From: Viktor Szakats <commit@vsz.me>
Date: Mon, 16 Jun 2025 08:16:17 +0000 (+0200)
Subject: windows: fixup `fopen()` in `CURLDEBUG` builds
X-Git-Tag: curl-8_15_0~253
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6828009695a951195efbd6def3856feaa0e769fd;p=thirdparty%2Fcurl.git

windows: fixup `fopen()` in `CURLDEBUG` builds

Introduce an immutable `CURL_FOPEN()` macro to store the `fopen()`
mapping on Windows. Then use that instead `(fopen)` from `memdebug.c`.
It makes CURLDEBUG builds use the correct `fopen` wrapper on Windows.
This macro is only defined on Windows, as of this patch.

This is necessary after cde81e4398f2944e60c73f38823dafa305a5a2f4,
which no longer applies the default `fopen()` override to `memdebug.c`.

Also:
- curl_setup.h: de-dupe, simplify Windows file I/O function overrides.
- curl_memory.h: fix to reset `fopen` to `curlx_win32_fopen()` on
  Windows. Before this patch it reset it to stock `fopen()`.

Follow-up to cde81e4398f2944e60c73f38823dafa305a5a2f4 #17631

Closes #16747
---

diff --git a/lib/curl_memory.h b/lib/curl_memory.h
index 00a26b6980..0faf928617 100644
--- a/lib/curl_memory.h
+++ b/lib/curl_memory.h
@@ -87,6 +87,9 @@
 #undef sclose
 #define sclose(x)  CURL_SCLOSE(x)
 #undef fopen
+#ifdef CURL_FOPEN
+#define fopen(fname, mode)  CURL_FOPEN(fname, mode)
+#endif
 #undef fdopen
 #undef fclose
 
diff --git a/lib/curl_setup.h b/lib/curl_setup.h
index ae89cc8e44..79a658fda5 100644
--- a/lib/curl_setup.h
+++ b/lib/curl_setup.h
@@ -470,62 +470,46 @@
 #include <curl/stdcheaders.h>
 #endif
 
-/*
- * Large file (>2Gb) support using Win32 functions.
- */
-
-#ifdef USE_WIN32_LARGE_FILES
+#ifdef _WIN32
 #  ifdef HAVE_IO_H
 #  include <io.h>
 #  endif
 #  include <sys/types.h>
 #  include <sys/stat.h>
-#  undef  lseek
-#  define lseek(fdes,offset,whence)  _lseeki64(fdes, offset, whence)
-#  undef  fstat
-#  define fstat(fdes,stp)            _fstati64(fdes, stp)
-#  undef  stat
-#  define stat(fname,stp)            curlx_win32_stat(fname, stp)
-#  define struct_stat                struct _stati64
-#  define LSEEK_ERROR                (__int64)-1
-#  define open                       curlx_win32_open
-#  define fopen(fname,mode)          curlx_win32_fopen(fname, mode)
-   int curlx_win32_open(const char *filename, int oflag, ...);
-   int curlx_win32_stat(const char *path, struct_stat *buffer);
-   FILE *curlx_win32_fopen(const char *filename, const char *mode);
-#endif
-
-#ifdef __DJGPP__
-/* Requires DJGPP 2.04 */
-#  include <unistd.h>
-#  undef  lseek
-#  define lseek(fdes,offset,whence)  llseek(fdes, offset, whence)
-#  define LSEEK_ERROR                (offset_t)-1
-#endif
-
-/*
- * Small file (<2Gb) support using Win32 functions.
- */
-
-#if defined(_WIN32) && !defined(USE_WIN32_LARGE_FILES)
-#  ifdef HAVE_IO_H
-#  include <io.h>
+#  ifdef USE_WIN32_LARGE_FILES
+     /* Large file (>2Gb) support using Win32 functions. */
+#    undef  lseek
+#    define lseek(fdes, offset, whence)  _lseeki64(fdes, offset, whence)
+#    undef  fstat
+#    define fstat(fdes,stp)              _fstati64(fdes, stp)
+#    undef  stat
+#    define struct_stat                  struct _stati64
+#    define LSEEK_ERROR                  (__int64)-1
+#  else
+     /* Small file (<2Gb) support using Win32 functions. */
+#    ifndef UNDER_CE
+#      undef  lseek
+#      define lseek(fdes, offset, whence)  _lseek(fdes, (long)offset, whence)
+#      define fstat(fdes, stp)             _fstat(fdes, stp)
+#      define struct_stat                  struct _stat
+#    endif
+#    define LSEEK_ERROR                  (long)-1
 #  endif
-#  include <sys/types.h>
-#  include <sys/stat.h>
 #  ifndef UNDER_CE
-#    undef  lseek
-#    define lseek(fdes,offset,whence)  _lseek(fdes, (long)offset, whence)
-#    define fstat(fdes,stp)            _fstat(fdes, stp)
-#    define stat(fname,stp)            curlx_win32_stat(fname, stp)
-#    define struct_stat                struct _stat
-#    define open                       curlx_win32_open
-#    define fopen(fname,mode)          curlx_win32_fopen(fname, mode)
      int curlx_win32_stat(const char *path, struct_stat *buffer);
      int curlx_win32_open(const char *filename, int oflag, ...);
      FILE *curlx_win32_fopen(const char *filename, const char *mode);
+#    define stat(fname, stp)           curlx_win32_stat(fname, stp)
+#    define open                       curlx_win32_open
+#    define CURL_FOPEN(fname, mode)    curlx_win32_fopen(fname, mode)
+#    define fopen(fname, mode)         CURL_FOPEN(fname, mode)
 #  endif
-#  define LSEEK_ERROR                (long)-1
+#elif defined(__DJGPP__)
+   /* Requires DJGPP 2.04 */
+#  include <unistd.h>
+#  undef  lseek
+#  define lseek(fdes,offset,whence)  llseek(fdes, offset, whence)
+#  define LSEEK_ERROR                (offset_t)-1
 #endif
 
 #ifndef struct_stat
diff --git a/lib/memdebug.c b/lib/memdebug.c
index 832944d2b0..5bce90bd93 100644
--- a/lib/memdebug.c
+++ b/lib/memdebug.c
@@ -78,7 +78,11 @@ void curl_dbg_memdebug(const char *logname)
 {
   if(!curl_dbg_logfile) {
     if(logname && *logname)
+#ifdef CURL_FOPEN
+      curl_dbg_logfile = CURL_FOPEN(logname, FOPEN_WRITETEXT);
+#else
       curl_dbg_logfile = (fopen)(logname, FOPEN_WRITETEXT);
+#endif
     else
       curl_dbg_logfile = stderr;
 #ifdef MEMDEBUG_LOG_SYNC
@@ -414,7 +418,12 @@ ALLOC_FUNC
 FILE *curl_dbg_fopen(const char *file, const char *mode,
                      int line, const char *source)
 {
-  FILE *res = (fopen)(file, mode);
+  FILE *res;
+#ifdef CURL_FOPEN
+  res = CURL_FOPEN(file, mode);
+#else
+  res = (fopen)(file, mode);
+#endif
 
   if(source)
     curl_dbg_log("FILE %s:%d fopen(\"%s\",\"%s\") = %p\n",