For historical reasons, incrementing a boolean was allowed (because anything
non-0 is true), while decrementing is forbidden. This has now changed, and
since C++17 even ++ on bool is invalid. And C++ 03/11/14 [depr.incr.bool]
says that ++ is deprecated, but we never diagnosed this.
A bunch of testcases needed updating, but nothing unexpected.
(Even though I recently changed out documentation to use "boolean" rather
than "Boolean", I'm keeping this as it is. I can tweak that in a follow
up.)
Bootstrapped/regtested on x86_64-linux/ppc64-linux, ok for trunk?
2016-09-13 Marek Polacek <pola...@redhat.com>
* typeck.c (cp_build_unary_op): Diagnose incrementing boolean
expressions.
* c-c++-common/gomp/atomic-12.c: Use -Wno-deprecated.
* c-c++-common/gomp/atomic-13.c: Likewise.
* c-c++-common/gomp/atomic-14.c: Likewise.
* g++.dg/cpp1y/lambda-init11.C: Remove invalid code.
* g++.dg/cpp1z/bool-increment1.C: New test.
* c-c++-common/pr60439.c: Add dg-warning.
* g++.dg/expr/bitfield4.C: Likewise.
* g++.dg/expr/bitfield5.C: Likewise.
* g++.dg/expr/bitfield6.C: Likewise.
* g++.dg/expr/bool1.C: Likewise.
* g++.dg/expr/bool3.C: Likewise.
* g++.dg/expr/lval3.C: Likewise.
* g++.dg/expr/lval4.C: Likewise.
* g++.old-deja/g++.jason/bool5.C: Likewise.
diff --git gcc/cp/typeck.c gcc/cp/typeck.c
index a591d29..341f722 100644
--- gcc/cp/typeck.c
+++ gcc/cp/typeck.c
@@ -6030,7 +6030,7 @@ cp_build_unary_op (enum tree_code code, tree xarg, int
noconvert,
complain))
return error_mark_node;
- /* Forbid using -- on `bool'. */
+ /* Forbid using -- or ++ in C++17 on `bool'. */
if (TREE_CODE (declared_type) == BOOLEAN_TYPE)
{
if (code == POSTDECREMENT_EXPR || code == PREDECREMENT_EXPR)
@@ -6040,6 +6040,20 @@ cp_build_unary_op (enum tree_code code, tree xarg, int
noconvert,
"to %<operator--%>");
return error_mark_node;
}
+ else
+ {
+ if (cxx_dialect >= cxx1z)
+ {
+ if (complain & tf_error)
+ error ("use of Boolean expression as operand "
+ "to %<operator++%> is forbidden in C++1z");
+ return error_mark_node;
+ }
+ /* Otherwise, [depr.incr.bool] says this is deprecated. */
+ else if (!in_system_header_at (input_location))
+ warning (OPT_Wdeprecated, "use of Boolean expression as "
+ "operand to %<operator++%> is deprecated");
+ }
val = boolean_increment (code, arg);
}
else if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
diff --git gcc/testsuite/c-c++-common/gomp/atomic-12.c
gcc/testsuite/c-c++-common/gomp/atomic-12.c
index 145e420..e9ca650 100644
--- gcc/testsuite/c-c++-common/gomp/atomic-12.c
+++ gcc/testsuite/c-c++-common/gomp/atomic-12.c
@@ -1,6 +1,6 @@
/* PR middle-end/45423 */
/* { dg-do compile } */
-/* { dg-options "-fopenmp -fdump-tree-gimple -g0" } */
+/* { dg-options "-fopenmp -fdump-tree-gimple -g0 -Wno-deprecated" } */
/* atomicvar should never be referenced in between the barrier and
following #pragma omp atomic_load. */
/* { dg-final { scan-tree-dump-not "barrier\[^#\]*atomicvar" "gimple" } } */
diff --git gcc/testsuite/c-c++-common/gomp/atomic-13.c
gcc/testsuite/c-c++-common/gomp/atomic-13.c
index 2452035..7f4afcf 100644
--- gcc/testsuite/c-c++-common/gomp/atomic-13.c
+++ gcc/testsuite/c-c++-common/gomp/atomic-13.c
@@ -1,6 +1,6 @@
/* PR middle-end/45423 */
/* { dg-do compile } */
-/* { dg-options "-fopenmp -fdump-tree-gimple -g0 -O2" } */
+/* { dg-options "-fopenmp -fdump-tree-gimple -g0 -O2 -Wno-deprecated" } */
/* atomicvar should never be referenced in between the barrier and
following #pragma omp atomic_load. */
/* { dg-final { scan-tree-dump-not "barrier\[^#\]*atomicvar" "gimple" } } */
diff --git gcc/testsuite/c-c++-common/gomp/atomic-14.c
gcc/testsuite/c-c++-common/gomp/atomic-14.c
index f8fc9d8..7e23453 100644
--- gcc/testsuite/c-c++-common/gomp/atomic-14.c
