How can I specify additional clang options for Xcode project?

Question

I have created my custom clang plugin with help of this tutorial and I want to run it automatically on my Xcode iOS project.

I need to run following additional commands on clang,

-Xclang -load \
-Xclang ~/static_analysis/llvm/Debug+Asserts/lib/libPluginExample.so \
-Xclang -plugin -Xclang -example-plugin \

I would like to save all other commands generated by Xcode, because it is difficult to create and pass those commands for every Xcode project. That is the reason why I choose to use clang plugin but not clang tool.

How can I do achieve this?

Or how can I extract compiler flags generated by xcode aoutomtically, to use them in clang tool? (becouse, for correct using tool I need to specify all include directories, and all sources, and all frameworks)

Update:

I have added thous commands in Project

Settings -> Build Phases -> Compile Sources (double click on source)

, but in compile time there is error (plugin is standard example libPrintFunctionNames.dylib from clang sources):

error: unable to load plugin '/Users/...llvm/Debug+Asserts/lib/libPrintFunctionNames.dylib': 'dlopen(/Users/.../llvm/Debug+Asserts/lib/libPrintFunctionNames.dylib, 9): Symbol not found: __ZN5clang11ASTConsumer21HandleInterestingDeclENS_12DeclGroupRefE Referenced from: /Users/.../llvm/Debug+Asserts/lib/libPrintFunctionNames.dylib Expected in: flat namespace in /Users/.../llvm/Debug+Asserts/lib/libPrintFunctionNames.dylib' Command /Applications/Xcode 2.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang failed with exit code 1

I have tried to use libPrintFunctionNames.a instead of libPrintFunctionNames.dylib, but it doe not help.

Maybe the cause is that I built my plugin on separated source files of llvm and clang, and in xcode I use other version of clang. I will check that.

Answer 1

I would specify additional Clang options in build option OTHER_CFLAGS. You can do so in

target/project Build Settings -> Apple LLVM 5.0 - Custom Compiler Flags -> Other C Flags

Or you can specify OTHER_CFLAGS for xcodebuild, for example,

xcodebuild -scheme SampleProject build OTHER_CFLAGS="-Xclang -load -Xclang /path/to/libPrintFunctionNames.dylib -Xclang -plugin -Xclang print-fns"

xcodebuild is convenient when you don't want to maintain 2 targets which differ only in OTHER_CFLAGS.

But you're right, it looks like you really need to link against the same libraries as clang itself is linked. At least I've downloaded Clang+LLVM 3.3 binaries from http://llvm.org/releases/download.html , built the plugin with downloaded libraries and it works with clang from http://llvm.org, but doesn't work with clang from Xcode - I encounter the following error:

error: unable to find plugin 'print-fns'

I've created Xcode workspace which builds Clang plugin and shows how you can try to use it with default iOS application. You can find it at https://github.com/vsapsai/ClangPluginExample