[gcc r13-1885] LoongArch: Define the macro ASM_PREFERRED_EH_DATA_FORMAT by checking the assembler's support for eh_

[LuluCheng <chenglulu@gcc.gnu.org>]

https://gcc.gnu.org/g:201e8d9f82444403682cd583ce0a03e3e3dd2b73

commit r13-1885-g201e8d9f82444403682cd583ce0a03e3e3dd2b73
Author: Lulu Cheng <chenglulu@loongson.cn>
Date:   Fri Jul 29 09:44:52 2022 +0800

    LoongArch: Define the macro ASM_PREFERRED_EH_DATA_FORMAT by checking the assembler's support for eh_frame encoding.
    
    .eh_frame DW_EH_PE_pcrel encoding format is not supported by gas <= 2.39.
    Check if the assembler support DW_EH_PE_PCREL encoding and define .eh_frame
    encoding type.
    
    gcc/ChangeLog:
    
            * config.in: Regenerate.
            * config/loongarch/loongarch.h (ASM_PREFERRED_EH_DATA_FORMAT):
            Select the value of the macro definition according to whether
            HAVE_AS_EH_FRAME_PCREL_ENCODING_SUPPORT is defined.
            * configure: Regenerate.
            * configure.ac: Reinstate HAVE_AS_EH_FRAME_PCREL_ENCODING_SUPPORT test.

Diff:
---
 gcc/config.in                    |  8 +++++++-
 gcc/config/loongarch/loongarch.h |  5 +++++
 gcc/configure                    | 34 ++++++++++++++++++++++++++++++++++
 gcc/configure.ac                 |  8 ++++++++
 4 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/gcc/config.in b/gcc/config.in
index 16bb963b45b..413b2bd36cb 100644
--- a/gcc/config.in
+++ b/gcc/config.in
@@ -404,13 +404,19 @@
 #endif
 
 
+/* Define if your assembler supports eh_frame pcrel encoding. */
+#ifndef USED_FOR_TARGET
+#undef HAVE_AS_EH_FRAME_PCREL_ENCODING_SUPPORT
+#endif
+
+
 /* Define if your assembler supports the R_PPC64_ENTRY relocation. */
 #ifndef USED_FOR_TARGET
 #undef HAVE_AS_ENTRY_MARKERS
 #endif
 
 
-/* Define if your assembler supports explicit relocations. */
+/* Define if your assembler supports explicit relocation. */
 #ifndef USED_FOR_TARGET
 #undef HAVE_AS_EXPLICIT_RELOCS
 #endif
diff --git a/gcc/config/loongarch/loongarch.h b/gcc/config/loongarch/loongarch.h
index 89a5bd728fe..8b1288961e4 100644
--- a/gcc/config/loongarch/loongarch.h
+++ b/gcc/config/loongarch/loongarch.h
@@ -1127,8 +1127,13 @@ struct GTY (()) machine_function
 };
 #endif
 
+#ifdef HAVE_AS_EH_FRAME_PCREL_ENCODING_SUPPORT
+#define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL) \
+  (((GLOBAL) ? DW_EH_PE_indirect : 0) | DW_EH_PE_pcrel | DW_EH_PE_sdata4)
+#else
 #define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL) \
   (((GLOBAL) ? DW_EH_PE_indirect : 0) | DW_EH_PE_absptr)
+#endif
 
 /* Do emit .note.GNU-stack by default.  */
 #ifndef NEED_INDICATE_EXEC_STACK
diff --git a/gcc/configure b/gcc/configure
index 7eb9479ae8e..05efa5b01ef 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -28836,6 +28836,40 @@ if test $gcc_cv_as_loongarch_explicit_relocs = yes; then
 
 $as_echo "#define HAVE_AS_EXPLICIT_RELOCS 1" >>confdefs.h
 
+fi
+
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking assembler for eh_frame pcrel encoding support" >&5
+$as_echo_n "checking assembler for eh_frame pcrel encoding support... " >&6; }
+if ${gcc_cv_as_loongarch_eh_frame_pcrel_encoding_support+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  gcc_cv_as_loongarch_eh_frame_pcrel_encoding_support=no
+  if test x$gcc_cv_as != x; then
+    $as_echo '.cfi_startproc
+       .cfi_personality 0x9b,a
+       .cfi_lsda 0x1b,b
+       .cfi_endproc' > conftest.s
+    if { ac_try='$gcc_cv_as $gcc_cv_as_flags  -o conftest.o conftest.s >&5'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; }
+    then
+	gcc_cv_as_loongarch_eh_frame_pcrel_encoding_support=yes
+    else
+      echo "configure: failed program was" >&5
+      cat conftest.s >&5
+    fi
+    rm -f conftest.o conftest.s
+  fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $gcc_cv_as_loongarch_eh_frame_pcrel_encoding_support" >&5
+$as_echo "$gcc_cv_as_loongarch_eh_frame_pcrel_encoding_support" >&6; }
+if test $gcc_cv_as_loongarch_eh_frame_pcrel_encoding_support = yes; then
+
+$as_echo "#define HAVE_AS_EH_FRAME_PCREL_ENCODING_SUPPORT 1" >>confdefs.h
+
 fi
 
     ;;
diff --git a/gcc/configure.ac b/gcc/configure.ac
index e5f708c6b38..f70b6c24fda 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -5302,6 +5302,14 @@ x:
       [a:pcalau12i $t0,%pc_hi20(a)],,
       [AC_DEFINE(HAVE_AS_EXPLICIT_RELOCS, 1,
 	  [Define if your assembler supports explicit relocation.])])
+    gcc_GAS_CHECK_FEATURE([eh_frame pcrel encoding support],
+      gcc_cv_as_loongarch_eh_frame_pcrel_encoding_support,,
+      [.cfi_startproc
+       .cfi_personality 0x9b,a
+       .cfi_lsda 0x1b,b
+       .cfi_endproc],,
+      [AC_DEFINE(HAVE_AS_EH_FRAME_PCREL_ENCODING_SUPPORT, 1,
+	  [Define if your assembler supports eh_frame pcrel encoding.])])
     ;;
     s390*-*-*)
     gcc_GAS_CHECK_FEATURE([.gnu_attribute support],