update dwarf2 asm unwind info

[Richard Henderson]

This should solve the problem Andreas reported with missing 
.cfi_personality, in that we should emit asm unwind for C,
but not C++.  It should also solve the problem that Steve
reported for HPPA, by not using asm unwind at all.

H.J., I can't reproduce the failures you reported at all.


r~


        * configure.ac (HAVE_GAS_CFI_PERSONALITY_DIRECTIVE): New.
        * configure, config.in: Rebuild.
        * debug.h (dwarf2out_do_cfi_asm): Declare.
        * c-cppbuiltin.c (c_cpp_builtins): Use it.
        * dwarf2out.c (dwarf2out_do_cfi_asm): New.
        (dwarf2out_cfi_label, add_fde_cfi, output_call_frame_info,
        dwarf2out_begin_prologue, dwarf2out_end_epilogue): Use it.

--- c-cppbuiltin.c	(revision 138854)
+++ c-cppbuiltin.c	(local)
@@ -693,7 +693,7 @@ c_cpp_builtins (cpp_reader *pfile)
 #endif
 
 #ifdef DWARF2_UNWIND_INFO
-  if (flag_dwarf2_cfi_asm && dwarf2out_do_frame ())
+  if (dwarf2out_do_cfi_asm ())
     cpp_define (pfile, "__GCC_HAVE_DWARF2_CFI_ASM");
 #endif
 
--- config.in	(revision 138854)
+++ config.in	(local)
@@ -827,6 +827,12 @@
 #endif
 
 
+/* Define 0/1 if your assembler supports .cfi_personality. */
+#ifndef USED_FOR_TARGET
+#undef HAVE_GAS_CFI_PERSONALITY_DIRECTIVE
+#endif
+
+
 /* Define if your assembler uses the new HImode fild and fist notation. */
 #ifndef USED_FOR_TARGET
 #undef HAVE_GAS_FILDS_FISTS
--- configure	(revision 138854)
+++ configure	(local)
@@ -20851,7 +20851,6 @@ fi
 	.cfi_same_value 1
 	.cfi_def_cfa 1, 2
 	.cfi_escape 1, 2, 3, 4, 5
-	.cfi_personality 0, symbol
 	.cfi_endproc' > conftest.s
     if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'
   { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
@@ -20877,6 +20876,47 @@ cat >>confdefs.h <<_ACEOF
 _ACEOF
 
 
+echo "$as_me:$LINENO: checking assembler for cfi personality directive" >&5
+echo $ECHO_N "checking assembler for cfi personality directive... $ECHO_C" >&6
+if test "${gcc_cv_as_cfi_personality_directive+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  gcc_cv_as_cfi_personality_directive=no
+    if test $in_tree_gas = yes; then
+    if test $in_tree_gas_is_elf = yes \
+  && test $gcc_cv_gas_vers -ge `expr \( \( 2 \* 1000 \) + 17 \) \* 1000 + 0`
+  then gcc_cv_as_cfi_personality_directive=yes
+fi
+  elif test x$gcc_cv_as != x; then
+    echo '	.text
+	.cfi_startproc,
+	.cfi_personality 0, symbol
+	.cfi_endproc' > conftest.s
+    if { ac_try='$gcc_cv_as  -o conftest.o conftest.s >&5'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }
+    then
+	gcc_cv_as_cfi_personality_directive=yes
+    else
+      echo "configure: failed program was" >&5
+      cat conftest.s >&5
+    fi
+    rm -f conftest.o conftest.s
+  fi
+fi
+echo "$as_me:$LINENO: result: $gcc_cv_as_cfi_personality_directive" >&5
+echo "${ECHO_T}$gcc_cv_as_cfi_personality_directive" >&6
+
+
+cat >>confdefs.h <<_ACEOF
+#define HAVE_GAS_CFI_PERSONALITY_DIRECTIVE `if test $gcc_cv_as_cfi_personality_directive = yes;
+    then echo 1; else echo 0; fi`
+_ACEOF
+
+
 # GAS versions up to and including 2.11.0 may mis-optimize
 # .eh_frame data.
 echo "$as_me:$LINENO: checking assembler for eh_frame optimization" >&5
--- configure.ac	(revision 138854)
+++ configure.ac	(local)
@@ -2189,11 +2189,21 @@ gcc_GAS_CHECK_FEATURE([cfi directives], 
 	.cfi_same_value 1
 	.cfi_def_cfa 1, 2
 	.cfi_escape 1, 2, 3, 4, 5
-	.cfi_personality 0, symbol
 	.cfi_endproc])
 AC_DEFINE_UNQUOTED(HAVE_GAS_CFI_DIRECTIVE,
   [`if test $gcc_cv_as_cfi_directive = yes; then echo 1; else echo 0; fi`],
-[Define 0/1 if your assembler supports CFI directives.])
+  [Define 0/1 if your assembler supports CFI directives.])
+
+gcc_GAS_CHECK_FEATURE([cfi personality directive],
+  gcc_cv_as_cfi_personality_directive, [elf,2,17,0],,
+[	.text
+	.cfi_startproc,
+	.cfi_personality 0, symbol
+	.cfi_endproc])
+AC_DEFINE_UNQUOTED(HAVE_GAS_CFI_PERSONALITY_DIRECTIVE,
+  [`if test $gcc_cv_as_cfi_personality_directive = yes;
+    then echo 1; else echo 0; fi`],
+  [Define 0/1 if your assembler supports .cfi_personality.])
 
