lib/msun: Exclude ignored-pragmas from -Werror

This avoids build failures due to the clang 12 warning:
    '#pragma FENV_ACCESS' is not supported on this target - ignored

Clang 12 currently emits this warning for all non-x86 architectures.
While this can result in incorrect code generation (e.g. on AArch64 some
exceptions are not raised as expected), this is a pre-existing issue and
we should not fail the build due to this warning.

Reviewed By:	dim, emaste
MFC after:	1 week
Differential Revision: https://reviews.freebsd.org/D29743

2 files changed, 12 insertions, 0 deletions

diff --git a/lib/msun/Makefile b/lib/msun/Makefile
index 0a486bb5a086..7107aad56aa7 100644
--- a/lib/msun/Makefile
+++ b/lib/msun/Makefile
@@ -255,4 +255,10 @@ MLINKS+=trunc.3 truncf.3 trunc.3 truncl.3
 HAS_TESTS=
 SUBDIR.${MK_TESTS}+= tests
 
+.include <bsd.compiler.mk>
+.if ${COMPILER_TYPE} == "clang" && ${COMPILER_VERSION} >= 120000
+# Silence '#pragma FENV_ACCESS' is not supported on this target - ignored
+CWARNFLAGS+=	-Wno-error=ignored-pragmas
+.endif
+
 .include <bsd.lib.mk>
diff --git a/lib/msun/tests/Makefile b/lib/msun/tests/Makefile
index 70f7d2fe5135..d33a1b04888d 100644
--- a/lib/msun/tests/Makefile
+++ b/lib/msun/tests/Makefile
@@ -100,6 +100,12 @@ CFLAGS+=	-DLDBL_PREC=${LDBL_PREC}
 
 CFLAGS.fe_round_test+=	-D__HAVE_FENV
 
+.include <bsd.compiler.mk>
+.if ${COMPILER_TYPE} == "clang" && ${COMPILER_VERSION} >= 120000
+# Silence '#pragma FENV_ACCESS' is not supported on this target - ignored
+CWARNFLAGS+=	-Wno-error=ignored-pragmas
+.endif
+
 .include <netbsd-tests.test.mk>
 
 .include <bsd.test.mk>