* C++ PATCH to tweak cp_fully_fold (PR c++/84590)
@ 2018-03-01 19:12 Marek Polacek
2018-03-01 19:30 ` Jason Merrill
0 siblings, 1 reply; 4+ messages in thread
From: Marek Polacek @ 2018-03-01 19:12 UTC (permalink / raw)
To: Jason Merrill, GCC Patches
In this testcase we find ourselves in split_nonconstant_init:
init = cp_fully_fold (init);
code = push_stmt_list ();
if (split_nonconstant_init_1 (dest, init))
where initially INIT was a CONSTRUCTOR, but cp_fully_fold returned
a TARGET_EXPR. This confuses split_nonconstant_init_1 which only expects
a CONSTRUCTOR or a VECTOR_CST. Jason suggested stripping TARGET_EXPRs /
VIEW_CONVERT_EXPRs, so here it is.
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2018-03-01 Marek Polacek <polacek@redhat.com>
PR c++/84590
* cp-gimplify.c (cp_fully_fold): Unwrap TARGET_EXPR or a CONSTRUCTOR
wrapped in VIEW_CONVERT_EXPR.
* c-c++-common/ubsan/shift-11.c: New test.
diff --git gcc/cp/cp-gimplify.c gcc/cp/cp-gimplify.c
index 55a9d278dbe..1fa9c466e6b 100644
--- gcc/cp/cp-gimplify.c
+++ gcc/cp/cp-gimplify.c
@@ -2038,7 +2038,18 @@ cp_fully_fold (tree x)
have to call both. */
if (cxx_dialect >= cxx11)
x = maybe_constant_value (x);
- return cp_fold_rvalue (x);
+ x = cp_fold_rvalue (x);
+
+ /* Sometimes we are given a CONSTRUCTOR but cxx_eval_outermost_constant_expr
+ wraps it into a TARGET_EXPR; undo that here. */
+ if (TREE_CODE (x) == TARGET_EXPR)
+ x = TARGET_EXPR_INITIAL (x);
+ else if (TREE_CODE (x) == VIEW_CONVERT_EXPR
+ && TREE_CODE (TREE_OPERAND (x, 0)) == CONSTRUCTOR
+ && TREE_TYPE (TREE_OPERAND (x, 0)) == TREE_TYPE (x))
+ x = TREE_OPERAND (x, 0);
+
+ return x;
}
/* c-common interface to cp_fold. If IN_INIT, this is in a static initializer
diff --git gcc/testsuite/c-c++-common/ubsan/shift-11.c gcc/testsuite/c-c++-common/ubsan/shift-11.c
index e69de29bb2d..03a72e217a2 100644
--- gcc/testsuite/c-c++-common/ubsan/shift-11.c
+++ gcc/testsuite/c-c++-common/ubsan/shift-11.c
@@ -0,0 +1,13 @@
+/* PR c++/84590 */
+/* { dg-do compile } */
+/* { dg-options "-fsanitize=shift" } */
+
+struct S {
+ int b;
+};
+
+void
+fn (void)
+{
+ struct S c1 = { 1 << -1 }; /* { dg-warning "left shift" } */
+}
Marek
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: C++ PATCH to tweak cp_fully_fold (PR c++/84590)
2018-03-01 19:12 C++ PATCH to tweak cp_fully_fold (PR c++/84590) Marek Polacek
@ 2018-03-01 19:30 ` Jason Merrill
2018-03-01 21:38 ` Marek Polacek
0 siblings, 1 reply; 4+ messages in thread
From: Jason Merrill @ 2018-03-01 19:30 UTC (permalink / raw)
To: Marek Polacek; +Cc: GCC Patches
On Thu, Mar 1, 2018 at 2:12 PM, Marek Polacek <polacek@redhat.com> wrote:
> In this testcase we find ourselves in split_nonconstant_init:
>
> init = cp_fully_fold (init);
> code = push_stmt_list ();
> if (split_nonconstant_init_1 (dest, init))
>
> where initially INIT was a CONSTRUCTOR, but cp_fully_fold returned
> a TARGET_EXPR. This confuses split_nonconstant_init_1 which only expects
> a CONSTRUCTOR or a VECTOR_CST. Jason suggested stripping TARGET_EXPRs /
> VIEW_CONVERT_EXPRs, so here it is.