 # GAS versions up to and including 2.11.0 may mis-optimize
 # .eh_frame data.
--- debug.h	(revision 138854)
+++ debug.h	(local)
@@ -160,6 +160,7 @@ extern void dwarf2out_frame_finish (void
 /* Decide whether we want to emit frame unwind information for the current
    translation unit.  */
 extern int dwarf2out_do_frame (void);
+extern int dwarf2out_do_cfi_asm (void);
 extern void dwarf2out_switch_text_section (void);
 
 extern void debug_flush_symbol_queue (void);
--- dwarf2out.c	(revision 138854)
+++ dwarf2out.c	(local)
@@ -130,6 +130,32 @@ dwarf2out_do_frame (void)
 	  );
 }
 
+/* Decide whether to emit frame unwind via assembler directives.  */
+
+int
+dwarf2out_do_cfi_asm (void)
+{
+  int enc;
+
+  if (!flag_dwarf2_cfi_asm || !dwarf2out_do_frame ())
+    return false;
+  if (!eh_personality_libfunc)
+    return true;
+  if (!HAVE_GAS_CFI_PERSONALITY_DIRECTIVE)
+    return false;
+
+  /* Make sure the personality encoding is one the assembler can support.
+     In particular, aligned addresses can't be handled.  */
+  enc = ASM_PREFERRED_EH_DATA_FORMAT (/*code=*/2,/*global=*/1);
+  if ((enc & 0x70) != 0 && (enc & 0x70) != DW_EH_PE_pcrel)
+    return false;
+  enc = ASM_PREFERRED_EH_DATA_FORMAT (/*code=*/0,/*global=*/0);
+  if ((enc & 0x70) != 0 && (enc & 0x70) != DW_EH_PE_pcrel)
+    return false;
+
+  return true;
+}
+
 /* The size of the target's pointer type.  */
 #ifndef PTR_SIZE
 #define PTR_SIZE (POINTER_SIZE / BITS_PER_UNIT)
@@ -667,7 +693,7 @@ dwarf2out_cfi_label (void)
 {
   static char label[20];
 
-  if (flag_dwarf2_cfi_asm)
+  if (dwarf2out_do_cfi_asm ())
     {
       /* In this case, we will be emitting the asm directive instead of
 	 the label, so just return a placeholder to keep the rest of the
@@ -691,7 +717,7 @@ add_fde_cfi (const char *label, dw_cfi_r
 {
   dw_cfi_ref *list_head = &cie_cfi_head;
 
-  if (flag_dwarf2_cfi_asm)
+  if (dwarf2out_do_cfi_asm ())
     {
       if (label)
 	{
@@ -2767,7 +2793,7 @@ output_call_frame_info (int for_eh)
     return;
 
   /* Nothing to do if the assembler's doing it all.  */
-  if (flag_dwarf2_cfi_asm)
+  if (dwarf2out_do_cfi_asm ())
     return;
 
   /* If we make FDEs linkonce, we may have to emit an empty label for
@@ -3187,7 +3213,7 @@ dwarf2out_begin_prologue (unsigned int l
     dwarf2out_source_line (line, file);
 #endif
 
-  if (flag_dwarf2_cfi_asm)
+  if (dwarf2out_do_cfi_asm ())
     {
       int enc;
       rtx ref;
@@ -3242,7 +3268,7 @@ dwarf2out_end_epilogue (unsigned int lin
   dw_fde_ref fde;
   char label[MAX_ARTIFICIAL_LABEL_BYTES];
 
-  if (flag_dwarf2_cfi_asm)
+  if (dwarf2out_do_cfi_asm ())
     fprintf (asm_out_file, "\t.cfi_endproc\n");
 
   /* Output a label to mark the endpoint of the code generated for this