gmio_core: provide a POSIX implementation for gmio_stream_stdio_size()

CMakeLists.txt

@@ -25,7 +25,7 @@ project(gmio C)
 
 # Options
 option(BUILD_SHARED_LIBS  "Build shared libraries (DLL)" ON)
-option(BUILD_STRICT_C90   "Build with strict conformance to C90 standard. If disabled, C99 features can be used (eg. strtof(), <stdint.h>, ...)" ON)
+option(BUILD_STRICT_C90   "Build with strict conformance to C90 standard" OFF)
 option(BUILD_WITH_LIBSTL  "Build the libSTL module" ON)
 
 # Add core source files
@@ -39,31 +39,49 @@ math(EXPR GMIO_TARGET_ARCH_BIT_SIZE "8 * ${CMAKE_SIZEOF_VOID_P}")
 include(TestBigEndian)
 test_big_endian(GMIO_HOST_IS_BIG_ENDIAN)
 
-# Find available C99 features
+# Adapt C compiler flags to satisfy the BUILD_STRICT_C90 option
-if(NOT BUILD_STRICT_C90)
+#    It must be done before checking of C99 and POSIX features
-    # Have <stdint.h> ?
+if(BUILD_STRICT_C90)
-    check_include_files(stdint.h GMIO_HAVE_STDINT_H)
+    if(CMAKE_COMPILER_IS_GNUCC)
-
+        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -ansi")
-    # Have strtof() ?
+    elseif(MSVC)
-    check_function_exists(strtof GMIO_HAVE_STRTOF_FUNC)
+        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} /Za")
-
+    endif()
-    # Have powf() ?
-    check_function_exists(powf GMIO_HAVE_POWF_FUNC)
-
-    # Have <stdbool.h> ?
-    check_include_files(stdbool.h GMIO_HAVE_STDBOOL_H)
 endif()
 
-# Have alloca()-like function ?
+set(CMAKE_REQUIRED_FLAGS "${CMAKE_C_FLAGS}")
-check_c_source_compiles(
-    "#include <alloca.h>
-     int main() { void* ptr = alloca(256); return 0; }"
-    GMIO_HAVE_BSD_ALLOCA_FUNC)
 
-check_c_source_compiles(
+# Some compilers (like GCC v4.9) don't disable <stdint.h> in STRICT_ANSI mode
-    "#include <malloc.h>
+check_include_files(stdint.h GMIO_HAVE_STDINT_H)
-     int main() { void* ptr = _alloca(256); return 0; }"
+
-    GMIO_HAVE_WIN_ALLOCA_FUNC)
+check_include_files(sys/types.h GMIO_HAVE_SYS_TYPES_H)
+check_include_files(sys/stat.h GMIO_HAVE_SYS_STAT_H)
+check_function_exists(fileno GMIO_HAVE_POSIX_FILENO_FUNC)
+check_function_exists(fstat64 GMIO_HAVE_POSIX_FSTAT64_FUNC)
+if(WIN32)
+    check_function_exists(_fstat64 GMIO_HAVE_WIN__FSTAT64_FUNC)
+endif()
+
+# Find available C99 and compiler/OS specific features
+if(NOT BUILD_STRICT_C90)
+    check_function_exists(strtof GMIO_HAVE_STRTOF_FUNC)
+    check_function_exists(powf GMIO_HAVE_POWF_FUNC)
+    check_include_files(stdbool.h GMIO_HAVE_STDBOOL_H)
+
+    # Have BSD-like alloca() function ?
+    check_c_source_compiles(
+        "#include <alloca.h>
+         int main() { void* ptr = alloca(256); return 0; }"
+        GMIO_HAVE_BSD_ALLOCA_FUNC)
+
+    if(WIN32)
+        # Have Win32 _alloca() function ?
+        check_c_source_compiles(
+            "#include <malloc.h>
+             int main() { void* ptr = _alloca(256); return 0; }"
+            GMIO_HAVE_WIN_ALLOCA_FUNC) # TODO: rename to GMIO_HAVE_WIN__ALLOCA_FUNC
+    endif() # WIN32
+endif()
 
