* [PATCH] include: Fix -Wundef warnings in ansidecl.h
@ 2021-07-20 22:01 Marek Polacek
2021-07-23 17:38 ` Jeff Law
0 siblings, 1 reply; 2+ messages in thread
From: Marek Polacek @ 2021-07-20 22:01 UTC (permalink / raw)
To: GCC Patches
This quashes -Wundef warnings in ansidecl.h when compiled in C or C++.
In C, __cpp_constexpr and __cplusplus aren't defined so we evaluate
them to 0; conversely, __STDC_VERSION__ is not defined in C++.
This has caused grief when -Wundef is used with -Werror.
I've also tested -traditional-cpp.
Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
include/ChangeLog:
* ansidecl.h: Check if __cplusplus is defined before checking
the value of __cpp_constexpr and __cplusplus. Don't check
__STDC_VERSION__ in C++.
---
include/ansidecl.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/include/ansidecl.h b/include/ansidecl.h
index 0515228f325..2efe3e85e59 100644
--- a/include/ansidecl.h
+++ b/include/ansidecl.h
@@ -79,7 +79,7 @@ So instead we use the macro below and test it against specific values. */
/* inline requires special treatment; it's in C99, and GCC >=2.7 supports
it too, but it's not in C89. */
#undef inline
-#if __STDC_VERSION__ >= 199901L || defined(__cplusplus) || (defined(__SUNPRO_C) && defined(__C99FEATURES__))
+#if (!defined(__cplusplus) && __STDC_VERSION__ >= 199901L) || defined(__cplusplus) || (defined(__SUNPRO_C) && defined(__C99FEATURES__))
/* it's a keyword */
#else
# if GCC_VERSION >= 2007
@@ -356,7 +356,7 @@ So instead we use the macro below and test it against specific values. */
#define ENUM_BITFIELD(TYPE) unsigned int
#endif
-#if __cpp_constexpr >= 200704
+#if defined(__cplusplus) && __cpp_constexpr >= 200704
#define CONSTEXPR constexpr
#else
#define CONSTEXPR
@@ -419,7 +419,7 @@ So instead we use the macro below and test it against specific values. */
so that most attempts at copy are caught at compile-time. */
-#if __cplusplus >= 201103
+#if defined(__cplusplus) && __cplusplus >= 201103
#define DISABLE_COPY_AND_ASSIGN(TYPE) \
TYPE (const TYPE&) = delete; \
void operator= (const TYPE &) = delete
base-commit: 4eea703e7d87b1e0b116c93782cab82c9b1e842a
--
2.31.1
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH] include: Fix -Wundef warnings in ansidecl.h
2021-07-20 22:01 [PATCH] include: Fix -Wundef warnings in ansidecl.h Marek Polacek
@ 2021-07-23 17:38 ` Jeff Law
0 siblings, 0 replies; 2+ messages in thread
From: Jeff Law @ 2021-07-23 17:38 UTC (permalink / raw)
To: Marek Polacek, GCC Patches
On 7/20/2021 4:01 PM, Marek Polacek via Gcc-patches wrote:
> This quashes -Wundef warnings in ansidecl.h when compiled in C or C++.
> In C, __cpp_constexpr and __cplusplus aren't defined so we evaluate
> them to 0; conversely, __STDC_VERSION__ is not defined in C++.
> This has caused grief when -Wundef is used with -Werror.
>
> I've also tested -traditional-cpp.
>
> Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
>
> include/ChangeLog:
>
> * ansidecl.h: Check if __cplusplus is defined before checking
> the value of __cpp_constexpr and __cplusplus. Don't check
> __STDC_VERSION__ in C++.
OK
jeff
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