>
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
>
> 2018-03-01 Marek Polacek <polacek@redhat.com>
>
> PR c++/84590
> * cp-gimplify.c (cp_fully_fold): Unwrap TARGET_EXPR or a CONSTRUCTOR
> wrapped in VIEW_CONVERT_EXPR.
>
> * c-c++-common/ubsan/shift-11.c: New test.
>
> diff --git gcc/cp/cp-gimplify.c gcc/cp/cp-gimplify.c
> index 55a9d278dbe..1fa9c466e6b 100644
> --- gcc/cp/cp-gimplify.c
> +++ gcc/cp/cp-gimplify.c
> @@ -2038,7 +2038,18 @@ cp_fully_fold (tree x)
> have to call both. */
> if (cxx_dialect >= cxx11)
> x = maybe_constant_value (x);
> - return cp_fold_rvalue (x);
> + x = cp_fold_rvalue (x);
> +
> + /* Sometimes we are given a CONSTRUCTOR but cxx_eval_outermost_constant_expr
> + wraps it into a TARGET_EXPR; undo that here. */
> + if (TREE_CODE (x) == TARGET_EXPR)
> + x = TARGET_EXPR_INITIAL (x);
> + else if (TREE_CODE (x) == VIEW_CONVERT_EXPR
> + && TREE_CODE (TREE_OPERAND (x, 0)) == CONSTRUCTOR
> + && TREE_TYPE (TREE_OPERAND (x, 0)) == TREE_TYPE (x))
> + x = TREE_OPERAND (x, 0);
I think this should happen in the block with maybe_constant_value;
cp_fold_rvalue doesn't do this.
Jason
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: C++ PATCH to tweak cp_fully_fold (PR c++/84590)
2018-03-01 19:30 ` Jason Merrill
@ 2018-03-01 21:38 ` Marek Polacek
2018-03-02 0:59 ` Jason Merrill
0 siblings, 1 reply; 4+ messages in thread
From: Marek Polacek @ 2018-03-01 21:38 UTC (permalink / raw)
To: Jason Merrill; +Cc: GCC Patches
On Thu, Mar 01, 2018 at 02:29:47PM -0500, Jason Merrill wrote:
> I think this should happen in the block with maybe_constant_value;
> cp_fold_rvalue doesn't do this.
This, then:
Bootstrapped/regtested on x86_64-linux, ok for trunk?
2018-03-01 Marek Polacek <polacek@redhat.com>
PR c++/84590
* cp-gimplify.c (cp_fully_fold): Unwrap TARGET_EXPR or a CONSTRUCTOR
wrapped in VIEW_CONVERT_EXPR.
* c-c++-common/ubsan/shift-11.c: New test.
diff --git gcc/cp/cp-gimplify.c gcc/cp/cp-gimplify.c
index 55a9d278dbe..0ddd435454c 100644
--- gcc/cp/cp-gimplify.c
+++ gcc/cp/cp-gimplify.c
@@ -2037,7 +2037,17 @@ cp_fully_fold (tree x)
/* FIXME cp_fold ought to be a superset of maybe_constant_value so we don't
have to call both. */
if (cxx_dialect >= cxx11)
- x = maybe_constant_value (x);
+ {
+ x = maybe_constant_value (x);
+ /* Sometimes we are given a CONSTRUCTOR but the call above wraps it into
+ a TARGET_EXPR; undo that here. */
+ if (TREE_CODE (x) == TARGET_EXPR)
+ x = TARGET_EXPR_INITIAL (x);
+ else if (TREE_CODE (x) == VIEW_CONVERT_EXPR
+ && TREE_CODE (TREE_OPERAND (x, 0)) == CONSTRUCTOR
+ && TREE_TYPE (TREE_OPERAND (x, 0)) == TREE_TYPE (x))
+ x = TREE_OPERAND (x, 0);
+ }
return cp_fold_rvalue (x);
}
diff --git gcc/testsuite/c-c++-common/ubsan/shift-11.c gcc/testsuite/c-c++-common/ubsan/shift-11.c
index e69de29bb2d..03a72e217a2 100644
--- gcc/testsuite/c-c++-common/ubsan/shift-11.c
+++ gcc/testsuite/c-c++-common/ubsan/shift-11.c
@@ -0,0 +1,13 @@
+/* PR c++/84590 */
+/* { dg-do compile } */
+/* { dg-options "-fsanitize=shift" } */
+
+struct S {
+ int b;
+};
+
+void
+fn (void)
+{
+ struct S c1 = { 1 << -1 }; /* { dg-warning "left shift" } */
+}
Marek
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: C++ PATCH to tweak cp_fully_fold (PR c++/84590)
2018-03-01 21:38 ` Marek Polacek
@ 2018-03-02 0:59 ` Jason Merrill
0 siblings, 0 replies; 4+ messages in thread
From: Jason Merrill @ 2018-03-02 0:59 UTC (permalink / raw)
To: Marek Polacek; +Cc: gcc-patches List
Ok.
