diff --git a/float.h b/float.h
index b8887ed..4299bad 100644
--- a/float.h
+++ b/float.h
@@ -1,5 +1,5 @@
-#if !defined(_FLOAT_H) || defined(__LIBC_GUARDLESS_INCLUDE)
-#if !defined(__LIBC_GUARDLESS_INCLUDE)
+#if !defined(_FLOAT_H) || defined(__LIBC_CXX_WRAP)
+#if !defined(__LIBC_CXX_WRAP)
 #define _FLOAT_H 1
 #endif
 
@@ -54,6 +54,14 @@
 #define DBL_MIN __DBL_MIN__
 #define LDBL_MIN __LDBL_MIN__
 
+#define FLT_TRUE_MIN __FLT_DENORM_MIN__
+#define DBL_TRUE_MIN __DBL_DENORM_MIN__
+#define LDBL_TRUE_MIN __LDBL_DENORM_MIN__
+
+#define FLT_HAS_SUBNORM __FLT_HAS_DENORM__
+#define DBL_HAS_SUBNORM __DBL_HAS_DENORM__
+#define LDBL_HAS_SUBNORM __LDBL_HAS_DENORM__
+
 #endif
 
 #endif
diff --git a/limits.h b/limits.h
index 0ef495a..5a1e5a9 100644
--- a/limits.h
+++ b/limits.h
@@ -1,5 +1,5 @@
-#if !defined(_LIMITS_H) || defined(__LIBC_GUARDLESS_INCLUDE)
-#if !defined(__LIBC_GUARDLESS_INCLUDE)
+#if !defined(_LIMITS_H) || defined(__LIBC_CXX_WRAP)
+#if !defined(__LIBC_CXX_WRAP)
 #define _LIMITS_H 1
 #endif
 
diff --git a/stdalign.h b/stdalign.h
index abdea0c..45bdce8 100644
--- a/stdalign.h
+++ b/stdalign.h
@@ -1,5 +1,5 @@
-#if !defined(_STDALIGN_H) || defined(__LIBC_GUARDLESS_INCLUDE)
-#if !defined(__LIBC_GUARDLESS_INCLUDE)
+#if !defined(_STDALIGN_H) || defined(__LIBC_CXX_WRAP)
+#if !defined(__LIBC_CXX_WRAP)
 #define _STDALIGN_H 1
 #endif
 
diff --git a/stdarg.h b/stdarg.h
index d756a59..72df8c7 100644
--- a/stdarg.h
+++ b/stdarg.h
@@ -1,5 +1,5 @@
-#if !defined(_STDARG_H) || defined(__LIBC_GUARDLESS_INCLUDE)
-#if !defined(__LIBC_GUARDLESS_INCLUDE)
+#if !defined(_STDARG_H) || defined(__LIBC_CXX_WRAP)
+#if !defined(__LIBC_CXX_WRAP)
 #define _STDARG_H 1
 #endif
 
diff --git a/stdbool.h b/stdbool.h
index 365536c..46dc75b 100644
--- a/stdbool.h
+++ b/stdbool.h
@@ -1,5 +1,5 @@
-#if !defined(_STDBOOL_H) || defined(__LIBC_GUARDLESS_INCLUDE)
-#if !defined(__LIBC_GUARDLESS_INCLUDE)
+#if !defined(_STDBOOL_H) || defined(__LIBC_CXX_WRAP)
+#if !defined(__LIBC_CXX_WRAP)
 #define _STDBOOL_H 1
 #endif
 
diff --git a/stddef.h b/stddef.h
index b40d82d..066bb3f 100644
--- a/stddef.h
+++ b/stddef.h
@@ -1,5 +1,5 @@
-#if !defined(_STDDEF_H) || defined(__LIBC_GUARDLESS_INCLUDE)
-#if !defined(__LIBC_GUARDLESS_INCLUDE)
+#if !defined(_STDDEF_H) || defined(__LIBC_CXX_WRAP)
+#if !defined(__LIBC_CXX_WRAP)
 #define _STDDEF_H 1
 #endif
 
diff --git a/stdint.h b/stdint.h
index 6b993a3..3fccff0 100644
--- a/stdint.h
+++ b/stdint.h
@@ -1,5 +1,5 @@
-#if !defined(_STDINT_H) || defined(__LIBC_GUARDLESS_INCLUDE)
-#if !defined(__LIBC_GUARDLESS_INCLUDE)
+#if !defined(_STDINT_H) || defined(__LIBC_CXX_WRAP)
+#if !defined(__LIBC_CXX_WRAP)
 #define _STDINT_H 1
 #endif
 
@@ -44,15 +44,17 @@ typedef __INTMAX_TYPE__ intmax_t;
 
 /* Clang and GCC have different mechanisms for INT32_C and friends. */
 #ifdef __clang__
-#   define __LIBC_C_EXPAND_JOIN(x, suffix) x ## suffix
-#   define __LIBC_C_JOIN(x, suffix) __LIBC_C_EXPAND_JOIN(x, suffix)
+#   ifndef __LIBC_C_JOIN
+#       define __LIBC_C_EXPAND_JOIN(x, suffix) x ## suffix
+#       define __LIBC_C_JOIN(x, suffix) __LIBC_C_EXPAND_JOIN(x, suffix)
+#   endif
 
-#   define INT8_C(x)  __LIBC_C_JOIN(x, __INT8_C_SUFFIX__)
+#   define INT8_C(x) __LIBC_C_JOIN(x, __INT8_C_SUFFIX__)
 #   define INT16_C(x) __LIBC_C_JOIN(x, __INT16_C_SUFFIX__)
 #   define INT32_C(x) __LIBC_C_JOIN(x, __INT32_C_SUFFIX__)
 #   define INT64_C(x) __LIBC_C_JOIN(x, __INT64_C_SUFFIX__)
 
-#   define UINT8_C(x)  __LIBC_C_JOIN(x, __UINT8_C_SUFFIX__)
+#   define UINT8_C(x) __LIBC_C_JOIN(x, __UINT8_C_SUFFIX__)
 #   define UINT16_C(x) __LIBC_C_JOIN(x, __UINT16_C_SUFFIX__)
 #   define UINT32_C(x) __LIBC_C_JOIN(x, __UINT32_C_SUFFIX__)
 #   define UINT64_C(x) __LIBC_C_JOIN(x, __UINT64_C_SUFFIX__)
@@ -60,12 +62,12 @@ typedef __INTMAX_TYPE__ intmax_t;
 #   define INTMAX_C(x) __LIBC_C_JOIN(x, __INTMAX_C_SUFFIX__)
 #   define UINTMAX_C(x) __LIBC_C_JOIN(x, __UINTMAX_C_SUFFIX__)
 #else
-#   define INT8_C(x)  __INT8_C(x)
+#   define INT8_C(x) __INT8_C(x)
 #   define INT16_C(x) __INT16_C(x)
 #   define INT32_C(x) __INT32_C(x)
 #   define INT64_C(x) __INT64_C(x)
 
-#   define UINT8_C(x)  __UINT8_C(x)
+#   define UINT8_C(x) __UINT8_C(x)
 #   define UINT16_C(x) __UINT16_C(x)
 #   define UINT32_C(x) __UINT32_C(x)
 #   define UINT64_C(x) __UINT64_C(x)