Add minimal line tables at -g1.

    
2013-11-21  Cary Coutant  <ccoutant@google.com>

gcc/
	* dwarf2out.c (want_pubnames): Don't do pubnames for -g1.
	(add_linkage_name): Don't add linkage name for -g1.
	(decls_for_scope): Process subblocks for -g1.
	(dwarf2out_source_line): Output line tables for -g1.
	(dwarf2out_finish): Likewise.
	* tree-ssa-live.c (remove_unused_scope_block_p): Don't prune
	unused scopes for -g1.
	* opts.c (common_handle_option): Handle -g same as -g2.
	* doc/invoke.texi: Update description for -g1.

gcc/testsuite/
	* gcc.dg/debug/dwarf2/mlt1.c: New test.
	* gcc.dg/debug/dwarf2/mlt2.c: New test.

From-SVN: r205235

6 files changed, 53 insertions, 25 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c50c99e..fe8ea8f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+2013-11-21  Cary Coutant  <ccoutant@google.com>
+
+	* dwarf2out.c (want_pubnames): Don't do pubnames for -g1.
+	(add_linkage_name): Don't add linkage name for -g1.
+	(decls_for_scope): Process subblocks for -g1.
+	(dwarf2out_source_line): Output line tables for -g1.
+	(dwarf2out_finish): Likewise.
+	* tree-ssa-live.c (remove_unused_scope_block_p): Don't prune
+	unused scopes for -g1.
+	* opts.c (common_handle_option): Handle -g same as -g2.
+	* doc/invoke.texi: Update description for -g1.
+
 2013-11-21  Peter Bergner  <bergner@vnet.ibm.com>
 
 	* doc/extend.texi: Document htm builtins.
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 6fc56b9..0a26212 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -5233,8 +5233,8 @@ Level 0 produces no debug information at all.  Thus, @option{-g0} negates
 
 Level 1 produces minimal information, enough for making backtraces in
 parts of the program that you don't plan to debug.  This includes
-descriptions of functions and external variables, but no information
-about local variables and no line numbers.
+descriptions of functions and external variables, and line number
+tables, but no information about local variables.
 
 Level 3 includes extra information, such as all the macro definitions
 present in the program.  Some debuggers support macro expansion when
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index 23cd726..1c0effd 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -8849,6 +8849,8 @@ output_comp_unit (dw_die_ref die, int output_if_empty)
 static inline bool
 want_pubnames (void)
 {
+  if (debug_info_level <= DINFO_LEVEL_TERSE)
+    return false;
   if (debug_generate_pub_sections != -1)
     return debug_generate_pub_sections;
   return targetm.want_debug_pub_sections;
@@ -16563,11 +16565,12 @@ add_src_coords_attributes (dw_die_ref die, tree decl)
 static void
 add_linkage_name (dw_die_ref die, tree decl)
 {
-  if ((TREE_CODE (decl) == FUNCTION_DECL || TREE_CODE (decl) == VAR_DECL)
-       && TREE_PUBLIC (decl)
-       && !DECL_ABSTRACT (decl)
-       && !(TREE_CODE (decl) == VAR_DECL && DECL_REGISTER (decl))
-       && die->die_tag != DW_TAG_member)
+  if (debug_info_level > DINFO_LEVEL_TERSE
+      && (TREE_CODE (decl) == FUNCTION_DECL || TREE_CODE (decl) == VAR_DECL)
+      && TREE_PUBLIC (decl)
+      && !DECL_ABSTRACT (decl)
+      && !(TREE_CODE (decl) == VAR_DECL && DECL_REGISTER (decl))
+      && die->die_tag != DW_TAG_member)
     {
       /* Defer until we have an assembler name set.  */
       if (!DECL_ASSEMBLER_NAME_SET_P (decl))
@@ -19963,16 +19966,19 @@ decls_for_scope (tree stmt, dw_die_ref context_die, int depth)
   /* Output the DIEs to represent all of the data objects and typedefs
      declared directly within this block but not within any nested
      sub-blocks.  Also, nested function and tag DIEs have been
-     generated with a parent of NULL; fix that up now.  */
-  for (decl = BLOCK_VARS (stmt); decl != NULL; decl = DECL_CHAIN (decl))
-    process_scope_var (stmt, decl, NULL_TREE, context_die);
-  for (i = 0; i < BLOCK_NUM_NONLOCALIZED_VARS (stmt); i++)
-    process_scope_var (stmt, NULL, BLOCK_NONLOCALIZED_VAR (stmt, i),
-    		       context_die);
+     generated with a parent of NULL; fix that up now.  We don't
+     have to do this if we're at -g1.  */
+  if (debug_info_level > DINFO_LEVEL_TERSE)
+    {
+      for (decl = BLOCK_VARS (stmt); decl != NULL; decl = DECL_CHAIN (decl))
+	process_scope_var (stmt, decl, NULL_TREE, context_die);
+      for (i = 0; i < BLOCK_NUM_NONLOCALIZED_VARS (stmt); i++)
+	process_scope_var (stmt, NULL, BLOCK_NONLOCALIZED_VAR (stmt, i),
+			   context_die);
+    }
 
