[PATCH v2] RISC-V: PR32014, .option directives shuoldn't affect elf attribute.

Nelson Chu nelson@rivosinc.com
Fri Aug 9 03:14:31 GMT 2024


Committed, thanks.

Nelson

On Fri, Aug 2, 2024 at 11:01 AM Nelson Chu <nelson@rivosinc.com> wrote:

> The .option arch/rvc/norvc/push/pop directives can only take effect for a
> small/large specific code region, so they are not file-level architecture
> setting.  They should only affect the mapping symbols only rather than the
> file-level elf architecture attribute.  Otherwise, the elf architecture
> attribute will appear to missing some extensions when -flto merges files
> with different .option architecture settings.
>
> gas/
>         PR 32014
>         * config/tc-riscv.c (file_arch_str): New const char *, rather than
> the
>         arch_str in the riscv_rps_as.subset_list, it's file-level so only
> be
>         affected by .attribute arch directive.
>         (riscv_reset_subsets_list_arch_str): Renamed to
> riscv_set_arch_str, and
>         also can handle both file_arch_str and arch_str in subset_list,
> just
>         give the pointer address as the input.
>         (riscv_set_arch): Called by -march and .attribute arch, so set both
>         file_arch_str and arch_str in subset_list.
>         (s_riscv_option): Updated .option arch/rvc/norvc/push/pop that only
>         set the arch_str in subset_list.
>         (riscv_write_out_attrs): Output elf architecture attribute
> according to
>         file_arch_str.  Freed file_arch_str.
>         * doc/c-riscv.texi: Added destrbution that .option directives
> shouldn't
>         affect the elf attribute settings.
>         * testsuite/gas/riscv/option-arch.s: From option-arch-01/02/03
> merged.
>         * testsuite/gas/riscv/option-arch-dis.d: Likewise, for
> dis-assembler.
>         * testsuite/gas/riscv/option-arch-attr.d: Likewise, to check
> readelf -A.
> ---
>  gas/config/tc-riscv.c                         | 28 +++++++++++--------
>  gas/doc/c-riscv.texi                          |  7 ++++-
>  gas/testsuite/gas/riscv/option-arch-01.s      | 10 -------
>  gas/testsuite/gas/riscv/option-arch-01a.d     | 14 ----------
>  gas/testsuite/gas/riscv/option-arch-02.d      |  8 ------
>  gas/testsuite/gas/riscv/option-arch-02.s      |  8 ------
>  gas/testsuite/gas/riscv/option-arch-03.d      |  8 ------
>  gas/testsuite/gas/riscv/option-arch-03.s      |  3 --
>  .../{option-arch-01b.d => option-arch-attr.d} |  3 +-
>  gas/testsuite/gas/riscv/option-arch-dis.d     | 26 +++++++++++++++++
>  gas/testsuite/gas/riscv/option-arch.s         | 11 ++++++++
>  11 files changed, 60 insertions(+), 66 deletions(-)
>  delete mode 100644 gas/testsuite/gas/riscv/option-arch-01.s
>  delete mode 100644 gas/testsuite/gas/riscv/option-arch-01a.d
>  delete mode 100644 gas/testsuite/gas/riscv/option-arch-02.d
>  delete mode 100644 gas/testsuite/gas/riscv/option-arch-02.s
>  delete mode 100644 gas/testsuite/gas/riscv/option-arch-03.d
>  delete mode 100644 gas/testsuite/gas/riscv/option-arch-03.s
>  rename gas/testsuite/gas/riscv/{option-arch-01b.d => option-arch-attr.d}
> (77%)
>  create mode 100644 gas/testsuite/gas/riscv/option-arch-dis.d
>  create mode 100644 gas/testsuite/gas/riscv/option-arch.s
>
> diff --git a/gas/config/tc-riscv.c b/gas/config/tc-riscv.c
> index c09bd429bab..142a9e4754d 100644
> --- a/gas/config/tc-riscv.c
> +++ b/gas/config/tc-riscv.c
> @@ -162,6 +162,7 @@ struct riscv_ip_error
>
>  static const char default_arch[] = DEFAULT_ARCH;
>  static const char *default_arch_with_ext = DEFAULT_RISCV_ARCH_WITH_EXT;
> +static const char *file_arch_str = NULL;
>  static enum riscv_spec_class default_isa_spec = ISA_SPEC_CLASS_NONE;
