src: drop detecting and redefining system symbol ftruncate

Introduce `toolx_ftruncate()` macro and map it to existing replacements
for non-mingw-w64 Windows and DJGPP, or to `ftruncate` otherwise.

Follow-up to 6041b9b11b #21109

Closes #21130

CMake/unix-cache.cmake

@@ -88,7 +88,6 @@ elseif(CYGWIN OR
   set(HAVE_FSETXATTR_5 1)
   set(HAVE_FSETXATTR_6 0)
 endif()
-set(HAVE_FTRUNCATE 1)
 set(HAVE_GETADDRINFO 1)
 if(CMAKE_SYSTEM_NAME STREQUAL "OpenBSD")
   set(HAVE_GETADDRINFO_THREADSAFE 0)

CMake/win32-cache.cmake

@@ -29,7 +29,6 @@ if(MINGW)
   set(HAVE_BASENAME 1)
   set(HAVE_BOOL_T 1)  # = HAVE_STDBOOL_H
   set(HAVE_DIRENT_H 1)
-  set(HAVE_FTRUNCATE 1)
   set(HAVE_GETTIMEOFDAY 1)
   set(HAVE_LIBGEN_H 1)
   set(HAVE_OPENDIR 1)
@@ -42,7 +41,6 @@ if(MINGW)
   set(HAVE_UTIME_H 1)  # wrapper to sys/utime.h
 else()
   set(HAVE_DIRENT_H 0)
-  set(HAVE_FTRUNCATE 0)
   set(HAVE_GETTIMEOFDAY 0)
   set(HAVE_LIBGEN_H 0)
   set(HAVE_OPENDIR 0)

CMakeLists.txt

@@ -1637,7 +1637,6 @@ check_symbol_exists("freeaddrinfo"    "${CURL_INCLUDES}" HAVE_FREEADDRINFO)  # w
 check_function_exists("pipe"          HAVE_PIPE)
 check_function_exists("pipe2"         HAVE_PIPE2)
 check_function_exists("eventfd"       HAVE_EVENTFD)
-check_symbol_exists("ftruncate"       "unistd.h" HAVE_FTRUNCATE)
 check_symbol_exists("getpeername"     "${CURL_INCLUDES}" HAVE_GETPEERNAME)  # winsock2.h unistd.h proto/bsdsocket.h
 check_symbol_exists("getsockname"     "${CURL_INCLUDES}" HAVE_GETSOCKNAME)  # winsock2.h unistd.h proto/bsdsocket.h
 check_function_exists("getrlimit"     HAVE_GETRLIMIT)

configure.ac

@@ -4086,7 +4086,6 @@ CURL_CHECK_FUNC_CLOSESOCKET_CAMEL
 CURL_CHECK_FUNC_FCNTL
 CURL_CHECK_FUNC_FREEADDRINFO
 CURL_CHECK_FUNC_FSETXATTR
-CURL_CHECK_FUNC_FTRUNCATE
 CURL_CHECK_FUNC_GETADDRINFO
 CURL_CHECK_FUNC_GETHOSTBYNAME_R
 CURL_CHECK_FUNC_GETHOSTNAME

lib/config-mac.h

@@ -51,7 +51,6 @@
 #define HAVE_SYS_UTIME_H        1
 #define HAVE_SYS_IOCTL_H        1
 #define HAVE_ALARM              1
-#define HAVE_FTRUNCATE          1
 #define HAVE_UTIME              1
 #define HAVE_SELECT             1
 #define HAVE_SOCKET             1

lib/config-os400.h

@@ -69,9 +69,6 @@
 /* Define to 1 if you have the freeaddrinfo function. */
 #define HAVE_FREEADDRINFO       1
 
-/* Define to 1 if you have the ftruncate function. */
-#define HAVE_FTRUNCATE                  1
-
 /* Define to 1 if you have a working getaddrinfo function. */
 #define HAVE_GETADDRINFO                1
 

lib/config-riscos.h

@@ -48,9 +48,6 @@
 /* Define if you have the <fcntl.h> header file. */
 #define HAVE_FCNTL_H
 
-/* Define if you have the `ftruncate' function. */
-#define HAVE_FTRUNCATE
-
 /* Define if getaddrinfo exists and works */
 #define HAVE_GETADDRINFO
 

lib/config-win32.h

@@ -86,11 +86,6 @@
 /* Define if you have the closesocket function. */
 #define HAVE_CLOSESOCKET 1
 
