libstdc++: Address '-Wunused-function' for 'print_raw' (was: [committed] libstdc++: Simplify print_raw function for debug assertions)

  Hi!

On 2022-10-14T15:36:02+0100, Jonathan Wakely via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
> Tested powerpc64le-linux. Pushed to trunk.
>
> -- >8 --
>
> Replace two uses of print_raw where it's clearer to just use fprintf
> directly. Then the only remaining use of print_raw is as the print_func
> argument of pretty_print.

OK to push the attached
"libstdc++: Address '-Wunused-function' for 'print_raw'",
or should this be addressed differently?


Grüße
 Thomas


> When called by pretty_print the count is
> either a positive integer or -1, so we can simplify print_raw itself.
>
> Remove the default argument, because it's never used. Remove the check
> for nbc == 0, which never happens (but would be harmless if it did).
> Replace the conditional expression with a single call to fprintf, using
> INT_MAX as the maximum length.
>
> libstdc++-v3/ChangeLog:
>
>       * src/c++11/debug.cc (print_raw): Simplify.
>       (print_word): Print indentation by calling fprintf directly.
>       (_Error_formatter::_M_error): Print unindented string by calling
>       fprintf directly.
> ---
>  libstdc++-v3/src/c++11/debug.cc | 21 ++++++++-------------
>  1 file changed, 8 insertions(+), 13 deletions(-)
>
> diff --git a/libstdc++-v3/src/c++11/debug.cc b/libstdc++-v3/src/c++11/debug.cc
> index abc4124c01e..f2b25fbefce 100644
> --- a/libstdc++-v3/src/c++11/debug.cc
> +++ b/libstdc++-v3/src/c++11/debug.cc
> @@ -37,6 +37,7 @@
>  #include <cstdlib>   // for std::abort
>  #include <cctype>    // for std::isspace.
>  #include <cstring>   // for std::strstr.
> +#include <climits>   // for INT_MAX
>
>  #include <algorithm> // for std::min.
>
> @@ -609,14 +610,11 @@ namespace
>      { print_word(ctx, word, Length - 1); }
>
>    void
> -  print_raw(PrintContext& ctx, const char* str, ptrdiff_t nbc = -1)
> +  print_raw(PrintContext& ctx, const char* str, ptrdiff_t nbc)
>    {
> -    if (nbc != 0)
> -      {
> -     ctx._M_column += (nbc > 0)
> -       ? fprintf(stderr, "%.*s", (int)nbc, str)
> -       : fprintf(stderr, "%s", str);
> -      }
> +    if (nbc == -1)
> +      nbc = INT_MAX;
> +    ctx._M_column += fprintf(stderr, "%.*s", (int)nbc, str);
>    }
>
>    void
> @@ -645,12 +643,9 @@ namespace
>       || (ctx._M_column + visual_length < ctx._M_max_length)
>       || (visual_length >= ctx._M_max_length && ctx._M_column == 1))
>        {
> -     // If this isn't the first line, indent
> +     // If this isn't the first line, indent.
>       if (ctx._M_column == 1 && !ctx._M_first_line)
> -       {
> -         const char spacing[PrintContext::_S_indent + 1] = "    ";
> -         print_raw(ctx, spacing, PrintContext::_S_indent);
> -       }
> +       ctx._M_column += fprintf(stderr, "%*c", PrintContext::_S_indent, ' ');
>
>       int written = fprintf(stderr, "%.*s", (int)length, word);
>
> @@ -1166,7 +1161,7 @@ namespace __gnu_debug
>      PrintContext ctx;
>      if (_M_file)
>        {
> -     print_raw(ctx, _M_file);
> +     ctx._M_column += fprintf(stderr, "%s", _M_file);
>       print_literal(ctx, ":");
>       go_to_next_line = true;
>        }


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On Sat, 15 Oct 2022 at 11:52, Thomas Schwinge <thomas@codesourcery.com> wrote:
>
> Hi!
>
> On 2022-10-14T15:36:02+0100, Jonathan Wakely via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
> > Tested powerpc64le-linux. Pushed to trunk.
> >
> > -- >8 --
> >
> > Replace two uses of print_raw where it's clearer to just use fprintf
> > directly. Then the only remaining use of print_raw is as the print_func
> > argument of pretty_print.
>
> OK to push the attached
> "libstdc++: Address '-Wunused-function' for 'print_raw'",
> or should this be addressed differently?

Oh yes, I didn't notice it's only used within the conditional block,
because I only tested with stacktrace enabled.

I think it would be a little better to move print_raw down to where
it's actually needed:

--- a/libstdc++-v3/src/c++11/debug.cc
+++ b/libstdc++-v3/src/c++11/debug.cc
@@ -609,14 +609,6 @@ namespace
    print_literal(PrintContext& ctx, const char(&word)[Length])
    { print_word(ctx, word, Length - 1); }

-  void
-  print_raw(PrintContext& ctx, const char* str, ptrdiff_t nbc)
-  {
-    if (nbc == -1)
-      nbc = INT_MAX;
-    ctx._M_column += fprintf(stderr, "%.*s", (int)nbc, str);
-  }
-
  void
  print_word(PrintContext& ctx, const char* word, ptrdiff_t nbc = -1)
  {
@@ -1092,6 +1084,14 @@ namespace
  { print_string(ctx, str, nbc, nullptr, 0); }

#if _GLIBCXX_HAVE_STACKTRACE
+  void
+  print_raw(PrintContext& ctx, const char* str, ptrdiff_t nbc)
+  {
+    if (nbc == -1)
+      nbc = INT_MAX;
+    ctx._M_column += fprintf(stderr, "%.*s", (int)nbc, str);
+  }
+
  int
  print_backtrace(void* data, __UINTPTR_TYPE__ pc, const char* filename,
                 int lineno, const char* function)


I'll push that later today, or feel free to do it yourself if you want
the warning to go away :-)
  

On Sat, 15 Oct 2022 at 14:30, Jonathan Wakely <jwakely@redhat.com> wrote:
>
> On Sat, 15 Oct 2022 at 11:52, Thomas Schwinge <thomas@codesourcery.com> wrote:
> >
> > Hi!
> >
> > On 2022-10-14T15:36:02+0100, Jonathan Wakely via Gcc-patches <gcc-patches@gcc.gnu.org> wrote:
> > > Tested powerpc64le-linux. Pushed to trunk.
> > >
> > > -- >8 --
> > >
> > > Replace two uses of print_raw where it's clearer to just use fprintf
> > > directly. Then the only remaining use of print_raw is as the print_func
> > > argument of pretty_print.
> >
> > OK to push the attached
> > "libstdc++: Address '-Wunused-function' for 'print_raw'",
> > or should this be addressed differently?
>
> Oh yes, I didn't notice it's only used within the conditional block,
> because I only tested with stacktrace enabled.
>
> I think it would be a little better to move print_raw down to where
> it's actually needed:
>
> --- a/libstdc++-v3/src/c++11/debug.cc
> +++ b/libstdc++-v3/src/c++11/debug.cc
> @@ -609,14 +609,6 @@ namespace
>     print_literal(PrintContext& ctx, const char(&word)[Length])
>     { print_word(ctx, word, Length - 1); }
>
> -  void
> -  print_raw(PrintContext& ctx, const char* str, ptrdiff_t nbc)
> -  {
> -    if (nbc == -1)
> -      nbc = INT_MAX;
> -    ctx._M_column += fprintf(stderr, "%.*s", (int)nbc, str);
> -  }
> -
>   void
>   print_word(PrintContext& ctx, const char* word, ptrdiff_t nbc = -1)
>   {
> @@ -1092,6 +1084,14 @@ namespace
>   { print_string(ctx, str, nbc, nullptr, 0); }
>
> #if _GLIBCXX_HAVE_STACKTRACE
> +  void
> +  print_raw(PrintContext& ctx, const char* str, ptrdiff_t nbc)
> +  {
> +    if (nbc == -1)
> +      nbc = INT_MAX;
> +    ctx._M_column += fprintf(stderr, "%.*s", (int)nbc, str);
> +  }
> +
>   int
>   print_backtrace(void* data, __UINTPTR_TYPE__ pc, const char* filename,
>                  int lineno, const char* function)
>
>
> I'll push that later today, or feel free to do it yourself if you want
> the warning to go away :-)

Now pushed as r13-3314-g030a08c8572049

Thanks for pointing out the warning.