I want to build an existing application using xcrun under Mac OS X 10.9. The application integrates with libxml. It comes with includes such as:
#include <libxml/parser.h>
For testing, I ran:
echo '#include <libxml/parser.h>' | xcrun clang -xc -v -
which gives me
#include "..." search starts here:
#include <...> search starts here:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../lib/clang/5.0/include
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/include
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/System/Library/Frameworks (framework directory)
End of search list.
<stdin>:1:10: fatal error: 'libxml/parser.h' file not found
#include <libxml/parser.h>
While the critical header search paths seem up under xcrun, libxml2 is missing. As a matter of fact, libxml/*.h reside in a subdir of
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/include
namely
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/include/libxml2
How can I add this dir (.../usr/include/libxml2) to the search path respected by xcrun?
Click on your project at the top of the Project Navigator, then make sure the appropriate target is selected. Towards the top center of the screen click on "Build Settings." Now go down to the section that says "Search Paths" and find the path you want to edit (e.g., framework search path, header search path, library search path). There will be several columns because you can configure these variables at the project level, in an xcconfig file, at the target level, etc., and the ultimate value that filters down is displayed in the "Resolved" column. Pick whatever level is appropriate for you and double click into the field and type your path in.
Note: If your path has spaces you should enclose it in double quotes; HOWEVER, there is presently a bug in Xcode that causes Xcode to occasionally re-interpret search path strings and double-escape them. So when you enter "my/path/here" Xcode stores it as \"my/path/here\" which is correct. But later Xcode may store it as \\"my/path/here\\" which means Xcode tries to pull the file from \"my/path/here\" which causes a failure. So if that crops up just get rid of the double-escaping.