Hello,
This patch fixes a regression when folding a cast cond expression to a
constant in case label.
The problem came from the removal of the lines in
c-common.c:check_case_value
/* ??? Can we ever get nops here for a valid case value? We
shouldn't for C. */
STRIP_TYPE_NOPS (value);
so the check for INTEGER_CST) now fails.
The NOP is stripped after folding in 'c_fully_fold' and recreated in the
fly even if no change of type is needed (the constant's type was
converted to an integer, same than the case's type).
Removal of this NOP_EXPR if !CAN_HAVE_LOCATION_P fixes the problem.
looks safe from my testing, because the loc is inserted using
'protected_set_expr_location', whereas no loc for a constant case
doesn't seem to introduce new problems with the debugging information.
But in case I also added a few paranoid gcc_assert.
The motivating failing case is added in the attached testsuite part,
The test now compiles and generates the expected error with -pedantic or
-pedantic-error
Bootstrapped/Regression tested on x86
Thanks for any comment, and if OK to go for 4.6 and trunk
Many thanks
Christian
2010-02-15 Christian Bruel <[email protected]>
* gcc.dg/case-const-1.c: Add cond expr label and cast case.
* gcc.dg/case-const-2.c: Likewise.
* gcc.dg/case-const-3.c: Likewise.
Index: testsuite/gcc.dg/case-const-1.c
===================================================================
--- testsuite/gcc.dg/case-const-1.c (revision 184254)
+++ testsuite/gcc.dg/case-const-1.c (working copy)
@@ -4,6 +4,8 @@
/* { dg-options "" } */
extern int i;
+extern unsigned int u;
+
void
f (int c)
{
@@ -13,3 +15,13 @@
;
}
}
+
+void
+b (int c)
+{
+ switch (c)
+ {
+ case (int) (2 | ((4 < 8) ? 8 : u)):
+ ;
+ }
+}
Index: testsuite/gcc.dg/case-const-2.c
===================================================================
--- testsuite/gcc.dg/case-const-2.c (revision 184254)
+++ testsuite/gcc.dg/case-const-2.c (working copy)
@@ -4,6 +4,8 @@
/* { dg-options "-pedantic" } */
extern int i;
+extern unsigned int u;
+
void
f (int c)
{
@@ -13,3 +15,14 @@
;
}
}
+
+void
+b (int c)
+{
+ switch (c)
+ {
+ case (int) (2 | ((4 < 8) ? 8 : u)): /* { dg-warning "case label is not an integer constant expression" } */
+ ;
+ }
+}
+
Index: testsuite/gcc.dg/case-const-3.c
===================================================================
--- testsuite/gcc.dg/case-const-3.c (revision 184254)
+++ testsuite/gcc.dg/case-const-3.c (working copy)
@@ -4,6 +4,8 @@
/* { dg-options "-pedantic-errors" } */
extern int i;
+extern unsigned int u;
+
void
f (int c)
{
@@ -13,3 +15,13 @@
;
}
}
+
+void
+b (int c)
+{
+ switch (c)
+ {
+ case (int) (2 | ((4 < 8) ? 8 : u)): /* { dg-error "case label is not an integer constant expression" } */
+ ;
+ }
+}
2010-02-15 Christian Bruel <[email protected]>
* gcc/c-common.c (c_fully_fold_internal): Don't create a new NOP expr.
* gcc/fold-const.c (try_move_mult_to_index): assert CAN_HAVE_LOCATION_P.
(fold_comparison): Likewise.
* gcc/tree.c (build_case_label): Likewise.
Index: c-family/c-common.c
===================================================================
--- c-family/c-common.c (revision 184254)
+++ c-family/c-common.c (working copy)
@@ -1435,12 +1435,9 @@
have been done by this point, so remove them again. */
nowarning |= TREE_NO_WARNING (ret);
STRIP_TYPE_NOPS (ret);
- if (nowarning && !TREE_NO_WARNING (ret))
- {
- if (!CAN_HAVE_LOCATION_P (ret))
- ret = build1 (NOP_EXPR, TREE_TYPE (ret), ret);
- TREE_NO_WARNING (ret) = 1;
- }
+ if (nowarning)
+ TREE_NO_WARNING (ret) = 1;
+
if (ret != expr)
protected_set_expr_location (ret, loc);
return ret;
Index: tree.c
===================================================================
--- tree.c (revision 184254)
+++ tree.c (working copy)
@@ -1678,6 +1678,7 @@
tree t = make_node (CASE_LABEL_EXPR);
TREE_TYPE (t) = void_type_node;
+ gcc_assert (CAN_HAVE_LOCATION_P (t));
SET_EXPR_LOCATION (t, DECL_SOURCE_LOCATION (label_decl));
CASE_LOW (t) = low_value;
Index: fold-const.c
===================================================================
--- fold-const.c (revision 184254)
+++ fold-const.c (working copy)
@@ -6972,6 +6972,7 @@
pref = TREE_OPERAND (addr, 0);
ret = copy_node (pref);
+ gcc_assert (CAN_HAVE_LOCATION_P (ret));
SET_EXPR_LOCATION (ret, loc);
pos = ret;
@@ -9427,6 +9428,7 @@
if (save_p)
{
tem = save_expr (build2 (code, type, cval1, cval2));
+ gcc_assert (CAN_HAVE_LOCATION_P (tem));
SET_EXPR_LOCATION (tem, loc);
return tem;
}
