btf_with_core_debuginfo_p ())
> btf_ext_init ();
> }
>
> @@ -279,8 +274,11 @@ bpf_asm_init_sections (void)
> static void
> bpf_file_end (void)
> {
> - if (TARGET_BPF_CORE)
> - btf_ext_output ();
> + if (btf_debuginfo_p () && btf_with_core_debuginfo_p ())
> + {
> + btf_ext_output ();
> + btf_finalize ();
> + }
> }
>
> #undef TARGET_ASM_FILE_END
> diff --git a/gcc/dwarf2ctf.cc b/gcc/dwarf2ctf.cc
> index 93e5619933fa..dca86edfffa9 100644
> --- a/gcc/dwarf2ctf.cc
> +++ b/gcc/dwarf2ctf.cc
> @@ -944,7 +944,10 @@ ctf_debug_finalize (const char *filename, bool btf)
> if (btf)
> {
> btf_output (filename);
> - btf_finalize ();
> + /* btf_finalize when compiling BPF applciations gets deallocated by the
> + BPF target in bpf_file_end. */
> + if (btf_debuginfo_p () && !btf_with_core_debuginfo_p ())
> + btf_finalize ();
> }
>
> else
> @@ -1027,11 +1030,8 @@ ctf_debug_finish (const char * filename)
> /* Emit BTF debug info here when CO-RE relocations need to be generated.
> BTF with CO-RE relocations needs to be generated when CO-RE is in effect
> for the BPF target. */
> - if (btf_with_core_debuginfo_p ())
> - {
> - gcc_assert (btf_debuginfo_p ());
> - ctf_debug_finalize (filename, btf_debuginfo_p ());
> - }
> + if (btf_debuginfo_p () && btf_with_core_debuginfo_p ())
> + ctf_debug_finalize (filename, btf_debuginfo_p ());
> }
>
> #include "gt-dwarf2ctf.h"
