[RFA] symtab.h: Remove cplus_specific.

[dje at google dot com (Doug Evans)]

Hi.

symtab.h:cplus_specific was moved out of general_symbol_info here:

2010-07-16  Sami Wagiaalla  <swagiaal@redhat.com>

        * symtab.h (symbol_set_demangled_name): Now takes an optional objfile*
        argument.
        (cplus_specific): New struct.
        * symtab.c (symbol_set_demangled_name): Updated.
        Use cplus_specific for cplus symbols.
        (symbol_get_demangled_name): Retrive the name from the cplus_specific
        struct for cplus symbols.
        (symbol_init_language_specific): Set cplus_specific for cplus symbols.
        (symbol_set_names): Pass objfile to symbol_set_demangled_name.
        * symtab.c (symbol_init_cplus_specific): New function.

originally proposed here:
http://sourceware.org/ml/gdb-patches/2010-05/msg00594.html

However it still has only has one member: demangled_name.
Does Redhat have further plans for cplus_specific?

This patch simplifies things a fair bit.
Maybe too much, but OTOH are there currently any plans to add, say,
more to struct mangled_lang?  [Setting aside cplus_specific which is
my first question above.]  I suspect not, and thus I'd like to
keep things simple until the complexity is needed.
[And if/when one might want to add more to, say, mangled_lang,
I suspect one would instead create a new struct, mylang_specific,
or some such.]

2011-12-10  Doug Evans  <dje@google.com>

	* symtab.h (cplus_specific): Delete.
	(struct general_symbol_info): Merge language_specific members
	mangled_lang and cplus_specific into one: demangled_name.  All uses
	updated.
	* symtab.c (symbol_init_cplus_specific): Delete.
	(symbol_set_demangled_name): Delete parameter `objfile', all callers
	updated.
	* cp-namespace.c (cp_lookup_symbol_imports_or_template): Delete unused
	locals i, cps.

Index: ada-lang.c
===================================================================
RCS file: /cvs/src/src/gdb/ada-lang.c,v
retrieving revision 1.318
diff -u -p -r1.318 ada-lang.c
--- ada-lang.c	6 Dec 2011 18:54:38 -0000	1.318
+++ ada-lang.c	11 Dec 2011 01:29:32 -0000
@@ -1250,7 +1250,7 @@ char *
 ada_decode_symbol (const struct general_symbol_info *gsymbol)
 {
   char **resultp =
-    (char **) &gsymbol->language_specific.mangled_lang.demangled_name;
+    (char **) &gsymbol->language_specific.demangled_name;
 
   if (*resultp == NULL)
     {
Index: cp-namespace.c
===================================================================
RCS file: /cvs/src/src/gdb/cp-namespace.c,v
retrieving revision 1.56
diff -u -p -r1.56 cp-namespace.c
--- cp-namespace.c	4 Nov 2011 16:37:17 -0000	1.56
+++ cp-namespace.c	11 Dec 2011 01:29:32 -0000
@@ -474,10 +474,6 @@ cp_lookup_symbol_imports_or_template (co
 
   if (function != NULL && SYMBOL_LANGUAGE (function) == language_cplus)
     {
-      int i;
-      struct cplus_specific *cps
-	= function->ginfo.language_specific.cplus_specific;
-
       /* Search the function's template parameters.  */
       if (SYMBOL_IS_CPLUS_TEMPLATE_FUNCTION (function))
 	{
Index: dwarf2read.c
===================================================================
RCS file: /cvs/src/src/gdb/dwarf2read.c,v
retrieving revision 1.586
diff -u -p -r1.586 dwarf2read.c
--- dwarf2read.c	10 Dec 2011 23:57:39 -0000	1.586
+++ dwarf2read.c	11 Dec 2011 01:29:32 -0000
@@ -11741,8 +11737,7 @@ new_symbol_full (struct die_info *die, s
       if (cu->language == language_fortran
           && symbol_get_demangled_name (&(sym->ginfo)) == NULL)
 	symbol_set_demangled_name (&(sym->ginfo),
-				   (char *) dwarf2_full_name (name, die, cu),
-	                           NULL);
+				   (char *) dwarf2_full_name (name, die, cu));
 
       /* Default assumptions.
          Use the passed type or decode it from the die.  */
Index: symtab.c
===================================================================
RCS file: /cvs/src/src/gdb/symtab.c,v
retrieving revision 1.288
diff -u -p -r1.288 symtab.c
--- symtab.c	6 Dec 2011 18:54:39 -0000	1.288
+++ symtab.c	11 Dec 2011 01:29:32 -0000
@@ -404,55 +404,22 @@ gdb_mangle_name (struct type *type, int 
   return (mangled_name);
 }
 
-/* Initialize the cplus_specific structure.  'cplus_specific' should
-   only be allocated for use with cplus symbols.  */
-
-static void
-symbol_init_cplus_specific (struct general_symbol_info *gsymbol,
-                           struct objfile *objfile)
-{
-  /* A language_specific structure should not have been previously
-     initialized.  */
-  gdb_assert (gsymbol->language_specific.cplus_specific == NULL);
-  gdb_assert (objfile != NULL);
-
-  gsymbol->language_specific.cplus_specific =
-      OBSTACK_ZALLOC (&objfile->objfile_obstack, struct cplus_specific);
-}
-
 /* Set the demangled name of GSYMBOL to NAME.  NAME must be already
-   correctly allocated.  For C++ symbols a cplus_specific struct is
-   allocated so OBJFILE must not be NULL.  If this is a non C++ symbol
-   OBJFILE can be NULL.  */
+   correctly allocated.  */
+
 void
 symbol_set_demangled_name (struct general_symbol_info *gsymbol,
-                           char *name,
-                           struct objfile *objfile)
+                           char *name)
 {
-  if (gsymbol->language == language_cplus)
-    {
-      if (gsymbol->language_specific.cplus_specific == NULL)
-	symbol_init_cplus_specific (gsymbol, objfile);
-
-      gsymbol->language_specific.cplus_specific->demangled_name = name;
-    }
-  else
-    gsymbol->language_specific.mangled_lang.demangled_name = name;
+  gsymbol->language_specific.demangled_name = name;
 }
 
 /* Return the demangled name of GSYMBOL.  */
+
 char *
 symbol_get_demangled_name (const struct general_symbol_info *gsymbol)
 {
-  if (gsymbol->language == language_cplus)
-    {
-      if (gsymbol->language_specific.cplus_specific != NULL)
-	return gsymbol->language_specific.cplus_specific->demangled_name;
-      else
-	return NULL;
-    }
-  else
-    return gsymbol->language_specific.mangled_lang.demangled_name;
+  return gsymbol->language_specific.demangled_name;
 }
 
 
@@ -464,14 +431,13 @@ symbol_set_language (struct general_symb
 {
   gsymbol->language = language;
   if (gsymbol->language == language_d
+      || gsymbol->language == language_cplus
       || gsymbol->language == language_java
       || gsymbol->language == language_objc
       || gsymbol->language == language_fortran)
     {
-      symbol_set_demangled_name (gsymbol, NULL, NULL);
+      symbol_set_demangled_name (gsymbol, NULL);
     }
-  else if (gsymbol->language == language_cplus)
-    gsymbol->language_specific.cplus_specific = NULL;
   else
     {
       memset (&gsymbol->language_specific, 0,
@@ -653,7 +619,7 @@ symbol_set_names (struct general_symbol_
 	  memcpy (gsymbol->name, linkage_name, len);
 	  gsymbol->name[len] = '\0';
 	}
-      symbol_set_demangled_name (gsymbol, NULL, NULL);
+      symbol_set_demangled_name (gsymbol, NULL);
 
       return;
     }
@@ -749,9 +715,9 @@ symbol_set_names (struct general_symbol_
 
   gsymbol->name = (*slot)->mangled + lookup_len - len;
   if ((*slot)->demangled[0] != '\0')
-    symbol_set_demangled_name (gsymbol, (*slot)->demangled, objfile);
+    symbol_set_demangled_name (gsymbol, (*slot)->demangled);
   else
-    symbol_set_demangled_name (gsymbol, NULL, objfile);
+    symbol_set_demangled_name (gsymbol, NULL);
 }
 
 /* Return the source code name of a symbol.  In languages where
Index: symtab.h
===================================================================
RCS file: /cvs/src/src/gdb/symtab.h,v
retrieving revision 1.193
diff -u -p -r1.193 symtab.h
--- symtab.h	6 Dec 2011 18:54:39 -0000	1.193
+++ symtab.h	11 Dec 2011 01:29:32 -0000
@@ -78,13 +78,6 @@ struct language_defn;
 
    --chastain 2003-08-21  */
 
-/* Struct for storing C++ specific information.  Allocated when needed.  */
-
-struct cplus_specific
-{
-  char *demangled_name;
-};
-
 /* Define a structure for the information that is common to all symbol types,
    including minimal symbols, partial symbols, and full symbols.  In a
    multilanguage environment, some language specific information may need to
@@ -128,19 +121,20 @@ struct general_symbol_info
   value;
 
   /* Since one and only one language can apply, wrap the language specific
-     information inside a union.  */
+     information inside a union.
+
+     N.B.  Since the size of this struct is important to keep minimal, if you
+     need to add something that would otherwise grow the size of this union,
+     allocate it separately and record a pointer to the allocated data here.
+     This will avoid penalizing other languages.
+     For an example of this see the implementation of cplus_specific in
+     GDB 7.3.  */
 
   union
   {
     /* This is used by languages which wish to store a demangled name.
-       currently used by Ada, Java, and Objective C.  */
-    struct mangled_lang
-    {
-      char *demangled_name;
-    }
-    mangled_lang;
-
-    struct cplus_specific *cplus_specific;
+       currently used by Ada, C++, Java, and Objective C.  */
+    char *demangled_name;
   }
   language_specific;
 
@@ -164,8 +158,7 @@ struct general_symbol_info
   struct obj_section *obj_section;
 };
 
-extern void symbol_set_demangled_name (struct general_symbol_info *, char *,
-                                       struct objfile *);
+extern void symbol_set_demangled_name (struct general_symbol_info *, char *);
 
 extern char *symbol_get_demangled_name (const struct general_symbol_info *);