Automatically determine whether INCOMPLETE_TYPES_BROKEN should be defined

git-svn-id: svn+ssh://svn.code.sf.net/p/libjpeg-turbo/code/trunk@227 632fc199-4ca6-4c93-a231-07263d6284db

ChangeLog.txt

@@ -8,6 +8,9 @@ crash under certain circumstances.
 [2] Fixed typo in SIMD dispatch routines which was causing 4:2:2 upsampling to
 be used instead of 4:2:0 when decompressing JPEG images using SSE2 code.
 
+[3] configure script will now automatically determine whether the
+INCOMPLETE_TYPES_BROKEN macro should be defined.
+
 
 Significant changes since 0.0.93
 ================================

configure.ac

@@ -10,8 +10,6 @@ AC_PREFIX_DEFAULT(/opt/libjpeg-turbo)
 
 # Always build with prototypes
 AC_DEFINE([HAVE_PROTOTYPES], 1, [Define if your compiler supports prototypes])
-# Don't use undefined types
-AC_DEFINE([INCOMPLETE_TYPES_BROKEN], 1, [Define if you want use complete types])
 
 # Checks for programs.
 SAVED_CFLAGS=${CFLAGS}
@@ -23,6 +21,13 @@ AC_PROG_INSTALL
 AC_PROG_LIBTOOL
 AC_PROG_LN_S
 
+# Check whether compiler supports pointers to undefined structures
+AC_MSG_CHECKING(whether compiler supports pointers to undefined structures)
+AC_TRY_COMPILE([ typedef struct undefined_structure * undef_struct_ptr; ], ,
+AC_MSG_RESULT(yes),
+[AC_MSG_RESULT(no)
+AC_DEFINE([INCOMPLETE_TYPES_BROKEN],[1],[Compiler does not support pointers to undefined structures.])])
+
 AC_MSG_CHECKING([whether the linker supports version scripts])
 VERSION_SCRIPT=no
 LDVER=`$LD --help </dev/null 2>&1 | grep "\-\-version-script"`