Bug 1694280 - Add clang 12.0.0 rc2 toolchains (not yet used) r=firefox-build-system-reviewers,glandium

Just adding the toolchain tasks for now. They are not yet used by anything, but bug 1693288 might be interested eventually. As with earlier releases, clang-tidy and mingw builds are not included here, they'll be separate patches. Differential Revision: https://phabricator.services.mozilla.com/D106554
2021-03-03 16:53:28 +00:00
parent 3ec8e15624
commit d7a2fa25bf
16 changed files with 1826 additions and 9 deletions
--- a/build/build-clang/android-mangling-error_clang_12.patch
+++ b/build/build-clang/android-mangling-error_clang_12.patch
@@ -0,0 +1,24 @@
+Workaround segfault in clang's mangling code that is tickled when
+attempting to mangle the declaration:
+ std:__ndk1::__find_detail::__find_exactly_one_checked::__matches
+in the <tuple> header in the Android NDK.
+This codepath is exercised by MozsearchIndexer.cpp (the searchfox
+indexer) when indexing on Android. See also
+https://bugs.llvm.org/show_bug.cgi?id=40747
+
+diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
+index 4420f6a2c1c3..39792e6b7350 100644
+--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
+@@ -3954,6 +3954,11 @@ void CXXNameMangler::mangleExpression(const Expr *E, unsigned Arity,
+   // produces no output, where ImplicitlyConvertedToType and AsTemplateArg need
+   // to be preserved.
+ recurse:
+  if (!E) {
+    Out << "MOZ_WE_HACKED_AROUND_BUG_1500941";
+    return;
+  }
+
+   switch (E->getStmtClass()) {
+   case Expr::NoStmtClass:
+ #define ABSTRACT_STMT(Type)
--- a/build/build-clang/clang-12-android.json
+++ b/build/build-clang/clang-12-android.json
@@ -0,0 +1,56 @@
+{
+    "stages": "2",
+    "build_libcxx": true,
+    "build_type": "Release",
+    "assertions": false,
+    "python_path": "/usr/bin/python2.7",
+    "gcc_dir": "{MOZ_FETCHES_DIR}/gcc",
+    "cc": "{MOZ_FETCHES_DIR}/gcc/bin/gcc",
+    "cxx": "{MOZ_FETCHES_DIR}/gcc/bin/g++",
+    "as": "{MOZ_FETCHES_DIR}/gcc/bin/gcc",
+    "android_targets": {
+      "armv7-linux-android": {
+        "ndk_toolchain": "{MOZ_FETCHES_DIR}/android-ndk/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64",
+        "ndk_sysroot": "{MOZ_FETCHES_DIR}/android-ndk/platforms/android-16/arch-arm",
+        "ndk_includes": [
+          "{MOZ_FETCHES_DIR}/android-ndk/sysroot/usr/include/arm-linux-androideabi",
+          "{MOZ_FETCHES_DIR}/android-ndk/sysroot/usr/include"
+        ],
+        "api_level": 16
+      },
+      "i686-linux-android": {
+        "ndk_toolchain": "{MOZ_FETCHES_DIR}/android-ndk/toolchains/x86-4.9/prebuilt/linux-x86_64",
+        "ndk_sysroot": "{MOZ_FETCHES_DIR}/android-ndk/platforms/android-16/arch-x86",
+        "ndk_includes": [
+          "{MOZ_FETCHES_DIR}/android-ndk/sysroot/usr/include/i686-linux-android",
+          "{MOZ_FETCHES_DIR}/android-ndk/sysroot/usr/include"
+        ],
+        "api_level": 16
+      },
+      "aarch64-linux-android": {
