# [PATCH 1/4] git-compat-util.h: xsize_t() - avoid -Wsign-compare warnings 4 messages from 2017-09-21 to 2017-09-21. Participants: Ramsay Jones, Torsten Bögershausen, Stefan Beller. Thread: https://gitlist.dev/t/46800 ## Ramsay Jones, 2017-09-21 16:46 Subject: [PATCH 1/4] git-compat-util.h: xsize_t() - avoid -Wsign-compare warnings Message-ID: <15367a04-754c-f6b8-a89b-2c1ff65dedf5@ramsayjones.plus.com> URL: https://gitlist.dev/e/15367a04-754c-f6b8-a89b-2c1ff65dedf5%40ramsayjones.plus.com ``` Signed-off-by: Ramsay Jones --- git-compat-util.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/git-compat-util.h b/git-compat-util.h index 9bc15b036..cedad4d58 100644 --- a/git-compat-util.h +++ b/git-compat-util.h @@ -898,9 +898,11 @@ static inline char *xstrdup_or_null(const char *str) static inline size_t xsize_t(off_t len) { - if (len > (size_t) len) + size_t size = (size_t) len; + + if (len != (off_t) size) die("Cannot handle files this big"); - return (size_t)len; + return size; } __attribute__((format (printf, 3, 4))) -- 2.14.0 ``` ## Torsten Bögershausen, 2017-09-21 18:49 Subject: Re: [PATCH 1/4] git-compat-util.h: xsize_t() - avoid -Wsign-compare warnings Message-ID: <75416139-74c5-8a60-22e8-79c53dd062c1@web.de> URL: https://gitlist.dev/e/75416139-74c5-8a60-22e8-79c53dd062c1%40web.de In-Reply-To: <15367a04-754c-f6b8-a89b-2c1ff65dedf5@ramsayjones.plus.com> ``` On 2017-09-21 18:46, Ramsay Jones wrote: > > Signed-off-by: Ramsay Jones > --- > git-compat-util.h | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/git-compat-util.h b/git-compat-util.h > index 9bc15b036..cedad4d58 100644 > --- a/git-compat-util.h > +++ b/git-compat-util.h > @@ -898,9 +898,11 @@ static inline char *xstrdup_or_null(const char *str) > > static inline size_t xsize_t(off_t len) > { > - if (len > (size_t) len) > + size_t size = (size_t) len; > + > + if (len != (off_t) size) > die("Cannot handle files this big"); > - return (size_t)len; > + return size; Hm, can someone help me out ? Why is the cast not needed ? > } > > __attribute__((format (printf, 3, 4))) > ``` ## Stefan Beller, 2017-09-21 18:57 Subject: Re: [PATCH 1/4] git-compat-util.h: xsize_t() - avoid -Wsign-compare warnings Message-ID: URL: https://gitlist.dev/e/CAGZ79kYuGpO5Ji9vwqwy_2%3Dea2Vd9CG2ethzyhXUc709KQSSaQ%40mail.gmail.com In-Reply-To: <75416139-74c5-8a60-22e8-79c53dd062c1@web.de> ``` On Thu, Sep 21, 2017 at 11:49 AM, Torsten Bögershausen wrote: > On 2017-09-21 18:46, Ramsay Jones wrote: >> >> Signed-off-by: Ramsay Jones >> --- >> git-compat-util.h | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/git-compat-util.h b/git-compat-util.h >> index 9bc15b036..cedad4d58 100644 >> --- a/git-compat-util.h >> +++ b/git-compat-util.h >> @@ -898,9 +898,11 @@ static inline char *xstrdup_or_null(const char *str) >> >> static inline size_t xsize_t(off_t len) >> { >> - if (len > (size_t) len) >> + size_t size = (size_t) len; >> + >> + if (len != (off_t) size) >> die("Cannot handle files this big"); >> - return (size_t)len; >> + return size; > > Hm, can someone help me out ? > Why is the cast not needed ? Because 'size' is already size_t, (cast was done in first line of the function: size_t size = (size_t) len; ), previously we cast len multiple times, now we cast it once and use size thereafter. > >> } >> >> __attribute__((format (printf, 3, 4))) >> > ``` ## Ramsay Jones, 2017-09-21 19:02 Subject: Re: [PATCH 1/4] git-compat-util.h: xsize_t() - avoid -Wsign-compare warnings Message-ID: <1b778d3b-56d5-4cda-1b75-b0e81e19874e@ramsayjones.plus.com> URL: https://gitlist.dev/e/1b778d3b-56d5-4cda-1b75-b0e81e19874e%40ramsayjones.plus.com In-Reply-To: <75416139-74c5-8a60-22e8-79c53dd062c1@web.de> ``` On 21/09/17 19:49, Torsten Bögershausen wrote: > On 2017-09-21 18:46, Ramsay Jones wrote: >> >> Signed-off-by: Ramsay Jones >> --- >> git-compat-util.h | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> >> diff --git a/git-compat-util.h b/git-compat-util.h >> index 9bc15b036..cedad4d58 100644 >> --- a/git-compat-util.h >> +++ b/git-compat-util.h >> @@ -898,9 +898,11 @@ static inline char *xstrdup_or_null(const char *str) >> >> static inline size_t xsize_t(off_t len) >> { >> - if (len > (size_t) len) >> + size_t size = (size_t) len; >> + >> + if (len != (off_t) size) >> die("Cannot handle files this big"); >> - return (size_t)len; >> + return size; > > Hm, can someone help me out ? > Why is the cast not needed ? The cast in the return statement? If so, because the 'size' variable has been declared with the size_t type. (The truncation, if any, would happen when 'size' is initialised in the declaration). Hope that helps. ATB, Ramsay Jones ```