Re: [PATCH] c++: fix ICE with -Wduplicated-cond [PR107593]
On Fri, 27 Jan 2023, 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,
> > > > );
> > >
> > > 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.
>
> Ah that's unfortunate :( ISTM desirable to conservatively assume an
> inst-dep cond has side effects though (possibly directly from
oops, "has side effects and clear the chain" rather
> cp_parser_selection_statement), to avoid false positives as in:
>
> int n;
>
> template bool g() { n = 42; }
>
> template
> void f() {
> if (n)
> ;
> else if (g())
> ;
> else if (n)
> ;
> }
>
Re: [PATCH] c++: fix ICE with -Wduplicated-cond [PR107593]
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,
> > > );
> >
> > 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.
Ah that's unfortunate :( ISTM desirable to conservatively assume an
inst-dep cond has side effects though (possibly directly from
cp_parser_selection_statement), to avoid false positives as in:
int n;
template bool g() { n = 42; }
template
void f() {
if (n)
;
else if (g())
;
else if (n)
;
}
Re: [PATCH] c++: fix ICE with -Wduplicated-cond [PR107593]
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, > > ); > > 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. Marek
Re: [PATCH] c++: fix ICE with -Wduplicated-cond [PR107593]
On 1/27/23 17:15, 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,
);
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?
Makes sense.
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 000..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
+void
+foo ()
+{
+ if (T() && T() && int())
+;
+ else if (T() && T() && int())
+;
+}
+
+template
+void bar(T a)
+{
+ if (a)
+;
+ else if (a)
+;
+}
+
+template
+void baz(int a)
+{
+ if (a)
+;
+ else if (a) // { dg-warning "duplicated" }
+;
+}
+void
+f ()
+{
+ foo();
+ bar(1);
+ baz(1);
+}
base-commit: 94673a121cfc7f9d51c9d05e31795477f4dc8dc7
--
2.39.1
Re: [PATCH] c++: fix ICE with -Wduplicated-cond [PR107593]
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,
> );
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?
>
> 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 000..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
> +void
> +foo ()
> +{
> + if (T() && T() && int())
> +;
> + else if (T() && T() && int())
> +;
> +}
> +
> +template
> +void bar(T a)
> +{
> + if (a)
> +;
> + else if (a)
> +;
> +}
> +
> +template
> +void baz(int a)
> +{
> + if (a)
> +;
> + else if (a) // { dg-warning "duplicated" }
> +;
> +}
> +void
> +f ()
> +{
> + foo();
> + bar(1);
> + baz(1);
> +}
>
> base-commit: 94673a121cfc7f9d51c9d05e31795477f4dc8dc7
> --
> 2.39.1
>
>
[PATCH] c++: fix ICE with -Wduplicated-cond [PR107593]
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,
);
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 000..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
+void
+foo ()
+{
+ if (T() && T() && int())
+;
+ else if (T() && T() && int())
+;
+}
+
+template
+void bar(T a)
+{
+ if (a)
+;
+ else if (a)
+;
+}
+
+template
+void baz(int a)
+{
+ if (a)
+;
+ else if (a) // { dg-warning "duplicated" }
+;
+}
+void
+f ()
+{
+ foo();
+ bar(1);
+ baz(1);
+}
base-commit: 94673a121cfc7f9d51c9d05e31795477f4dc8dc7
--
2.39.1
