Re: [PATCH v2] gettext.h: add parentheses around N_ expansion if supported
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Jan 9, 2015, 22:22 UTC
- Message-ID
- <xmqqwq4vbnm1.fsf@gitster.dls.corp.google.com>
- In-Reply-To
- <61CC69D2-A0F2-4BE2-B37A-F1D8FE19C45A@gmail.com>
"Kyle J. McKay" <mackyle@gmail.com> writes:
Show 6 quoted lines
> I'm not super attached to this change, it's just that it seems to me > that translation support for Git is a scarce resource. I'm guessing > that when considering the 7 complete translations (bg, ca, de, fr, sv, > vi and zh_CN) the average number of translators per language is in the > low single digits. So I hate to see unnecessary translation churn, > not when it can be so easily prevented.
Yes, I share the same feeling and I agree that it is a worthy goal.
I just did not want an unconditional "#ifdef __GNUC__" that nobody can override without editing the source, when __GNUC__ is a rough approximation whether a specific language extension exists and is enabled (we do not know which -W<option> or options like --pedantic that will be added in the future would interfere with us).
What I had in mind instead was something along this line (but with a better make variable name). In an unconfigured build, it decides between ("msg") and "msg" using the same __GNUC__ heuristic, but that can be overridden from the $(MAKE) command line in a pinch.
I do not do autoconf, but it would be trivial to set CAN_USE_* by try-compiling a small program.
Makefile | 17 ++++++++++++++++- gettext.h | 24 ++++++++++++++++++++++++ git-compat-util.h | 7 +++++++ 3 files changed, 47 insertions(+), 1 deletion(-)
diff --git a/Makefile b/Makefile index 06e5d24..48f4ce2 100644 --- a/Makefile +++ b/Makefile @@ -343,6 +343,12 @@ all:: # return NULL when it receives a bogus time_t. # # Define HAVE_CLOCK_GETTIME if your platform has clock_gettime in librt. +# +# Define CAN_USE_CONSTANT_STRING_IN_PARENTHESES to Yes if your compiler +# happily compiles the following initialization: +# static const char s[] = ("FOO"); +# and define it to No if you need to remove the parentheses () around the +# constant. GIT-VERSION-FILE: FORCE @$(SHELL_PATH) ./GIT-VERSION-GEN @@ -950,6 +956,16 @@ ifneq (,$(SOCKLEN_T)) BASIC_CFLAGS += -Dsocklen_t=$(SOCKLEN_T) endif +ifeq (Yes,$(CAN_USE_CONSTANT_STRING_IN_PARENTHESES)) + BASIC_CFLAGS += -DUSE_PARENS_AROUND_N=1 +else +ifneq (,$(CAN_USE_CONSTANT_STRING_IN_PARENTHESES)) + BASIC_CFLAGS += -DUSE_PARENS_AROUND_N=0 +else + BASIC_CFLAGS += -DUSE_PARENS_AROUND_N=-1 +endif +endif + ifeq ($(uname_S),Darwin) ifndef NO_FINK ifeq ($(shell test -d /sw/lib && echo y),y) @@ -2486,4 +2502,3 @@ cover_db: coverage-report cover_db_html: cover_db cover -report html -outputdir cover_db_html cover_db - diff --git a/gettext.h b/gettext.h index 7671d09..9b54ded 100644 --- a/gettext.h +++ b/gettext.h @@ -63,6 +63,30 @@ const char *Q_(const char *msgid, const char *plu, unsigned long n) } /* Mark msgid for translation but do not translate it. */ +#if !USE_PARENS_AROUND_N #define N_(msgid) msgid +#else +/* + * Strictly speaking, this will lead to invalid C when + * used this way: + * static const char s[] = N_("FOO"); + * which will expand to + * static const char s[] = ("FOO"); + * and in valid C, the initializer on the right hand side must + * be without the parentheses. But many compilers do accept it + * as a language extension and it will allow us to catch mistakes + * like: + * static const char **msgs = { + * N_("one") + * N_("two"), + * N_("three"), + * NULL + * } + * (notice the missing comma on one of the lines) by forcing + * an compilation error, because parenthesised ("one") ("two") + * will not get silently turned into ("onetwo"). + */ +#define N_(msgid) (msgid) +#endif #endif diff --git a/git-compat-util.h b/git-compat-util.h index dcecd85..8640163 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -867,4 +867,11 @@ struct tm *git_gmtime_r(const time_t *, struct tm *); #define gmtime_r git_gmtime_r #endif +#if USE_PARENS_AROUND_N == -1 +# ifdef __GNUC__ +# undef USE_PARENS_AROUND_N +# define USE_PARENS_AROUND_N 1 +# endif +#endif + #endif