>  static enum riscv_spec_class default_priv_spec = PRIV_SPEC_CLASS_NONE;
>
> @@ -305,15 +306,17 @@ static riscv_parse_subset_t riscv_rps_as =
>    true,                        /* check_unknown_prefixed_ext.  */
>  };
>
> -/* Update the architecture string in the subset_list.  */
> +/* Update file/function-level architecture string according to the
> +   subset_list.  */
>
>  static void
> -riscv_reset_subsets_list_arch_str (void)
> +riscv_set_arch_str (const char **arch_str_p)
>  {
>    riscv_subset_list_t *subsets = riscv_rps_as.subset_list;
> -  if (subsets->arch_str != NULL)
> -    free ((void *) subsets->arch_str);
> -  subsets->arch_str = riscv_arch_str (xlen, subsets);
> +  const char *arch_str = *arch_str_p;
> +  if (arch_str != NULL)
> +    free ((void *) arch_str);
> +  *arch_str_p = riscv_arch_str (xlen, subsets);
>  }
>
>  /* This structure is used to hold a stack of .option values.  */
> @@ -347,7 +350,8 @@ riscv_set_arch (const char *s)
>      }
>    riscv_release_subset_list (riscv_rps_as.subset_list);
>    riscv_parse_subset (&riscv_rps_as, s);
> -  riscv_reset_subsets_list_arch_str ();
> +  riscv_set_arch_str (&file_arch_str);
> +  riscv_set_arch_str (&riscv_rps_as.subset_list->arch_str);
>
>    riscv_set_rvc (false);
>    if (riscv_subset_supports (&riscv_rps_as, "c")
> @@ -4811,13 +4815,13 @@ s_riscv_option (int x ATTRIBUTE_UNUSED)
>    if (strcmp (name, "rvc") == 0)
>      {
>        riscv_update_subset (&riscv_rps_as, "+c");
> -      riscv_reset_subsets_list_arch_str ();
> +      riscv_set_arch_str (&riscv_rps_as.subset_list->arch_str);
>        riscv_set_rvc (true);
>      }
>    else if (strcmp (name, "norvc") == 0)
>      {
>        riscv_update_subset (&riscv_rps_as, "-c");
> -      riscv_reset_subsets_list_arch_str ();
> +      riscv_set_arch_str (&riscv_rps_as.subset_list->arch_str);
>        riscv_set_rvc (false);
>      }
>    else if (strcmp (name, "pic") == 0)
> @@ -4838,7 +4842,7 @@ s_riscv_option (int x ATTRIBUTE_UNUSED)
>        if (ISSPACE (*name) && *name != '\0')
>         name++;
>        riscv_update_subset (&riscv_rps_as, name);
> -      riscv_reset_subsets_list_arch_str ();
> +      riscv_set_arch_str (&riscv_rps_as.subset_list->arch_str);
>
>        riscv_set_rvc (false);
>        if (riscv_subset_supports (&riscv_rps_as, "c")
> @@ -5363,7 +5367,7 @@ s_riscv_insn (int x ATTRIBUTE_UNUSED)
>  static void
>  riscv_write_out_attrs (void)
>  {
> -  const char *arch_str, *priv_str, *p;
> +  const char *priv_str, *p;
>    /* versions[0]: major version.
>       versions[1]: minor version.
>       versions[2]: revision version.  */
> @@ -5371,10 +5375,10 @@ riscv_write_out_attrs (void)
>    unsigned int i;
>
>    /* Re-write architecture elf attribute.  */
> -  arch_str = riscv_rps_as.subset_list->arch_str;
> -  if (!bfd_elf_add_proc_attr_string (stdoutput, Tag_RISCV_arch, arch_str))
> +  if (!bfd_elf_add_proc_attr_string (stdoutput, Tag_RISCV_arch,
> file_arch_str))
>      as_fatal (_("error adding attribute: %s"),
>               bfd_errmsg (bfd_get_error ()));
> +  free ((void *) file_arch_str);
>
>    /* For the file without any instruction, we don't set the
> default_priv_spec
>       according to the privileged elf attributes since the md_assemble
> isn't
> diff --git a/gas/doc/c-riscv.texi b/gas/doc/c-riscv.texi
> index d3966692625..84bd5e339b1 100644
> --- a/gas/doc/c-riscv.texi
> +++ b/gas/doc/c-riscv.texi
> @@ -178,7 +178,12 @@ instead of just
>  It's not expected that options are changed in this manner during regular
> use,
>  but there are a handful of esoteric cases like the one above where users
> need
>  to disable particular features of the assembler for particular code
> sequences.
