ENH: Support large file systems in kwsys

3 files changed, 59 insertions, 0 deletions

diff --git a/Source/kwsys/CMakeLists.txt b/Source/kwsys/CMakeLists.txt
index 2145b7d..aee68e2 100644
--- a/Source/kwsys/CMakeLists.txt
+++ b/Source/kwsys/CMakeLists.txt
@@ -241,6 +241,23 @@ IF(NOT KWSYS_IN_SOURCE_BUILD)
     ${PROJECT_BINARY_DIR}/kwsysPrivate.h COPY_ONLY IMMEDIATE)
 ENDIF(NOT KWSYS_IN_SOURCE_BUILD)
 
+
+IF("${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION}" LESS 2.4)
+  MESSAGE(STATUS "Skip large files support because CMake is earlier than 2.4")
+ELSE("${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION}" LESS 2.4)
+  INCLUDE(CheckCXXSourceRuns)
+  FILE(READ "${CMAKE_CURRENT_SOURCE_DIR}/RequireLargeFilesSupport.cxx"
+    __kwsys_require_large_files_support)
+  CHECK_CXX_SOURCE_RUNS("${__kwsys_require_large_files_support}"
+    REQUIRE_LARGE_FILE_SUPPORT
+    "Support for 64 bit file systems")
+  IF(REQUIRE_LARGE_FILE_SUPPORT)
+    SET(KWSYS_REQUIRE_LARGE_FILE_SUPPORT 1)
+  ELSE(REQUIRE_LARGE_FILE_SUPPORT)
+    SET(KWSYS_REQUIRE_LARGE_FILE_SUPPORT 0)
+  ENDIF(REQUIRE_LARGE_FILE_SUPPORT)
+ENDIF("${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION}" LESS 2.4)
+
 #-----------------------------------------------------------------------------
 # We require ANSI support from the C compiler.  Add any needed flags.
 IF(CMAKE_ANSI_CFLAGS)
diff --git a/Source/kwsys/Configure.h.in b/Source/kwsys/Configure.h.in
index 744e884..5456467 100644
--- a/Source/kwsys/Configure.h.in
+++ b/Source/kwsys/Configure.h.in
@@ -22,6 +22,20 @@
 # define kwsysEXPORT @KWSYS_NAMESPACE@_EXPORT
 #endif
 
+/* This is a support for files on the disk that are larger than 2GB.  Since
+   this is the first place that any include should happen, do this here. */
+#if @KWSYS_REQUIRE_LARGE_FILE_SUPPORT@
+#  ifndef _LARGEFILE_SOURCE
+#    define _LARGEFILE_SOURCE
+#  endif
+#  ifndef _LARGE_FILES
+#    define _LARGE_FILES
+#  endif
+#  ifndef _FILE_OFFSET_BITS
+#    define _FILE_OFFSET_BITS 64
+#  endif
+#endif
+
 /* Setup the export macro.  */
 #if defined(_WIN32) && @KWSYS_BUILD_SHARED@
 # if defined(@KWSYS_NAMESPACE@_EXPORTS)
diff --git a/Source/kwsys/RequireLargeFilesSupport.cxx b/Source/kwsys/RequireLargeFilesSupport.cxx
new file mode 100644
index 0000000..596bd60
--- /dev/null
+++ b/Source/kwsys/RequireLargeFilesSupport.cxx
@@ -0,0 +1,28 @@
+#define _LARGEFILE_SOURCE
+#define _LARGE_FILES
+#define _FILE_OFFSET_BITS 64
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <assert.h>
+#include <stdio.h>
+
+int main( int, char **argv )
+{
+  // check that off_t can hold 2^63 - 1 and perform basic operations...
+#define OFF_T_64 (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+  if (OFF_T_64 % 2147483647 != 1)
+    return 1;
+
+  // stat breaks on SCO OpenServer
+  struct stat buf;
+  stat( argv[0], &buf );
+  if (!S_ISREG(buf.st_mode))
+    return 2;
+
+  FILE *file = fopen( argv[0], "r" );
+  off_t offset = ftello( file );
+  fseek( file, offset, SEEK_CUR );
+  fclose( file );
+  return 0;
+}
+