Test errno setting on strtod overflow in tst-strtod-round

[Joseph Myers]

We have no tests that errno is set to ERANGE on overflow of
strtod-family functions (we do have some tests for underflow, in
tst-strtod-underflow).  Add such tests to tst-strtod-round.

Tested for x86_64.

diff --git a/stdlib/tst-strtod-round-skeleton.c b/stdlib/tst-strtod-round-skeleton.c
index 6fba4b5228..184ec07b67 100644
--- a/stdlib/tst-strtod-round-skeleton.c
+++ b/stdlib/tst-strtod-round-skeleton.c
@@ -21,6 +21,7 @@
    declared in the headers.  */
 #define _LIBC_TEST 1
 #define __STDC_WANT_IEC_60559_TYPES_EXT__
+#include <errno.h>
 #include <fenv.h>
 #include <float.h>
 #include <math.h>
@@ -205,7 +206,9 @@ struct test {
 #define GEN_ONE_TEST(FSUF, FTYPE, FTOSTR, LSUF, CSUF)		\
 {								\
   feclearexcept (FE_ALL_EXCEPT);				\
+  errno = 0;							\
   FTYPE f = STRTO (FSUF) (s, NULL);				\
+  int new_errno = errno;					\
   if (f != expected->FSUF					\
       || (copysign ## CSUF) (1.0 ## LSUF, f)			\
 	 != (copysign ## CSUF) (1.0 ## LSUF, expected->FSUF))	\
@@ -254,6 +257,13 @@ struct test {
 		printf ("ignoring this exception error\n");	\
 	    }							\
 	}							\
+      if (overflow->FSUF && new_errno != ERANGE)		\
+	{							\
+	  printf (FNPFXS "to" #FSUF				\
+		  " (" STRM ") did not set errno to ERANGE\n",	\
+		  s);						\
+	  result = 1;						\
+	}							\
     }								\
 }
 

-- 
Joseph S. Myers
josmyers@redhat.com