[gcc r13-5491] riscv: Enable -fasynchronous-unwind-tables by default on Linux

[Andreas Schwab <schwab@gcc.gnu.org>]

https://gcc.gnu.org/g:3cd08f7168c196d7a481b9ed9f4289fd1f14eea8

commit r13-5491-g3cd08f7168c196d7a481b9ed9f4289fd1f14eea8
Author: Andreas Schwab <schwab@suse.de>
Date:   Wed Jan 25 12:00:09 2023 +0100

    riscv: Enable -fasynchronous-unwind-tables by default on Linux
    
    This follows the example of aarch64.
    
    gcc/:
            * common/config/riscv/riscv-common.cc
            (riscv_option_optimization_table)
            [TARGET_DEFAULT_ASYNC_UNWIND_TABLES]: Enable
            -fasynchronous-unwind-tables and -funwind-tables.
            * config.gcc (riscv*-*-linux*): Define
            TARGET_DEFAULT_ASYNC_UNWIND_TABLES.

Diff:
---
 gcc/common/config/riscv/riscv-common.cc | 4 ++++
 gcc/config.gcc                          | 1 +
 2 files changed, 5 insertions(+)

diff --git a/gcc/common/config/riscv/riscv-common.cc b/gcc/common/config/riscv/riscv-common.cc
index 2e3116e7673..616e2f897b9 100644
--- a/gcc/common/config/riscv/riscv-common.cc
+++ b/gcc/common/config/riscv/riscv-common.cc
@@ -1756,6 +1756,10 @@ static const struct default_options riscv_option_optimization_table[] =
   {
     { OPT_LEVELS_1_PLUS, OPT_fsection_anchors, NULL, 1 },
     { OPT_LEVELS_2_PLUS, OPT_free, NULL, 1 },
+#if TARGET_DEFAULT_ASYNC_UNWIND_TABLES == 1
+    { OPT_LEVELS_ALL, OPT_fasynchronous_unwind_tables, NULL, 1 },
+    { OPT_LEVELS_ALL, OPT_funwind_tables, NULL, 1},
+#endif
     { OPT_LEVELS_NONE, 0, NULL, 0 }
   };
 
diff --git a/gcc/config.gcc b/gcc/config.gcc
index 89f56047cfe..744b46fb3b0 100644
--- a/gcc/config.gcc
+++ b/gcc/config.gcc
@@ -2417,6 +2417,7 @@ riscv*-*-linux*)
 	*) echo "Unknown value for enable_multilib"; exit 1
 	esac
 	tmake_file="${tmake_file} riscv/t-riscv riscv/t-linux"
+	tm_defines="${tm_defines} TARGET_DEFAULT_ASYNC_UNWIND_TABLES=1"
 	gnu_ld=yes
 	gas=yes
 	case $target in