From 8b5a7a6e8ceb34f8e82aa361ee91ec25e0049774 Mon Sep 17 00:00:00 2001 From: Simon Marchi Date: Mon, 26 Jun 2017 15:08:35 +0200 Subject: [PATCH] vec: Silence -Wunused-function warnings on clang clang has a too aggressive (or broken, depends on how you want to see it) -Wunused-function warning, which is triggered by the functions defined by DEF_VEC_* but not used in the current source file. Normally, it won't warn about unused static inline functions defined in header files, because it's expected that a source file won't use all functions defined in a header file it includes. However, if the DEF_VEC_* macro is used in a source file, it considers those functions as defined in the source file, which leads it to think that we should remove those functions. It is therefore missing a check to see whether those functions are resulting from macro expansion. A bug already exists for that: https://bugs.llvm.org//show_bug.cgi?id=22712 It's quite easy to silence this warning in a localized way, that is in the DEF_VEC_* macros. gdb/ChangeLog: * common/diagnostics.h: Define macros for GCC. (DIAGNOSTIC_IGNORE_UNUSED_FUNCTION): New macro. * common/vec.h: Include diagnostics.h. (DIAGNOSTIC_IGNORE_UNUSED_VEC_FUNCTION): New macro. (DEF_VEC_I, DEF_VEC_P, DEF_VEC_O): Ignore -Wunused-function warning. --- gdb/ChangeLog | 9 +++++++++ gdb/common/diagnostics.h | 17 +++++++++++++++-- gdb/common/vec.h | 25 +++++++++++++++++++++++++ 3 files changed, 49 insertions(+), 2 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 5b048627c9..e817dc7997 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,12 @@ +2017-06-26 Simon Marchi + + * common/diagnostics.h: Define macros for GCC. + (DIAGNOSTIC_IGNORE_UNUSED_FUNCTION): New macro. + * common/vec.h: Include diagnostics.h. + (DIAGNOSTIC_IGNORE_UNUSED_VEC_FUNCTION): New macro. + (DEF_VEC_I, DEF_VEC_P, DEF_VEC_O): Ignore -Wunused-function + warning. + 2017-06-26 Simon Marchi * common/diagnostics.h (DIAGNOSTIC_IGNORE_DEPRECATED_REGISTER): diff --git a/gdb/common/diagnostics.h b/gdb/common/diagnostics.h index 35bacf25bb..d6ab698916 100644 --- a/gdb/common/diagnostics.h +++ b/gdb/common/diagnostics.h @@ -31,13 +31,26 @@ # define DIAGNOSTIC_IGNORE(option) #endif -#ifdef __clang__ +#if defined (__clang__) /* clang */ + # define DIAGNOSTIC_IGNORE_SELF_MOVE DIAGNOSTIC_IGNORE ("-Wself-move") # define DIAGNOSTIC_IGNORE_DEPRECATED_REGISTER \ DIAGNOSTIC_IGNORE ("-Wdeprecated-register") -#else +# define DIAGNOSTIC_IGNORE_UNUSED_FUNCTION \ + DIAGNOSTIC_IGNORE ("-Wunused-function") + +#elif defined (__GNUC__) /* GCC */ + +# define DIAGNOSTIC_IGNORE_SELF_MOVE +# define DIAGNOSTIC_IGNORE_DEPRECATED_REGISTER +# define DIAGNOSTIC_IGNORE_UNUSED_FUNCTION \ + DIAGNOSTIC_IGNORE ("-Wunused-function") + +#else /* Other compilers */ + # define DIAGNOSTIC_IGNORE_SELF_MOVE # define DIAGNOSTIC_IGNORE_DEPRECATED_REGISTER +# define DIAGNOSTIC_IGNORE_UNUSED_FUNCTION #endif #endif /* COMMON_DIAGNOSTICS_H */ diff --git a/gdb/common/vec.h b/gdb/common/vec.h index 982f7718ad..98d4576201 100644 --- a/gdb/common/vec.h +++ b/gdb/common/vec.h @@ -20,6 +20,22 @@ #if !defined (GDB_VEC_H) #define GDB_VEC_H +#include "diagnostics.h" + +/* clang has a bug that makes it warn (-Wunused-function) about unused functions + that are the result of the DEF_VEC_* macro expansion. See: + + https://bugs.llvm.org/show_bug.cgi?id=22712 + + We specifically ignore this warning for the vec functions when the compiler + is clang. */ +#ifdef __clang__ +# define DIAGNOSTIC_IGNORE_UNUSED_VEC_FUNCTION \ + DIAGNOSTIC_IGNORE_UNUSED_FUNCTION +#else +# define DIAGNOSTIC_IGNORE_UNUSED_VEC_FUNCTION +#endif + /* The macros here implement a set of templated vector types and associated interfaces. These templates are implemented with macros, as we're not in C++ land. The interface functions are @@ -408,6 +424,8 @@ typedef struct VEC(T) \ /* Vector of integer-like object. */ #define DEF_VEC_I(T) \ +DIAGNOSTIC_PUSH \ +DIAGNOSTIC_IGNORE_UNUSED_VEC_FUNCTION \ static inline void VEC_OP (T,must_be_integral_type) (void) \ { \ (void)~(T)0; \ @@ -416,10 +434,13 @@ static inline void VEC_OP (T,must_be_integral_type) (void) \ VEC_T(T); \ DEF_VEC_FUNC_P(T) \ DEF_VEC_ALLOC_FUNC_I(T) \ +DIAGNOSTIC_POP \ struct vec_swallow_trailing_semi /* Vector of pointer to object. */ #define DEF_VEC_P(T) \ +DIAGNOSTIC_PUSH \ +DIAGNOSTIC_IGNORE_UNUSED_VEC_FUNCTION \ static inline void VEC_OP (T,must_be_pointer_type) (void) \ { \ (void)((T)1 == (void *)1); \ @@ -428,13 +449,17 @@ static inline void VEC_OP (T,must_be_pointer_type) (void) \ VEC_T(T); \ DEF_VEC_FUNC_P(T) \ DEF_VEC_ALLOC_FUNC_P(T) \ +DIAGNOSTIC_POP \ struct vec_swallow_trailing_semi /* Vector of object. */ #define DEF_VEC_O(T) \ +DIAGNOSTIC_PUSH \ +DIAGNOSTIC_IGNORE_UNUSED_VEC_FUNCTION \ VEC_T(T); \ DEF_VEC_FUNC_O(T) \ DEF_VEC_ALLOC_FUNC_O(T) \ +DIAGNOSTIC_POP \ struct vec_swallow_trailing_semi /* Avoid offsetof (or its usual C implementation) as it triggers -- 2.34.1