Avoid spurious failures from <fenv.h> fallback functions (bug 15654).

ChangeLog

@@ -1,3 +1,19 @@
+2013-06-20  Joseph Myers  <joseph@codesourcery.com>
+
+	[BZ #15654]
+	* math/fedisblxcpt.c (fedisableexcept): Return 0.
+	* math/feenablxcpt.c (feenableexcept): Return 0 for argument 0.
+	* math/fegetenv.c (__fegetenv): Return 0.
+	* math/fegetexcept.c (fegetexcept): Return 0.
+	* math/fegetround.c (fegetround) [FE_TONEAREST]: Return
+	FE_TONEAREST.
+	* math/feholdexcpt.c (feholdexcept): Return 0.
+	* math/fesetenv.c (__fesetenv): Return 0.
+	* math/fesetround.c (fesetround) [FE_TONEAREST]: Return 0 for
+	argument FE_TONEAREST.
+	* math/feupdateenv.c (__feupdateenv): Return 0.
+	* math/fgetexcptflg.c (__fegetexceptflag): Return 0.
+
 2013-06-18  Roland McGrath  <roland@hack.frob.com>
 
 	* elf/rtld-Rules (rtld-compile-command.S): New variable.

NEWS

@@ -20,7 +20,7 @@ Version 2.18
   15361, 15366, 15380, 15381, 15394, 15395, 15405, 15406, 15409, 15416,
   15418, 15419, 15423, 15424, 15426, 15429, 15431, 15432, 15441, 15442,
   15448, 15465, 15480, 15485, 15488, 15490, 15492, 15493, 15497, 15506,
-  15529, 15536, 15553, 15577, 15583, 15618, 15627, 15631.
+  15529, 15536, 15553, 15577, 15583, 15618, 15627, 15631, 15654.
 
 * CVE-2013-0242 Buffer overrun in regexp matcher has been fixed (Bugzilla
   #15078).

math/fedisblxcpt.c

@@ -22,7 +22,7 @@
 int
 fedisableexcept (int excepts)
 {
-  /* Signal failure.  */
-  return -1;
+  /* All exception traps are disabled.  */
+  return 0;
 }
 stub_warning (fedisableexcept)

math/feenablxcpt.c

@@ -22,7 +22,10 @@
 int
 feenableexcept (int excepts)
 {
-  /* Signal failure.  */
-  return -1;
+  /* Signal failure if any exception traps are to be enabled.  */
+  if (excepts != 0)
+    return -1;
+  else
+    return 0;
 }
 stub_warning (feenableexcept)

math/fegetenv.c

@@ -23,8 +23,8 @@
 int
 __fegetenv (fenv_t *envp)
 {
-  /* This always fails.  */
-  return 1;
+  /* Nothing to do.  */
+  return 0;
 }
 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
 strong_alias (__fegetenv, __old_fegetenv)

math/fegetexcept.c

@@ -22,7 +22,7 @@
 int
 fegetexcept (void)
 {
-  /* Signal failure.  */
-  return -1;
+  /* All exception traps are disabled.  */
+  return 0;
 }
 stub_warning (fegetexcept)

math/fegetround.c

@@ -22,6 +22,10 @@
 int
 fegetround (void)
 {
+#ifdef FE_TONEAREST
+  return FE_TONEAREST;
+#else
   return 0;
+#endif
 }
 stub_warning (fegetround)

math/feholdexcpt.c

@@ -22,7 +22,8 @@
 int
 feholdexcept (fenv_t *envp)
 {
-  return 1;		/* Signal failure.  */
+  /* No exception traps to disable and no state to save.  */
+  return 0;
 }
 libm_hidden_def (feholdexcept)
 stub_warning (feholdexcept)

math/fesetenv.c

@@ -23,8 +23,8 @@
 int
 __fesetenv (const fenv_t *envp)
 {
-  /* This always fails.  */
-  return 1;
+  /* Nothing to do.  */
+  return 0;
 }
 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
 strong_alias (__fesetenv, __old_fesetenv)

math/fesetround.c

@@ -22,7 +22,11 @@
 int
 fesetround (int round)
 {
+#ifdef FE_TONEAREST
+  return (round == FE_TONEAREST) ? 0 : 1;
+#else
   return 1;	/* Signal we are unable to set the direction.  */
+#endif
 }
 libm_hidden_def (fesetround)
 stub_warning (fesetround)

math/feupdateenv.c

@@ -23,8 +23,8 @@
 int
 __feupdateenv (const fenv_t *envp)
 {
-  /* This always fails.  */
-  return 1;
+  /* Nothing to do.  */
+  return 0;
 }
 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
 strong_alias (__feupdateenv, __old_feupdateenv)

math/fgetexcptflg.c

@@ -23,8 +23,8 @@
 int
 __fegetexceptflag (fexcept_t *flagp, int excepts)
 {
-  /* This always fails.  */
-  return 1;
+  /* Nothing to do.  */
+  return 0;
 }
 #if SHLIB_COMPAT (libm, GLIBC_2_1, GLIBC_2_2)
 strong_alias (__fegetexceptflag, __old_fegetexceptflag)