Question

使用Xcode 8.0，我可以使用sysroot：

对iOS进行交叉编译

/Applications/Xcode.app/Contents/Developer/usr/bin/g++ \
    --sysroot=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS10.0.sdk \
    -miphoneos-version-min=10.0 -arch armv7s -stdlib=libc++ -std=gnu++11 \
    helloworld.cpp

然而，随着Xcode 8.1的出现，这个问题就出现了：

/Applications/Xcode.app/Contents/Developer/usr/bin/g++ \
    --sysroot=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS10.1.sdk \
    -miphoneos-version-min=10.1 -arch armv7s -stdlib=libc++ -std=gnu++11 \
    helloworld.cpp
clang: warning: using sysroot for 'MacOSX' but targeting 'iPhone'
In file included from helloworld.cpp:1:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/iostream:38:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/ios:215:
In file included from /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/iosfwd:90:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/usr/include/wchar.h:70:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/usr/include/_types.h:27:
In file included from /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/usr/include/sys/_types.h:32:
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.12.sdk/usr/include/sys/cdefs.h:761:2: error: Unsupported architecture
#error Unsupported architecture

警告using sysroot for 'MacOSX' but targeting 'iPhone'似乎表明sysroot参数被忽略（并且在错误中明确表示它使用MacOSX10.12.sdk）。

这些参数有变化吗？如何正确指定sysroot？

Answer 1

由于Apple的gcc / g ++只是在clang / clang ++之上，我们可以直接使用clang吗？

事实证明有效：

/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ \
    --sysroot=/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS10.1.sdk \
    -miphoneos-version-min=10.1 -arch armv7s -stdlib=libc++ -std=gnu++11 \
    helloworld.cpp

Apple的gcc / g ++似乎因更改sysroot而被破坏。但是我们似乎能够使用gcc样式的--sysroot参数。方便！

奇怪的是，如果我尝试使用未加前缀的铿锵声，我必须使用-isysroot：

clang++ \
    -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS10.1.sdk \ 
    -miphoneos-version-min=10.1 -arch armv7s -stdlib=libc++ -std=gnu++11 \
    helloworld.cpp

Answer 2

将-isysroot与较新的Xcode而不是--sysroot一起使用，并使用空格代替等号。

带有iOS sysroot和xcode 8.1的g ++

2 个答案: