Re: [PATCH 2/4] libbacktrace: detect executable path on windows

[Ian Lance Taylor via Gcc]

On Mon, Nov 20, 2023 at 11:57 AM Björn Schäpers <g...@hazardy.de> wrote:
>
> this is what I'm using with GCC 12 and 13 on my windows machines, rebased onto
> the current HEAD.

Thanks.  Committed as follows.

Ian

            * fileline.c: Include <windows.h> if available.
            (windows_get_executable_path): New static function.
            (fileline_initialize): Call windows_get_executable_path.
            * configure.ac: Checked for windows.h
            * configure: Regenerate.
            * config.h.in: Regenerate.

0ee01dfacbcc9bc05d11433a69c0a0ac13afa42f
diff --git a/libbacktrace/config.h.in b/libbacktrace/config.h.in
index a4f5bddddf6..ee2616335c7 100644
--- a/libbacktrace/config.h.in
+++ b/libbacktrace/config.h.in
@@ -104,6 +104,9 @@
 /* Define to 1 if you have the <unistd.h> header file. */
 #undef HAVE_UNISTD_H
 
+/* Define to 1 if you have the <windows.h> header file. */
+#undef HAVE_WINDOWS_H
+
 /* Define if -lz is available. */
 #undef HAVE_ZLIB
 
diff --git a/libbacktrace/configure b/libbacktrace/configure
index 0ccc060901d..7ade966b54d 100755
--- a/libbacktrace/configure
+++ b/libbacktrace/configure
@@ -13509,6 +13509,19 @@ $as_echo "#define HAVE_LOADQUERY 1" >>confdefs.h
 
 fi
 
+for ac_header in windows.h
+do :
+  ac_fn_c_check_header_mongrel "$LINENO" "windows.h" "ac_cv_header_windows_h" 
"$ac_includes_default"
+if test "x$ac_cv_header_windows_h" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_WINDOWS_H 1
+_ACEOF
+
+fi
+
+done
+
+
 # Check for the fcntl function.
 if test -n "${with_target_subdir}"; then
    case "${host}" in
diff --git a/libbacktrace/configure.ac b/libbacktrace/configure.ac
index 71cd50f8cdf..00acb42eb6d 100644
--- a/libbacktrace/configure.ac
+++ b/libbacktrace/configure.ac
@@ -379,6 +379,8 @@ if test "$have_loadquery" = "yes"; then
   AC_DEFINE(HAVE_LOADQUERY, 1, [Define if AIX loadquery is available.])
 fi
 
+AC_CHECK_HEADERS(windows.h)
+
 # Check for the fcntl function.
 if test -n "${with_target_subdir}"; then
    case "${host}" in
diff --git a/libbacktrace/fileline.c b/libbacktrace/fileline.c
index 0e560b44e7a..773f3a92969 100644
--- a/libbacktrace/fileline.c
+++ b/libbacktrace/fileline.c
@@ -47,6 +47,18 @@ POSSIBILITY OF SUCH DAMAGE.  */
 #include <mach-o/dyld.h>
 #endif
 
+#ifdef HAVE_WINDOWS_H
+#ifndef WIN32_MEAN_AND_LEAN
+#define WIN32_MEAN_AND_LEAN
+#endif
+
+#ifndef NOMINMAX
+#define NOMINMAX
+#endif
+
+#include <windows.h>
+#endif
+
 #include "backtrace.h"
 #include "internal.h"
 
@@ -165,6 +177,37 @@ macho_get_executable_path (struct backtrace_state *state,
 
 #endif /* !HAVE_DECL__PGMPTR */
 
+#ifdef HAVE_WINDOWS_H
+
+#define FILENAME_BUF_SIZE (MAX_PATH)
+
+static char *
+windows_get_executable_path (char *buf, backtrace_error_callback 
error_callback,
+                            void *data)
+{
+  size_t got;
+  int error;
+
+  got = GetModuleFileNameA (NULL, buf, FILENAME_BUF_SIZE - 1);
+  error = GetLastError ();
+  if (got == 0
+      || (got == FILENAME_BUF_SIZE - 1 && error == ERROR_INSUFFICIENT_BUFFER))
+    {
+      error_callback (data,
+                     "could not get the filename of the current executable",
+                     error);
+      return NULL;
+    }
+  return buf;
+}
+
+#else /* !defined (HAVE_WINDOWS_H) */
+
+#define windows_get_executable_path(buf, error_callback, data) NULL
+#define FILENAME_BUF_SIZE 64
+
+#endif /* !defined (HAVE_WINDOWS_H) */
+
 /* Initialize the fileline information from the executable.  Returns 1
    on success, 0 on failure.  */
 
@@ -178,7 +221,7 @@ fileline_initialize (struct backtrace_state *state,
   int called_error_callback;
   int descriptor;
   const char *filename;
-  char buf[64];
+  char buf[FILENAME_BUF_SIZE];
 
   if (!state->threaded)
     failed = state->fileline_initialization_failed;
@@ -202,7 +245,7 @@ fileline_initialize (struct backtrace_state *state,
 
   descriptor = -1;
   called_error_callback = 0;
-  for (pass = 0; pass < 9; ++pass)
+  for (pass = 0; pass < 10; ++pass)
     {
       int does_not_exist;
 
@@ -239,6 +282,9 @@ fileline_initialize (struct backtrace_state *state,
        case 8:
          filename = macho_get_executable_path (state, error_callback, data);
          break;
+       case 9:
+         filename = windows_get_executable_path (buf, error_callback, data);
+         break;
        default:
          abort ();
        }