On Mon, Jan 30, 2023 at 01:12:00PM -0500, Jason Merrill wrote:
> On 1/30/23 11:00, Marek Polacek wrote:
> > On Fri, Jan 27, 2023 at 06:17:00PM -0500, Patrick Palka wrote:
> > > On Fri, 27 Jan 2023, Marek Polacek wrote:
> > >
> > > > On Fri, Jan 27, 2023 at 05:15:00PM -0500, Patrick Palka wrote:
> > > > > On Thu, 26 Jan 2023, Marek Polacek via Gcc-patches wrote:
> > > > >
> > > > > > Here we crash because a CAST_EXPR, representing T(), doesn't have
> > > > > > its operand, and operand_equal_p's STRIP_ANY_LOCATION_WRAPPER
> > > > > > doesn't
> > > > > > expect that. (o_e_p is called from
> > > > > > warn_duplicated_cond_add_or_warn.)
> > > > > >
> > > > > > In the past we've adjusted o_e_p to better cope with template codes,
> > > > > > but in this case I think we just want to avoid attempting to warn
> > > > > > about inst-dependent expressions; I don't think I've ever envisioned
> > > > > > -Wduplicated-cond to warn about them.
> > > > > >
> > > > > > The ICE started with r12-6022, two-stage name lookup for overloaded
> > > > > > operators, which gave dependent operators a TREE_TYPE (in
> > > > > > particular,
> > > > > > DEPENDENT_OPERATOR_TYPE), so we no longer bail out here in o_e_p:
> > > > > >
> > > > > > /* Similar, if either does not have a type (like a template id),
> > > > > > they aren't equal. */
> > > > > > if (!TREE_TYPE (arg0) || !TREE_TYPE (arg1))
> > > > > > return false;
> > > > > >
> > > > > > Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
> > > > > >
> > > > > > PR c++/107593
> > > > > >
> > > > > > gcc/cp/ChangeLog:
> > > > > >
> > > > > > * parser.cc (cp_parser_selection_statement): Don't do
> > > > > > -Wduplicated-cond when the condition is dependent.
> > > > > >
> > > > > > gcc/testsuite/ChangeLog:
> > > > > >
> > > > > > * g++.dg/warn/Wduplicated-cond3.C: New test.
> > > > > > ---
> > > > > > gcc/cp/parser.cc | 3 +-
> > > > > > gcc/testsuite/g++.dg/warn/Wduplicated-cond3.C | 38
> > > > > > +++++++++++++++++++
> > > > > > 2 files changed, 40 insertions(+), 1 deletion(-)
> > > > > > create mode 100644 gcc/testsuite/g++.dg/warn/Wduplicated-cond3.C
> > > > > >
> > > > > > diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
> > > > > > index 4cdc1cd472f..3df85d49e16 100644
> > > > > > --- a/gcc/cp/parser.cc
> > > > > > +++ b/gcc/cp/parser.cc
> > > > > > @@ -13209,7 +13209,8 @@ cp_parser_selection_statement (cp_parser*
> > > > > > parser, bool *if_p,
> > > > > > /* Add the condition. */
> > > > > > condition = finish_if_stmt_cond (condition, statement);
> > > > > > - if (warn_duplicated_cond)
> > > > > > + if (warn_duplicated_cond
> > > > > > + && !instantiation_dependent_expression_p (condition))
> > > > > > warn_duplicated_cond_add_or_warn (token->location,
> > > > > > condition,
> > > > > > &chain);
> > > > >
> > > > > I noticed warn_duplicated_cond_add_or_warn already has logic to handle
> > > > > TREE_SIDE_EFFECTS conditions by invaliding the entire chain. I wonder
> > > > > if we'd want to do the same for instantiation-dep conditions?
> > > >
> > > > warn_duplicated_cond_add_or_warn lives in c-family/c-warn.cc so I can't
> > > > use instantiation_dependent_expression_p there. Sure, I could write a
> > > > C++ wrapper but with my patch we just won't add CONDITION to the chain
> > > > which I thought would work just as well.
