[gcc r15-631] libstdc++: detect DLLs on windows with <stacktrace>

[gcc r15-631] libstdc++: detect DLLs on windows with <stacktrace>

[Jonathan Wakely]

https://gcc.gnu.org/g:d4635b504c73b653b815d2c2543c86c91b00e373

commit r15-631-gd4635b504c73b653b815d2c2543c86c91b00e373
Author: Björn Schäpers <bjoern@hazardy.de>
Date:   Fri May 17 11:45:28 2024 +0100

    libstdc++: detect DLLs on windows with <stacktrace>
    
    libstdc++-v3/ChangeLog:
    
            * acinclude.m4 (GLIBCXX_ENABLE_BACKTACE): Add check for
            tlhelp32.h, matching libbacktrace.
            * config.h.in: Regenerate.
            * configure: Regenerate.
    
    Signed-off-by: Björn Schäpers <bjoern@hazardy.de>

Diff:
---
 libstdc++-v3/acinclude.m4 |  5 +++++
 libstdc++-v3/config.h.in  |  3 +++
 libstdc++-v3/configure    | 16 ++++++++++++++++
 3 files changed, 24 insertions(+)

diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4
index 51a08bcc8b1d..e04aae25360d 100644
--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -5481,6 +5481,11 @@ AC_DEFUN([GLIBCXX_ENABLE_BACKTRACE], [
     BACKTRACE_CPPFLAGS="$BACKTRACE_CPPFLAGS -DHAVE_DL_ITERATE_PHDR=1"
   fi
   AC_CHECK_HEADERS(windows.h)
+  AC_CHECK_HEADERS(tlhelp32.h, [], [],
+  [#ifdef HAVE_WINDOWS_H
+  #  include <windows.h>
+  #endif
+  ])
 
   # Check for the fcntl function.
   if test -n "${with_target_subdir}"; then
diff --git a/libstdc++-v3/config.h.in b/libstdc++-v3/config.h.in
index 906e0143099e..486ba4507499 100644
--- a/libstdc++-v3/config.h.in
+++ b/libstdc++-v3/config.h.in
@@ -490,6 +490,9 @@
 /* Define to 1 if you have the `timespec_get' function. */
 #undef HAVE_TIMESPEC_GET
 
+/* Define to 1 if you have the <tlhelp32.h> header file. */
+#undef HAVE_TLHELP32_H
+
 /* Define to 1 if the target supports thread-local storage. */
 #undef HAVE_TLS
 
diff --git a/libstdc++-v3/configure b/libstdc++-v3/configure
index 21abaeb07788..5179cc507f12 100755
--- a/libstdc++-v3/configure
+++ b/libstdc++-v3/configure
@@ -53865,6 +53865,22 @@ _ACEOF
 
 fi
 
+done
+
+  for ac_header in tlhelp32.h
+do :
+  ac_fn_c_check_header_compile "$LINENO" "tlhelp32.h" "ac_cv_header_tlhelp32_h" "#ifdef HAVE_WINDOWS_H
+  #  include <windows.h>
+  #endif
+
+"
+if test "x$ac_cv_header_tlhelp32_h" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_TLHELP32_H 1
+_ACEOF
+
+fi
+
 done