+        "ndk_toolchain": "{MOZ_FETCHES_DIR}/android-ndk/toolchains/aarch64-linux-android-4.9/prebuilt/linux-x86_64",
+        "ndk_sysroot": "{MOZ_FETCHES_DIR}/android-ndk/platforms/android-21/arch-arm64",
+        "ndk_includes": [
+          "{MOZ_FETCHES_DIR}/android-ndk/sysroot/usr/include/aarch64-linux-android",
+          "{MOZ_FETCHES_DIR}/android-ndk/sysroot/usr/include"
+        ],
+        "api_level": 21
+      },
+      "x86_64-linux-android": {
+        "ndk_toolchain": "{MOZ_FETCHES_DIR}/android-ndk/toolchains/x86_64-4.9/prebuilt/linux-x86_64",
+        "ndk_sysroot": "{MOZ_FETCHES_DIR}/android-ndk/platforms/android-21/arch-x86_64",
+        "ndk_includes": [
+          "{MOZ_FETCHES_DIR}/android-ndk/sysroot/usr/include/x86_64-linux-android",
+          "{MOZ_FETCHES_DIR}/android-ndk/sysroot/usr/include"
+        ],
+        "api_level": 21
+      }
+    },
+    "patches": [
+      "static-llvm-symbolizer_clang_12.patch",
+      "find_symbolizer_linux_clang_10.patch",
+      "revert-llvmorg-12-init-7827-g2a078c307204.patch",
+      "revert-llvmorg-12-init-16421-gb688c5875d08.patch",
+      "revert-r362047-and-r362065_clang_12.patch"
+    ]
+}
--- a/build/build-clang/clang-12-linux64.json
+++ b/build/build-clang/clang-12-linux64.json
@@ -0,0 +1,23 @@
+{
+    "stages": "4",
+    "pgo" : true,
+    "build_libcxx": true,
+    "build_wasm": true,
+    "build_type": "Release",
+    "assertions": false,
+    "python_path": "/usr/bin/python2.7",
+    "gcc_dir": "{MOZ_FETCHES_DIR}/gcc",
+    "cc": "{MOZ_FETCHES_DIR}/gcc/bin/gcc",
+    "cxx": "{MOZ_FETCHES_DIR}/gcc/bin/g++",
+    "as": "{MOZ_FETCHES_DIR}/gcc/bin/gcc",
+    "wasi-sysroot": "{MOZ_FETCHES_DIR}/wasi-sysroot",
+    "patches": [
+      "static-llvm-symbolizer_clang_12.patch",
+      "find_symbolizer_linux_clang_10.patch",
+      "android-mangling-error_clang_12.patch",
+      "unpoison-thread-stacks_clang_10.patch",
+      "downgrade-mangling-error_clang_12.patch",
+      "revert-llvmorg-12-init-7827-g2a078c307204.patch",
+      "loosen-msvc-detection.patch"
+    ]
+}
--- a/build/build-clang/clang-12-macosx64.json
+++ b/build/build-clang/clang-12-macosx64.json
@@ -0,0 +1,22 @@
+{
+    "stages": "1",
+    "build_libcxx": true,
+    "build_type": "Release",
+    "assertions": false,
+    "osx_cross_compile": true,
+    "python_path": "/usr/bin/python2.7",
+    "gcc_dir": "{MOZ_FETCHES_DIR}/gcc",
+    "cc": "{MOZ_FETCHES_DIR}/clang/bin/clang",
+    "cxx": "{MOZ_FETCHES_DIR}/clang/bin/clang++",
+    "as": "{MOZ_FETCHES_DIR}/clang/bin/clang",
+    "ar": "{MOZ_FETCHES_DIR}/cctools/bin/x86_64-apple-darwin-ar",
+    "ranlib": "{MOZ_FETCHES_DIR}/cctools/bin/x86_64-apple-darwin-ranlib",
+    "libtool": "{MOZ_FETCHES_DIR}/cctools/bin/x86_64-apple-darwin-libtool",
+    "ld": "{MOZ_FETCHES_DIR}/clang/bin/clang",
+    "patches": [
+      "static-llvm-symbolizer_clang_12.patch",
+      "compiler-rt-cross-compile.patch",
+      "revert-llvmorg-12-init-7827-g2a078c307204.patch",