 # Have builtin byte swap functions ?
 if(CMAKE_COMPILER_IS_GNUCC)
@@ -87,9 +105,6 @@ include_directories(${CMAKE_BINARY_DIR}) # For generated "config.h"
 
 # Specific flags for GCC
 if(CMAKE_COMPILER_IS_GNUCC)
-    if(BUILD_STRICT_C90)
-        set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -ansi")
-    endif()
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -pedantic-errors -fstrict-aliasing")
     set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Winline -Wextra -Wstrict-aliasing -Wcast-align -Wlogical-op -Wfloat-equal")
 

src/gmio_core/config.h.cmake

@@ -23,6 +23,12 @@
 #cmakedefine GMIO_HAVE_STRTOF_FUNC
 #cmakedefine GMIO_HAVE_POWF_FUNC
 
+#cmakedefine GMIO_HAVE_SYS_TYPES_H
+#cmakedefine GMIO_HAVE_SYS_STAT_H
+#cmakedefine GMIO_HAVE_POSIX_FILENO_FUNC
+#cmakedefine GMIO_HAVE_POSIX_FSTAT64_FUNC
+#cmakedefine GMIO_HAVE_WIN__FSTAT64_FUNC
+
 #cmakedefine GMIO_HAVE_GCC_BUILTIN_BSWAP16_FUNC
 #cmakedefine GMIO_HAVE_GCC_BUILTIN_BSWAP32_FUNC
 

src/gmio_core/global.h

@@ -23,6 +23,18 @@
 #if defined(WIN64) || defined(_WIN64) || defined(__WIN64__) \
       || defined(WIN32) || defined(_WIN32) || defined(__WIN32__) \
       || defined(__NT__)
+#  define GMIO_OS_WIN
+#endif /* Windows */
+
+#if defined(__linux) || defined(__linux__) || defined(linux)
+#  define GMIO_OS_LINUX
+#endif /* Linux */
+
+#if defined(__APPLE__)
+#  define GMIO_OS_MAC
+#endif /* Apple */
+
+#ifdef GMIO_OS_WIN
 #  define GMIO_DECL_EXPORT __declspec(dllexport)
 #  define GMIO_DECL_IMPORT __declspec(dllimport)
 #else
@@ -118,7 +130,7 @@ typedef double gmio_float64_t;
 #  elif defined(_MSC_VER)
 #    define GMIO_INLINE __inline static
 #  elif !defined(DOXYGEN)
-#    define GMIO_INLINE
+#    define GMIO_INLINE static
 #  else
 /*! Expands to the C compiler specific inline keyword (if any) */
 #    define GMIO_INLINE

