Bug 1604615 - Fix wrench build issues on CI arising from glslopt. r=jrmuizel

* For wrench builds, the clang toolchain must now be fetched and be
  present in PATH for bindgen to work. When building OSMesa, we must
  therefore set `LLVM_CONFIG=no` so that it does not attempt to build
  llvmpipe.

* For wrench Mac cross-compiles, we must be careful to expose CFLAGS
  and similar variables using the target-specific variable names, so
  that host builds do not attempt to use flags intended for the
  target. When building OSMesa we must use the generic variable `CC`,
  so now we additionally set `HOST_CC`, so that host builds use the
  host variable rather than the generic one.

* Similarily, for wrench android builds we must use a fork of
  cargo-apk which sets the target-specific variables rather than the
  generic ones. Otherwise we would attempt to use the NDK toolchain
  for host builds.

Differential Revision: https://phabricator.services.mozilla.com/D70031

taskcluster/ci/fetch/toolchains.yml

@@ -392,8 +392,8 @@ android-rs-glue:
     description: android-rs-glue source code
     fetch:
         type: git
-        repo: https://github.com/rust-windowing/android-rs-glue
-        revision: e3ac6edea5814e1faca0c31ea8fac6877cb929ea
+        repo: https://github.com/jamienicol/android-rs-glue
+        revision: 7a57ad320de79c74a57a8ce02b1dc69b1ea7332a
 
 clang-5.0:
     description: clang 5.0.2 source code

taskcluster/ci/webrender/kind.yml

@@ -52,12 +52,14 @@ jobs:
             docker-image: {in-tree: webrender}
         fetches:
             toolchain:
+                - linux64-clang
                 - linux64-rust
                 - wrench-deps
         run:
             using: run-task
             command: >-
-                export PATH=$PATH:$MOZ_FETCHES_DIR/rustc/bin &&
+                export PATH=$PATH:$MOZ_FETCHES_DIR/clang/bin:$MOZ_FETCHES_DIR/rustc/bin &&
+                export LLVM_CONFIG=no &&
                 cd $HOME/checkouts/gecko/gfx/wr &&
                 mv $MOZ_FETCHES_DIR/wrench-deps/{vendor,.cargo} ./ &&
                 CARGOFLAGS="--verbose --frozen" ci-scripts/linux-release-tests.sh
@@ -76,12 +78,14 @@ jobs:
             docker-image: {in-tree: webrender}
         fetches:
             toolchain:
+                - linux64-clang
                 - linux64-rust
                 - wrench-deps
         run:
             using: run-task
             command: >-
-                export PATH=$PATH:$MOZ_FETCHES_DIR/rustc/bin &&
+                export PATH=$PATH:$MOZ_FETCHES_DIR/clang/bin:$MOZ_FETCHES_DIR/rustc/bin &&
+                export LLVM_CONFIG=no &&
                 cd $HOME/checkouts/gecko/gfx/wr &&
                 mv $MOZ_FETCHES_DIR/wrench-deps/{vendor,.cargo} ./ &&
                 CARGOFLAGS="--verbose --frozen" ci-scripts/linux-debug-tests.sh
@@ -225,6 +229,7 @@ jobs:
                 TOOLTOOL_MANIFEST: 'browser/config/tooltool-manifests/win64/vs2017.manifest'
         fetches:
             toolchain:
+                - win64-clang-cl
                 - win64-rust
                 - wrench-deps
         run:
@@ -267,6 +272,7 @@ jobs:
                 - android-gradle-dependencies
                 - android-ndk-linux
                 - android-sdk-linux
+                - linux64-clang
                 - linux64-rust-android
                 - wrench-deps
         treeherder:
@@ -302,6 +308,7 @@ jobs:
                 - android-gradle-dependencies
                 - android-ndk-linux
                 - android-sdk-linux
+                - linux64-clang
                 - linux64-rust-android
                 - wrench-deps
         treeherder:

taskcluster/scripts/misc/wr-macos-cross-build-setup.sh

@@ -31,14 +31,13 @@ END_PKGCONFIG_WRAPPER
 chmod +x "${TARGET_TRIPLE}-pkg-config"
 popd
 
-# The PATH intentionally excludes clang/bin because osmesa will try to
-# build llvmpipe if it finds a llvm-config. And that will fail because
-# we don't have a target libLLVM library to link with. We don't need
-# llvmpipe anyway since we only use the softpipe driver. If for whatever
-# reason we need to add clang/bin to the path here, we should be able to
-# instead set LLVM_CONFIG=no to disable llvmpipe, but that might impact
-# other parts of the build.
-export PATH="${MOZ_FETCHES_DIR}/rustc/bin:${MOZ_FETCHES_DIR}/cctools/bin:${MOZ_FETCHES_DIR}/llvm-dsymutil/bin:${PATH}"
+# Set LLVM_CONFIG=no to disable building llvmpipe, otherwise it will
+# be built automatically because clang is present in PATH (which is
+# required for bindgen), and that will fail because we don't have a
+# target libLLVM library to link with. We don't need llvmpipe anyway
+# since we only use the softpipe driver.
+export LLVM_CONFIG=no
+export PATH="${MOZ_FETCHES_DIR}/clang/bin:${MOZ_FETCHES_DIR}/rustc/bin:${MOZ_FETCHES_DIR}/cctools/bin:${MOZ_FETCHES_DIR}/llvm-dsymutil/bin:${PATH}"
 