On Mar 1, 2018 4:38 PM, "Marek Polacek" <polacek@redhat.com> wrote:
> On Thu, Mar 01, 2018 at 02:29:47PM -0500, Jason Merrill wrote:
> > I think this should happen in the block with maybe_constant_value;
> > cp_fold_rvalue doesn't do this.
>
> This, then:
>
> Bootstrapped/regtested on x86_64-linux, ok for trunk?
>
> 2018-03-01 Marek Polacek <polacek@redhat.com>
>
> PR c++/84590
> * cp-gimplify.c (cp_fully_fold): Unwrap TARGET_EXPR or a
> CONSTRUCTOR
> wrapped in VIEW_CONVERT_EXPR.
>
> * c-c++-common/ubsan/shift-11.c: New test.
>
> diff --git gcc/cp/cp-gimplify.c gcc/cp/cp-gimplify.c
> index 55a9d278dbe..0ddd435454c 100644
> --- gcc/cp/cp-gimplify.c
> +++ gcc/cp/cp-gimplify.c
> @@ -2037,7 +2037,17 @@ cp_fully_fold (tree x)
> /* FIXME cp_fold ought to be a superset of maybe_constant_value so we
> don't
> have to call both. */
> if (cxx_dialect >= cxx11)
> - x = maybe_constant_value (x);
> + {
> + x = maybe_constant_value (x);
> + /* Sometimes we are given a CONSTRUCTOR but the call above wraps it
> into
> + a TARGET_EXPR; undo that here. */
> + if (TREE_CODE (x) == TARGET_EXPR)
> + x = TARGET_EXPR_INITIAL (x);
> + else if (TREE_CODE (x) == VIEW_CONVERT_EXPR
> + && TREE_CODE (TREE_OPERAND (x, 0)) == CONSTRUCTOR
> + && TREE_TYPE (TREE_OPERAND (x, 0)) == TREE_TYPE (x))
> + x = TREE_OPERAND (x, 0);
> + }
> return cp_fold_rvalue (x);
> }
>
> diff --git gcc/testsuite/c-c++-common/ubsan/shift-11.c
> gcc/testsuite/c-c++-common/ubsan/shift-11.c
> index e69de29bb2d..03a72e217a2 100644
> --- gcc/testsuite/c-c++-common/ubsan/shift-11.c
> +++ gcc/testsuite/c-c++-common/ubsan/shift-11.c
> @@ -0,0 +1,13 @@
> +/* PR c++/84590 */
> +/* { dg-do compile } */
> +/* { dg-options "-fsanitize=shift" } */
> +
> +struct S {
> + int b;
> +};
> +
> +void
> +fn (void)
> +{
> + struct S c1 = { 1 << -1 }; /* { dg-warning "left shift" } */
> +}
>
> Marek
>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2018-03-01 19:12 C++ PATCH to tweak cp_fully_fold (PR c++/84590) Marek Polacek
2018-03-01 19:30 ` Jason Merrill
2018-03-01 21:38 ` Marek Polacek
2018-03-02 0:59 ` Jason Merrill
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