gcc/

2010-04-27  Shujing Zhao  <pearly.zhao@oracle.com>

        PR c/32207
        * c-typeck.c (build_binary_op): Move forward check for comparison
        pointer with null pointer constant and adjust the diagnostic message.

gcc/testsuite/
2010-04-27  Shujing Zhao  <pearly.zhao@oracle.com>

        PR c/32207
        * gcc.dg/pr32207.c: New test.
        * gcc.dg/misc-column.c: Adjust expected warning.
        * gcc.dg/Walways-true-1.c: Likewise.
        * gcc.dg/Walways-true-2.c: Likewise.
        * gcc.dg/warn-addr-cmp.c: Likewise.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@158765 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 0ccf935..326bae6 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2010-04-27  Shujing Zhao  <pearly.zhao@oracle.com>
+       
+       PR c/32207
+       * c-typeck.c (build_binary_op): Move forward check for comparison
+       pointer with null pointer constant and adjust the diagnostic message.
+
 2010-04-27  Dave Korn  <dave.korn.cygwin@gmail.com>
 
        PR lto/42776

diff --git a/gcc/c-typeck.c b/gcc/c-typeck.c
index df02975..96b2ab1 100644 (file)
--- a/gcc/c-typeck.c
+++ b/gcc/c-typeck.c
@@ -9503,6 +9503,46 @@ build_binary_op (location_t location, enum tree_code code,
          && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
              || code1 == FIXED_POINT_TYPE || code1 == COMPLEX_TYPE))
        short_compare = 1;
+      else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
+       {
+         if (TREE_CODE (op0) == ADDR_EXPR
+             && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
+           {
+             if (code == EQ_EXPR)
+               warning_at (location,
+                           OPT_Waddress,
+                           "the comparison will always evaluate as %<false%> "
+                           "for the address of %qD will never be NULL",
+                           TREE_OPERAND (op0, 0));
+             else
+               warning_at (location,
+                           OPT_Waddress,
+                           "the comparison will always evaluate as %<true%> "
+                           "for the address of %qD will never be NULL",
+                           TREE_OPERAND (op0, 0));
+           }
+         result_type = type0;
+       }
+      else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
+       {
+         if (TREE_CODE (op1) == ADDR_EXPR
+             && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
+           {
+             if (code == EQ_EXPR)
+               warning_at (location,
+                           OPT_Waddress, 
+                           "the comparison will always evaluate as %<false%> "
+                           "for the address of %qD will never be NULL",
+                           TREE_OPERAND (op1, 0));
+             else
+               warning_at (location,
+                           OPT_Waddress,
+                           "the comparison will always evaluate as %<true%> "
+                           "for the address of %qD will never be NULL",
+                           TREE_OPERAND (op1, 0));
+           }
+         result_type = type1;
+       }
       else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
        {
          tree tt0 = TREE_TYPE (type0);
@@ -9516,10 +9556,6 @@ build_binary_op (location_t location, enum tree_code code,
             and both must be object or both incomplete.  */
          if (comp_target_types (location, type0, type1))
            result_type = common_pointer_type (type0, type1);
-         else if (null_pointer_constant_p (orig_op0))
-           result_type = type1;
-         else if (null_pointer_constant_p (orig_op1))
-           result_type = type0;
          else if (!addr_space_superset (as0, as1, &as_common))
            {
              error_at (location, "comparison of pointers to "
@@ -9551,24 +9587,6 @@ build_binary_op (location_t location, enum tree_code code,
                              (build_qualified_type (void_type_node, qual));
            }
        }
-      else if (code0 == POINTER_TYPE && null_pointer_constant_p (orig_op1))
-       {
-         if (TREE_CODE (op0) == ADDR_EXPR
-             && decl_with_nonnull_addr_p (TREE_OPERAND (op0, 0)))
-           warning_at (location,
-                       OPT_Waddress, "the address of %qD will never be NULL",
-                       TREE_OPERAND (op0, 0));
-         result_type = type0;
-       }
-      else if (code1 == POINTER_TYPE && null_pointer_constant_p (orig_op0))
-       {
-         if (TREE_CODE (op1) == ADDR_EXPR
-             && decl_with_nonnull_addr_p (TREE_OPERAND (op1, 0)))
-           warning_at (location,
-                       OPT_Waddress, "the address of %qD will never be NULL",
-                       TREE_OPERAND (op1, 0));
-         result_type = type1;
-       }
       else if (code0 == POINTER_TYPE && code1 == INTEGER_TYPE)
        {
          result_type = type0;

