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From: Jakub Jelinek <jakub@gcc.gnu.org>
To: gcc-cvs@gcc.gnu.org
Subject: [gcc r12-8721] c++: Implement P2327R1 - De-deprecating volatile compound operations
Date: Mon, 29 Aug 2022 10:06:01 +0000 (GMT) [thread overview]
Message-ID: <20220829100601.881BE3858439@sourceware.org> (raw)
https://gcc.gnu.org/g:0ce3c8ea09d08469235c7c91975aab610bcda2c8
commit r12-8721-g0ce3c8ea09d08469235c7c91975aab610bcda2c8
Author: Jakub Jelinek <jakub@redhat.com>
Date: Tue Aug 16 13:15:32 2022 +0200
c++: Implement P2327R1 - De-deprecating volatile compound operations
From what I can see, this has been voted in as a DR and as it means
we warn less often than before in -std={gnu,c}++2{0,3} modes or with
-Wvolatile, I wonder if it shouldn't be backported to affected release
branches as well.
2022-08-16 Jakub Jelinek <jakub@redhat.com>
* typeck.cc (cp_build_modify_expr): Implement
P2327R1 - De-deprecating volatile compound operations. Don't warn
for |=, &= or ^= with volatile lhs.
* expr.cc (mark_use) <case MODIFY_EXPR>: Adjust warning wording,
leave out simple.
* g++.dg/cpp2a/volatile1.C: Adjust for de-deprecation of volatile
compound |=, &= and ^= operations.
* g++.dg/cpp2a/volatile3.C: Likewise.
* g++.dg/cpp2a/volatile5.C: Likewise.
(cherry picked from commit 6e790ca4615443fa395ac5cdba1ab6c87810985c)
Diff:
---
gcc/cp/expr.cc | 4 ++--
gcc/cp/typeck.cc | 8 ++++++--
gcc/testsuite/g++.dg/cpp2a/volatile1.C | 11 ++++++++---
gcc/testsuite/g++.dg/cpp2a/volatile3.C | 11 ++++++++---
gcc/testsuite/g++.dg/cpp2a/volatile5.C | 8 ++++----
5 files changed, 28 insertions(+), 14 deletions(-)
diff --git a/gcc/cp/expr.cc b/gcc/cp/expr.cc
index 56fc11f425b..f3e155b7ba3 100644
--- a/gcc/cp/expr.cc
+++ b/gcc/cp/expr.cc
@@ -220,7 +220,7 @@ mark_use (tree expr, bool rvalue_p, bool read_p,
case MODIFY_EXPR:
{
tree lhs = TREE_OPERAND (expr, 0);
- /* [expr.ass] "A simple assignment whose left operand is of
+ /* [expr.ass] "An assignment whose left operand is of
a volatile-qualified type is deprecated unless the assignment
is either a discarded-value expression or appears in an
unevaluated context." */
@@ -230,7 +230,7 @@ mark_use (tree expr, bool rvalue_p, bool read_p,
&& !TREE_THIS_VOLATILE (expr))
{
if (warning_at (location_of (expr), OPT_Wvolatile,
- "using value of simple assignment with "
+ "using value of assignment with "
"%<volatile%>-qualified left operand is "
"deprecated"))
/* Make sure not to warn about this assignment again. */
diff --git a/gcc/cp/typeck.cc b/gcc/cp/typeck.cc
index ceb80d9744f..341869fc550 100644
--- a/gcc/cp/typeck.cc
+++ b/gcc/cp/typeck.cc
@@ -9126,10 +9126,14 @@ cp_build_modify_expr (location_t loc, tree lhs, enum tree_code modifycode,
/* An expression of the form E1 op= E2. [expr.ass] says:
"Such expressions are deprecated if E1 has volatile-qualified
- type." We warn here rather than in cp_genericize_r because
+ type and op is not one of the bitwise operators |, &, ^."