+      "compiler-rt-no-codesign.patch"
+    ]
+}
--- a/build/build-clang/clang-12-win64-2stage.json
+++ b/build/build-clang/clang-12-win64-2stage.json
@@ -0,0 +1,14 @@
+{
+    "stages": "2",
+    "build_libcxx": false,
+    "build_type": "Release",
+    "assertions": false,
+    "python_path": "c:/mozilla-build/python/python.exe",
+    "cc": "cl.exe",
+    "cxx": "cl.exe",
+    "ml": "ml64.exe",
+    "patches": [
+      "unpoison-thread-stacks_clang_10.patch",
+      "bug47258-extract-symbols-mbcs.patch"
+    ]
+}
--- a/build/build-clang/clang-12-win64.json
+++ b/build/build-clang/clang-12-win64.json
@@ -0,0 +1,18 @@
+{
+    "stages": "4",
+    "pgo" : true,
+    "build_libcxx": false,
+    "build_type": "Release",
+    "assertions": false,
+    "python_path": "c:/mozilla-build/python/python.exe",
+    "cc": "cl.exe",
+    "cxx": "cl.exe",
+    "ml": "ml64.exe",
+    "patches": [
+      "unpoison-thread-stacks_clang_10.patch",
+      "downgrade-mangling-error_clang_12.patch",
+      "bug47258-extract-symbols-mbcs.patch",
+      "revert-llvmorg-12-init-7827-g2a078c307204.patch",
+      "loosen-msvc-detection.patch"
+    ]
+}
--- a/build/build-clang/downgrade-mangling-error_clang_12.patch
+++ b/build/build-clang/downgrade-mangling-error_clang_12.patch
@@ -0,0 +1,23 @@
+Downgrade unimplemented mangling diagnostic from error to note.
+This codepath is exercised by MozsearchIndexer.cpp (the searchfox
+indexer) when indexing on Windows. We can do without having the
+unimplemented bits for now as long the compiler doesn't fail the
+build. See also https://bugs.llvm.org/show_bug.cgi?id=39294
+
+diff --git a/clang/lib/AST/ItaniumMangle.cpp b/clang/lib/AST/ItaniumMangle.cpp
+index 4420f6a2c1c3..4d9a6434d245 100644
+--- a/clang/lib/AST/ItaniumMangle.cpp
+++ b/clang/lib/AST/ItaniumMangle.cpp
+@@ -4028,10 +4028,11 @@ recurse:
+     if (!NullOut) {
+       // As bad as this diagnostic is, it's better than crashing.
+       DiagnosticsEngine &Diags = Context.getDiags();
+-      unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
+      unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Remark,
+                                        "cannot yet mangle expression type %0");
+       Diags.Report(E->getExprLoc(), DiagID)
+         << E->getStmtClassName() << E->getSourceRange();
+      Out << "MOZ_WE_HACKED_AROUND_BUG_1418415";
+       return;
+     }
+     break;
--- a/build/build-clang/revert-llvmorg-12-init-16421-gb688c5875d08.patch
+++ b/build/build-clang/revert-llvmorg-12-init-16421-gb688c5875d08.patch
--- a/build/build-clang/revert-llvmorg-12-init-7827-g2a078c307204.patch
+++ b/build/build-clang/revert-llvmorg-12-init-7827-g2a078c307204.patch
@@ -0,0 +1,17 @@
+llvmorg-12-init-7827-g2a078c307204 leads to linker complaints in shippable
+builds. It may be related to LTO with IR from rustc. The patch author and I
+were unable to get to the bottom of it, and in the end they suggested that
+it's safe to undo the change locally.
