[libc++] Fix tests on musl.

One or two of the tests need slight tweaks to make them pass when
building with musl.

rdar://118885724

Author: al45tair

libcxx/test/std/diagnostics/syserr/syserr.errcat/syserr.errcat.objects/generic_category.pass.cpp

@@ -27,11 +27,9 @@ void test_message_for_bad_value() {
     const std::error_category& e_cat1 = std::generic_category();
     const std::string msg = e_cat1.message(-1);
     // Exact message format varies by platform.
-#if defined(_AIX)
-    LIBCPP_ASSERT(msg.rfind("Error -1 occurred", 0) == 0);
-#else
-    LIBCPP_ASSERT(msg.rfind("Unknown error", 0) == 0);
-#endif
+    LIBCPP_ASSERT(msg.rfind("Error -1 occurred", 0) == 0
+                  || msg.rfind("No error information", 0) == 0
+                  || msg.rfind("Unknown error", 0) == 0);
     assert(errno == E2BIG);
 }
 

libcxx/test/std/diagnostics/syserr/syserr.errcat/syserr.errcat.objects/system_category.pass.cpp

@@ -27,11 +27,11 @@ void test_message_for_bad_value() {
     const std::error_category& e_cat1 = std::system_category();
     const std::string msg = e_cat1.message(-1);
     // Exact message format varies by platform.
-#if defined(_AIX)
-    LIBCPP_ASSERT(msg.rfind("Error -1 occurred", 0) == 0);
-#else
-    LIBCPP_ASSERT(msg.rfind("Unknown error", 0) == 0);
-#endif
+    LIBCPP_ASSERT(
+        msg.rfind("No error information", 0) == 0
+        || msg.rfind("Unknown error", 0) == 0     // Musl
+        || msg.rfind("Error -1 occurred", 0) == 0 // AIX
+    );
     assert(errno == E2BIG);
 }
 

libcxx/test/std/localization/locale.categories/category.numeric/locale.nm.put/facet.num.put.members/put_long_double.pass.cpp

@@ -17,6 +17,7 @@
 #include <locale>
 #include <ios>
 #include <cassert>
+#include <cstdio>
 #include <streambuf>
 #include <cmath>
 #include "test_macros.h"
@@ -8929,11 +8930,12 @@ void test4()
     char str[200];
     std::locale lc = std::locale::classic();
     std::locale lg(lc, new my_numpunct);
-#ifdef _AIX
-    std::string inf = "INF";
-#else
-    std::string inf = "inf";
-#endif
+
+    std::string inf;
+
+    // This should match the underlying C library
+    std::sprintf(str, "%f", INFINITY);
+    inf = str;
 
     const my_facet f(1);
     {
@@ -10722,24 +10724,28 @@ void test5()
     std::locale lc = std::locale::classic();
     std::locale lg(lc, new my_numpunct);
     const my_facet f(1);
-#if defined(_AIX)
-    std::string nan= "NaNQ";
-    std::string NaN = "NaNQ";
-    std::string nan_padding25 = "*********************";
-    std::string pnan_sign = "+";
-    std::string pnan_padding25 = "********************";
-#else
-    std::string nan= "nan";
-    std::string NaN = "NAN";
-    std::string nan_padding25 = "**********************";
-#if defined(TEST_HAS_GLIBC) || defined(_WIN32)
-    std::string pnan_sign = "+";
-    std::string pnan_padding25 = "*********************";
-#else
-    std::string pnan_sign = "";
-    std::string pnan_padding25 = "**********************";
-#endif
-#endif
+
+    std::string nan;
+    std::string NaN;
+    std::string pnan_sign;
+
+    // The output here depends on the underlying C library, so work out what
+    // that does.
+    std::sprintf(str, "%f", std::nan(""));
+    nan = str;
+
+    std::sprintf(str, "%F", std::nan(""));
+    NaN = str;
+
+    std::sprintf(str, "%+f", std::nan(""));
+    if (str[0] == '+') {
+      pnan_sign = "+";
+    }
+
+    std::string nan_padding25 = std::string(25 - nan.length(), '*');
+    std::string pnan_padding25 = std::string(25 - nan.length()
+                                             - pnan_sign.length(), '*');
+
     {
         long double v = std::nan("");
         std::ios ios(0);