src/gmio_core/stream.c

@@ -19,9 +19,53 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-/* TODO: add cmake step to check availability of <sys/xxx.h> header files */
+#if defined(GMIO_HAVE_SYS_TYPES_H) && defined(GMIO_HAVE_SYS_STAT_H)
-#include <sys/types.h>
+
-#include <sys/stat.h>
+/* Activate 64bit variants of stat(), fstat(), ...
+ * See:
+ *   http://linux.die.net/man/2/fstat64
+ *   https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man2/fstat.2.html
+ */
+#  ifdef GMIO_OS_LINUX
+#    if defined(_FILE_OFFSET_BITS) && _FILE_OFFSET_BITS != 64
+#      undef _FILE_OFFSET_BITS
+#    endif
+#    if !defined(_FILE_OFFSET_BITS)
+#      define _FILE_OFFSET_BITS=64
+#    endif
+#    if !defined(_POSIX_C_SOURCE)
+       /* This enables fileno() */
+#      define _POSIX_C_SOURCE
+#    endif
+#    define GMIO_FSTAT64_OVERRIDE
+#  endif /* Linux */
+
+#  ifdef GMIO_OS_MAC
+#    if !defined(_DARWIN_USE_64_BIT_INODE)
+#      define _DARWIN_USE_64_BIT_INODE
+#    endif
+#    define GMIO_FSTAT64_OVERRIDE
+#  endif /* Apple */
+
+#  include <sys/types.h>
+#  include <sys/stat.h>
+
+/* Define wrapper around the stat structure and the fstat() function */
+#  ifdef GMIO_HAVE_WIN__FSTAT64_FUNC
+typedef struct __stat64 gmio_stat_t;
+GMIO_INLINE int gmio_fstat(int fd, gmio_stat_t* buf)
+{ return _fstat64(fd, buf); }
+#  elif defined(GMIO_FSTAT64_OVERRIDE) || !defined(GMIO_HAVE_POSIX_FSTAT64_FUNC)
+typedef struct stat gmio_stat_t;
+GMIO_INLINE int gmio_fstat(int fd, gmio_stat_t* buf)
+{ return fstat(fd, buf); }
+#  elif defined(GMIO_HAVE_POSIX_FSTAT64_FUNC)
+typedef struct stat64 gmio_stat_t;
+GMIO_INLINE int gmio_fstat(int fd, gmio_stat_t* buf)
+{ return fstat64(fd, buf); }
+#  endif
+
+#endif /* GMIO_HAVE_SYS_TYPES_H && GMIO_HAVE_SYS_STAT_H */
 
 gmio_stream_t gmio_stream_null()
 {
@@ -53,9 +97,58 @@ static size_t gmio_stream_stdio_write(
 
 static size_t gmio_stream_stdio_size(void* cookie)
 {
-    struct stat stat_buf;
+    FILE* file = (FILE*) cookie;
-    fstat(fileno((FILE*) cookie), &stat_buf);
+
-    return stat_buf.st_size;
+#if defined(GMIO_HAVE_SYS_TYPES_H) \
+    && defined(GMIO_HAVE_SYS_STAT_H) \
+    && defined(GMIO_HAVE_POSIX_FILENO_FUNC)
+
+    const int fd = fileno(file);
+    if (fd != -1) {
+        gmio_stat_t buf;
+        if (gmio_fstat(fd, &buf) == 0)
+            return buf.st_size;
+    }
+    return 0;
+
+#else
+
+    /* Excerpted from: https://www.securecoding.cert.org
+     *                 item FIO19-C
+     *
+     * Subclause 7.21.9.2 of the C Standard [ISO/IEC 9899:2011] specifies the
+     * following behavior for fseek() when opening a binary file in binary mode:
+     *     A binary stream need not meaningfully support fseek calls with a
+     *     whence value of SEEK_END.
+     *
+     * In addition, footnote 268 of subclause 7.21.3 says:
+     *     Setting the file position indicator to end-of-file, as with
+     *     fseek(file, 0, SEEK_END), has undefined behavior for a binary stream
+     *     (because of possible trailing null characters) or for any stream with
+     *     state-dependent encoding that does not assuredly end in the initial
+     *     shift state.
+     *
+     * Subclause 7.21.9.4 of the C Standard [ISO/IEC 9899:2011] specifies the
+     * following behavior for ftell() when opening a text file in text mode:
+     *     For a text stream, its file position indicator contains unspecified
+     *     information, usable by the fseek function for returning the file
+     *     position indicator for the stream to its position at the time of the
+     *     ftell call.
+     * Consequently, the return value of ftell() for streams opened in text mode
+     * should never be used for offset calculations other than in calls to
+     * fseek().
+     */
+
+    long size = 0L;
+    const long old_pos = ftell(file);
+
+    fseek(file, 0L, SEEK_END);
+    size = ftell(file);
+    fseek(file, old_pos, SEEK_SET);
+
+    return size;
+
+#endif
 }
 
 static void gmio_stream_stdio_rewind(void* cookie)