RISC-V: Generalize -march support, add ELF attribute support.

	Kito Cheng  <kito.cheng@gmail.com>
	Monk Chiang  <sh.chiang04@gmail.com>

	gcc/
	* common/config/riscv/riscv-common.c: Include sstream.
	(riscv_subset_list::to_string): New.
	(riscv_arch_str): Likewise.
	* config.gcc (riscv*-*-*): Handle --with-riscv-attribute=
	* config.in: Regen.
	* config/riscv/riscv-protos.h (riscv_arch_str): New.
	* config/riscv/riscv.c (INCLUDE_STRING): Defined.
	(riscv_emit_attribute): New.
	(riscv_file_start): Emit attribute if needed.
	(riscv_option_override): Init riscv_emit_attribute_p.
	* config/riscv/riscv.opt (mriscv-attribute): New option.
	* configure.ac (riscv*-*-*): Check binutils is supporting ELF
	* configure: Regen.
	* doc/install.texi: Document --with-riscv-attribute.
	* doc/invoke.texi: Document -mriscv-attribute.

	* common/config/riscv/riscv-common.c:
	Include config/riscv/riscv-protos.h.
	(INCLUDE_STRING): Defined.
	(RISCV_DONT_CARE_VERSION): Defined.
	(riscv_subset_t): Declare.
	(riscv_subset_t::riscv_subset_t): New.
	(riscv_subset_list): Declare.
	(riscv_subset_list::riscv_subset_list): New.
	(riscv_subset_list::~riscv_subset_list): Likewise.
	(riscv_subset_list::parsing_subset_version): Likewise.
	(riscv_subset_list::parse_std_ext): Likewise.
	(riscv_subset_list::parse_sv_or_non_std_ext): Likewise.
	(riscv_subset_list::add): Likewise.
	(riscv_subset_list::lookup): Likewise.
	(riscv_subset_list::xlen): Likewise.
	(riscv_subset_list::parse): Likewise.
	(riscv_supported_std_ext): Likewise.
	(current_subset_list): Likewise.
	(riscv_parse_arch_string): Using riscv_subset_list::parse to
	parse.

	gcc/testsuite/
	* gcc.target/riscv/attribute-1.c: New.
	* gcc.target/riscv/attribute-2.c: Likewise.
	* gcc.target/riscv/attribute-3.c: Likewise.
	* gcc.target/riscv/attribute-4.c: Likewise.
	* gcc.target/riscv/attribute-5.c: Likewise.
	* gcc.target/riscv/attribute-6.c: Likewise.
	* gcc.target/riscv/attribute-7.c: Likewise.
	* gcc.target/riscv/attribute-8.c: Likewise.
	* gcc.target/riscv/attribute-9.c: Likewise.

	* gcc.target/riscv/arch-1.c: New.
	* gcc.target/riscv/arch-2.c: Likewise.
	* gcc.target/riscv/arch-3.c: Likewise.
	* gcc.target/riscv/arch-4.c: Likewise.

Co-Authored-By: Monk Chiang <sh.chiang04@gmail.com>

From-SVN: r269337

2 files changed, 13 insertions, 1 deletions

diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
index 1d925eb..8d7bee5 100644
--- a/gcc/doc/install.texi
+++ b/gcc/doc/install.texi
@@ -2161,6 +2161,13 @@ is used, it is enabled on Linux/x86 if target binutils
 supports @code{Intel CET} instructions and disabled otherwise.
 In this case the target libraries are configured to get additional
 @option{-fcf-protection} option.
+
+@item --with-riscv-attribute=@samp{yes}, @samp{no} or @samp{default}
+Generate RISC-V attribute by default, in order to record extra build
+information in object.
+
+The option is disabled by default. It is enabled on RISC-V/ELF (bare-metal)
+target if target binutils supported.
 @end table
 
 @subheading Cross-Compiler-Specific Options
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index a8efa1a..df0883f 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -1057,7 +1057,8 @@ See RS/6000 and PowerPC Options.
 -mstrict-align  -mno-strict-align @gol
 -mcmodel=medlow  -mcmodel=medany @gol
 -mexplicit-relocs  -mno-explicit-relocs @gol
--mrelax  -mno-relax}
+-mrelax  -mno-relax @gol
+-mriscv-attribute  -mmo-riscv-attribute}
 
 @emph{RL78 Options}
 @gccoptlist{-msim  -mmul=none  -mmul=g13  -mmul=g14  -mallregs @gol
@@ -23825,6 +23826,10 @@ Take advantage of linker relaxations to reduce the number of instructions
 required to materialize symbol addresses. The default is to take advantage of
 linker relaxations.
 
+@item -memit-attribute
+@itemx -mno-emit-attribute
+Emit (do not emit) RISC-V attribute to record extra information into ELF
+objects.  This feature requires at least binutils 2.32.
 @end table
 
 @node RL78 Options