c-typeck.c (build_c_cast): Always warn when casting from a pointer to an integer of different size...

gcc/

2006-01-05  Carlos O'Donell  <carlos@codesourcery.com>

	* c-typeck.c (build_c_cast): Always warn when casting
	from a pointer to an integer of different size, even if
	the node was constant.

gcc/testsuite

2006-01-05  Carlos O'Donell  <carlos@codesourcery.com>

	* gcc.dg/cast-1.c: Add new warning.
	* gcc.dg/cast-2.c: Likewise.
	* gcc.dg/cast-3.c: Likewise.
	* gcc.dg/format/cast-1.c: Likewise.
	* gcc.dg/cast-4.c: New testcase.

From-SVN: r109386

8 files changed, 37 insertions, 6 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 026dade..6f86398 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2006-01-05  Carlos O'Donell  <carlos@codesourcery.com>
+
+	* c-typeck.c (build_c_cast): Always warn when casting
+	from a pointer to an integer of different size, even if
+	the node was constant.
+
 2006-01-05  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/22555
diff --git a/gcc/c-typeck.c b/gcc/c-typeck.c
index 81fc40b..176ba7e 100644
--- a/gcc/c-typeck.c
+++ b/gcc/c-typeck.c
@@ -3508,8 +3508,12 @@ build_c_cast (tree type, tree expr)
 
       if (TREE_CODE (type) == INTEGER_TYPE
 	  && TREE_CODE (otype) == POINTER_TYPE
-	  && TYPE_PRECISION (type) != TYPE_PRECISION (otype)
-	  && !TREE_CONSTANT (value))
+	  && TYPE_PRECISION (type) != TYPE_PRECISION (otype))
+      /* Unlike conversion of integers to pointers, where the 
+         warning is disabled for converting constants because 
+         of cases such as SIG_*, warn about converting constant 
+         pointers to integers. In some cases it may cause unwanted 
+         sign extension, and a warning is appropriate.  */
 	warning (OPT_Wpointer_to_int_cast,
 		 "cast from pointer to integer of different size");
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 640c926..eb11257 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2006-01-05  Carlos O'Donell  <carlos@codesourcery.com>
+
+	* gcc.dg/cast-1.c: Add new warning.
+	* gcc.dg/cast-2.c: Likewise.
+	* gcc.dg/cast-3.c: Likewise.
+	* gcc.dg/format/cast-1.c: Likewise.
+	* gcc.dg/cast-4.c: New testcase.
+
 2006-01-05  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/22555
diff --git a/gcc/testsuite/gcc.dg/cast-1.c b/gcc/testsuite/gcc.dg/cast-1.c
index e3d79db..8924264 100644
--- a/gcc/testsuite/gcc.dg/cast-1.c
+++ b/gcc/testsuite/gcc.dg/cast-1.c
@@ -37,5 +37,5 @@ f (void)
   (void *) c; /* { dg-warning "warning: cast to pointer from integer of different size" } */
   (void *) (char) 1;
   (char) p; /* { dg-warning "warning: cast from pointer to integer of different size" } */
-  (char) (void *) 1;
+  (char) (void *) 1; /* { dg-warning "warning: cast from pointer to integer of different size" } */
 }
diff --git a/gcc/testsuite/gcc.dg/cast-2.c b/gcc/testsuite/gcc.dg/cast-2.c
index 0f84c22..eff465e 100644
--- a/gcc/testsuite/gcc.dg/cast-2.c
+++ b/gcc/testsuite/gcc.dg/cast-2.c
@@ -37,5 +37,5 @@ f (void)
   (void *) c; /* { dg-warning "warning: cast to pointer from integer of different size" } */
   (void *) (char) 1;
   (char) p; /* { dg-warning "warning: cast from pointer to integer of different size" } */
-  (char) (void *) 1;
+  (char) (void *) 1; /* { dg-warning "warning: cast from pointer to integer of different size" } */
 }
diff --git a/gcc/testsuite/gcc.dg/cast-3.c b/gcc/testsuite/gcc.dg/cast-3.c
index 656bf6d..26a38cb 100644
--- a/gcc/testsuite/gcc.dg/cast-3.c
+++ b/gcc/testsuite/gcc.dg/cast-3.c
@@ -37,5 +37,5 @@ f (void)
   (void *) c; /* { dg-warning "warning: cast to pointer from integer of different size" } */
   (void *) (char) 1;
   (char) p; /* { dg-warning "warning: cast from pointer to integer of different size" } */
-  (char) (void *) 1;
+  (char) (void *) 1; /* { dg-warning "warning: cast from pointer to integer of different size" } */
 }
diff --git a/gcc/testsuite/gcc.dg/cast-4.c b/gcc/testsuite/gcc.dg/cast-4.c
new file mode 100644
index 0000000..32b02cb
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cast-4.c
@@ -0,0 +1,13 @@
+/* Test warnings when casting from a constant integer to pointer.  
+   Test with -pedantic-errors.  */
+/* Origin: Carlos O'Donell <carlos@codesourcery.com> */
+/* { dg-do compile } */
+/* { dg-options "-std=gnu99 -pedantic-errors" } */
+
+extern int i;
+char c;
+void
+f (void)
+{
+  c = (char)&i; /* { dg-warning "warning: cast from pointer to integer of different size" } */
+}
diff --git a/gcc/testsuite/gcc.dg/format/cast-1.c b/gcc/testsuite/gcc.dg/format/cast-1.c
index 78a4f52..76e7cc5 100644
--- a/gcc/testsuite/gcc.dg/format/cast-1.c
+++ b/gcc/testsuite/gcc.dg/format/cast-1.c
@@ -12,5 +12,5 @@ f (int x)
 {
   printf("%s", x); /* { dg-warning "format" } */
   printf((char *)(size_t)"%s", x); /* { dg-warning "format" } */
-  printf((char *)(char)"%s", x);
+  printf((char *)(char)"%s", x); /* { dg-warning "warning: cast from pointer to integer of different size" } */
 }