+ We warn here rather than in cp_genericize_r because
for compound assignments we are supposed to warn even if the
assignment is a discarded-value expression. */
- if (TREE_THIS_VOLATILE (lhs) || CP_TYPE_VOLATILE_P (lhstype))
+ if (modifycode != BIT_AND_EXPR
+ && modifycode != BIT_IOR_EXPR
+ && modifycode != BIT_XOR_EXPR
+ && (TREE_THIS_VOLATILE (lhs) || CP_TYPE_VOLATILE_P (lhstype)))
warning_at (loc, OPT_Wvolatile,
"compound assignment with %<volatile%>-qualified left "
"operand is deprecated");
diff --git a/gcc/testsuite/g++.dg/cpp2a/volatile1.C b/gcc/testsuite/g++.dg/cpp2a/volatile1.C
index 7ea6b477ca2..a0264a47bc7 100644
--- a/gcc/testsuite/g++.dg/cpp2a/volatile1.C
+++ b/gcc/testsuite/g++.dg/cpp2a/volatile1.C
@@ -56,6 +56,9 @@ fn2 ()
vi = i;
vi = i = 42;
i = vi = 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } }
+ i = vi |= 42; // { dg-warning "using value of assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } }
+ i = vi &= 42; // { dg-warning "using value of assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } }
+ i = vi ^= 42; // { dg-warning "using value of assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } }
&(vi = i); // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } }
(vi = 42, 45);
(i = vi = 42, 10); // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } }
@@ -74,8 +77,9 @@ fn2 ()
vi += i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } }
vi -= i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } }
vi %= i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } }
- vi ^= i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } }
- vi |= i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } }
+ vi ^= i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" }
+ vi |= i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" }
+ vi &= i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" }
vi /= i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } }
vi = vi += 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } }
vi += vi = 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } }
@@ -131,7 +135,8 @@ void raccoon ()
volatile T t, u;
t = 42;
u = t = 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } }
- t &= 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } }
+ t += 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" "" { target c++20 } }
+ t &= 42; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" }
}
void
diff --git a/gcc/testsuite/g++.dg/cpp2a/volatile3.C b/gcc/testsuite/g++.dg/cpp2a/volatile3.C
index f10a29756a9..58816dc3084 100644
--- a/gcc/testsuite/g++.dg/cpp2a/volatile3.C
+++ b/gcc/testsuite/g++.dg/cpp2a/volatile3.C
@@ -57,6 +57,9 @@ fn2 ()
vi = i;
vi = i = 42;
i = vi = 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" }
+ i = vi |= 42; // { dg-warning "using value of assignment with .volatile.-qualified left operand is deprecated" }
+ i = vi &= 42; // { dg-warning "using value of assignment with .volatile.-qualified left operand is deprecated" }
+ i = vi ^= 42; // { dg-warning "using value of assignment with .volatile.-qualified left operand is deprecated" }
&(vi = i); // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" }
(vi = 42, 45);
(i = vi = 42, 10); // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" }
@@ -75,8 +78,9 @@ fn2 ()
vi += i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" }
vi -= i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" }
vi %= i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" }
- vi ^= i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" }
- vi |= i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" }
+ vi ^= i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" }
+ vi |= i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" }
+ vi &= i; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" }
vi /= i; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" }
vi = vi += 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" }
vi += vi = 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" }
@@ -132,7 +136,8 @@ void raccoon ()
volatile T t, u;
t = 42;
u = t = 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" }
- t &= 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" }
+ t += 42; // { dg-warning "assignment with .volatile.-qualified left operand is deprecated" }
+ t &= 42; // { dg-bogus "assignment with .volatile.-qualified left operand is deprecated" }
}
void
diff --git a/gcc/testsuite/g++.dg/cpp2a/volatile5.C b/gcc/testsuite/g++.dg/cpp2a/volatile5.C
index 1f9d23845b4..3684be9837e 100644
--- a/gcc/testsuite/g++.dg/cpp2a/volatile5.C
+++ b/gcc/testsuite/g++.dg/cpp2a/volatile5.C
@@ -8,8 +8,8 @@ f (bool b)
{
(b ? x : y) = 1;
(b ? x : y) += 1; // { dg-warning "compound assignment" "" { target c++20 } }
- z = (b ? x : y) = 1; // { dg-warning "using value of simple assignment" "" { target c++20 } }
- ((z = 2) ? x : y) = 1; // { dg-warning "using value of simple assignment" "" { target c++20 } }
- (b ? (x = 2) : y) = 1; // { dg-warning "using value of simple assignment" "" { target c++20 } }
- (b ? x : (y = 5)) = 1; // { dg-warning "using value of simple assignment" "" { target c++20 } }
+ z = (b ? x : y) = 1; // { dg-warning "using value of assignment" "" { target c++20 } }
+ ((z = 2) ? x : y) = 1; // { dg-warning "using value of assignment" "" { target c++20 } }
+ (b ? (x = 2) : y) = 1; // { dg-warning "using value of assignment" "" { target c++20 } }
+ (b ? x : (y = 5)) = 1; // { dg-warning "using value of assignment" "" { target c++20 } }
}
reply other threads:[~2022-08-29 10:06 UTC|newest]
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