-/* Define if you have the ftruncate function. */
-#ifdef __MINGW32__
-#define HAVE_FTRUNCATE 1
-#endif
-
 /* Define to 1 if you have the `getpeername' function. */
 #define HAVE_GETPEERNAME 1
 

lib/curl_config-cmake.h.in

@@ -252,9 +252,6 @@
 /* Define to 1 if you have the fseeko declaration. */
 #cmakedefine HAVE_DECL_FSEEKO 1
 
-/* Define to 1 if you have the ftruncate function. */
-#cmakedefine HAVE_FTRUNCATE 1
-
 /* Define to 1 if you have a working getaddrinfo function. */
 #cmakedefine HAVE_GETADDRINFO 1
 

m4/curl-functions.m4

@@ -1172,91 +1172,6 @@ AC_DEFUN([CURL_CHECK_FUNC_FSETXATTR], [
 ])
 
 
-dnl CURL_CHECK_FUNC_FTRUNCATE
-dnl -------------------------------------------------
-dnl Verify if ftruncate is available, prototyped, and
-dnl can be compiled. If all of these are true, and
-dnl usage has not been previously disallowed with
-dnl shell variable curl_disallow_ftruncate, then
-dnl HAVE_FTRUNCATE will be defined.
-
-AC_DEFUN([CURL_CHECK_FUNC_FTRUNCATE], [
-  AC_REQUIRE([CURL_INCLUDES_UNISTD])dnl
-  #
-  tst_links_ftruncate="unknown"
-  tst_proto_ftruncate="unknown"
-  tst_compi_ftruncate="unknown"
-  tst_allow_ftruncate="unknown"
-  #
-  AC_MSG_CHECKING([if ftruncate can be linked])
-  AC_LINK_IFELSE([
-    AC_LANG_FUNC_LINK_TRY([ftruncate])
-  ],[
-    AC_MSG_RESULT([yes])
-    tst_links_ftruncate="yes"
-  ],[
-    AC_MSG_RESULT([no])
-    tst_links_ftruncate="no"
-  ])
-  #
-  if test "$tst_links_ftruncate" = "yes"; then
-    AC_MSG_CHECKING([if ftruncate is prototyped])
-    AC_EGREP_CPP([ftruncate],[
-      $curl_includes_unistd
-    ],[
-      AC_MSG_RESULT([yes])
-      tst_proto_ftruncate="yes"
-    ],[
-      AC_MSG_RESULT([no])
-      tst_proto_ftruncate="no"
-    ])
-  fi
-  #
-  if test "$tst_proto_ftruncate" = "yes"; then
-    AC_MSG_CHECKING([if ftruncate is compilable])
-    AC_COMPILE_IFELSE([
-      AC_LANG_PROGRAM([[
-        $curl_includes_unistd
-      ]],[[
-        if(ftruncate(0, 0) != 0)
-          return 1;
-      ]])
-    ],[
-      AC_MSG_RESULT([yes])
-      tst_compi_ftruncate="yes"
-    ],[
-      AC_MSG_RESULT([no])
-      tst_compi_ftruncate="no"
-    ])
-  fi
-  #
-  if test "$tst_compi_ftruncate" = "yes"; then
-    AC_MSG_CHECKING([if ftruncate usage allowed])
-    if test "x$curl_disallow_ftruncate" != "xyes"; then
-      AC_MSG_RESULT([yes])
-      tst_allow_ftruncate="yes"
-    else
-      AC_MSG_RESULT([no])
-      tst_allow_ftruncate="no"
-    fi
-  fi
-  #
-  AC_MSG_CHECKING([if ftruncate might be used])
-  if test "$tst_links_ftruncate" = "yes" &&
-     test "$tst_proto_ftruncate" = "yes" &&
-     test "$tst_compi_ftruncate" = "yes" &&
-     test "$tst_allow_ftruncate" = "yes"; then
-    AC_MSG_RESULT([yes])
-    AC_DEFINE_UNQUOTED(HAVE_FTRUNCATE, 1,
-      [Define to 1 if you have the ftruncate function.])
-    curl_cv_func_ftruncate="yes"
-  else
-    AC_MSG_RESULT([no])
-    curl_cv_func_ftruncate="no"
-  fi
-])
-
-
 dnl CURL_CHECK_FUNC_GETADDRINFO
 dnl -------------------------------------------------
 dnl Verify if getaddrinfo is available, prototyped, can