+
+diff --git a/llvm/lib/IR/Attributes.cpp b/llvm/lib/IR/Attributes.cpp
+index b21d4527484..e9602f1aaf1 100644
+--- a/llvm/lib/IR/Attributes.cpp
+++ b/llvm/lib/IR/Attributes.cpp
+@@ -1848,7 +1848,6 @@ AttrBuilder AttributeFuncs::typeIncompatible(Type *Ty) {
+         .addAttribute(Attribute::NoAlias)
+         .addAttribute(Attribute::NoCapture)
+         .addAttribute(Attribute::NonNull)
+-        .addAlignmentAttr(1)             // the int here is ignored
+         .addDereferenceableAttr(1)       // the int here is ignored
+         .addDereferenceableOrNullAttr(1) // the int here is ignored
+         .addAttribute(Attribute::ReadNone)
--- a/build/build-clang/revert-r362047-and-r362065_clang_12.patch
+++ b/build/build-clang/revert-r362047-and-r362065_clang_12.patch
@@ -0,0 +1,68 @@
+Bisection found that r362047 (and its followup build fix r362065) cause the
+build to install the android PGO library into the following location:
+stage2/clang/lib/linux/libclang_rt.profile-arm-android.a
+rather than the expected:
+stage2/clang/lib64/clang/$VERSION/lib/linux/libclang_rt.profile-arm-android.a
+
+For lack of any progress in debugging this, revert those two patches.
+
+diff --git a/llvm/runtimes/CMakeLists.txt b/llvm/runtimes/CMakeLists.txt
+index d2f5d6bf80f0..424f4da01f77 100644
+--- a/llvm/runtimes/CMakeLists.txt
+++ b/llvm/runtimes/CMakeLists.txt
+@@ -59,7 +59,6 @@ if(${CMAKE_SOURCE_DIR} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR})
+   cmake_minimum_required(VERSION 3.13.4)
+   project(Runtimes C CXX ASM)
+ 
+-  find_package(LLVM PATHS "${LLVM_BINARY_DIR}" NO_DEFAULT_PATH NO_CMAKE_FIND_ROOT_PATH)
+   find_package(Clang PATHS "${LLVM_BINARY_DIR}" NO_DEFAULT_PATH NO_CMAKE_FIND_ROOT_PATH)
+ 
+   # Add the root project's CMake modules, and the LLVM build's modules to the
+@@ -67,6 +66,7 @@ if(${CMAKE_SOURCE_DIR} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR})
+   list(INSERT CMAKE_MODULE_PATH 0
+     "${CMAKE_CURRENT_SOURCE_DIR}/../cmake"
+     "${CMAKE_CURRENT_SOURCE_DIR}/../cmake/modules"
+    "${LLVM_LIBRARY_DIR}/cmake/llvm"
+   )
+ 
+   # Some of the runtimes will conditionally use the compiler-rt sanitizers
+@@ -81,6 +81,11 @@ if(${CMAKE_SOURCE_DIR} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR})
+     endif()
+   endif()
+ 
+  # LLVMConfig.cmake contains a bunch of CMake variables from the LLVM build.
+  # This file is installed as part of LLVM distributions, so this can be used
+  # either from a build directory or an installed LLVM.
+  include(LLVMConfig)
+
+   # Setting these variables will allow the sub-build to put their outputs into
+   # the library and bin directories of the top-level build.
+   set(LLVM_LIBRARY_OUTPUT_INTDIR ${LLVM_LIBRARY_DIR})
+@@ -90,9 +95,6 @@ if(${CMAKE_SOURCE_DIR} STREQUAL ${CMAKE_CURRENT_SOURCE_DIR})
+   set(LLVM_MAIN_SRC_DIR ${LLVM_BUILD_MAIN_SRC_DIR})
+   set(LLVM_CMAKE_PATH ${LLVM_MAIN_SRC_DIR}/cmake/modules)
+ 
+-  # This variable is used by individual runtimes to locate LLVM files.
+-  set(LLVM_PATH ${LLVM_BUILD_MAIN_SRC_DIR})
+-
+   if(APPLE)
+     set(LLVM_ENABLE_LIBCXX ON CACHE BOOL "")
+   endif()
+@@ -421,6 +423,8 @@ ${error} Set RUNTIMES_BUILD_ALLOW_DARWIN to allow a single darwin triple.")
