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From:
Jeremie Courreges-Anglas <jca@wxcvbn.org>
Subject:
gcc/15 libestdc++: drop sprintf/strcpy ld warnings
To:
ports@openbsd.org
Cc:
Pascal Stumpf <pascal@stumpf.co>
Date:
Sun, 14 Sep 2025 19:36:07 +0200

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On Sun, Sep 14, 2025 at 05:51:17PM +0200, Jeremie Courreges-Anglas wrote:
> 
> ld.bfd spots it with a "hello, world!" program, ld.lld doesn't.  The
> sprintf_ld() change is adapted from code already in lang/gcc/15.
> Since that function is internal, it's not a problem.
> 
> With this, eg++ (-fuse-ld=bfd) doesn't warn about the sprintf use.
> This matters for some overly picky ports that fail to find a working
> C++ compiler when ld(1) spits any warning.  Diff for gcc/15 to follow.

Same for gcc/15 where more occurrences have crept up.

ok?


Index: Makefile
===================================================================
RCS file: /home/cvs/ports/lang/gcc/15/Makefile,v
diff -u -p -r1.6 Makefile
--- Makefile	13 Sep 2025 14:45:15 -0000	1.6
+++ Makefile	14 Sep 2025 16:00:49 -0000
@@ -16,6 +16,8 @@ V = 15.2.0
 FULL_VERSION = $V
 FULL_PKGVERSION = $V
 
+REVISION = 0
+
 ADASTRAP-amd64 = adastrap-amd64-11.2.0-5.tar.xz
 ADASTRAP-arm = adastrap-arm-4.9.4-0.tar.xz
 ADASTRAP-hppa = adastrap-hppa-8.3.0-1.tar.xz
Index: patches/patch-libiberty_cp-demangle_c
===================================================================
RCS file: /home/cvs/ports/lang/gcc/15/patches/patch-libiberty_cp-demangle_c,v
diff -u -p -r1.1.1.1 patch-libiberty_cp-demangle_c
--- patches/patch-libiberty_cp-demangle_c	18 Aug 2025 19:49:24 -0000	1.1.1.1
+++ patches/patch-libiberty_cp-demangle_c	14 Sep 2025 17:33:56 -0000
@@ -1,12 +1,25 @@
+Avoid using sprintf and strcpy: aside from their unsafety they trigger ld(1)
+warnings, leading to broken feature detection when linking test
+programs with libestdc++.
+
 Index: libiberty/cp-demangle.c
 --- libiberty/cp-demangle.c.orig
 +++ libiberty/cp-demangle.c
+@@ -2832,7 +2832,7 @@ cplus_demangle_type (struct d_info *di)
+ 					      &cplus_demangle_builtin_types[34],
+ 					      arg, suffix);
+ 	    d_advance (di, 1);
+-	    sprintf (buf, "%d", arg);
++	    snprintf (buf, sizeof buf, "%d", arg);
+ 	    di->expansion += ret->u.s_extended_builtin.type->len
+ 			     + strlen (buf) + (suffix != 0);
+ 	    break;
 @@ -4618,7 +4618,7 @@ static inline void
  d_append_num (struct d_print_info *dpi, int l)
  {
    char buf[25];
 -  sprintf (buf,"%d", l);
-+  snprintf (buf, 25, "%d", l);
++  snprintf (buf, sizeof buf, "%d", l);
    d_append_string (dpi, buf);
  }
  
Index: patches/patch-libstdc++-v3_src_c++11_debug_cc
===================================================================
RCS file: /home/cvs/ports/lang/gcc/15/patches/patch-libstdc++-v3_src_c++11_debug_cc,v
diff -u -p -r1.1.1.1 patch-libstdc++-v3_src_c++11_debug_cc
--- patches/patch-libstdc++-v3_src_c++11_debug_cc	18 Aug 2025 19:49:25 -0000	1.1.1.1
+++ patches/patch-libstdc++-v3_src_c++11_debug_cc	14 Sep 2025 17:33:28 -0000
@@ -1,3 +1,7 @@
+Avoid using sprintf: aside from its unsafety it triggers ld(1)
+warnings, leading to broken feature detection when linking test
+programs with libestdc++.
+
 Index: libstdc++-v3/src/c++11/debug.cc
 --- libstdc++-v3/src/c++11/debug.cc.orig
 +++ libstdc++-v3/src/c++11/debug.cc
@@ -19,3 +23,30 @@ Index: libstdc++-v3/src/c++11/debug.cc
      print_word(ctx, buf, written);
    }
  