>
> Or maybe define instantiation_dependent_expression_p in the C front-end to
> just return false?
Like this?
Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
-- >8 --
Here we crash because a CAST_EXPR, representing T(), doesn't have
its operand, and operand_equal_p's STRIP_ANY_LOCATION_WRAPPER doesn't
expect that. (o_e_p is called from warn_duplicated_cond_add_or_warn.)
In the past we've adjusted o_e_p to better cope with template codes,
but in this case I think we just want to avoid attempting to warn
about inst-dependent expressions; I don't think I've ever envisioned
-Wduplicated-cond to warn about them. Also destroy the chain when
an inst-dependent expression is encountered to not warn in
Wduplicated-cond4.C.
The ICE started with r12-6022, two-stage name lookup for overloaded
operators, which gave dependent operators a TREE_TYPE (in particular,
DEPENDENT_OPERATOR_TYPE), so we no longer bail out here in o_e_p:
/* Similar, if either does not have a type (like a template id),
they aren't equal. */
if (!TREE_TYPE (arg0) || !TREE_TYPE (arg1))
return false;
PR c++/107593
PR c++/108597
gcc/c-family/ChangeLog:
* c-common.h (instantiation_dependent_expression_p): Declare.
* c-warn.cc (warn_duplicated_cond_add_or_warn): If the condition
is dependent, invalidate the chain.
gcc/c/ChangeLog:
* c-objc-common.cc (instantiation_dependent_expression_p): New.
gcc/cp/ChangeLog:
* cp-tree.h (instantiation_dependent_expression_p): Don't
declare here.
gcc/testsuite/ChangeLog:
* g++.dg/warn/Wduplicated-cond3.C: New test.
* g++.dg/warn/Wduplicated-cond4.C: New test.
* g++.dg/warn/Wduplicated-cond5.C: New test.
---
gcc/c-family/c-common.h | 1 +
gcc/c-family/c-warn.cc | 2 +-
gcc/c/c-objc-common.cc | 8 ++++
gcc/cp/cp-tree.h | 1 -
gcc/testsuite/g++.dg/warn/Wduplicated-cond3.C | 38 +++++++++++++++++++
gcc/testsuite/g++.dg/warn/Wduplicated-cond4.C | 17 +++++++++
gcc/testsuite/g++.dg/warn/Wduplicated-cond5.C | 16 ++++++++
7 files changed, 81 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/warn/Wduplicated-cond3.C
create mode 100644 gcc/testsuite/g++.dg/warn/Wduplicated-cond4.C
create mode 100644 gcc/testsuite/g++.dg/warn/Wduplicated-cond5.C
diff --git a/gcc/c-family/c-common.h b/gcc/c-family/c-common.h
index bb6271d4a83..2dadb33476c 100644
--- a/gcc/c-family/c-common.h
+++ b/gcc/c-family/c-common.h
@@ -1101,6 +1101,7 @@ extern tree lookup_label (tree);
extern tree lookup_name (tree);
extern bool lvalue_p (const_tree);
extern int maybe_adjust_arg_pos_for_attribute (const_tree);
+extern bool instantiation_dependent_expression_p (tree);
extern bool vector_targets_convertible_p (const_tree t1, const_tree t2);
extern bool vector_types_convertible_p (const_tree t1, const_tree t2, bool
emit_lax_note);
diff --git a/gcc/c-family/c-warn.cc b/gcc/c-family/c-warn.cc
index 5ed7bcab16a..29efce3f2c0 100644
--- a/gcc/c-family/c-warn.cc
+++ b/gcc/c-family/c-warn.cc
@@ -2535,7 +2535,7 @@ warn_duplicated_cond_add_or_warn (location_t loc, tree