+                              # Builtins were built separately above
+                              CMAKE_ARGS -DCOMPILER_RT_BUILD_BUILTINS=Off
+                                         -DLLVM_INCLUDE_TESTS=${LLVM_INCLUDE_TESTS}
+                                        -DLLVM_BINARY_DIR=${LLVM_BINARY_DIR}
+                                        -DLLVM_LIBRARY_DIR=${LLVM_LIBRARY_DIR}
+                                         -DLLVM_DEFAULT_TARGET_TRIPLE=${TARGET_TRIPLE}
+                                         -DLLVM_ENABLE_PROJECTS_USED=${LLVM_ENABLE_PROJECTS_USED}
+                                         -DLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=${LLVM_ENABLE_PER_TARGET_RUNTIME_DIR_default}
+@@ -527,6 +531,8 @@ ${error} Set RUNTIMES_BUILD_ALLOW_DARWIN to allow a single darwin triple.")
+                              # Builtins were built separately above
+                              CMAKE_ARGS -DCOMPILER_RT_BUILD_BUILTINS=Off
+                                         -DLLVM_INCLUDE_TESTS=${LLVM_INCLUDE_TESTS}
+                                        -DLLVM_BINARY_DIR=${LLVM_BINARY_DIR}
+                                        -DLLVM_LIBRARY_DIR=${LLVM_LIBRARY_DIR}
+                                         -DLLVM_DEFAULT_TARGET_TRIPLE=${target}
+                                         -DLLVM_ENABLE_PROJECTS_USED=${LLVM_ENABLE_PROJECTS_USED}
+                                         -DLLVM_ENABLE_PER_TARGET_RUNTIME_DIR=ON
--- a/build/build-clang/static-llvm-symbolizer_clang_12.patch
+++ b/build/build-clang/static-llvm-symbolizer_clang_12.patch
@@ -0,0 +1,12 @@
+diff --git a/llvm/tools/llvm-symbolizer/CMakeLists.txt b/llvm/tools/llvm-symbolizer/CMakeLists.txt
+index c112e344da7..f0f16f1ba2d 100644
+--- a/llvm/tools/llvm-symbolizer/CMakeLists.txt
+++ b/llvm/tools/llvm-symbolizer/CMakeLists.txt
+@@ -18,6 +18,7 @@ set(LLVM_LINK_COMPONENTS
+   )
+ 
+ add_llvm_tool(llvm-symbolizer
+  DISABLE_LLVM_LINK_LLVM_DYLIB
+   llvm-symbolizer.cpp
+   DEPENDS
+   SymbolizerOptsTableGen
--- a/taskcluster/ci/fetch/toolchains.yml
+++ b/taskcluster/ci/fetch/toolchains.yml
@@ -431,6 +431,13 @@ clang-11:
        repo: https://github.com/llvm/llvm-project
        revision: 43ff75f2c3feef64f9d73328230d34dac8832a91

+clang-12:
+    description: clang 12.0.0-rc2 source code
+    fetch:
+        type: git
+        repo: https://github.com/llvm/llvm-project
+        revision: 4918a3d138b907a571f496661b5367e090e1e8bb
+
 rust-1.47.0-dev:
    description: Rust 1.47.0-dev source code
    fetch:
--- a/taskcluster/ci/toolchain/cctools-port.yml
+++ b/taskcluster/ci/toolchain/cctools-port.yml
@@ -25,3 +25,15 @@ linux64-cctools-port-clang-11:
        toolchain:
            - linux64-clang-11
            - linux64-binutils
+
+linux64-cctools-port-clang-12:
+    treeherder:
+        symbol: TL(cctools-clang-12)
+    run:
+        script: build-cctools-port.sh
+        toolchain-artifact: public/build/cctools.tar.xz
+        tooltool-downloads: internal
+    fetches:
+        toolchain:
+            - linux64-clang-12
+            - linux64-binutils
--- a/taskcluster/ci/toolchain/clang.yml
+++ b/taskcluster/ci/toolchain/clang.yml
@@ -347,3 +347,220 @@ win64-clang-11-2stage:
            - clang-11
            - cmake
            - ninja
+
+linux64-clang-12:
+    description: "Clang 12 toolchain build"
+    attributes:
+        local-toolchain: true
+    treeherder:
+        symbol: TL(clang12)
+    run-on-projects: [trunk]
+    run:
