Matthieu Longo <matthieu.lo...@arm.com> writes:
> GNU properties are emitted to provide some information about the features
> used in the generated code like BTI, GCS, or PAC. However, no debug
> comment are emitted in the generated assembly even if -dA is provided.
> It makes understanding the information stored in the .note.gnu.property
> section more difficult than needed.
>
> This patch adds assembly comments (if -dA is provided) next to the GNU
> properties. For instance, if BTI and PAC are enabled, it will emit:
> .word 0x3 // GNU_PROPERTY_AARCH64_FEATURE_1_AND (BTI, PAC)
>
> gcc/ChangeLog:
>
> * config/aarch64/aarch64.cc
> (aarch64_file_end_indicate_exec_stack): Emit assembly comments.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/aarch64/bti-1.c: Emit assembly comments, and update
> test assertion.
OK, thanks.
Richard
> ---
> gcc/config/aarch64/aarch64.cc | 35 ++++++++++++++++++++++--
> gcc/testsuite/gcc.target/aarch64/bti-1.c | 13 +++++----
> 2 files changed, 40 insertions(+), 8 deletions(-)
>
> diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
> index 59ac08483f4..bc6e16ce807 100644
> --- a/gcc/config/aarch64/aarch64.cc
> +++ b/gcc/config/aarch64/aarch64.cc
> @@ -30028,10 +30028,41 @@ aarch64_file_end_indicate_exec_stack ()
> type = GNU_PROPERTY_AARCH64_FEATURE_1_AND
> datasz = 4
> data = feature_1_and. */
> - assemble_integer (GEN_INT (GNU_PROPERTY_AARCH64_FEATURE_1_AND), 4, 32,
> 1);
> + fputs (integer_asm_op (4, true), asm_out_file);
> + fprint_whex (asm_out_file, GNU_PROPERTY_AARCH64_FEATURE_1_AND);
> + putc ('\n', asm_out_file);
> assemble_integer (GEN_INT (4), 4, 32, 1);
> - assemble_integer (GEN_INT (feature_1_and), 4, 32, 1);
>
> + fputs (integer_asm_op (4, true), asm_out_file);
> + fprint_whex (asm_out_file, feature_1_and);
> + if (flag_debug_asm)
> + {
> + struct flag_name
> + {
> + unsigned int mask;
> + const char *name;
> + };
> + static const flag_name flags[] = {
> + { GNU_PROPERTY_AARCH64_FEATURE_1_BTI, "BTI" },
> + { GNU_PROPERTY_AARCH64_FEATURE_1_PAC, "PAC" },
> + { GNU_PROPERTY_AARCH64_FEATURE_1_GCS, "GCS" },
> + };
> +
> + const char *separator = "";
> + std::string s_features;
> + for (auto &flag : flags)
> + if (feature_1_and & flag.mask)
> + {
> + s_features.append (separator).append (flag.name);
> + separator = ", ";
> + }
> +
> + asm_fprintf (asm_out_file,
> + "\t%s GNU_PROPERTY_AARCH64_FEATURE_1_AND (%s)\n",
> + ASM_COMMENT_START, s_features.c_str ());
> + }
> + else
> + putc ('\n', asm_out_file);
> /* Pad the size of the note to the required alignment. */
> assemble_align (POINTER_SIZE);
> }
> diff --git a/gcc/testsuite/gcc.target/aarch64/bti-1.c
> b/gcc/testsuite/gcc.target/aarch64/bti-1.c
> index 5a556b08ed1..53dc2d3cd8b 100644
> --- a/gcc/testsuite/gcc.target/aarch64/bti-1.c
> +++ b/gcc/testsuite/gcc.target/aarch64/bti-1.c
> @@ -1,6 +1,6 @@
> /* { dg-do compile } */
> /* -Os to create jump table. */
> -/* { dg-options "-Os" } */
> +/* { dg-options "-Os -dA" } */
> /* { dg-require-effective-target lp64 } */
> /* If configured with --enable-standard-branch-protection, don't use
> command line option. */
> @@ -44,8 +44,8 @@ f_jump_table (int y, int n)
> return (y == 0)? y+1:4;
> }
> /* f_jump_table should have PACIASP and AUTIASP. */
> -/* { dg-final { scan-assembler-times "hint\t25" 1 } } */
> -/* { dg-final { scan-assembler-times "hint\t29" 1 } } */
> +/* { dg-final { scan-assembler-times "hint\t25 // paciasp" 1 } } */
> +/* { dg-final { scan-assembler-times "hint\t29 // autiasp" 1 } } */
>
> int
> f_label_address ()
> @@ -59,6 +59,7 @@ lab2:
> addr = &&lab1;
> return 2;
> }
> -/* { dg-final { scan-assembler-times "hint\t34" 1 } } */
> -/* { dg-final { scan-assembler-times "hint\t36" 12 } } */
> -/* { dg-final { scan-assembler ".note.gnu.property" { target *-*-linux* } }
> } */
> +/* { dg-final { scan-assembler-times "hint\t34 // bti c" 1 } } */
> +/* { dg-final { scan-assembler-times "hint\t36 // bti j" 12 } } */
> +/* { dg-final { scan-assembler "\.section\t\.note\.gnu\.property" { target
> *-*-linux* } } } */
> +/* { dg-final { scan-assembler "\.word\t0x7\t\/\/
> GNU_PROPERTY_AARCH64_FEATURE_1_AND \\(BTI, PAC, GCS\\)" { target *-*-linux* }
> } } */
> \ No newline at end of file
