From cfa27c399ec9236a100ef794505d35f60da41a6d Mon Sep 17 00:00:00 2001 From: Simon Marchi Date: Sat, 30 Dec 2017 23:33:26 -0500 Subject: [PATCH 1/1] Only ignore -Wenum-compare-switch if it exists My patch dwarf2read: Silence -Wenum-compare-switch warning 132448f8359a268f34f074b0908b5255b568da06 made some parts of dwarf2read.c ignore warnings about switch using enums of different kinds. What I did not realize was that older Clang versions (prior to 6) did not have that warning, and therefore give this error: /home/emaisin/src/binutils-gdb/gdb/dwarf2read.c:24187:7: error: unknown warning group '-Wenum-compare-switch', ignored [-Werror,-Wunknown-pragmas] DIAGNOSTIC_IGNORE_SWITCH_DIFFERENT_ENUM_TYPES ^ /home/emaisin/src/binutils-gdb/gdb/common/diagnostics.h:42:3: note: expanded from macro 'DIAGNOSTIC_IGNORE_SWITCH_DIFFERENT_ENUM_TYPES' DIAGNOSTIC_IGNORE ("-Wenum-compare-switch") ^ /home/emaisin/src/binutils-gdb/gdb/common/diagnostics.h:27:3: note: expanded from macro 'DIAGNOSTIC_IGNORE' _Pragma (STRINGIFY (GCC diagnostic ignored option)) ^ :10:25: note: expanded from here GCC diagnostic ignored "-Wenum-compare-switch" ^ Clang has a way to test if it knows about a particular warning. This patch uses that feature to only define DIAGNOSTIC_IGNORE_SWITCH_DIFFERENT_ENUM_TYPES to something if the warning is recognized by the Clang version being used. I tested building dwarf2read.c with clang 4, 5, 6, as well as gcc. gdb/ChangeLog: * common/diagnostics.h (DIAGNOSTIC_IGNORE_SWITCH_DIFFERENT_ENUM_TYPES): Only define if the compiler knows about -Wenum-compare-switch. --- gdb/ChangeLog | 6 ++++++ gdb/common/diagnostics.h | 9 ++++++--- 2 files changed, 12 insertions(+), 3 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 7689e0e1ab4..edb3cd452fc 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2017-12-30 Simon Marchi + + * common/diagnostics.h + (DIAGNOSTIC_IGNORE_SWITCH_DIFFERENT_ENUM_TYPES): Only + define if the compiler knows about -Wenum-compare-switch. + 2017-12-30 Simon Marchi * dwarf2read.c (dwarf_decode_macro_bytes): Ignore diff --git a/gdb/common/diagnostics.h b/gdb/common/diagnostics.h index 30c0fd6172a..c9ef6b645f9 100644 --- a/gdb/common/diagnostics.h +++ b/gdb/common/diagnostics.h @@ -38,9 +38,12 @@ DIAGNOSTIC_IGNORE ("-Wdeprecated-register") # define DIAGNOSTIC_IGNORE_UNUSED_FUNCTION \ DIAGNOSTIC_IGNORE ("-Wunused-function") -# define DIAGNOSTIC_IGNORE_SWITCH_DIFFERENT_ENUM_TYPES \ - DIAGNOSTIC_IGNORE ("-Wenum-compare-switch") - +# if __has_warning ("-Wenum-compare-switch") +# define DIAGNOSTIC_IGNORE_SWITCH_DIFFERENT_ENUM_TYPES \ + DIAGNOSTIC_IGNORE ("-Wenum-compare-switch") +# else +# define DIAGNOSTIC_IGNORE_SWITCH_DIFFERENT_ENUM_TYPES +# endif #elif defined (__GNUC__) /* GCC */ # define DIAGNOSTIC_IGNORE_SELF_MOVE -- 2.30.2