re PR libfortran/50192 (Wrong character comparision with wide strings)

2011-08-29  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR libfortran/50192
	* intrinsics/string_intrinsics.c (memcmp_char4):  New function.
	* intrinsics/string_intrinsics_inc.c:  New macro MEMCMP, either
	set to memcmp or memcmp_char4.
	(compare_string):  Use MEMCMP, with correct size for it.
	* libgfortran.h:  Add prototype for memcmp_char4.

2011-08-29  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR libfortran/50192
	* gfortran.dg/widechar_compare_1.f90:  New test.

From-SVN: r178173

6 files changed, 50 insertions, 1 deletions

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 03a45a4..7c6f93f 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2011-08-29  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR libfortran/50192
+	* gfortran.dg/widechar_compare_1.f90:  New test.
+
 2011-08-26  Jason Merrill  <jason@redhat.com>
 
 	Core DR 342
diff --git a/gcc/testsuite/gfortran.dg/widechar_compare_1.f90 b/gcc/testsuite/gfortran.dg/widechar_compare_1.f90
new file mode 100644
index 0000000..4410110
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/widechar_compare_1.f90
@@ -0,0 +1,10 @@
+! { dg-do run }
+! PR 50192 - on little-endian systems, this used to fail.
+program main
+  character(kind=4,len=2) :: c1, c2
+  c1 = 4_' '
+  c2 = 4_' '
+  c1(1:1) = transfer(257, mold=c1(1:1))
+  c2(1:1) = transfer(64, mold=c2(1:1))
+  if (c1 < c2) call abort
+end program main
diff --git a/libgfortran/ChangeLog b/libgfortran/ChangeLog
index 427e4b6..6c57beb 100644
--- a/libgfortran/ChangeLog
+++ b/libgfortran/ChangeLog
@@ -1,3 +1,12 @@
+2011-08-29  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR libfortran/50192
+	* intrinsics/string_intrinsics.c (memcmp_char4):  New function.
+	* intrinsics/string_intrinsics_inc.c:  New macro MEMCMP, either
+	set to memcmp or memcmp_char4.
+	(compare_string):  Use MEMCMP, with correct size for it.
+	* libgfortran.h:  Add prototype for memcmp_char4.
+
 2011-08-28  Thomas Koenig  <tkoenig@gcc.gnu.org>
 
 	PR fortran/40866
diff --git a/libgfortran/intrinsics/string_intrinsics.c b/libgfortran/intrinsics/string_intrinsics.c
index e2e14e0..a1d3b31 100644
--- a/libgfortran/intrinsics/string_intrinsics.c
+++ b/libgfortran/intrinsics/string_intrinsics.c
@@ -51,6 +51,23 @@ memset_char4 (gfc_char4_t *b, gfc_char4_t c, size_t len)
   return b;
 }
 
+/* Compare wide character types, which are handled internally as
+   unsigned 4-byte integers.  */
+int
+memcmp_char4 (const void *a, const void *b, size_t len)
+{
+  const GFC_UINTEGER_4 *pa = a;
+  const GFC_UINTEGER_4 *pb = b;
+  while (len-- > 0)
+    {
+      if (*pa != *pb)
+	return *pa < *pb ? -1 : 1;
+      pa ++;
+      pb ++;
+    }
+  return 0;
+}
+
 
 /* All other functions are defined using a few generic macros in
    string_intrinsics_inc.c, so we avoid code duplication between the
@@ -64,6 +81,8 @@ memset_char4 (gfc_char4_t *b, gfc_char4_t c, size_t len)
 #define SUFFIX(x) x
 #undef  MEMSET
 #define MEMSET memset
+#undef  MEMCMP
+#define MEMCMP memcmp
 
 #include "string_intrinsics_inc.c"
 
@@ -76,6 +95,8 @@ memset_char4 (gfc_char4_t *b, gfc_char4_t c, size_t len)
 #define SUFFIX(x) x ## _char4
 #undef  MEMSET
 #define MEMSET memset_char4
+#undef  MEMCMP
+#define MEMCMP memcmp_char4
 
 #include "string_intrinsics_inc.c"
 
diff --git a/libgfortran/intrinsics/string_intrinsics_inc.c b/libgfortran/intrinsics/string_intrinsics_inc.c
index 64f5cd7..8335a38 100644
--- a/libgfortran/intrinsics/string_intrinsics_inc.c
+++ b/libgfortran/intrinsics/string_intrinsics_inc.c
@@ -90,7 +90,7 @@ compare_string (gfc_charlen_type len1, const CHARTYPE *s1,
   gfc_charlen_type len;
   int res;
 
-  res = memcmp (s1, s2, ((len1 < len2) ? len1 : len2) * sizeof (CHARTYPE));
+  res = MEMCMP (s1, s2, ((len1 < len2) ? len1 : len2));
   if (res != 0)
     return res;
 
diff --git a/libgfortran/libgfortran.h b/libgfortran/libgfortran.h
index b72b250..148dcfb 100644
--- a/libgfortran/libgfortran.h
+++ b/libgfortran/libgfortran.h
@@ -1266,6 +1266,10 @@ extern int compare_string_char4 (gfc_charlen_type, const gfc_char4_t *,
 				 gfc_charlen_type, const gfc_char4_t *);
 iexport_proto(compare_string_char4);
 
+extern int memcmp_char4 (const void *, const void *, size_t);
+internal_proto(memcmp_char4);
+
+
 /* random.c */
 
 extern void random_seed_i4 (GFC_INTEGER_4 * size, gfc_array_i4 * put,