From c81e9deba2f73ddc6f62a9d41684824c854366c6 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Wed, 10 Dec 2014 00:43:36 +0000 Subject: [PATCH] Disable -Wdiv-by-zero for some tests in stdio-common/tst-unlockedio.c. This patch uses diagnostic control pragmas to disable some division-by-zero warnings in stdio-common/tst-unlockedio.c. This is another test where disabling warnings using diagnostic pragmas seems appropriate (the warnings are not wildly inappropriate for what the test deliberately does; the deliberate use of unusual arguments to the macros being tested means that changing the arguments in a way that avoids the warning would also unduly perturb what is being tested). Tested for x86_64. * stdio-common/tst-unlockedio.c: Include . (do_test): Disable -Wdiv-by-zero around some calls to fwrite_unlocked and fread_unlocked. --- ChangeLog | 4 ++++ stdio-common/tst-unlockedio.c | 13 +++++++++++++ 2 files changed, 17 insertions(+) diff --git a/ChangeLog b/ChangeLog index cfbaf86faa..04804b077b 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,9 @@ 2014-12-10 Joseph Myers + * stdio-common/tst-unlockedio.c: Include . + (do_test): Disable -Wdiv-by-zero around some calls to + fwrite_unlocked and fread_unlocked. + * include/libc-internal.h (DIAG_PUSH_NEEDS_COMMENT): New macro. (DIAG_POP_NEEDS_COMMENT): Likewise. (_DIAG_STR1): Likewise. diff --git a/stdio-common/tst-unlockedio.c b/stdio-common/tst-unlockedio.c index 4d17a4cb62..e557b59262 100644 --- a/stdio-common/tst-unlockedio.c +++ b/stdio-common/tst-unlockedio.c @@ -20,6 +20,7 @@ #include #include #include +#include int fd; static void do_prepare (void); @@ -44,6 +45,13 @@ do_test (void) f = fp; cp = blah; + /* These tests deliberately use fwrite_unlocked with the size + argument specified as 0, which results in "division by zero" + warnings from the expansion of that macro (in code that is not + evaluated for a size of 0). This applies to the tests of + fread_unlocked below as well. */ + DIAG_PUSH_NEEDS_COMMENT; + DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wdiv-by-zero"); if (ftello (fp) != 0 || fwrite_unlocked (blah, blah - blah, strlen (blah), f++) != 0 || f != fp + 1 @@ -59,6 +67,7 @@ do_test (void) puts ("One of fwrite_unlocked tests failed"); exit (1); } + DIAG_POP_NEEDS_COMMENT; if (fwrite_unlocked (blah, 1, strlen (blah) - 2, fp) != strlen (blah) - 2) { @@ -93,6 +102,9 @@ do_test (void) f = fp; wp = buf; memset (buf, ' ', sizeof (buf)); + /* See explanation above. */ + DIAG_PUSH_NEEDS_COMMENT; + DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wdiv-by-zero"); if (ftello (fp) != 0 || fread_unlocked (buf, buf - buf, strlen (blah), f++) != 0 || f != fp + 1 @@ -109,6 +121,7 @@ do_test (void) puts ("One of fread_unlocked tests failed"); exit (1); } + DIAG_POP_NEEDS_COMMENT; if (fread_unlocked (buf, 1, strlen (blah) - 2, fp) != strlen (blah) - 2) { -- 2.11.4.GIT