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 80bbaab..aa6c3f8 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,12 @@
+2010-04-27  Shujing Zhao  <pearly.zhao@oracle.com>
+
+       PR c/32207
+       * gcc.dg/pr32207.c: New test.
+       * gcc.dg/misc-column.c: Adjust expected warning.
+       * gcc.dg/Walways-true-1.c: Likewise.
+       * gcc.dg/Walways-true-2.c: Likewise.
+       * gcc.dg/warn-addr-cmp.c: Likewise.
+
 2010-04-27  Dave Korn  <dave.korn.cygwin@gmail.com>
 
        PR lto/42776

diff --git a/gcc/testsuite/gcc.dg/Walways-true-1.c b/gcc/testsuite/gcc.dg/Walways-true-1.c
index e4e4596..274ec32 100644 (file)
--- a/gcc/testsuite/gcc.dg/Walways-true-1.c
+++ b/gcc/testsuite/gcc.dg/Walways-true-1.c
@@ -26,32 +26,32 @@ bar (int a)
     foo (5);
   if (&&lab)   /* { dg-warning "7:always evaluate as" "correct warning" } */
     foo (6);
-  if (foo == 0)        /* { dg-warning "11:the comparison will always evaluate as 'false'" "correct warning" } */
+  if (foo == 0)        /* { dg-warning "11:the comparison will always evaluate to 'false'" "correct warning" } */
     foo (7);
   if (foo (1) == 0)
     foo (8);
-  if (&i == 0) /* { dg-warning "10:the comparison will always evaluate as 'false'" "correct warning" } */
+  if (&i == 0) /* { dg-warning "10:the comparison will always evaluate to 'false'" "correct warning" } */
     foo (9);
   if (i == 0)
     foo (10);
-  if (&a == 0) /* { dg-warning "10:the comparison will always evaluate as 'false'" "correct warning" } */
+  if (&a == 0) /* { dg-warning "10:the comparison will always evaluate to 'false'" "correct warning" } */
     foo (11);
   if (a == 0)
     foo (12);
-  if (&&lab == 0) /* { dg-warning "13:the comparison will always evaluate as 'false'" "correct warning" } */
+  if (&&lab == 0) /* { dg-warning "13:the comparison will always evaluate to 'false'" "correct warning" } */
     foo (13);
-  if (0 == foo)        /* { dg-warning "9:the comparison will always evaluate as 'false'" "correct warning" } */
+  if (0 == foo)        /* { dg-warning "9:the comparison will always evaluate to 'false'" "correct warning" } */
     foo (14);
   if (0 == foo (1))
     foo (15);
-  if (0 == &i) /* { dg-warning "9:the comparison will always evaluate as 'false'" "correct warning" } */
+  if (0 == &i) /* { dg-warning "9:the comparison will always evaluate to 'false'" "correct warning" } */
     foo (16);
   if (0 == i)
     foo (17);
-  if (0 == &a) /* { dg-warning "9:the comparison will always evaluate as 'false'" "correct warning" } */
+  if (0 == &a) /* { dg-warning "9:the comparison will always evaluate to 'false'" "correct warning" } */
     foo (18);
   if (0 == a)
     foo (19);
-  if (0 == &&lab) /* { dg-warning "9:the comparison will always evaluate as 'false'" "correct warning" } */
+  if (0 == &&lab) /* { dg-warning "9:the comparison will always evaluate to 'false'" "correct warning" } */
     foo (20);
 }

diff --git a/gcc/testsuite/gcc.dg/Walways-true-2.c b/gcc/testsuite/gcc.dg/Walways-true-2.c
index af40ba6..3978a44 100644 (file)
--- a/gcc/testsuite/gcc.dg/Walways-true-2.c
+++ b/gcc/testsuite/gcc.dg/Walways-true-2.c
@@ -37,11 +37,11 @@ bar (int a)
     foo (9);
   if (i == 0)
     foo (10);
-  if (&a == 0) /* { dg-warning "the comparison will always evaluate as 'false'" "correct warning" } */
+  if (&a == 0) /* { dg-warning "the comparison will always evaluate to 'false'" "correct warning" } */
     foo (11);
   if (a == 0)
     foo (12);
-  if (&&lab == 0) /* { dg-warning "the comparison will always evaluate as 'false'" "correct warning" } */
+  if (&&lab == 0) /* { dg-warning "the comparison will always evaluate to 'false'" "correct warning" } */
     foo (13);
   if (0 == foo)
     foo (14);
@@ -51,10 +51,10 @@ bar (int a)
     foo (16);
   if (0 == i)
     foo (17);
-  if (0 == &a) /* { dg-warning "the comparison will always evaluate as 'false'" "correct warning" } */
+  if (0 == &a) /* { dg-warning "the comparison will always evaluate to 'false'" "correct warning" } */
     foo (18);
   if (0 == a)
     foo (19);
-  if (0 == &&lab) /* { dg-warning "the comparison will always evaluate as 'false'" "correct warning" } */
+  if (0 == &&lab) /* { dg-warning "the comparison will always evaluate to 'false'" "correct warning" } */
     foo (20);
 }