+        using: toolchain-script
+        script: build-clang.sh
+        arguments:
+            - 'build/build-clang/clang-12-linux64.json'
+        resources:
+            - 'build/build-clang/clang-12-linux64.json'
+        toolchain-artifact: public/build/clang.tar.zst
+    fetches:
+        fetch:
+            - clang-12
+        toolchain:
+            - linux64-binutils
+            - linux64-gcc-7
+            - linux64-toolchain-sysroot
+            - wasi-sysroot-12
+
+linux64-clang-12-android-cross:
+    description: "Clang 12 toolchain build"
+    treeherder:
+        symbol: TL(clang12-android)
+    run:
+        using: toolchain-script
+        script: build-clang.sh
+        arguments:
+            - 'build/build-clang/clang-12-android.json'
+        resources:
+            - 'build/build-clang/clang-12-android.json'
+        toolchain-artifact: public/build/clang.tar.zst
+    fetches:
+        fetch:
+            - clang-12
+        toolchain:
+            - linux64-binutils
+            - linux64-gcc-7
+            - linux64-android-ndk-linux-repack
+            - linux64-toolchain-sysroot
+
+linux64-clang-12-aarch64-cross:
+    description: "Clang 12 toolchain build with aarch64 runtime"
+    treeherder:
+        symbol: TL(clang12-aarch64)
+    worker-type: b-linux
+    worker:
+        max-run-time: 600
+    run:
+        script: repack-clang-linux-cross.sh
+        toolchain-artifact: public/build/clang.tar.zst
+    dependencies:
+        linux64-aarch64-compiler-rt-12: toolchain-linux64-aarch64-compiler-rt-12
+    fetches:
+        toolchain:
+            - linux64-clang-12
+        linux64-aarch64-compiler-rt-12:
+            - artifact: compiler-rt.tar.zst
+
+linux64-clang-12-macosx-cross:
+    description: "Clang 12 toolchain repack with MacOS Compiler RT libs"
+    treeherder:
+        symbol: TL(clang12-macosx-cross)
+    worker-type: b-linux
+    worker:
+        max-run-time: 600
+    run:
+        script: repack-clang-linux-macosx-cross.sh
+        toolchain-artifact: public/build/clang.tar.zst
+    dependencies:
+        macosx64-aarch64-compiler-rt-12: toolchain-macosx64-aarch64-compiler-rt-12
+        macosx64-x64-compiler-rt-12: toolchain-macosx64-x64-compiler-rt-12
+    fetches:
+        toolchain:
+            - linux64-cctools-port-clang-12
+            - linux64-clang-12
+        macosx64-aarch64-compiler-rt-12:
+            - artifact: compiler-rt.tar.zst
+              dest: aarch64
+        macosx64-x64-compiler-rt-12:
+            - artifact: compiler-rt.tar.zst
+              dest: x86_64
+
+linux64-clang-12-win-cross:
+    description: "Clang 12 toolchain repack with Windows Compiler RT libs"
+    treeherder:
+        symbol: TL(clang12-win-cross)
+    worker-type: b-linux
+    worker:
+        max-run-time: 600
+    run:
+        script: repack-clang-linux-win-cross.sh
+        toolchain-artifact: public/build/clang.tar.zst
+    dependencies:
+        win64-clang-12-2stage: toolchain-win64-clang-12-2stage
+    fetches:
+        toolchain:
+            - linux64-clang-12
+        win64-clang-12-2stage:
+            # Put this into a new directory so it doesn't conflict with the linux toolchain
+            - artifact: clang.tar.zst
+              dest: clang-cl
+              extract: false
+
+macosx64-clang-12:
+    description: "Clang 12 toolchain build"
+    attributes:
+        local-toolchain: true
+    treeherder:
+        symbol: TM(clang-12)