> -The complete list of option arguments is shown below:
> +However, it's also useful to enable/disable the extensions for some
> specific
> +code regions by @samp{.option arch, +-}.  This is very common in the ifunc
> +libraries.  We can support functions which are implemented by different
> +extensions in the same library, but these should not affect any file-level
> +settings, like the elf architecture attribute.  The complete list of
> option
> +arguments is shown below:
>
>  @table @code
>  @item push
> diff --git a/gas/testsuite/gas/riscv/option-arch-01.s
> b/gas/testsuite/gas/riscv/option-arch-01.s
> deleted file mode 100644
> index 50285fc8c73..00000000000
> --- a/gas/testsuite/gas/riscv/option-arch-01.s
> +++ /dev/null
> @@ -1,10 +0,0 @@
> -.attribute arch, "rv64ic"
> -add    a0, a0, a1
> -.option push
> -.option arch, +d2p0, -c, +xvendor1p0
> -add    a0, a0, a1
> -frcsr  a0      # Should add mapping symbol with ISA here, and then dump
> it to frcsr.
> -.option push
> -.option arch, +m3p0, +d3p0
> -.option pop
> -.option pop
> diff --git a/gas/testsuite/gas/riscv/option-arch-01a.d
> b/gas/testsuite/gas/riscv/option-arch-01a.d
> deleted file mode 100644
> index 1d14c604dec..00000000000
> --- a/gas/testsuite/gas/riscv/option-arch-01a.d
> +++ /dev/null
> @@ -1,14 +0,0 @@
> -#as: -misa-spec=2.2
> -#source: option-arch-01.s
> -#objdump: -d
> -
> -.*:[   ]+file format .*
> -
> -
> -Disassembly of section .text:
> -
> -0+000 <.text>:
> -[      ]+[0-9a-f]+:[   ]+952e[         ]+add[          ]+a0,a0,a1
> -[      ]+[0-9a-f]+:[   ]+00b50533[     ]+add[          ]+a0,a0,a1
> -[      ]+[0-9a-f]+:[   ]+00302573[     ]+frcsr[                ]+a0
> -#...
> diff --git a/gas/testsuite/gas/riscv/option-arch-02.d
> b/gas/testsuite/gas/riscv/option-arch-02.d
> deleted file mode 100644
> index 3c27419f9d3..00000000000
> --- a/gas/testsuite/gas/riscv/option-arch-02.d
> +++ /dev/null
> @@ -1,8 +0,0 @@
> -#as: -misa-spec=2.2
> -#readelf: -A
> -#source: option-arch-02.s
> -
> -Attribute Section: riscv
> -File Attributes
> -  Tag_RISCV_arch: "rv64i2p0_m3p0_f2p0_d3p0_c2p0_zmmul1p0_xvendor32x3p0"
> -#...
> diff --git a/gas/testsuite/gas/riscv/option-arch-02.s
> b/gas/testsuite/gas/riscv/option-arch-02.s
> deleted file mode 100644
> index e0f5de321d6..00000000000
> --- a/gas/testsuite/gas/riscv/option-arch-02.s
> +++ /dev/null
> @@ -1,8 +0,0 @@
> -.attribute arch, "rv64ic"
> -add    a0, a0, a1
> -.option push
> -.option arch, +d2p0, -c, +xvendor1p0
> -add    a0, a0, a1
> -frcsr  a0
> -.option pop
> -.option arch, +m3p0, +d3p0, +xvendor32x3p0
> diff --git a/gas/testsuite/gas/riscv/option-arch-03.d
> b/gas/testsuite/gas/riscv/option-arch-03.d
> deleted file mode 100644
> index 62d7f7d5ed2..00000000000
> --- a/gas/testsuite/gas/riscv/option-arch-03.d
> +++ /dev/null
> @@ -1,8 +0,0 @@
> -#as:
> -#readelf: -A
> -#source: option-arch-03.s
> -
> -Attribute Section: riscv
> -File Attributes
> -  Tag_RISCV_arch: "rv32i2p1_c2p0"
> -#...
