Changeset 35554

Timestamp:

2021-10-12T14:55:23+13:00 (3 years ago)

Author:

davidb

Message:

While it was discovered that JAVAGDBM had some macros defined to help with type-casting between pointers and "int/long/jlong" where the pointer is handled 'numerically' as a memory location, it was found during testing under Windows 64-bit that the actual #ifdef that picks out the macro to use wasn't 'firing' correctly as SIZEOF_VOID_P and SIZEOF_LONG were not defined AT ALLsvn status The code change here takes a conservative line: it tests to see if these values are defined, and if not, resorts to a sequence of further #ifdef tests using values that gcc and VisualStudio set based on the 'size of' model for int, long, and pointers, to correcty determine what values they should be

File:

• main/trunk/greenstone3/src/packages/javagdbm/jni/gdbmjava.c (modified) (2 diffs)

main/trunk/greenstone3/src/packages/javagdbm/jni/gdbmjava.c

@@ -41 +41 @@
 #define GDBM_FILE gdbm_file_info *
 extern char* gdbm_version;
+extern char *gdbm_strerror(gdbm_error);
 #else
 #include <gdbm.h>
@@ -90 +91 @@
 jbyteArray datumToArray(JNIEnv *env, datum *fromDatum);
 
+/* 
+   The macros defined below for DBF_TO_JLONG(x) and JLONG_TO_DBF(x)
+   expect SIZEOF_VOID_P and SIZEOF_LONG to be defined.
+
+   It's possible for autoconf to determine these, but:
+   (a) This currently doesn't appear to be bound into JAVAGDBM
+       compilation sequence (config.h would need to be #included)
+   (b) Even if this was done for Unix system, there would still
+       need to be a way to do this for Windows: both 32-bit and
+       64-bit as the values would be differnt
+
+   In the event SIZEOF_VOID_P and SIZEON_LONG are not already set,
+   the solution taken here is to test for various #ifdef values 
+   known to be set by Unix/Windows *compilers* that indicate
+   the type sizes they use for int, long, pointer, and
+   from that information explicitly set the values used in
+   the macro definition tests below.
+
+   For more details on what these sizes are, two useful references are:
+
+     https://en.cppreference.com/w/cpp/language/types
+     https://unix.org/version2/whatsnew/lp64_wp.html
+*/
+
+#ifndef SIZEOF_VOID_P
+#  if defined ( _MSC_VER ) /* i.e., Microsoft Visual Studio, not a Mingw based GCC */
+#    if defined( _WIN64 )
+#      define SIZEOF_VOID_P 8
+
+#    elif defined( _WIN32 )
+#      define SIZEOF_VOID_P 4
+
+#    else
+#      error Windows OS neither 32-bit nor 64-bit.  SIZEOF_VOID_P not specified
+#    endif
+
+#  else /* Presumably Unix */
+#    if defined( __ILP32 )     /* i.e., int, long and pointer are all 32-bits */
+#      define SIZEOF_VOID_P 4
+
+#    elif defined( __LP64 )    /* i.e., long, and pointer are both 64-bits */
+#      define SIZEOF_VOID_P 8
+
+#    else
+#      error Compiler's 'sizeof' model not matched as either IILP32 or LP64.  SIZEOF_VOID_P not specified
+#    endif
+#  endif
+#endif
+
+
+
+#ifndef SIZEOF_LONG
+#  if defined ( _MSC_VER ) /* i.e., Microsoft Visual Studio, not a Mingw based GCC */
+#    if defined( _WIN64 )
+#      define SIZEOF_LONG 4 /* but note that SIZEOF_VOID_P above is 8 ! */
+
+#    elif defined( _WIN32 )
+#      define SIZEOF_LONG 4
+
+#    else
+#      error Windows OS neither 32-bit nor 64-bit.  SIZEOF_LONG not specified
+#    endif
+
+#  else /* Presumably Unix */
+#    if defined( __ILP32 )
+#      define SIZEOF_LONG 4
+
+#    elif defined( __LP64 )
+#      define SIZEOF_LONG 8
+
+#    else
+#      error Compiler's 'sizeof' model not matched as either IILP32 or LP64.  SIZEOF_LONG not specified
+#    endif
+#  endif
+#endif
+
+
+
 /* Convert between a jlong and a void ptr using a well-defined cast.
  * (Casting between a pointer and an integer of different sizes spooks
  * both gcc and mbp. */
+
 #if (SIZEOF_VOID_P == SIZEOF_LONG)
 #  define DBF_TO_JLONG(x) ((jlong)((long) x))