src/tool_cb_hdr.c

@@ -270,7 +270,7 @@ static size_t save_etag(const char *etag_h, const char *endp,
       if((fd != -1) &&
          !curlx_fstat(fd, &file) &&
          (S_ISREG(file.st_mode) &&
-          ftruncate(fd, 0)))
+          toolx_ftruncate(fd, 0)))
         return CURL_WRITEFUNC_ERROR;
 
       fwrite(etag_h, 1, etag_length, etag_save->stream);

src/tool_operate.c

@@ -559,7 +559,7 @@ static CURLcode retrycheck(struct OperationConfig *config,
         notef("Throwing away %" CURL_FORMAT_CURL_OFF_T " bytes", outs->bytes);
         /* truncate file at the position where we started appending */
 
-        if(ftruncate(fileno(outs->stream), outs->init)) {
+        if(toolx_ftruncate(fileno(outs->stream), outs->init)) {
           /* when truncate fails, we cannot append as then we
              create something strange, bail out */
           errorf("Failed to truncate file");

src/tool_setup.h

@@ -94,26 +94,16 @@ extern FILE *tool_stderr;
 #ifdef _WIN32
 /* set in init_terminal() */
 extern bool tool_term_has_bold;
+#endif
 
-#ifndef HAVE_FTRUNCATE
+#if defined(_WIN32) && !defined(__MINGW32__)
-
+int toolx_ftruncate_win32(int fd, curl_off_t where);
-int tool_ftruncate64(int fd, curl_off_t where);
+#define toolx_ftruncate toolx_ftruncate_win32
-
+#elif defined(__DJGPP__)
-#undef  ftruncate
+int toolx_ftruncate_djgpp(int fd, curl_off_t where);
-#define ftruncate(fd, where) tool_ftruncate64(fd, where)
+#define toolx_ftruncate toolx_ftruncate_djgpp
-
+#else
-#define HAVE_FTRUNCATE 1
+#define toolx_ftruncate ftruncate
-#define USE_TOOL_FTRUNCATE 1
-
-#endif /* !HAVE_FTRUNCATE */
-#endif /* _WIN32 */
-
-#ifdef __DJGPP__
-int msdos_ftruncate(int fd, curl_off_t where);
-#undef HAVE_FTRUNCATE
-#undef ftruncate /* to be sure */
-#define ftruncate(fd, where) msdos_ftruncate(fd, where)
-#define USE_MSDOS_FTRUNCATE 1
 #endif
 
 #ifdef CURL_CA_EMBED

src/tool_util.c

@@ -78,11 +78,11 @@ int struplocompare4sort(const void *p1, const void *p2)
   return struplocompare(*(char * const *)p1, *(char * const *)p2);
 }
 
-#ifdef USE_TOOL_FTRUNCATE
+#if defined(_WIN32) && !defined(__MINGW32__)
 /*
  * Truncate a file handle at a 64-bit position 'where'.
  */
-int tool_ftruncate64(int fd, curl_off_t where)
+int toolx_ftruncate_win32(int fd, curl_off_t where)
 {
   intptr_t handle = _get_osfhandle(fd);
 
@@ -94,21 +94,18 @@ int tool_ftruncate64(int fd, curl_off_t where)
 
   return 0;
 }
-#endif /* USE_TOOL_FTRUNCATE */
+#elif defined(__DJGPP__)
-
-#ifdef USE_MSDOS_FTRUNCATE
 /*
  * Only supports 'off_t' (signed 32 bit) as file size.
  */
-int msdos_ftruncate(int fd, curl_off_t where)
+int toolx_ftruncate_djgpp(int fd, curl_off_t where)
 {
   if(where > INT_MAX)
     return -1;
 
-  /* avoid using the macro for this */
+  return ftruncate(fd, (off_t)where);
-  return (ftruncate)(fd, (off_t) where);
 }
-#endif /* USE_MSDOS_FTRUNCATE */
+#endif
 
 #ifdef _WIN32
 FILE *tool_execpath(const char *filename, char **pathp)