cond, vec<tree> **chain)
if (*chain == NULL)
return;
- if (TREE_SIDE_EFFECTS (cond))
+ if (TREE_SIDE_EFFECTS (cond) || instantiation_dependent_expression_p (cond))
{
/* Uh-oh! This condition has a side-effect, thus invalidates
the whole chain. */
diff --git a/gcc/c/c-objc-common.cc b/gcc/c/c-objc-common.cc
index d4f0b262ebb..0350733250b 100644
--- a/gcc/c/c-objc-common.cc
+++ b/gcc/c/c-objc-common.cc
@@ -400,3 +400,11 @@ maybe_adjust_arg_pos_for_attribute (const_tree)
{
return 0;
}
+
+/* In C, no expression is dependent. */
+
+bool
+instantiation_dependent_expression_p (tree)
+{
+ return false;
+}
diff --git a/gcc/cp/cp-tree.h b/gcc/cp/cp-tree.h
index 9f188724cf2..31fd8af4f21 100644
--- a/gcc/cp/cp-tree.h
+++ b/gcc/cp/cp-tree.h
@@ -7428,7 +7428,6 @@ extern bool any_type_dependent_arguments_p (const
vec<tree, va_gc> *);
extern bool any_type_dependent_elements_p (const_tree);
extern bool type_dependent_expression_p_push (tree);
extern bool value_dependent_expression_p (tree);
-extern bool instantiation_dependent_expression_p (tree);
extern bool instantiation_dependent_uneval_expression_p (tree);
extern bool any_value_dependent_elements_p (const_tree);
extern bool dependent_omp_for_p (tree, tree, tree,
tree);
diff --git a/gcc/testsuite/g++.dg/warn/Wduplicated-cond3.C
b/gcc/testsuite/g++.dg/warn/Wduplicated-cond3.C
new file mode 100644
index 00000000000..3da054e5485
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wduplicated-cond3.C
@@ -0,0 +1,38 @@
+// PR c++/107593
+// { dg-do compile }
+// { dg-options "-Wduplicated-cond" }
+
+template <typename T>
+void
+foo ()
+{
+ if (T() && T() && int())
+ ;
+ else if (T() && T() && int())
+ ;
+}
+
+template <typename T>
+void bar(T a)
+{
+ if (a)
+ ;
+ else if (a)
+ ;
+}
+
+template <typename>
+void baz(int a)
+{
+ if (a)
+ ;
+ else if (a) // { dg-warning "duplicated" }
+ ;
+}
+void
+f ()
+{
+ foo<int>();
+ bar(1);
+ baz<int>(1);
+}
diff --git a/gcc/testsuite/g++.dg/warn/Wduplicated-cond4.C
b/gcc/testsuite/g++.dg/warn/Wduplicated-cond4.C
new file mode 100644
index 00000000000..41bb9f09b4f
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wduplicated-cond4.C
@@ -0,0 +1,17 @@
+// PR c++/107593
+// { dg-do compile }
+// { dg-options "-Wduplicated-cond" }
+
+int n;
+
+template<class T> bool g() { n = 42; return false; }
+
+template<class T>
+void f() {
+ if (n)
+ ;
+ else if (g<T>())
+ ;
+ else if (n)
+ ;
+}
diff --git a/gcc/testsuite/g++.dg/warn/Wduplicated-cond5.C
b/gcc/testsuite/g++.dg/warn/Wduplicated-cond5.C
new file mode 100644
index 00000000000..23a0bf212b5
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wduplicated-cond5.C
@@ -0,0 +1,16 @@
+// PR c++/108597
+// { dg-do compile }
+// { dg-options "-Wduplicated-cond" }
+
+template <typename T>
+struct MyStruct {
+
+ void check(int &x) {
+ if (&x == &_a) {
+ } else if (&x == &_b) {
+ }
+ }
+
+ int _a;
+ int _b;
+};
base-commit: 897a0502056e6cc6613f26e0b22d1c1e06b1490f
--
2.39.1