+    worker-type: b-linux-large
+    worker:
+        max-run-time: 3600
+    run-on-projects:
+        - trunk
+    run:
+        script: build-clang.sh
+        arguments:
+            - 'build/build-clang/clang-12-macosx64.json'
+        resources:
+            - 'build/build-clang/clang-12-macosx64.json'
+        toolchain-artifact: public/build/clang.tar.zst
+    fetches:
+        fetch:
+            - clang-12
+        toolchain:
+            - linux64-binutils
+            - linux64-cctools-port-clang-12
+            - linux64-clang-12-macosx-cross
+            - linux64-gcc-7
+            - macosx64-sdk-10.12
+
+macosx64-aarch64-clang-12:
+    description: "Clang 12 toolchain build"
+    attributes:
+        local-toolchain: true
+    treeherder:
+        symbol: TM(clang-12-aarch64)
+    worker-type: b-linux-large
+    worker:
+        env:
+            OSX_ARCH: arm64
+        max-run-time: 3600
+    run-on-projects:
+        - trunk
+    run:
+        script: build-clang.sh
+        arguments:
+            - 'build/build-clang/clang-12-macosx64.json'
+        resources:
+            - 'build/build-clang/clang-12-macosx64.json'
+        toolchain-artifact: public/build/clang.tar.zst
+    fetches:
+        fetch:
+            - clang-12
+        toolchain:
+            - linux64-binutils
+            - linux64-cctools-port-clang-12
+            - linux64-clang-12-macosx-cross
+            - linux64-gcc-7
+            - macosx64-sdk-11.0
+
+win64-clang-12:
+    description: "Clang-cl 12 toolchain build"
+    attributes:
+        local-toolchain: true
+    treeherder:
+        symbol: TW64(clang-12)
+    worker-type: b-win2012
+    worker:
+        env:
+            TOOLTOOL_MANIFEST: "browser/config/tooltool-manifests/win64/vs2017.manifest"
+        max-run-time: 9000
+    run-on-projects:
+        - trunk
+    run:
+        script: build-clang.sh
+        arguments:
+            - 'build/build-clang/clang-12-win64.json'
+        resources:
+            - 'build/build-clang/clang-12-win64.json'
+            - 'taskcluster/scripts/misc/tooltool-download.sh'
+        toolchain-artifact: public/build/clang.tar.zst
+        tooltool-downloads: internal
+    fetches:
+        fetch:
+            - clang-12
+            - cmake
+            - ninja
+
+win64-clang-12-2stage:
+    description: "Clang-cl 12 toolchain 2-stage quick build"
+    treeherder:
+        symbol: TW64(clang-12-2stage)
+    worker-type: b-win2012
+    worker:
+        env:
+            TOOLTOOL_MANIFEST: "browser/config/tooltool-manifests/win64/vs2017.manifest"
+    run:
+        script: build-clang.sh
+        arguments:
+            - 'build/build-clang/clang-12-win64-2stage.json'
+        resources:
+            - 'build/build-clang/clang-12-win64-2stage.json'
+            - 'taskcluster/scripts/misc/tooltool-download.sh'
+        toolchain-artifact: public/build/clang.tar.zst
+        tooltool-downloads: internal
+    fetches:
+        fetch:
+            - clang-12
+            - cmake
+            - ninja
--- a/taskcluster/ci/toolchain/compiler-rt.yml
+++ b/taskcluster/ci/toolchain/compiler-rt.yml
@@ -6,20 +6,21 @@ job-defaults:
    worker-type: b-linux
    worker:
        max-run-time: 1800
+    run:
+        using: toolchain-script
+        script: build-compiler-rt.sh
+        toolchain-artifact: public/build/compiler-rt.tar.zst

 linux64-aarch64-compiler-rt-11:
    description: "linux aarch64 Compiler-rt for Clang 11 toolchain build"
