[PATCH] Make n_spaces return a const char *

[PATCH] Make n_spaces return a const char *

[Tom Tromey]

n_spaces keeps the spaces in a static buffer.  If a caller overwrites
these, it may give an incorrect result to a subsequent caller.  So,
make the return type const to help avoid this outcome.
---
 gdb/utils.c | 2 +-
 gdb/utils.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/gdb/utils.c b/gdb/utils.c
index e27a8818b94..ea0f65c10e4 100644
--- a/gdb/utils.c
+++ b/gdb/utils.c
@@ -2303,7 +2303,7 @@ puts_unfiltered (const char *string)
 
 /* Return a pointer to N spaces and a null.  The pointer is good
    until the next call to here.  */
-char *
+const char *
 n_spaces (int n)
 {
   char *t;
diff --git a/gdb/utils.h b/gdb/utils.h
index 6f3a70213a4..f6fd32faf90 100644
--- a/gdb/utils.h
+++ b/gdb/utils.h
@@ -473,7 +473,7 @@ extern void print_spaces (int, struct ui_file *);
 
 extern void print_spaces_filtered (int, struct ui_file *);
 
-extern char *n_spaces (int);
+extern const char *n_spaces (int);
 
 extern void fputstr_filtered (const char *str, int quotr,
 			      struct ui_file * stream);
-- 
2.31.1

Re: [PATCH] Make n_spaces return a const char *

[Bruno Larsen]

On 12/11/21 19:11, Tom Tromey wrote:
> n_spaces keeps the spaces in a static buffer.  If a caller overwrites
> these, it may give an incorrect result to a subsequent caller.  So,
> make the return type const to help avoid this outcome.
> ---
>   gdb/utils.c | 2 +-
>   gdb/utils.h | 2 +-
>   2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/gdb/utils.c b/gdb/utils.c
> index e27a8818b94..ea0f65c10e4 100644
> --- a/gdb/utils.c
> +++ b/gdb/utils.c
> @@ -2303,7 +2303,7 @@ puts_unfiltered (const char *string)
>   
>   /* Return a pointer to N spaces and a null.  The pointer is good
>      until the next call to here.  */
> -char *
> +const char *
>   n_spaces (int n)
>   {
>     char *t;
> diff --git a/gdb/utils.h b/gdb/utils.h
> index 6f3a70213a4..f6fd32faf90 100644
> --- a/gdb/utils.h
> +++ b/gdb/utils.h
> @@ -473,7 +473,7 @@ extern void print_spaces (int, struct ui_file *);
>   
>   extern void print_spaces_filtered (int, struct ui_file *);
>   
> -extern char *n_spaces (int);
> +extern const char *n_spaces (int);
>   
>   extern void fputstr_filtered (const char *str, int quotr,
>   			      struct ui_file * stream);

LGTM. Looks like a good change and doesn't introduce any regressions

-- 
Cheers!
Bruno Larsen

Re: [PATCH] Make n_spaces return a const char *

[Tom Tromey]

>>>>> "Tom" == Tom Tromey <tom@tromey.com> writes:

Tom> n_spaces keeps the spaces in a static buffer.  If a caller overwrites
Tom> these, it may give an incorrect result to a subsequent caller.  So,
Tom> make the return type const to help avoid this outcome.

I'm checking this in now.

Sometimes I wonder if we want to split these utility things into
separate files and put them in gdbsupport.

Tom