[RFA 02/15] Remove some unneeded psymtab initializations

[Tom Tromey <tom@tromey.com>]

allocate_psymtab has long cleared the new psymtab that is returned.
This patch documents this behavior and then removes some redundant
initializations.

gdb/ChangeLog
2018-05-09  Tom Tromey  <tom@tromey.com>

	* xcoffread.c (xcoff_end_psymtab): Remove some initializations.
	* psymtab.c (allocate_psymtab): Add comment.
	* psympriv.h (allocate_psymtab): Add comment.
	* dwarf2read.c (dwarf2_create_include_psymtab): Remove some
	initializations.
	* dbxread.c (dbx_end_psymtab): Remove some initializations.
---
 gdb/ChangeLog    |  9 +++++++++
 gdb/dbxread.c    |  7 -------
 gdb/dwarf2read.c |  6 ------
 gdb/psympriv.h   | 10 ++++++++--
 gdb/psymtab.c    |  2 ++
 gdb/xcoffread.c  |  7 -------
 6 files changed, 19 insertions(+), 22 deletions(-)

diff --git a/gdb/dbxread.c b/gdb/dbxread.c
index 1c4f564f4e..84ade27b4d 100644
--- a/gdb/dbxread.c
+++ b/gdb/dbxread.c
@@ -2127,13 +2127,6 @@ dbx_end_psymtab (struct objfile *objfile, struct partial_symtab *pst,
       subpst->dependencies[0] = pst;
       subpst->number_of_dependencies = 1;
 
-      subpst->globals_offset =
-	subpst->n_global_syms =
-	subpst->statics_offset =
-	subpst->n_static_syms = 0;
-
-      subpst->readin = 0;
-      subpst->compunit_symtab = 0;
       subpst->read_symtab = pst->read_symtab;
     }
 
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index 8960fdc38d..be477e3d30 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -6517,13 +6517,7 @@ dwarf2_create_include_psymtab (const char *name, struct partial_symtab *pst,
   subpst->dependencies[0] = pst;
   subpst->number_of_dependencies = 1;
 
-  subpst->globals_offset = 0;
-  subpst->n_global_syms = 0;
-  subpst->statics_offset = 0;
-  subpst->n_static_syms = 0;
-  subpst->compunit_symtab = NULL;
   subpst->read_symtab = pst->read_symtab;
-  subpst->readin = 0;
 
   /* No private part is necessary for include psymtabs.  This property
      can be used to differentiate between such include psymtabs and
diff --git a/gdb/psympriv.h b/gdb/psympriv.h
index 487a34f053..2d81c16b40 100644
--- a/gdb/psympriv.h
+++ b/gdb/psympriv.h
@@ -295,8 +295,14 @@ extern struct partial_symtab *start_psymtab_common (struct objfile *,
 
 extern void end_psymtab_common (struct objfile *, struct partial_symtab *);
 
-extern struct partial_symtab *allocate_psymtab (const char *,
-						struct objfile *)
+/* Allocate a new partial symbol table associated with OBJFILE.
+   FILENAME (which must be non-NULL) is the filename of this partial
+   symbol table; it is copied into the appropriate storage.  A new
+   partial symbol table is returned; aside from "next" and "filename",
+   its fields are initialized to zero.  */
+
+extern struct partial_symtab *allocate_psymtab (const char *filename,
+						struct objfile *objfile)
   ATTRIBUTE_NONNULL (1);
 
 extern void discard_psymtab (struct objfile *, struct partial_symtab *);
diff --git a/gdb/psymtab.c b/gdb/psymtab.c
index 28935291e4..ee593494f6 100644
--- a/gdb/psymtab.c
+++ b/gdb/psymtab.c
@@ -1740,6 +1740,8 @@ init_psymbol_list (struct objfile *objfile, int total_symbols)
   objfile->static_psymbols.reserve (total_symbols / 10);
 }
 
+/* See psympriv.h.  */
+
 struct partial_symtab *
 allocate_psymtab (const char *filename, struct objfile *objfile)
 {
diff --git a/gdb/xcoffread.c b/gdb/xcoffread.c
index 611e954a08..a26f4fe88c 100644
--- a/gdb/xcoffread.c
+++ b/gdb/xcoffread.c
@@ -2109,13 +2109,6 @@ xcoff_end_psymtab (struct objfile *objfile, struct partial_symtab *pst,
       subpst->dependencies[0] = pst;
       subpst->number_of_dependencies = 1;
 
-      subpst->globals_offset =
-	subpst->n_global_syms =
-	subpst->statics_offset =
-	subpst->n_static_syms = 0;
-
-      subpst->readin = 0;
-      subpst->compunit_symtab = NULL;
       subpst->read_symtab = pst->read_symtab;
     }
 
-- 
2.13.6