Allow it syntactically, but diagnose it with a new -Wmaxof-bool, enabled
by -Wextra.
gcc/c-family/ChangeLog:
* c-common.cc (c_maxof_type, c_minof_type): Allow and warn bool.
* c.opt: Add -Wmaxof-bool.
gcc/ChangeLog:
* doc/invoke.texi: Document the new -Wmaxof-bool.
gcc/testsuite/ChangeLog:
* gcc.dg/Wmaxof-bool.c: New test.
* gcc.dg/maxof-compile.c: Update test.
Signed-off-by: Alejandro Colomar <[email protected]>
---
gcc/c-family/c-common.cc | 8 ++++++--
gcc/c-family/c.opt | 5 +++++
gcc/doc/invoke.texi | 10 ++++++++++
gcc/testsuite/gcc.dg/Wmaxof-bool.c | 8 ++++++++
gcc/testsuite/gcc.dg/maxof-compile.c | 8 ++++++--
5 files changed, 35 insertions(+), 4 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/Wmaxof-bool.c
diff --git a/gcc/c-family/c-common.cc b/gcc/c-family/c-common.cc
index 00e521974f22..33643007f300 100644
--- a/gcc/c-family/c-common.cc
+++ b/gcc/c-family/c-common.cc
@@ -4146,11 +4146,13 @@ c_countof_type (location_t loc, tree type)
tree
c_maxof_type (location_t loc, tree type)
{
- if (!INTEGRAL_TYPE_P (type) || TREE_CODE (type) == BOOLEAN_TYPE)
+ if (!INTEGRAL_TYPE_P (type))
{
error_at (loc, "invalid application of %<_Maxof%> to type %qT", type);
return error_mark_node;
}
+ if (TREE_CODE (type) == BOOLEAN_TYPE)
+ warning_at (loc, OPT_Wmaxof_bool, "%<_Maxof%> applied to type %qT", type);
return TYPE_MAX_VALUE (type);
}
@@ -4161,11 +4163,13 @@ c_maxof_type (location_t loc, tree type)
tree
c_minof_type (location_t loc, tree type)
{
- if (!INTEGRAL_TYPE_P (type) || TREE_CODE (type) == BOOLEAN_TYPE)
+ if (!INTEGRAL_TYPE_P (type))
{
error_at (loc, "invalid application of %<_Minof%> to type %qT", type);
return error_mark_node;
}
+ if (TREE_CODE (type) == BOOLEAN_TYPE)
+ warning_at (loc, OPT_Wmaxof_bool, "%<_Minof%> applied to type %qT", type);
return TYPE_MIN_VALUE (type);
}
diff --git a/gcc/c-family/c.opt b/gcc/c-family/c.opt
index 0d97b0d13ce5..746b042180e7 100644
--- a/gcc/c-family/c.opt
+++ b/gcc/c-family/c.opt
@@ -1004,6 +1004,11 @@ Wmain
LangEnabledBy(C ObjC C++ ObjC++,Wpedantic, 2, 0)
;
+Wmaxof-bool
+C Var(warn_maxof_bool) Warning EnabledBy(Wextra)
+Warn on _Maxof(bool) and _Minof(bool).
+Warn when _Maxof or _Minof are applied to the type bool.
+
Wmaybe-uninitialized
C ObjC C++ ObjC++ LTO LangEnabledBy(C ObjC C++ ObjC++ LTO,Wall)
;
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index df4331fbad07..4446fc4a93c4 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -417,6 +417,7 @@ Objective-C and Objective-C++ Dialects}.
-Wlarger-than=@var{byte-size} -Wleading-whitespace=@var{kind}
-Wlogical-not-parentheses -Wlogical-op
-Wlong-long -Wno-lto-type-mismatch -Wmain -Wmaybe-uninitialized
+-Wmaxof-bool
-Wmemset-elt-size -Wmemset-transposed-args
-Wmisleading-indentation -Wmissing-attributes -Wmissing-braces
-Wmissing-field-initializers -Wmissing-format-attribute
@@ -6841,6 +6842,7 @@ name is still supported, but the newer name is more
descriptive.)
-Wignored-qualifiers @r{(only for C/C++)}
-Wimplicit-fallthrough=3
-Wmaybe-uninitialized
+-Wmaxof-bool
-Wmissing-field-initializers
-Wmissing-parameter-name @r{(C/ObjC only)}
-Wmissing-parameter-type @r{(C/ObjC only)}
@@ -8562,6 +8564,14 @@ Attributes}.
This warning is enabled by @option{-Wall} or @option{-Wextra}.
+@opindex Wmaxof-bool
+@opindex Wno-maxof-bool
+@item -Wmaxof-bool
+Warn when @code{_Maxof} or @code{_Minof}
+are applied to the type @code{bool}.
+
+This warning is enabled by @option{-Wextra}.
+
@opindex Wunknown-pragmas
@opindex Wno-unknown-pragmas
@cindex warning for unknown pragmas
diff --git a/gcc/testsuite/gcc.dg/Wmaxof-bool.c
b/gcc/testsuite/gcc.dg/Wmaxof-bool.c
new file mode 100644
index 000000000000..c468925836a6
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wmaxof-bool.c
@@ -0,0 +1,8 @@
+/* { dg-do compile } */
+/* { dg-options "-Wmaxof-bool" } */
+
+int main (void)
+{
+ bool b1 = _Maxof(bool); /* { dg-warning "applied to type" } */
+ bool b2 = _Minof(bool); /* { dg-warning "applied to type" } */
+}
diff --git a/gcc/testsuite/gcc.dg/maxof-compile.c
b/gcc/testsuite/gcc.dg/maxof-compile.c
index f59df75791bc..69fc76092289 100644
--- a/gcc/testsuite/gcc.dg/maxof-compile.c
+++ b/gcc/testsuite/gcc.dg/maxof-compile.c
@@ -46,6 +46,9 @@ integer (void)
_Static_assert (_Minof (unsigned int) == 0);
_Static_assert (_Minof (unsigned long) == 0);
_Static_assert (_Minof (unsigned long long) == 0);
+
+ _Static_assert (_Maxof (bool) == true);
+ _Static_assert (_Minof (bool) == false);
}
void
@@ -98,8 +101,6 @@ non_int (void)
_Minof (struct s); /* { dg-error "to type" } */
_Maxof (union u); /* { dg-error "to type" } */
_Minof (union u); /* { dg-error "to type" } */
- _Maxof (bool); /* { dg-error "to type" } */
- _Minof (bool); /* { dg-error "to type" } */
_Maxof (int [1]); /* { dg-error "to type" } */
_Minof (int [1]); /* { dg-error "to type" } */
}
@@ -152,6 +153,9 @@ type (void)
_Generic (_Minof (unsigned long), unsigned long: 0);
_Generic (_Minof (unsigned long long), unsigned long long: 0);
+ _Generic (_Maxof (bool), bool: 0);
+ _Generic (_Minof (bool), bool: 0);
+
_Generic (_Maxof (_BitInt (5)), _BitInt (5): 0);
_Generic (_Minof (_BitInt (5)), _BitInt (5): 0);
_Generic (_Maxof (unsigned _BitInt (5)), unsigned _BitInt (5): 0);
--
2.51.0
