c++ - 如何摆脱 OSX10.10 SDK 中的 module.map 警告？

Question

自从将 Xcode 更新到 6.3 版本后，我在编译 C++ 代码时收到以下警告:

/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/usr/include/module.map:1:25: warning: unknown attribute 'extern_c' [-Wignored-attributes]
module Darwin [system] [extern_c] {
                        ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/usr/include/module.map:1561:21: warning: unknown attribute 'extern_c' [-Wignored-attributes]
module os [system] [extern_c] {
                    ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/usr/include/module.map:1577:26: warning: unknown attribute 'extern_c' [-Wignored-attributes]
module libkern [system] [extern_c] {
                         ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/usr/include/module.map:1602:23: warning: unknown attribute 'extern_c' [-Wignored-attributes]
module ldap [system] [extern_c] {
                      ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/usr/include/module.map:1635:23: warning: unknown attribute 'extern_c' [-Wignored-attributes]
module krb5 [system] [extern_c] {
                      ^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk/usr/include/module.map:1662:22: warning: unknown attribute 'extern_c' [-Wignored-attributes]
module XPC [system] [extern_c] {
                     ^

除了忽略 -Wignored-attributes 之外，还有人知道如何解决这个问题吗？

Answer 1

原来我使用的是旧版本的 clang 和 Xcode 的 SDK。使用默认的 clang 可以消除警告。