+@@ -1170,7 +1170,7 @@ namespace
+ 
+     PrintContext& ctx = *static_cast<PrintContext*>(data);
+ 
+-    int written = __builtin_sprintf(buf, "%p ", (void*)pc);
++    int written = __builtin_snprintf(buf, sizeof buf, "%p ", (void*)pc);
+     print_word(ctx, buf, written);
+ 
+     int ret = 0;
+@@ -1198,7 +1198,7 @@ namespace
+ 
+ 	if (lineno)
+ 	  {
+-	    written = __builtin_sprintf(buf, ":%u\n", lineno);
++	    written = __builtin_snprintf(buf, sizeof buf, ":%u\n", lineno);
+ 	    print_word(ctx, buf, written);
+ 	  }
+ 	else
+@@ -1221,7 +1221,7 @@ namespace
+     if (errnum > 0)
+       {
+ 	char buf[64];
+-	int written = __builtin_sprintf(buf, " (errno=%d)\n", errnum);
++	int written = __builtin_snprintf(buf, sizeof buf, " (errno=%d)\n", errnum);
+ 	print_word(ctx, buf, written);
+       }
+     else
Index: patches/patch-libstdc++-v3_src_c++17_floating_to_chars_cc
===================================================================
RCS file: patches/patch-libstdc++-v3_src_c++17_floating_to_chars_cc
diff -N patches/patch-libstdc++-v3_src_c++17_floating_to_chars_cc
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ patches/patch-libstdc++-v3_src_c++17_floating_to_chars_cc	14 Sep 2025 17:33:43 -0000
@@ -0,0 +1,24 @@
+Avoid using sprintf: aside from its unsafety it triggers ld(1)
+warnings, leading to broken feature detection when linking test
+programs with libestdc++.
+
+Index: libstdc++-v3/src/c++17/floating_to_chars.cc
+--- libstdc++-v3/src/c++17/floating_to_chars.cc.orig
++++ libstdc++-v3/src/c++17/floating_to_chars.cc
+@@ -1073,14 +1073,14 @@ namespace
+ 	  {
+ 	    // strfromf128 unfortunately doesn't allow .*
+ 	    char fmt[3 * sizeof(int) + 6];
+-	    sprintf(fmt, "%%.%d%c", args..., int(format_string[4]));
++	    snprintf(fmt, sizeof(fmt), "%%.%d%c", args..., int(format_string[4]));
+ 	    len = __strfromf128(buffer, length, fmt, value);
+ 	  }
+       }
+     else
+ #endif
+ #endif
+-    len = sprintf(buffer, format_string, args..., value);
++    len = snprintf(buffer, length, format_string, args..., value);
+ 
+ #if _GLIBCXX_USE_C99_FENV_TR1 && defined(FE_TONEAREST)
+     if (saved_rounding_mode != FE_TONEAREST)
Index: patches/patch-libstdc++-v3_src_c++20_format_cc
===================================================================
RCS file: patches/patch-libstdc++-v3_src_c++20_format_cc
diff -N patches/patch-libstdc++-v3_src_c++20_format_cc
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ patches/patch-libstdc++-v3_src_c++20_format_cc	14 Sep 2025 17:34:28 -0000
@@ -0,0 +1,19 @@
+Avoid using strcpy: aside from its unsafety it triggers ld(1)
+warnings, leading to broken feature detection when linking test
+programs with libestdc++.
+
+Index: libstdc++-v3/src/c++20/format.cc
+--- libstdc++-v3/src/c++20/format.cc.orig
++++ libstdc++-v3/src/c++20/format.cc
+@@ -189,8 +189,9 @@ __with_encoding_conversion(const locale& loc)
+   // just don't delete[] it in the locale(locale, Facet*) constructor.
+   if (const char* name = loc._M_impl->_M_names[0])
+     {
+-      loc2._M_impl->_M_names[0] = new char[strlen(name) + 1];
+-      strcpy(loc2._M_impl->_M_names[0], name);
++      size_t sz = strlen(name) + 1;
++      loc2._M_impl->_M_names[0] = new char[sz];
++      strlcpy(loc2._M_impl->_M_names[0], name, sz);
+     }
+   return loc2;
+ }

-- 
jca