Hi!
Again, because stage1 close is near, posting the following patch
to implement CWG 2654.
Ok for trunk if it passes bootstrap/regtest and is voted into C++23
and C++20 as a DR?
2022-11-11 Jakub Jelinek <ja...@redhat.com>
* typeck.cc (cp_build_modify_expr): Implement CWG 2654
- Un-deprecation of compound volatile assignments. Remove
-Wvolatile warning about compound volatile assignments.
* g++.dg/cpp2a/volatile1.C (fn2, fn3, racoon): Adjust expected
diagnostics.
* g++.dg/cpp2a/volatile3.C (fn2, fn3, racoon): Likewise.
* g++.dg/cpp2a/volatile5.C (f): Likewise.
--- gcc/cp/typeck.cc.jj 2022-11-09 11:22:42.617628059 +0100
+++ gcc/cp/typeck.cc 2022-11-10 23:19:00.394228067 +0100
@@ -9513,19 +9513,6 @@ cp_build_modify_expr (location_t loc, tr
&& MAYBE_CLASS_TYPE_P (TREE_TYPE (lhstype)))
|| MAYBE_CLASS_TYPE_P (lhstype)));
- /* An expression of the form E1 op= E2. [expr.ass] says:
- "Such expressions are deprecated if E1 has volatile-qualified
- 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 (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");
/* Preevaluate the RHS to make sure its evaluation is complete
before the lvalue-to-rvalue conversion of the LHS:
--- gcc/testsuite/g++.dg/cpp2a/volatile1.C.jj 2022-08-16 13:15:22.739043862
+0200
+++ gcc/testsuite/g++.dg/cpp2a/volatile1.C 2022-11-10 23:23:18.949717772
+0100
@@ -74,17 +74,17 @@ fn2 ()
decltype(i = vi = 42) x3 = i;
// Compound assignments.
- 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-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 /= i; // { dg-bogus "assignment with .volatile.-qualified left operand is
deprecated" }
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 } }
i *= vi;
- decltype(vi -= 42) x2 = vi; // { dg-warning "assignment with
.volatile.-qualified left operand is deprecated" "" { target c++20 } }
+ decltype(vi -= 42) x2 = vi; // { dg-bogus "assignment with
.volatile.-qualified left operand is deprecated" }
// Structured bindings.
int a[] = { 10, 5 };
@@ -107,12 +107,12 @@ fn3 ()
volatile U u;
u.c = 42;
i = u.c = 42; // { dg-warning "assignment with .volatile.-qualified left
operand is deprecated" "" { target c++20 } }
- u.c += 42; // { dg-warning "assignment with .volatile.-qualified left
operand is deprecated" "" { target c++20 } }
+ u.c += 42; // { dg-bogus "assignment with .volatile.-qualified left operand
is deprecated" }
volatile T t;
t.a = 3;
j = t.a = 3; // { dg-warning "assignment with .volatile.-qualified left
operand is deprecated" "" { target c++20 } }
- t.a += 3; // { dg-warning "assignment with .volatile.-qualified left operand
is deprecated" "" { target c++20 } }
+ t.a += 3; // { dg-bogus "assignment with .volatile.-qualified left operand
is deprecated" }
volatile int *src = &i;
*src; // No assignment, don't warn.
@@ -135,7 +135,7 @@ 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-bogus "assignment with .volatile.-qualified left operand is
deprecated" }
t &= 42; // { dg-bogus "assignment with .volatile.-qualified left operand is
deprecated" }
}
--- gcc/testsuite/g++.dg/cpp2a/volatile3.C.jj 2022-08-16 13:15:22.753043682
+0200
+++ gcc/testsuite/g++.dg/cpp2a/volatile3.C 2022-11-10 23:24:24.781823998
+0100
@@ -75,17 +75,17 @@ fn2 ()
decltype(i = vi = 42) x3 = i;
// Compound assignments.
- 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-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 /= i; // { dg-bogus "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" }
i *= vi;
- decltype(vi -= 42) x2 = vi; // { dg-warning "assignment with
.volatile.-qualified left operand is deprecated" }
+ decltype(vi -= 42) x2 = vi; // { dg-bogus "assignment with
.volatile.-qualified left operand is deprecated" }
// Structured bindings.
int a[] = { 10, 5 };
@@ -108,12 +108,12 @@ fn3 ()
volatile U u;
u.c = 42;
i = u.c = 42; // { dg-warning "assignment with .volatile.-qualified left
operand is deprecated" }
- u.c += 42; // { dg-warning "assignment with .volatile.-qualified left
operand is deprecated" }
+ u.c += 42; // { dg-bogus "assignment with .volatile.-qualified left operand
is deprecated" }
volatile T t;
t.a = 3;
j = t.a = 3; // { dg-warning "assignment with .volatile.-qualified left
operand is deprecated" }
- t.a += 3; // { dg-warning "assignment with .volatile.-qualified left operand
is deprecated" }
+ t.a += 3; // { dg-bogus "assignment with .volatile.-qualified left operand
is deprecated" }
volatile int *src = &i;
*src; // No assignment, don't warn.
@@ -136,7 +136,7 @@ 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-bogus "assignment with .volatile.-qualified left operand is
deprecated" }
t &= 42; // { dg-bogus "assignment with .volatile.-qualified left operand is
deprecated" }
}
--- gcc/testsuite/g++.dg/cpp2a/volatile5.C.jj 2022-08-16 13:15:22.778043359
+0200
+++ gcc/testsuite/g++.dg/cpp2a/volatile5.C 2022-11-10 23:25:07.445244776
+0100
@@ -7,7 +7,7 @@ void
f (bool b)
{
(b ? x : y) = 1;
- (b ? x : y) += 1; // { dg-warning "compound assignment" "" { target c++20 } }
+ (b ? x : y) += 1; // { dg-bogus "compound assignment" }
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 } }
Jakub