> diff --git a/gas/testsuite/gas/riscv/option-arch-03.s
> b/gas/testsuite/gas/riscv/option-arch-03.s
> deleted file mode 100644
> index ccdb1c354b0..00000000000
> --- a/gas/testsuite/gas/riscv/option-arch-03.s
> +++ /dev/null
> @@ -1,3 +0,0 @@
> -.attribute arch, "rv64ic"
> -.option arch, +d2p0, -c
> -.option arch, rv32i2p1c2p0
> diff --git a/gas/testsuite/gas/riscv/option-arch-01b.d
> b/gas/testsuite/gas/riscv/option-arch-attr.d
> similarity index 77%
> rename from gas/testsuite/gas/riscv/option-arch-01b.d
> rename to gas/testsuite/gas/riscv/option-arch-attr.d
> index 8f4284d5f15..8c1f6658796 100644
> --- a/gas/testsuite/gas/riscv/option-arch-01b.d
> +++ b/gas/testsuite/gas/riscv/option-arch-attr.d
> @@ -1,8 +1,7 @@
>  #as: -misa-spec=2.2
> +#source: option-arch.s
>  #readelf: -A
> -#source: option-arch-01.s
>
>  Attribute Section: riscv
>  File Attributes
>    Tag_RISCV_arch: "rv64i2p0_c2p0"
> -#...
> diff --git a/gas/testsuite/gas/riscv/option-arch-dis.d
> b/gas/testsuite/gas/riscv/option-arch-dis.d
> new file mode 100644
> index 00000000000..6768fe72806
> --- /dev/null
> +++ b/gas/testsuite/gas/riscv/option-arch-dis.d
> @@ -0,0 +1,26 @@
> +#as: -misa-spec=2.2
> +#source: option-arch.s
> +#objdump: -d --syms --special-syms
> +
> +.*:[   ]+file format .*
> +
> +SYMBOL TABLE:
> +0+00 l    d  .text     0+00 .text
> +0+00 l    d  .data     0+00 .data
> +0+00 l    d  .bss      0+00 .bss
> +0+00 l       .text     0+00 \$xrv64i2p0_c2p0
> +0+02 l       .text     0+00 \$xrv64i2p0_f2p0_d2p0_xvendor1p0
> +0+0a l       .text     0+00
> \$xrv64i2p0_m3p0_f2p0_d3p0_c2p0_zmmul1p0_xvendor32x3p0
> +0+0c l       .text     0+00 \$xrv32i2p1_c2p0
> +0+00 l    d  .riscv.attributes 0+00 .riscv.attributes
> +
> +
> +Disassembly of section .text:
> +
> +0+000 <.text>:
> +[      ]+0:[   ]+952e[         ]+add[          ]+a0,a0,a1
> +[      ]+2:[   ]+00b50533[     ]+add[          ]+a0,a0,a1
> +[      ]+6:[   ]+00302573[     ]+frcsr[                ]+a0
> +[      ]+a:[   ]+952e[         ]+add[          ]+a0,a0,a1
> +[      ]+c:[   ]+c8002573[     ]+.insn[        ]+4, 0xc8002573
> +#...
> diff --git a/gas/testsuite/gas/riscv/option-arch.s
> b/gas/testsuite/gas/riscv/option-arch.s
> new file mode 100644
> index 00000000000..4d2d261684a
> --- /dev/null
> +++ b/gas/testsuite/gas/riscv/option-arch.s
> @@ -0,0 +1,11 @@
> +.attribute arch, "rv64ic"      # file-level, rv64ic
> +add    a0, a0, a1
> +.option push
> +.option arch, +d2p0, -c, +xvendor1p0
> +add    a0, a0, a1              # func-level, rv64i_d2p0_xvendor1p0
> +frcsr  a0
> +.option pop
> +.option arch, +m3p0, +d3p0, +xvendor32x3p0
> +add a0, a0, a1                 # func-level,
> rv64i_m3p0_d3p0_c_xvendor32x3p0
> +.option arch, rv32i2p1c2p0     # FIXME: maybe we should adjust xlen in
> dis-assembler according to mappin symbols?
> +rdcycleh a0                    # func-level, rv32i2p1_c2p0
> --
> 2.39.3 (Apple Git-146)
>
>
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