 # The x86_64-darwin11-ld linker from cctools requires libraries provided
 # by clang, so we need to set LD_LIBRARY_PATH for that to work.
@@ -49,17 +48,20 @@ export LD_LIBRARY_PATH="${CLANGDIR}/lib:${LD_LIBRARY_PATH}"
 export ZLIB_CFLAGS="-I${MACOS_SYSROOT}/usr/include"
 export ZLIB_LIBS="-L${MACOS_SYSROOT}/usr/lib -lz"
 
-# Set up compiler and flags for cross-compile
+# Set up compiler and flags for cross-compile. Careful to only export the
+# target-specific CFLAGS/CXXFLAGS variables, to not break any host builds.
 LDPATH="${MOZ_FETCHES_DIR}/cctools/bin/${TARGET_TRIPLE}-ld"
 export CC="${CLANGDIR}/bin/clang"
-export CFLAGS="-fuse-ld=${LDPATH} -target ${TARGET_TRIPLE} -mmacosx-version-min=10.7 --rtlib=compiler-rt --sysroot ${MACOS_SYSROOT}"
+TARGET_CFLAGS="-fuse-ld=${LDPATH} -target ${TARGET_TRIPLE} -mmacosx-version-min=10.7 --rtlib=compiler-rt --sysroot ${MACOS_SYSROOT}"
+export CFLAGS_${TARGET_TRIPLE//-/_}="${TARGET_CFLAGS}"
 export CXX="${CLANGDIR}/bin/clang++"
-export CXXFLAGS="-fuse-ld=${LDPATH} -target ${TARGET_TRIPLE} -mmacosx-version-min=10.7 --rtlib=compiler-rt --sysroot ${MACOS_SYSROOT} -stdlib=libc++"
+TARGET_CXXFLAGS="-fuse-ld=${LDPATH} -target ${TARGET_TRIPLE} -mmacosx-version-min=10.7 --rtlib=compiler-rt --sysroot ${MACOS_SYSROOT} -stdlib=libc++"
+export CXXFLAGS_${TARGET_TRIPLE//-/_}="${TARGET_CXXFLAGS}"
 export AR="${CLANGDIR}/bin/llvm-ar"
 
 # See documentation in cargo-linker for why we need this. TL;DR is that passing
 # the right arguments to the linker when invoked by cargo is nigh impossible
 # without this.
 export MOZ_CARGO_WRAP_LD="${CC}"
-export MOZ_CARGO_WRAP_LDFLAGS="${CFLAGS}"
+export MOZ_CARGO_WRAP_LDFLAGS="${TARGET_CFLAGS}"
 export CARGO_TARGET_X86_64_APPLE_DARWIN_LINKER="${GECKO_PATH}/build/cargo-linker"

taskcluster/scripts/misc/wrench-android-build.sh

@@ -10,7 +10,7 @@ popd
 pushd "${GECKO_PATH}/gfx/wr/wrench"
 # These things come from the toolchain dependencies of the job that invokes
 # this script (webrender-wrench-android-build).
-export PATH="${PATH}:${MOZ_FETCHES_DIR}/rustc/bin"
+export PATH="${PATH}:${MOZ_FETCHES_DIR}/clang/bin:${MOZ_FETCHES_DIR}/rustc/bin"
 export ANDROID_HOME="${MOZ_FETCHES_DIR}/android-sdk-linux"
 export NDK_HOME="${MOZ_FETCHES_DIR}/android-ndk"
 

taskcluster/scripts/misc/wrench-macos-build.sh

@@ -6,10 +6,16 @@ source ${GECKO_PATH}/taskcluster/scripts/misc/wr-macos-cross-build-setup.sh
 # The osmesa-src build which we do as part of the headless build below
 # doesn't seem to always use CFLAGS/CXXFLAGS where expected. Instead we
 # just squash those flags into CC/CXX and everything works out.
-export CC="${CC} ${CFLAGS}"
-export CFLAGS=
-export CXX="${CXX} ${CXXFLAGS}"
-export CXXFLAGS=
+# Export HOST_CC and HOST_CXX without the squashed flags, so that host
+# builds use them and don't see the target flags.
+export HOST_CC="${CC}"
+export HOST_CXX="${CXX}"
+CFLAGS_VAR="CFLAGS_${TARGET_TRIPLE//-/_}"
+CXXFLAGS_VAR="CXXFLAGS_${TARGET_TRIPLE//-/_}"
+export CC="${CC} ${!CFLAGS_VAR}"
+export ${CFLAGS_VAR}=
+export CXX="${CXX} ${!CXXFLAGS_VAR}"
+export ${CXXFLAGS_VAR}=
 
 export UPLOAD_DIR="${HOME}/artifacts"
 mkdir -p "${UPLOAD_DIR}"

taskcluster/scripts/misc/wrench-windows-tests.sh

@@ -12,7 +12,7 @@ cd $GECKO_PATH
 
 # This will download the rustc, MSVC, and wrench-deps artifacts.
 . taskcluster/scripts/misc/tooltool-download.sh
-export PATH=$PATH:$(cd $MOZ_FETCHES_DIR && pwd)/rustc/bin
+export PATH=$PATH:$(cd $MOZ_FETCHES_DIR && pwd)/clang/bin:$(cd $MOZ_FETCHES_DIR && pwd)/rustc/bin
 
 .  taskcluster/scripts/misc/vs-setup.sh