configure.in (HAVE_AS_DWARF2_DEBUG_LINE): New.

        * configure.in (HAVE_AS_DWARF2_DEBUG_LINE): New.  Detect
        whether as accepts .file/.loc and produces dwarf2 line info.
        * dwarf2out.c (DWARF2_ASM_LINE_DEBUG_INFO): Default on if
        the assembler supports it.
        * config.in, configure: Regenerate.

From-SVN: r37534

gcc/ChangeLog

 2000-11-17  Richard Henderson  <rth@redhat.com>
 
+	* configure.in (HAVE_AS_DWARF2_DEBUG_LINE): New.  Detect
+	whether as accepts .file/.loc and produces dwarf2 line info.
+	* dwarf2out.c (DWARF2_ASM_LINE_DEBUG_INFO): Default on if
+	the assembler supports it.
+	* config.in, configure: Regenerate.
+
+2000-11-17  Richard Henderson  <rth@redhat.com>
+
 	* fixinc/mkfixinc.sh: Don't disable fixincludes for any linux*.
 
 2000-11-17  Jim Wilson  <wilson@redhat.com>

gcc/config.in

@@ -443,6 +443,9 @@
 /* Define if your assembler supports offsetable %lo(). */
 #undef HAVE_AS_OFFSETABLE_LO10
 
+/* Define if your assembler supports dwarf2 .file/.loc directives. */
+#undef HAVE_AS_DWARF2_DEBUG_LINE
+
 /* Define if you want to always select the new-abi for g++. */
 #undef ENABLE_NEW_GXX_ABI
 

gcc/configure

@@ -5851,7 +5851,7 @@ echo "$ac_t""$gcc_cv_nm" 1>&6
 # Figure out what assembler alignment features are present.
 echo $ac_n "checking assembler alignment features""... $ac_c" 1>&6
 echo "configure:5854: checking assembler alignment features" >&5
-gcc_cv_as_alignment_features=
+gcc_cv_as_alignment_features=none
 if test x$gcc_cv_gas_major_version != x -a x$gcc_cv_gas_minor_version != x; then
 	# Gas version 2.6 and later support for .balign and .p2align.
 	# bytes to skip when using .p2align.
@@ -5899,7 +5899,7 @@ echo "$ac_t""$gcc_cv_as_alignment_features" 1>&6
 
 echo $ac_n "checking assembler subsection support""... $ac_c" 1>&6
 echo "configure:5902: checking assembler subsection support" >&5
-gcc_cv_as_subsections=
+gcc_cv_as_subsections=no
 if test x$gcc_cv_gas_major_version != x -a x$gcc_cv_gas_minor_version != x; then
   if test "$gcc_cv_gas_major_version" -eq 2 -a "$gcc_cv_gas_minor_version" -ge 9 -o "$gcc_cv_gas_major_version" -gt 2 && grep 'obj_format = elf' ../gas/Makefile > /dev/null; then
     gcc_cv_as_subsections="working .subsection -1"
@@ -5939,7 +5939,7 @@ echo "$ac_t""$gcc_cv_as_subsections" 1>&6
 
 echo $ac_n "checking assembler weak support""... $ac_c" 1>&6
 echo "configure:5942: checking assembler weak support" >&5
-gcc_cv_as_weak=
+gcc_cv_as_weak=no
 if test x$gcc_cv_gas_major_version != x -a x$gcc_cv_gas_minor_version != x; then
   if test "$gcc_cv_gas_major_version" -eq 2 -a "$gcc_cv_gas_minor_version" -ge 2 -o "$gcc_cv_gas_major_version" -gt 2; then
     gcc_cv_as_weak="yes"
@@ -5962,7 +5962,7 @@ echo "$ac_t""$gcc_cv_as_weak" 1>&6
 
 echo $ac_n "checking assembler hidden support""... $ac_c" 1>&6
 echo "configure:5965: checking assembler hidden support" >&5
-gcc_cv_as_hidden=
+gcc_cv_as_hidden=no
 if test x$gcc_cv_gas_major_version != x -a x$gcc_cv_gas_minor_version != x; then
   if test "$gcc_cv_gas_major_version" -eq 2 -a "$gcc_cv_gas_minor_version" -ge 10 -o "$gcc_cv_gas_major_version" -gt 2 && grep 'obj_format = elf' ../gas/Makefile > /dev/null; then
     gcc_cv_as_hidden="yes"
@@ -6157,6 +6157,50 @@ EOF
     ;;
 esac
 
+echo $ac_n "checking assembler dwarf2 debug_line support""... $ac_c" 1>&6
+echo "configure:6162: checking assembler dwarf2 debug_line support" >&5
+gcc_cv_as_dwarf2_debug_line=no
+# ??? Not all targets support dwarf2 debug_line, even within a version
+# of gas.  Moreover, we need to emit a valid instruction to trigger any
+# info to the output file.  So, as supported targets are added to gas 2.11,
+# add some instruction here to (also) show we expect this might work.
+# ??? Once 2.11 is released, probably need to add first known working
+# version to the per-target configury.
+case "$target" in
+  i?86*-*-* | mips*-*-* | alpha*-*-*)
+    insn="nop"
+    ;;
+  ia64*-*-*)
+    insn="nop 0"
+    ;;
+  esac
+if test x$gcc_cv_gas_major_version != x -a x$gcc_cv_gas_minor_version != x;
+then
+  if test "$gcc_cv_gas_major_version" -eq 2 \
+	-a "$gcc_cv_gas_minor_version" -ge 11 \
+	-o "$gcc_cv_gas_major_version" -gt 2 \
+     && grep 'obj_format = elf' ../gas/Makefile > /dev/null \
+     && test x"$insn" != x ; then
+    gcc_cv_as_dwarf2_debug_line="yes"
+  fi
+elif test x$gcc_cv_as != x -a x"$insn" != x ; then
+	echo '	.file 0 "conftest.s"' > conftest.s
+	echo '	.loc 0 3 0' >> conftest.s
+	echo "	$insn" >> conftest.s
+	if $gcc_cv_as -o conftest.o conftest.s > /dev/null 2>&1 \
+	   && grep debug_line conftest.o > /dev/null 2>&1 ; then
+		gcc_cv_as_dwarf2_debug_line="yes"
+	fi
+	rm -f conftest.s conftest.o conftest.nm1 conftest.nm2
+fi
+if test x"$gcc_cv_as_dwarf2_debug_line" = xyes; then
+	cat >> confdefs.h <<\EOF
+#define HAVE_AS_DWARF2_DEBUG_LINE 1
+EOF
+
+fi
+echo "$ac_t""$gcc_cv_as_dwarf2_debug_line" 1>&6
+
 # Figure out what language subdirectories are present.
 # Look if the user specified --enable-languages="..."; if not, use
 # the environment variable $LANGUAGES if defined. $LANGUAGES might
@@ -6285,7 +6329,7 @@ EOF
 
 
 echo $ac_n "checking whether to enable maintainer-specific portions of Makefiles""... $ac_c" 1>&6
-echo "configure:6289: checking whether to enable maintainer-specific portions of Makefiles" >&5
+echo "configure:6333: checking whether to enable maintainer-specific portions of Makefiles" >&5
     # Check whether --enable-maintainer-mode or --disable-maintainer-mode was given.
 if test "${enable_maintainer_mode+set}" = set; then
   enableval="$enable_maintainer_mode"

gcc/configure.in

@@ -1210,7 +1210,7 @@ AC_MSG_RESULT($gcc_cv_nm)
 
 # Figure out what assembler alignment features are present.
 AC_MSG_CHECKING(assembler alignment features)
-gcc_cv_as_alignment_features=
+gcc_cv_as_alignment_features=none
 if test x$gcc_cv_gas_major_version != x -a x$gcc_cv_gas_minor_version != x; then
 	# Gas version 2.6 and later support for .balign and .p2align.
 	# bytes to skip when using .p2align.
@@ -1245,7 +1245,7 @@ fi
 AC_MSG_RESULT($gcc_cv_as_alignment_features)
 
 AC_MSG_CHECKING(assembler subsection support)
-gcc_cv_as_subsections=
+gcc_cv_as_subsections=no
 if test x$gcc_cv_gas_major_version != x -a x$gcc_cv_gas_minor_version != x; then
   if test "$gcc_cv_gas_major_version" -eq 2 -a "$gcc_cv_gas_minor_version" -ge 9 -o "$gcc_cv_gas_major_version" -gt 2 && grep 'obj_format = elf' ../gas/Makefile > /dev/null; then
     gcc_cv_as_subsections="working .subsection -1"
@@ -1283,7 +1283,7 @@ fi
 AC_MSG_RESULT($gcc_cv_as_subsections)
 
 AC_MSG_CHECKING(assembler weak support)
-gcc_cv_as_weak=
+gcc_cv_as_weak=no
 if test x$gcc_cv_gas_major_version != x -a x$gcc_cv_gas_minor_version != x; then
   if test "$gcc_cv_gas_major_version" -eq 2 -a "$gcc_cv_gas_minor_version" -ge 2 -o "$gcc_cv_gas_major_version" -gt 2; then
     gcc_cv_as_weak="yes"
@@ -1302,7 +1302,7 @@ fi
 AC_MSG_RESULT($gcc_cv_as_weak)
 
 AC_MSG_CHECKING(assembler hidden support)
-gcc_cv_as_hidden=
+gcc_cv_as_hidden=no
 if test x$gcc_cv_gas_major_version != x -a x$gcc_cv_gas_minor_version != x; then
   if test "$gcc_cv_gas_major_version" -eq 2 -a "$gcc_cv_gas_minor_version" -ge 10 -o "$gcc_cv_gas_major_version" -gt 2 && grep 'obj_format = elf' ../gas/Makefile > /dev/null; then
     gcc_cv_as_hidden="yes"
@@ -1457,6 +1457,47 @@ changequote([,])dnl
     ;;
 esac
 
+AC_MSG_CHECKING(assembler dwarf2 debug_line support)
+gcc_cv_as_dwarf2_debug_line=no
+# ??? Not all targets support dwarf2 debug_line, even within a version
+# of gas.  Moreover, we need to emit a valid instruction to trigger any
+# info to the output file.  So, as supported targets are added to gas 2.11,
+# add some instruction here to (also) show we expect this might work.
+# ??? Once 2.11 is released, probably need to add first known working
+# version to the per-target configury.
+case "$target" in
+  i?86*-*-* | mips*-*-* | alpha*-*-*)
+    insn="nop"
+    ;;
+  ia64*-*-*)
+    insn="nop 0"
+    ;;
+  esac
+if test x$gcc_cv_gas_major_version != x -a x$gcc_cv_gas_minor_version != x;
+then
+  if test "$gcc_cv_gas_major_version" -eq 2 \
+	-a "$gcc_cv_gas_minor_version" -ge 11 \
+	-o "$gcc_cv_gas_major_version" -gt 2 \
+     && grep 'obj_format = elf' ../gas/Makefile > /dev/null \
+     && test x"$insn" != x ; then
+    gcc_cv_as_dwarf2_debug_line="yes"
+  fi
+elif test x$gcc_cv_as != x -a x"$insn" != x ; then
+	echo '	.file 0 "conftest.s"' > conftest.s
+	echo '	.loc 0 3 0' >> conftest.s
+	echo "	$insn" >> conftest.s
+	if $gcc_cv_as -o conftest.o conftest.s > /dev/null 2>&1 \
+	   && grep debug_line conftest.o > /dev/null 2>&1 ; then
+		gcc_cv_as_dwarf2_debug_line="yes"
+	fi
+	rm -f conftest.s conftest.o conftest.nm1 conftest.nm2
+fi
+if test x"$gcc_cv_as_dwarf2_debug_line" = xyes; then
+	AC_DEFINE(HAVE_AS_DWARF2_DEBUG_LINE, 1,
+	  [Define if your assembler supports dwarf2 .file/.loc directives.])
+fi
+AC_MSG_RESULT($gcc_cv_as_dwarf2_debug_line)
+
 # Figure out what language subdirectories are present.
 # Look if the user specified --enable-languages="..."; if not, use
 # the environment variable $LANGUAGES if defined. $LANGUAGES might

gcc/dwarf2out.c

@@ -3127,10 +3127,14 @@ extern int flag_traditional;
   (DWARF_ROUND (2 * DWARF_OFFSET_SIZE + 4, DWARF2_ADDR_SIZE * 2) \
    - (2 * DWARF_OFFSET_SIZE + 4))
 
-/* The default is to have gcc emit the line number tables.  */
+/* Use assembler line directives if available.  */
 #ifndef DWARF2_ASM_LINE_DEBUG_INFO
+#ifdef HAVE_AS_DWARF2_DEBUG_LINE
+#define DWARF2_ASM_LINE_DEBUG_INFO 1
+#else
 #define DWARF2_ASM_LINE_DEBUG_INFO 0
 #endif
+#endif
 
 /* Define the architecture-dependent minimum instruction length (in bytes).
    In this implementation of DWARF, this field is used for information