re PR c/4697 (Warning 'value computed is not used' missing)

	PR c/4697:
	* stmt.c (warn_if_unused_value): Move side effects test once more.

	* gcc.dg/20020220-2.c: New test.

From-SVN: r49937

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e64cbb96a81539cc92aaa8be891e50be831b9650..7570480e189d846c1916fc20046e8f6ced088b9b 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2002-02-21  Jakub Jelinek  <jakub@redhat.com>
+
+       PR c/4697:
+       * stmt.c (warn_if_unused_value): Move side effects test once more.
+
 2002-02-20  Torbjorn Granlund  <tege@swox.com>
 
        * config/avr/avr.md: Add more patterns for mized-mode add and subtract

diff --git a/gcc/stmt.c b/gcc/stmt.c
index 17b4d0b197267b4d7e15e3682a366ef41f3ce3b7..fc968bcbab3cdf26277f72f960b113161e80ce1b 100644 (file)
--- a/gcc/stmt.c
+++ b/gcc/stmt.c
@@ -2303,10 +2303,6 @@ warn_if_unused_value (exp)
   if (VOID_TYPE_P (TREE_TYPE (exp)))
     return 0;
 
-  /* If this is an expression with side effects, don't warn.  */
-  if (TREE_SIDE_EFFECTS (exp))
-    return 0;
-
   switch (TREE_CODE (exp))
     {
     case PREINCREMENT_EXPR:
@@ -2366,7 +2362,7 @@ warn_if_unused_value (exp)
            || TREE_CODE (tem) == CALL_EXPR)
          return 0;
       }
-      goto warn;
+      goto maybe_warn;
 
     case INDIRECT_REF:
       /* Don't warn about automatic dereferencing of references, since
@@ -2389,7 +2385,11 @@ warn_if_unused_value (exp)
          && TREE_CODE_LENGTH (TREE_CODE (exp)) == 0)
        return 0;
 
-    warn:
+    maybe_warn:
+      /* If this is an expression with side effects, don't warn.  */
+      if (TREE_SIDE_EFFECTS (exp))
+       return 0;
+
       warning_with_file_and_line (emit_filename, emit_lineno,
                                  "value computed is not used");
       return 1;

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index a6653596fa66d0df012612ba4d7a653d67524949..c837e206d25419fdae83c1efe94a153721901ea7 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2002-02-21  Jakub Jelinek  <jakub@redhat.com>
+
+       * gcc.dg/20020220-2.c: New test.
+
 2002-02-20  Alexandre Oliva  <aoliva@redhat.com>
 
        * gcc.c-torture/compile/20020110.c: New test.

diff --git a/gcc/testsuite/gcc.dg/20020220-2.c b/gcc/testsuite/gcc.dg/20020220-2.c
new file mode 100644 (file)
index 0000000..c6c57a9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/20020220-2.c
@@ -0,0 +1,12 @@
+/* PR c/4697
+   Test whether value computed not used warning is given for compound
+   expression.  */
+/* { dg-do compile } */
+/* { dg-options "-O2 -Wunused" } */
+
+int b;
+int foo (int a)
+{
+  a = a + 1, 5 * b;    /* { dg-warning "value computed is not used" } */
+  return a;
+}