diff --git a/gcc/testsuite/gcc.dg/misc-column.c b/gcc/testsuite/gcc.dg/misc-column.c
index e68300b..f69f988 100644 (file)
--- a/gcc/testsuite/gcc.dg/misc-column.c
+++ b/gcc/testsuite/gcc.dg/misc-column.c
@@ -19,7 +19,7 @@ void foo (void)
   if (p < q) /* { dg-warning "9:comparison of distinct pointer types" } */
     bar ();
 
-  if (&p == 0) /* { dg-warning "10:comparison will always evaluate as 'false'" } */
+  if (&p == 0) /* { dg-warning "10:comparison will always evaluate to 'false'" } */
     bar();
 
   if (p == 4) /* { dg-warning "9:comparison between pointer and integer" } */

diff --git a/gcc/testsuite/gcc.dg/pr32207.c b/gcc/testsuite/gcc.dg/pr32207.c
index cf9bef8..549d51a 100644 (file)
--- a/gcc/testsuite/gcc.dg/pr32207.c
+++ b/gcc/testsuite/gcc.dg/pr32207.c
@@ -5,5 +5,5 @@
 extern void z();
 
 void f() { if ( z ) z(); } /* { dg-warning "always evaluate as" } */
-void g() { if ( z != 0 ) z(); } /* { dg-warning "the comparison will always evaluate as 'true'" } */
-void h() { if ( z != (void*)0 ) z(); } /* { dg-warning "the comparison will always evaluate as 'true'" } */
+void g() { if ( z != 0 ) z(); } /* { dg-warning "the comparison will always evaluate to 'true'" } */
+void h() { if ( z != (void*)0 ) z(); } /* { dg-warning "the comparison will always evaluate to 'true'" } */

diff --git a/gcc/testsuite/gcc.dg/warn-addr-cmp.c b/gcc/testsuite/gcc.dg/warn-addr-cmp.c
index 07491d1..c1e68f5 100644 (file)
--- a/gcc/testsuite/gcc.dg/warn-addr-cmp.c
+++ b/gcc/testsuite/gcc.dg/warn-addr-cmp.c
@@ -36,13 +36,13 @@ test_func_cmp (void)
 int
 test_func_cmp_rhs_zero (void)
 {
-  if (func == 0)     /* { dg-warning "the comparison will always evaluate as 'false'" } */
+  if (func == 0)     /* { dg-warning "the comparison will always evaluate to 'false'" } */
     return 1;
-  if (func != 0)     /* { dg-warning "the comparison will always evaluate as 'true'" } */
+  if (func != 0)     /* { dg-warning "the comparison will always evaluate to 'true'" } */
     return 1;
-  if (&var == 0)     /* { dg-warning "the comparison will always evaluate as 'false'" } */
+  if (&var == 0)     /* { dg-warning "the comparison will always evaluate to 'false'" } */
     return 1;
-  if (&var != 0)     /* { dg-warning "the comparison will always evaluate as 'true'" } */
+  if (&var != 0)     /* { dg-warning "the comparison will always evaluate to 'true'" } */
     return 1;
   if (weak_func == 0)
     return 1;
@@ -59,13 +59,13 @@ test_func_cmp_rhs_zero (void)
 int
 test_func_cmp_lhs_zero (void)
 {
-  if (0 == func)     /* { dg-warning "the comparison will always evaluate as 'false'" } */
+  if (0 == func)     /* { dg-warning "the comparison will always evaluate to 'false'" } */
     return 1;
-  if (0 != func)     /* { dg-warning "the comparison will always evaluate as 'true'" } */
+  if (0 != func)     /* { dg-warning "the comparison will always evaluate to 'true'" } */
     return 1;
-  if (0 == &var)     /* { dg-warning "the comparison will always evaluate as 'false'" } */
+  if (0 == &var)     /* { dg-warning "the comparison will always evaluate to 'false'" } */
     return 1;
-  if (0 != &var)     /* { dg-warning "the comparison will always evaluate as 'true'" } */
+  if (0 != &var)     /* { dg-warning "the comparison will always evaluate to 'true'" } */
     return 1;
   if (0 == weak_func)
     return 1;