Hi Karl,
I just built texinfo-4.3 (on ix86-linux-gnu with gcc-2.95.3) and saw
that there are a lots of gcc warnings. They all concern the use of constant
strings, i.e. `const char *' in assignments to non-constant `char *'
variables, as initializer for such variables, or as arguments of that type.
I think these warnings are all legitimate and point to the potential problem
that the constant strings could be modified by the program.
Therefore, I would like to suggest the attached patch. Except in one case
(in makeinfo/index.c index_node was used first for a constant a then for a
modifiable string) the patch just adds a bunch of `const's to existing
declarations. From the fact that the patch removes all gcc warnings, I
deduce that the above mentioned problem doesn't actually occur in the
texinfo-4.3 code (as far as the compiler can detect, since the majority of
functions is used without suitable prototypes).
NB: Does texinfo (and other GNU software) actually still support
prototype-unaware compilers. If not, it might be a good idea to supply all
necessary prototypes. Or even better supply them in any case with the
TYPE name _P((ARG TYES));
syntax. I know that doing this is rather tedious, but a lot of subtle bugs
have been found this way (in other programs).
regards
Peter Breitenlohner <[EMAIL PROTECTED]>
diff -ur texinfo-4.3.orig/info/indices.c texinfo-4.3/info/indices.c
--- texinfo-4.3.orig/info/indices.c 2002-08-26 01:38:38.000000000 +0200
+++ texinfo-4.3/info/indices.c 2002-11-15 21:23:31.000000000 +0100
@@ -390,7 +390,7 @@
/* Report to the user on what we have found. */
{
register int j;
- char *name = _("CAN'T SEE THIS");
+ const char *name = _("CAN'T SEE THIS");
char *match;
for (j = 0; index_nodenames[j]; j++)
diff -ur texinfo-4.3.orig/info/info.c texinfo-4.3/info/info.c
--- texinfo-4.3.orig/info/info.c 2002-08-26 01:38:38.000000000 +0200
+++ texinfo-4.3/info/info.c 2002-11-15 21:24:27.000000000 +0100
@@ -609,22 +609,22 @@
use them that way. This also has the advantage that there's only one
copy of the strings. */
-char *msg_cant_find_node;
-char *msg_cant_file_node;
-char *msg_cant_find_window;
-char *msg_cant_find_point;
-char *msg_cant_kill_last;
-char *msg_no_menu_node;
-char *msg_no_foot_node;
-char *msg_no_xref_node;
-char *msg_no_pointer;
-char *msg_unknown_command;
-char *msg_term_too_dumb;
-char *msg_at_node_bottom;
-char *msg_at_node_top;
-char *msg_one_window;
-char *msg_win_too_small;
-char *msg_cant_make_help;
+const char *msg_cant_find_node;
+const char *msg_cant_file_node;
+const char *msg_cant_find_window;
+const char *msg_cant_find_point;
+const char *msg_cant_kill_last;
+const char *msg_no_menu_node;
+const char *msg_no_foot_node;
+const char *msg_no_xref_node;
+const char *msg_no_pointer;
+const char *msg_unknown_command;
+const char *msg_term_too_dumb;
+const char *msg_at_node_bottom;
+const char *msg_at_node_top;
+const char *msg_one_window;
+const char *msg_win_too_small;
+const char *msg_cant_make_help;
static void
init_messages ()
diff -ur texinfo-4.3.orig/info/info.h texinfo-4.3/info/info.h
--- texinfo-4.3.orig/info/info.h 2002-08-26 01:38:38.000000000 +0200
+++ texinfo-4.3/info/info.h 2002-11-15 21:42:51.000000000 +0100
@@ -128,22 +128,22 @@
extern void info_error ();
/* Error message defines. */
-extern char *msg_cant_find_node;
-extern char *msg_cant_file_node;
-extern char *msg_cant_find_window;
-extern char *msg_cant_find_point;
-extern char *msg_cant_kill_last;
-extern char *msg_no_menu_node;
-extern char *msg_no_foot_node;
-extern char *msg_no_xref_node;
-extern char *msg_no_pointer;
-extern char *msg_unknown_command;
-extern char *msg_term_too_dumb;
-extern char *msg_at_node_bottom;
-extern char *msg_at_node_top;
-extern char *msg_one_window;
-extern char *msg_win_too_small;
-extern char *msg_cant_make_help;
+extern const char *msg_cant_find_node;
+extern const char *msg_cant_file_node;
+extern const char *msg_cant_find_window;
+extern const char *msg_cant_find_point;
+extern const char *msg_cant_kill_last;
+extern const char *msg_no_menu_node;
+extern const char *msg_no_foot_node;
+extern const char *msg_no_xref_node;
+extern const char *msg_no_pointer;
+extern const char *msg_unknown_command;
+extern const char *msg_term_too_dumb;
+extern const char *msg_at_node_bottom;
+extern const char *msg_at_node_top;
+extern const char *msg_one_window;
+extern const char *msg_win_too_small;
+extern const char *msg_cant_make_help;
extern char *filename_non_directory (); /* Found in info-utils.c. */
diff -ur texinfo-4.3.orig/info/nodemenu.c texinfo-4.3/info/nodemenu.c
--- texinfo-4.3.orig/info/nodemenu.c 2002-08-26 01:38:38.000000000 +0200
+++ texinfo-4.3/info/nodemenu.c 2002-11-15 21:20:28.000000000 +0100
@@ -22,7 +22,7 @@
#include "info.h"