+++ gcc/testsuite/c-c++-common/gomp/atomic-14.c
@@ -1,6 +1,6 @@
/* PR middle-end/45423 */
/* { dg-do compile } */
-/* { dg-options "-fopenmp" } */
+/* { dg-options "-fopenmp -Wno-deprecated" } */
#ifdef __cplusplus
bool *baz ();
diff --git gcc/testsuite/c-c++-common/pr60439.c
gcc/testsuite/c-c++-common/pr60439.c
index 68bd33c..71b397a 100644
--- gcc/testsuite/c-c++-common/pr60439.c
+++ gcc/testsuite/c-c++-common/pr60439.c
@@ -132,6 +132,7 @@ f6 (bool b)
break;
}
switch (b++) /* { dg-warning "switch condition has" } */
+ /* { dg-warning "is deprecated" "" { target c++ } 134 } */
{
case 3:
break;
diff --git gcc/testsuite/g++.dg/cpp1y/lambda-init11.C
gcc/testsuite/g++.dg/cpp1y/lambda-init11.C
index f7525d8..4d434cd 100644
--- gcc/testsuite/g++.dg/cpp1y/lambda-init11.C
+++ gcc/testsuite/g++.dg/cpp1y/lambda-init11.C
@@ -16,5 +16,4 @@ int main(){
foo(3.14f);
foo(0);
foo('a');
- foo(false);
}
diff --git gcc/testsuite/g++.dg/expr/bitfield4.C
gcc/testsuite/g++.dg/expr/bitfield4.C
index d824964..7fae086 100644
--- gcc/testsuite/g++.dg/expr/bitfield4.C
+++ gcc/testsuite/g++.dg/expr/bitfield4.C
@@ -14,6 +14,6 @@ template <>
void f(bool) {}
int main() {
- f(s.x++);
- f(++s.x);
+ f(s.x++); // { dg-warning "deprecated" }
+ f(++s.x); // { dg-warning "deprecated" }
}
diff --git gcc/testsuite/g++.dg/expr/bitfield5.C
gcc/testsuite/g++.dg/expr/bitfield5.C
index 3d18e15..0a37f9f 100644
--- gcc/testsuite/g++.dg/expr/bitfield5.C
+++ gcc/testsuite/g++.dg/expr/bitfield5.C
@@ -8,10 +8,10 @@ struct S {
S s;
int main() {
- s.x++;
+ s.x++; // { dg-warning "deprecated" }
if (s.x != 1)
return 1;
- ++s.x;
+ ++s.x; // { dg-warning "deprecated" }
if (s.x != 1)
return 2;
}
diff --git gcc/testsuite/g++.dg/expr/bitfield6.C
gcc/testsuite/g++.dg/expr/bitfield6.C
index 6f6d559..8523866 100644
--- gcc/testsuite/g++.dg/expr/bitfield6.C
+++ gcc/testsuite/g++.dg/expr/bitfield6.C
@@ -7,5 +7,5 @@ struct S {
S s;
void f() {
- ++s.x = false;
+ ++s.x = false; // { dg-warning "deprecated" }
}
diff --git gcc/testsuite/g++.dg/expr/bool1.C gcc/testsuite/g++.dg/expr/bool1.C
index bfb40e3..503e8b4 100644
--- gcc/testsuite/g++.dg/expr/bool1.C
+++ gcc/testsuite/g++.dg/expr/bool1.C
@@ -10,8 +10,8 @@ int main()
my_bool b = false;
int i;
- b++;
- b++;
+ b++; // { dg-warning "deprecated" }
+ b++; // { dg-warning "deprecated" }
i = b;
if (i != 1)
abort ();
diff --git gcc/testsuite/g++.dg/expr/bool3.C gcc/testsuite/g++.dg/expr/bool3.C
index 61669e2..1866ed4 100644
--- gcc/testsuite/g++.dg/expr/bool3.C
+++ gcc/testsuite/g++.dg/expr/bool3.C
@@ -10,8 +10,8 @@ int main()
my_bool b = false;
int i;
- b++;
- b++;
+ b++; // { dg-warning "deprecated" }
+ b++; // { dg-warning "deprecated" }
i = b;
if (i != 1)
abort ();
diff --git gcc/testsuite/g++.dg/expr/lval3.C gcc/testsuite/g++.dg/expr/lval3.C
index f106e69..8e0aead 100644
--- gcc/testsuite/g++.dg/expr/lval3.C
+++ gcc/testsuite/g++.dg/expr/lval3.C
@@ -4,6 +4,7 @@ f()
{
bool i = 0;
i++ = 3; // { dg-error "" }
+ // { dg-warning "deprecated" "" { target *-*-* } 6 }
}
diff --git gcc/testsuite/g++.dg/expr/lval4.C gcc/testsuite/g++.dg/expr/lval4.C
index c66e2f6..b903ec8 100644
--- gcc/testsuite/g++.dg/expr/lval4.C
+++ gcc/testsuite/g++.dg/expr/lval4.C
@@ -4,6 +4,7 @@ f()
{
bool i = 0;
++i = 3;
+ // { dg-warning "deprecated" "" { target *-*-* } 6 }
}
diff --git gcc/testsuite/g++.old-deja/g++.jason/bool5.C
gcc/testsuite/g++.old-deja/g++.jason/bool5.C
index 1d2f5b6..0a16ccb 100644
--- gcc/testsuite/g++.old-deja/g++.jason/bool5.C
+++ gcc/testsuite/g++.old-deja/g++.jason/bool5.C
@@ -2,10 +2,10 @@
int main ()
{
bool b = false;
- int i = b++;
+ int i = b++; // { dg-warning "deprecated" }
if (i != false || b != true)
return 1;
- i = b++;
+ i = b++; // { dg-warning "deprecated" }
if (i != true || b != true)
return 1;
}
Marek
