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authorJoseph Myers <joseph@codesourcery.com>2018-06-12 16:57:26 +0000
committerJoseph Myers <joseph@codesourcery.com>2018-06-12 16:57:26 +0000
commit48b12ed54ceb605ec3566249c0387612fd9c0ced (patch)
tree43a7f68212ad2c7597718969d1dd77e31188cee8 /math/Makefile
parentcb8f6affed52d81819037b2f5d6f3a089abb8811 (diff)
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Do not use const attribute for nan functions (bug 23277).
As in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86113 for
__builtin_nan, bits/mathcalls.h wrongly declares the nan function with
the __const__ attribute.  Because the function reads memory pointed to
by an argument, it's only pure, not const.  This patch removes the
incorrect attribute and adds a testcase for the bug.  No __pure__
attribute is added to replace the incorrect __const__ one, since that
would introduce problems when using GCC versions that have the
incorrect built-in __const__ attribute and warn for the combination of
those two attributes.

Tested for x86_64.

	[BZ #23277]
	* math/bits/mathcalls.h [__USE_ISOC99] (nan): Do not use __const__
	attribute.
	* math/test-nan-const.c: New file.
	* math/Makefile (tests): Add test-nan-const.
	(CFLAGS-test-nan-const.c): New variable.
Diffstat (limited to 'math/Makefile')
-rw-r--r--math/Makefile4
1 files changed, 3 insertions, 1 deletions
diff --git a/math/Makefile b/math/Makefile
index ea141cbf99..335b1fb197 100644
--- a/math/Makefile
+++ b/math/Makefile
@@ -235,7 +235,7 @@ tests = test-matherr-3 test-fenv basic-test \
 	test-iseqsig-excess-precision test-flt-eval-method \
 	test-fp-ilogb-constants test-fp-llogb-constants \
 	test-fe-snans-always-signal test-finite-macros test-narrow-macros \
-	$(tests-static)
+	test-nan-const $(tests-static)
 tests-static = test-fpucw-static test-fpucw-ieee-static \
 	       test-signgam-uchar-static test-signgam-uchar-init-static \
 	       test-signgam-uint-static test-signgam-uint-init-static \
@@ -442,6 +442,8 @@ CFLAGS-test-fe-snans-always-signal.c += -fsignaling-nans
 
 CFLAGS-test-finite-macros.c += -ffinite-math-only
 
+CFLAGS-test-nan-const.c += -fno-builtin
+
 include ../Rules
 
 gen-all-calls = $(gen-libm-calls) $(gen-calls)