depends: specify libc++ header location for darwin

theuni · dongcarl · commit 6b8e497eeaf3 · 2020-07-10T21:05:54.000-04:00
For depends builds this was fixed by fbcfcf6, which deleted the conflicting headers. When we no longer control the clang installation, we need to ensure that the SDK's libc++ headers are used rather than the ones shipped with clang. We can do that by turning off the default include path and hard-coding our own. This hard-coded path is ok because we control (via SDK packaging) where these headers end-up. Side-note: Now that this path is hard-coded in depends, we can potentially package the SDK differently, as the c++ folder can live wherever is most convenient for us.
diff --git a/depends/hosts/darwin.mk b/depends/hosts/darwin.mk
@@ -9,7 +9,7 @@ OSX_SDK=$(SDK_PATH)/Xcode-$(XCODE_VERSION)-$(XCODE_BUILD_ID)-extracted-SDK-with-
 # When cross-compiling for Darwin using Clang, -mlinker-version must be passed to
 # ensure that modern linker features are enabled.
 darwin_CC=clang -target $(host) -mmacosx-version-min=$(OSX_MIN_VERSION) --sysroot $(OSX_SDK) -mlinker-version=$(LD64_VERSION) -B$(build_prefix)/bin
-darwin_CXX=clang++ -target $(host) -mmacosx-version-min=$(OSX_MIN_VERSION) --sysroot $(OSX_SDK) -stdlib=libc++ -mlinker-version=$(LD64_VERSION) -B$(build_prefix)/bin
+darwin_CXX=clang++ -target $(host) -mmacosx-version-min=$(OSX_MIN_VERSION) --sysroot $(OSX_SDK) -stdlib=libc++ -mlinker-version=$(LD64_VERSION) -B$(build_prefix)/bin -nostdinc++ -isystem $(OSX_SDK)/usr/include/c++/v1
 
 darwin_CFLAGS=-pipe
 darwin_CXXFLAGS=$(darwin_CFLAGS)