-  /* If we're at -g1, we're not interested in subblocks.  */
-  if (debug_info_level <= DINFO_LEVEL_TERSE)
-    return;
+  /* Even if we're at -g1, we need to process the subblocks in order to get
+     inlined call information.  */
 
   /* Output the DIEs to represent all sub-blocks (and the items declared
      therein) of this block.  */
@@ -21381,7 +21387,7 @@ dwarf2out_source_line (unsigned int line, const char *filename,
   unsigned int file_num;
   dw_line_info_table *table;
 
-  if (debug_info_level < DINFO_LEVEL_NORMAL || line == 0)
+  if (debug_info_level < DINFO_LEVEL_TERSE || line == 0)
     return;
 
   /* The discriminator column was added in dwarf4.  Simplify the below
@@ -24073,7 +24079,7 @@ dwarf2out_finish (const char *filename)
 	}
     }
 
-  if (debug_info_level >= DINFO_LEVEL_NORMAL)
+  if (debug_info_level >= DINFO_LEVEL_TERSE)
     add_AT_lineptr (main_comp_unit_die, DW_AT_stmt_list,
 		    debug_line_section_label);
 
@@ -24130,7 +24136,7 @@ dwarf2out_finish (const char *filename)
       /* Add a pointer to the line table for the main compilation unit
          so that the debugger can make sense of DW_AT_decl_file
          attributes.  */
-      if (debug_info_level >= DINFO_LEVEL_NORMAL)
+      if (debug_info_level >= DINFO_LEVEL_TERSE)
         add_AT_lineptr (ctnode->root_die, DW_AT_stmt_list,
                         (!dwarf_split_debug_info
                          ? debug_line_section_label
diff --git a/gcc/opts.c b/gcc/opts.c
index d282d6d..5a9d7c8 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -1807,8 +1807,13 @@ common_handle_option (struct gcc_options *opts,
       break;
 
     case OPT_g:
-      set_debug_level (NO_DEBUG, DEFAULT_GDB_EXTENSIONS, arg, opts, opts_set,
-		       loc);
+      /* -g by itself should force -g2.  */
+      if (*arg == '\0')
+	set_debug_level (NO_DEBUG, DEFAULT_GDB_EXTENSIONS, "2", opts, opts_set,
+			 loc);
+      else
+	set_debug_level (NO_DEBUG, DEFAULT_GDB_EXTENSIONS, arg, opts, opts_set,
+			 loc);
       break;
 
     case OPT_gcoff:
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0b3f8ba..2bc0fcc 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2013-11-21  Cary Coutant  <ccoutant@google.com>
+
+	* gcc.dg/debug/dwarf2/mlt1.c: New test.
+	* gcc.dg/debug/dwarf2/mlt2.c: New test.
+
 2013-11-21  Jeff Law  <law@redhat.com>
 
 	PR tree-optimization/59221
diff --git a/gcc/tree-ssa-live.c b/gcc/tree-ssa-live.c
index 51b4101..e46f20a 100644
--- a/gcc/tree-ssa-live.c
+++ b/gcc/tree-ssa-live.c
@@ -599,11 +599,11 @@ remove_unused_scope_block_p (tree scope)
       eliminated.  */
    else if (!nsubblocks)
      ;
-   /* For terse debug info we can eliminate info on unused variables.  */
-   else if (debug_info_level == DINFO_LEVEL_NONE
-	    || debug_info_level == DINFO_LEVEL_TERSE)
+   /* When not generating debug info we can eliminate info on unused
+      variables.  */
+   else if (debug_info_level == DINFO_LEVEL_NONE)
      {
-       /* Even for -g0/-g1 don't prune outer scopes from artificial
+       /* Even for -g0 don't prune outer scopes from artificial
 	  functions, otherwise diagnostics using tree_nonartificial_location
 	  will not be emitted properly.  */
        if (inlined_function_outer_scope_p (scope))