    treeherder:
        symbol: TL(aarch64-crt)
    run:
-        using: toolchain-script
-        script: build-compiler-rt.sh
        arguments:
            - aarch64-unknown-linux-gnu
            - 'build/build-clang/find_symbolizer_linux_clang_10.patch'
        resources:
            - 'build/build-clang/find_symbolizer_linux_clang_10.patch'
-        toolchain-artifact: public/build/compiler-rt.tar.zst
    fetches:
        fetch:
            - clang-11
@@ -33,11 +34,8 @@ macosx64-x64-compiler-rt-11:
    treeherder:
        symbol: TM(x64-crt)
    run:
-        using: toolchain-script
-        script: build-compiler-rt.sh
        arguments:
            - x86_64-apple-darwin
-        toolchain-artifact: public/build/compiler-rt.tar.zst
    fetches:
        fetch:
            - clang-11
@@ -51,11 +49,8 @@ macosx64-aarch64-compiler-rt-11:
    treeherder:
        symbol: TM(aarch64-crt)
    run:
-        using: toolchain-script
-        script: build-compiler-rt.sh
        arguments:
            - aarch64-apple-darwin
-        toolchain-artifact: public/build/compiler-rt.tar.zst
    fetches:
        fetch:
            - clang-11
@@ -63,3 +58,51 @@ macosx64-aarch64-compiler-rt-11:
            - linux64-cctools-port-clang-11
            - linux64-clang-11
            - macosx64-sdk-11.0
+
+linux64-aarch64-compiler-rt-12:
+    description: "Linux aarch64 Compiler-rt for Clang 12 toolchain build"
+    treeherder:
+        symbol: TL(aarch64-crt-12)
+    run:
+        arguments:
+            - aarch64-unknown-linux-gnu
+            - 'build/build-clang/find_symbolizer_linux_clang_10.patch'
+        resources:
+            - 'build/build-clang/find_symbolizer_linux_clang_10.patch'
+    fetches:
+        fetch:
+            - clang-12
+        toolchain:
+            - linux64-binutils
+            - linux64-clang-12
+            - linux64-aarch64-sysroot
+
+macosx64-x64-compiler-rt-12:
+    description: "macOS x64 Compiler-rt for Clang 12 toolchain build"
+    treeherder:
+        symbol: TM(x64-crt-12)
+    run:
+        arguments:
+            - x86_64-apple-darwin
+    fetches:
+        fetch:
+            - clang-12
+        toolchain:
+            - linux64-cctools-port-clang-12
+            - linux64-clang-12
+            - macosx64-sdk-10.12
+
+macosx64-aarch64-compiler-rt-12:
+    description: "macOS aarch64 Compiler-rt for Clang 12 toolchain build"
+    treeherder:
+        symbol: TM(aarch64-crt-12)
+    run:
+        arguments:
+            - aarch64-apple-darwin
+    fetches:
+        fetch:
+            - clang-12
+        toolchain:
+            - linux64-cctools-port-clang-12
+            - linux64-clang-12
+            - macosx64-sdk-11.0
--- a/taskcluster/ci/toolchain/misc.yml
+++ b/taskcluster/ci/toolchain/misc.yml
@@ -166,6 +166,25 @@ wasi-sysroot-11:
            - linux64-binutils
            - linux64-gcc-7

+wasi-sysroot-12:
+    description: "wasi sysroot build using clang-12"
+    attributes:
+        local-toolchain: true
+    treeherder:
+        symbol: TL(wasi-sysroot-12)
+    run-on-projects: [trunk]
+    run:
+        script: build-wasi-sysroot.sh
+        sparse-profile: null
+        toolchain-artifact: public/build/wasi-sysroot.tar.xz
+    fetches:
+        fetch:
+            - clang-12
+            - wasi-sdk
+        toolchain:
+            - linux64-binutils
+            - linux64-gcc-7
+
 wrench-deps:
    description: "Downloads all the crates needed for building wrench"
    treeherder: