[gdb/symtab] Replace TYPE_ALLOC with TYPE_ZALLOC where required

Handle the remaining uses of TYPE_ALLOC, either by:
- replacing with TYPE_ZALLOC, or
- adding a comment explaining why zero-initialization is not necessary.

Tested on x86_64-linux.

Approved-By: Tom Tromey <tom@tromey.com>

2 files changed, 13 insertions, 5 deletions

diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index bc68c29..b45afa1 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -12376,8 +12376,8 @@ dwarf2_attach_fn_fields_to_type (struct field_info *fip, struct type *type,
 
   ALLOCATE_CPLUS_STRUCT_TYPE (type);
   TYPE_FN_FIELDLISTS (type) = (struct fn_fieldlist *)
-    TYPE_ALLOC (type,
-		sizeof (struct fn_fieldlist) * fip->fnfieldlists.size ());
+    TYPE_ZALLOC (type,
+		 sizeof (struct fn_fieldlist) * fip->fnfieldlists.size ());
 
   for (int i = 0; i < fip->fnfieldlists.size (); i++)
     {
@@ -12386,6 +12386,8 @@ dwarf2_attach_fn_fields_to_type (struct field_info *fip, struct type *type,
 
       TYPE_FN_FIELDLIST_NAME (type, i) = nf.name;
       TYPE_FN_FIELDLIST_LENGTH (type, i) = nf.fnfields.size ();
+      /* No need to zero-initialize, initialization is done by the copy in
+	 the loop below.  */
       fn_flp->fn_fields = (struct fn_field *)
 	TYPE_ALLOC (type, sizeof (struct fn_field) * nf.fnfields.size ());
 
@@ -13088,6 +13090,8 @@ process_structure_scope (struct die_info *die, struct dwarf2_cu *cu)
 	  int count = fi.typedef_field_list.size ();
 
 	  ALLOCATE_CPLUS_STRUCT_TYPE (type);
+	  /* No zero-initialization is needed, the elements are initialized by
+	     the copy in the loop below.  */
 	  TYPE_TYPEDEF_FIELD_ARRAY (type)
 	    = ((struct decl_field *)
 	       TYPE_ALLOC (type,
@@ -13106,6 +13110,8 @@ process_structure_scope (struct die_info *die, struct dwarf2_cu *cu)
 	  int count = fi.nested_types_list.size ();
 
 	  ALLOCATE_CPLUS_STRUCT_TYPE (type);
+	  /* No zero-initialization is needed, the elements are initialized by
+	     the copy in the loop below.  */
 	  TYPE_NESTED_TYPES_ARRAY (type)
 	    = ((struct decl_field *)
 	       TYPE_ALLOC (type, sizeof (struct decl_field) * count));
diff --git a/gdb/gdbtypes.c b/gdb/gdbtypes.c
index 65da995..6abe5ea 100644
--- a/gdb/gdbtypes.c
+++ b/gdb/gdbtypes.c
@@ -3207,7 +3207,7 @@ check_stub_method (struct type *type, int method_id, int signature_id)
   /* We need one extra slot, for the THIS pointer.  */
 
   argtypes = (struct field *)
-    TYPE_ALLOC (type, (argcount + 1) * sizeof (struct field));
+    TYPE_ZALLOC (type, (argcount + 1) * sizeof (struct field));
   p = argtypetext;
 
   /* Add THIS pointer for non-static methods.  */
@@ -3297,7 +3297,7 @@ allocate_cplus_struct_type (struct type *type)
 
   TYPE_SPECIFIC_FIELD (type) = TYPE_SPECIFIC_CPLUS_STUFF;
   TYPE_RAW_CPLUS_SPECIFIC (type) = (struct cplus_struct_type *)
-    TYPE_ALLOC (type, sizeof (struct cplus_struct_type));
+    TYPE_ZALLOC (type, sizeof (struct cplus_struct_type));
   *(TYPE_RAW_CPLUS_SPECIFIC (type)) = cplus_struct_default;
   set_type_vptr_fieldno (type, -1);
 }
@@ -3314,7 +3314,7 @@ allocate_gnat_aux_type (struct type *type)
 {
   TYPE_SPECIFIC_FIELD (type) = TYPE_SPECIFIC_GNAT_STUFF;
   TYPE_GNAT_SPECIFIC (type) = (struct gnat_aux_type *)
-    TYPE_ALLOC (type, sizeof (struct gnat_aux_type));
+    TYPE_ZALLOC (type, sizeof (struct gnat_aux_type));
   *(TYPE_GNAT_SPECIFIC (type)) = gnat_aux_default;
 }
 
@@ -3454,6 +3454,8 @@ init_complex_type (const char *name, struct type *target_type)
     {
       if (name == nullptr && target_type->name () != nullptr)
 	{
+	  /* No zero-initialization required, initialized by strcpy/strcat
+	     below.  */
 	  char *new_name
 	    = (char *) TYPE_ALLOC (target_type,
 				   strlen (target_type->name ())