/* Return a line describing the format of a node information line. */
-static char *
+static const char *
nodemenu_format_info ()
{
return (_("\n\
diff -ur texinfo-4.3.orig/info/session.c texinfo-4.3/info/session.c
--- texinfo-4.3.orig/info/session.c 2002-08-26 01:38:38.000000000 +0200
+++ texinfo-4.3/info/session.c 2002-11-15 21:28:43.000000000 +0100
@@ -2433,7 +2433,8 @@
info_follow_menus (initial_node, menus, errstr, errarg1, errarg2)
NODE *initial_node;
char **menus;
- char **errstr, **errarg1, **errarg2;
+ const char **errstr;
+ char **errarg1, **errarg2;
{
NODE *node = NULL;
*errstr = *errarg1 = *errarg2 = NULL;
@@ -2796,7 +2797,7 @@
DECLARE_INFO_COMMAND (info_goto_invocation_node,
_("Find the node describing program invocation"))
{
- char *invocation_prompt = _("Find Invocation node of [%s]: ");
+ const char *invocation_prompt = _("Find Invocation node of [%s]: ");
char *program_name, *line;
char *default_program_name, *prompt, *file_name;
NODE *top_node;
@@ -3848,7 +3849,8 @@
int failing_p;
{
register int i;
- char *prefix, *prompt, *p_rep;
+ const char *prefix;
+ char *prompt, *p_rep;
int prompt_len, p_rep_index, p_rep_size;
if (dir < 0)
diff -ur texinfo-4.3.orig/info/window.c texinfo-4.3/info/window.c
--- texinfo-4.3.orig/info/window.c 2002-08-26 01:38:38.000000000 +0200
+++ texinfo-4.3/info/window.c 2002-11-15 21:29:48.000000000 +0100
@@ -1144,7 +1144,7 @@
int modeline_len = 0;
char *parent = NULL, *filename = "*no file*";
char *nodename = "*no node*";
- char *update_message = NULL;
+ const char *update_message = NULL;
NODE *node = window->node;
if (node)
diff -ur texinfo-4.3.orig/makeinfo/defun.c texinfo-4.3/makeinfo/defun.c
--- texinfo-4.3.orig/makeinfo/defun.c 2002-11-11 09:01:55.000000000 +0100
+++ texinfo-4.3/makeinfo/defun.c 2002-11-15 21:32:02.000000000 +0100
@@ -331,7 +331,8 @@
{
enum insertion_type base_type;
char **defun_args, **scan_args;
- char *category, *defined_name, *type_name, *type_name2;
+ const char *category;
+ char *defined_name, *type_name, *type_name2;
{
char *line;
diff -ur texinfo-4.3.orig/makeinfo/html.c texinfo-4.3/makeinfo/html.c
--- texinfo-4.3.orig/makeinfo/html.c 2002-11-04 23:14:40.000000000 +0100
+++ texinfo-4.3/makeinfo/html.c 2002-11-15 21:32:54.000000000 +0100
@@ -33,7 +33,7 @@
void
html_output_head ()
{
- static char *html_title = NULL;
+ static const char *html_title = NULL;
if (html_output_head_p)
return;
diff -ur texinfo-4.3.orig/makeinfo/index.c texinfo-4.3/makeinfo/index.c
--- texinfo-4.3.orig/makeinfo/index.c 2002-11-07 23:16:20.000000000 +0100
+++ texinfo-4.3/makeinfo/index.c 2002-11-15 22:11:19.000000000 +0100
@@ -696,7 +696,7 @@
{
/* A pathological document might have an index entry outside of any
node. Don't crash; try using the section name instead. */
- char *index_node = index->node;
+ const char *index_node = index->node;
line_number = index->defining_line;
input_filename = index->defining_file;
@@ -741,12 +741,14 @@
if (index->node && *index->node)
{
/* Make sure any non-macros in the node name are expanded. */
+ char *expanded_index;
+
in_fixed_width_font++;
- index_node = expansion (index_node, 0);
+ expanded_index = expansion (index_node, 0);
in_fixed_width_font--;
- add_anchor_name (index_node, 1);
- add_word_args ("\">%s</a>", index_node);
- free (index_node);
+ add_anchor_name (expanded_index, 1);
+ add_word_args ("\">%s</a>", expanded_index);
+ free (expanded_index);
}
else if (STREQ (index_node, _("(outside of any node)")))
{
diff -ur texinfo-4.3.orig/makeinfo/insertion.c texinfo-4.3/makeinfo/insertion.c
--- texinfo-4.3.orig/makeinfo/insertion.c 2002-11-12 09:08:06.000000000 +0100
+++ texinfo-4.3/makeinfo/insertion.c 2002-11-15 22:13:09.000000000 +0100
@@ -190,7 +190,7 @@
/* Return a pointer to the print name of this
enumerated type. */
-char *
+const char *
insertion_type_pname (type)
enum insertion_type type;
{
@@ -979,7 +979,7 @@
break;
else
{
- char *offender = insertion_type_pname (insertion_stack->insertion);
+ const char *offender = insertion_type_pname (insertion_stack->insertion);
file_line_error (insertion_stack->filename,
insertion_stack->line_number,
diff -ur texinfo-4.3.orig/makeinfo/makeinfo.c texinfo-4.3/makeinfo/makeinfo.c
--- texinfo-4.3.orig/makeinfo/makeinfo.c 2002-11-13 01:34:10.000000000 +0100
+++ texinfo-4.3/makeinfo/makeinfo.c 2002-11-15 21:59:45.000000000 +0100
@@ -193,7 +193,7 @@
#if defined (VA_FPRINTF) && __STDC__
/* Unfortunately we must use prototypes if we are to use <stdarg.h>. */
-void add_word_args (char *, ...);
+void add_word_args (const char *, ...);
void execute_string (char *, ...);
#else
void add_word_args ();
@@ -218,10 +218,10 @@
/* Print an error message, and return false. */
void
#if defined (VA_FPRINTF) && __STDC__
-error (char *format, ...)
+error (const char *format, ...)
#else
error (format, va_alist)
- char *format;
+ const char *format;
va_dcl
#endif
{
@@ -245,12 +245,12 @@
/* Just like error (), but print the input file and line number as well. */
void
#if defined (VA_FPRINTF) && __STDC__
-file_line_error (char *infile, int lno, char *format, ...)
+file_line_error (char *infile, int lno, const char *format, ...)
#else
file_line_error (infile, lno, format, va_alist)
char *infile;
int lno;
- char *format;
+ const char *format;
va_dcl
#endif
{
@@ -276,10 +276,10 @@
number from global variables. */
void
#if defined (VA_FPRINTF) && __STDC__
-line_error (char *format, ...)
+line_error (const char *format, ...)
#else
line_error (format, va_alist)
- char *format;
+ const char *format;
va_dcl
#endif
{
@@ -303,10 +303,10 @@
void
#if defined (VA_FPRINTF) && __STDC__
-warning (char *format, ...)
+warning (const char *format, ...)
#else
warning (format, va_alist)
- char *format;
+ const char *format;
va_dcl
#endif
{
@@ -1362,7 +1362,7 @@
strcat (output_filename, basename);
if (mkdir (output_filename, 0777) == -1)
{
- char *errmsg = strerror (errno);
+ const char *errmsg = strerror (errno);
if ((errno == EEXIST
#ifdef __MSDOS__
@@ -2146,7 +2146,7 @@
/* Return the string which invokes PROC; a pointer to a function.
Always returns the first function in the command table if more than
one matches PROC. */
-static char *
+static const char *
find_proc_name (proc)
COMMAND_FUNCTION *proc;
{
@@ -2172,7 +2172,7 @@
{
if (brace_stack->proc != misplaced_brace)
{
- char *proc_name;
+ const char *proc_name;
proc_name = find_proc_name (brace_stack->proc);
file_line_error (input_filename, brace_stack->line,
@@ -2226,10 +2226,10 @@
void
#if defined (VA_FPRINTF) && __STDC__
-add_word_args (char *format, ...)
+add_word_args (const char *format, ...)
#else
add_word_args (format, va_alist)
- char *format;
+ const char *format;
va_dcl
#endif
{
diff -ur texinfo-4.3.orig/makeinfo/makeinfo.h texinfo-4.3/makeinfo/makeinfo.h
--- texinfo-4.3.orig/makeinfo/makeinfo.h 2002-09-29 21:15:20.000000000 +0200
+++ texinfo-4.3/makeinfo/makeinfo.h 2002-11-15 22:17:06.000000000 +0100
@@ -153,7 +153,7 @@
DECLARE (char *, copying_text, NULL);
/* @documentdescription ... @end documentdescription. */
-DECLARE (char *, document_description, NULL);
+DECLARE (const char *, document_description, NULL);
/* Nonzero if the last character inserted has the syntax class of NEWLINE. */
DECLARE (int, last_char_was_newline, 1);
diff -ur texinfo-4.3.orig/makeinfo/node.c texinfo-4.3/makeinfo/node.c
--- texinfo-4.3.orig/makeinfo/node.c 2002-11-05 04:04:26.000000000 +0100
+++ texinfo-4.3/makeinfo/node.c 2002-11-15 21:36:18.000000000 +0100
@@ -1291,7 +1291,7 @@
/* The strings here are followed in the message by `reference to...' in
the `validate' routine. They are only used in messages, thus are
translated. */
-static char *
+static const char *
reftype_type_string (type)
enum reftype type;
{
