Restore V8_LIBC_UCLIBC as a libc option.

include/v8config.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8CONFIG_H_
 #define V8CONFIG_H_
 
 // Platform headers for feature detection below.
 #if defined(__ANDROID__)
 # include <sys/cdefs.h>
@@ skipping 106 matching lines @@
 #endif
 
 
 // -----------------------------------------------------------------------------
 // C library detection
 //
 //  V8_LIBC_MSVCRT  - MSVC libc
 //  V8_LIBC_BIONIC  - Bionic libc
 //  V8_LIBC_BSD     - BSD libc derivate
 //  V8_LIBC_GLIBC   - GNU C library
+//  V8_LIBC_UCLIBC  - uClibc

[smcgruer2, 2015/04/13 16:41:25]

I'm on the fence about reintroducing this, as it's not actually used anywhere in
the code. It's main purpose is to stop uClibc from pretending to be glibc, which
could also be done by changing the V8_LIBC_GLIBC check to:

#elif (defined(__GLIBC__) || defined(__GNU_LIBRARY__)) && !defined(__UCLIBC__)

 //
 // Note that testing for libc must be done using #if not #ifdef. For example,
 // to test for the GNU C library, use:
 //  #if V8_LIBC_GLIBC
 //   ...
 //  #endif
 
 #if defined (_MSC_VER)
 # define V8_LIBC_MSVCRT 1
 #elif defined(__BIONIC__)
 # define V8_LIBC_BIONIC 1
 # define V8_LIBC_BSD 1
+#elif defined(__UCLIBC__)
+// Must test for UCLIBC before GLIBC, as UCLIBC pretends to be GLIBC.
+# define V8_LIBC_UCLIBC 1
 #elif defined(__GLIBC__) || defined(__GNU_LIBRARY__)
 # define V8_LIBC_GLIBC 1
 #else
 # define V8_LIBC_BSD V8_OS_BSD
 #endif
 
 
 // -----------------------------------------------------------------------------
 // Compiler detection
 //
@@ skipping 279 matching lines @@
 // Annotate a function indicating the caller must examine the return value.
 // Use like:
 //   int foo() WARN_UNUSED_RESULT;
 #if V8_HAS_ATTRIBUTE_WARN_UNUSED_RESULT
 #define V8_WARN_UNUSED_RESULT __attribute__((warn_unused_result))
 #else
 #define V8_WARN_UNUSED_RESULT /* NOT SUPPORTED */
 #endif
 
 #endif  // V8CONFIG_H_