[PATCH] Re: [RFC] introduction of a new language hook for DWARF2 names

[Nicolas Setton]

On May 14, 2006, at 23:20, Mark Mitchell wrote:
>
> While something like the types_compatible_p langhook is bad, I don't
> think that this case is a problem.  The LTO draft suggests writing out
> declarations by writing out DWARF2.  So, a language-hook to control
> DWARF2 would be OK because it would run during the original  
> processing,
> and therefore not be needed when generating the final code.
>

Here is a patch that implements this solution.

It passes the full regression testsuite on x86/linux with all languages.

Nicolas


===================================================================

         * dwarf2out.c (dwarf2_name): Make use of the dwarf_name
         language hook.
         * ada/misc.c (gnat_dwarf_name): New function.
         (LANG_HOOKS_DWARF_NAME): Define to gnat_dwarf_name.
         * langhooks.c (lhd_dwarf_name): New function.
         * langhooks.h (struct lang_hooks): Add language hook
         dwarf_name, used to allow languages to specify which string
         to use in DWARF2/3 public names for a given tree.
         * langhooks-def.h (lhd_dwarf_name): Declare.
         (LANG_HOOKS_DWARF_NAME): New macro, defaults to lhd_dwarf_name.

Index: gcc/dwarf2out.c
===================================================================
--- gcc/dwarf2out.c     (revision 113783)
+++ gcc/dwarf2out.c     (working copy)
@@ -7232,14 +7232,12 @@
      }
}

-/* The DWARF2 pubname for a nested thingy looks like "A::f".  The
-   output of lang_hooks.decl_printable_name for C++ looks like
-   "A::f(int)".  Let's drop the argument list, and maybe the scope.  */
+/* Return the DWARF2/3 pubname associated with a decl.  */

static const char *
dwarf2_name (tree decl, int scope)
{
-  return lang_hooks.decl_printable_name (decl, scope ? 1 : 0);
+  return lang_hooks.dwarf_name (decl, scope ? 1 : 0);
}

/* Add a new entry to .debug_pubnames if appropriate.  */
Index: gcc/ada/misc.c
===================================================================
--- gcc/ada/misc.c      (revision 113783)
+++ gcc/ada/misc.c      (working copy)
@@ -94,6 +94,7 @@
static void gnat_print_decl            (FILE *, tree, int);
static void gnat_print_type            (FILE *, tree, int);
static const char *gnat_printable_name (tree, int);
+static const char *gnat_dwarf_name     (tree, int);
static tree gnat_eh_runtime_type       (tree);
static int gnat_eh_type_covers         (tree, tree);
static void gnat_parse_file            (int);
@@ -144,6 +145,8 @@
#define LANG_HOOKS_TYPE_MAX_SIZE       gnat_type_max_size
#undef  LANG_HOOKS_DECL_PRINTABLE_NAME
#define LANG_HOOKS_DECL_PRINTABLE_NAME gnat_printable_name
+#undef  LANG_HOOKS_DWARF_NAME
+#define LANG_HOOKS_DWARF_NAME          gnat_dwarf_name
#undef  LANG_HOOKS_CALLGRAPH_EXPAND_FUNCTION
#define LANG_HOOKS_CALLGRAPH_EXPAND_FUNCTION gnat_expand_body
#undef  LANG_HOOKS_GIMPLIFY_EXPR
@@ -596,6 +599,14 @@
    return (const char *) ada_name;
}

+static const char *
+gnat_dwarf_name (tree t, int verbosity)
+{
+  gcc_assert (DECL_P (t));
+
+  return (const char *) IDENTIFIER_POINTER (DECL_NAME (t));
+}
+
/* Expands GNAT-specific GCC tree nodes.  The only ones we support
     here are  and NULL_EXPR.  */

Index: gcc/langhooks.c
===================================================================
--- gcc/langhooks.c     (revision 113783)
+++ gcc/langhooks.c     (working copy)
@@ -264,6 +264,17 @@
    return IDENTIFIER_POINTER (DECL_NAME (decl));
}

+
+/* This is the default dwarf_name function.  */
+
+const char *
+lhd_dwarf_name (tree t, int verbosity)
+{
+  gcc_assert (DECL_P (t));
+
+  return lang_hooks.decl_printable_name (t, verbosity);
+}
+
/* This compares two types for equivalence ("compatible" in C-based  
languages).
     This routine should only return 1 if it is sure.  It should not  
be used
     in contexts where erroneously returning 0 causes problems.  */
Index: gcc/langhooks.h
===================================================================
--- gcc/langhooks.h     (revision 113783)
+++ gcc/langhooks.h     (working copy)
@@ -382,6 +382,11 @@
       types in C++.  */
    const char *(*decl_printable_name) (tree decl, int verbosity);

+  /* Computes the dwarf-2/3 name for a tree.  VERBOSITY determines what
+     information will be printed: 0: DECL_NAME, demangled as
+     necessary.  1: and scope information.  */
+  const char *(*dwarf_name) (tree, int verbosity);
+
    /* This compares two types for equivalence ("compatible" in C- 
based languages).
       This routine should only return 1 if it is sure.  It should  
not be used
       in contexts where erroneously returning 0 causes problems.  */
Index: gcc/langhooks-def.h
===================================================================
--- gcc/langhooks-def.h (revision 113783)
+++ gcc/langhooks-def.h (working copy)
@@ -53,6 +53,7 @@
extern tree lhd_staticp (tree);
extern void lhd_print_tree_nothing (FILE *, tree, int);
extern const char *lhd_decl_printable_name (tree, int);
+extern const char *lhd_dwarf_name (tree, int);
extern int lhd_types_compatible_p (tree, tree);
extern rtx lhd_expand_expr (tree, rtx, enum machine_mode, int, rtx *);
extern int lhd_expand_decl (tree);
@@ -124,6 +125,7 @@
#define LANG_HOOKS_PRINT_IDENTIFIER    lhd_print_tree_nothing
#define LANG_HOOKS_PRINT_ERROR_FUNCTION lhd_print_error_function
#define LANG_HOOKS_DECL_PRINTABLE_NAME lhd_decl_printable_name
+#define LANG_HOOKS_DWARF_NAME          lhd_dwarf_name
#define LANG_HOOKS_GET_CALLEE_FNDECL   lhd_return_null_tree
#define LANG_HOOKS_EXPR_SIZE           lhd_expr_size
#define LANG_HOOKS_TREE_SIZE           lhd_tree_size
@@ -309,6 +311,7 @@
    LANG_HOOKS_PRINT_TYPE, \
    LANG_HOOKS_PRINT_IDENTIFIER, \
    LANG_HOOKS_DECL_PRINTABLE_NAME, \
+  LANG_HOOKS_DWARF_NAME, \
    LANG_HOOKS_TYPES_COMPATIBLE_P, \
    LANG_HOOKS_GET_CALLEE_FNDECL, \
    LANG_HOOKS_PRINT_ERROR_FUNCTION, \