From ebbf9fca0d2ab4cdb1ca4241144f59aa97cb8fc0 Mon Sep 17 00:00:00 2001
From: Mike Hommey <mh+mozilla@glandium.org>
Date: Tue, 25 Jan 2022 21:51:17 +0000
Subject: [PATCH] Bug 1751839 - Build clang stage 1 as a separate task.
 r=firefox-build-system-reviewers,andi

This allows to start building other toolchains, compiler runtimes, much
earlier, since we don't have to wait for a complete 4-stage-optimized
compiler to start these, while the output produced by clang is
presumably the same whether it's a stage 1 or a stage 4 clang.

Differential Revision: https://phabricator.services.mozilla.com/D136844
---
 build/build-clang/1stage.json                 |  4 +++
 build/build-clang/skip-stage-1.json           |  6 +++++
 taskcluster/ci/toolchain/clang.yml            | 27 ++++++++++++++++++-
 taskcluster/ci/toolchain/compiler-rt.yml      | 14 +++++-----
 taskcluster/docker/toolchain-build/Dockerfile |  1 +
 5 files changed, 44 insertions(+), 8 deletions(-)
 create mode 100644 build/build-clang/1stage.json
 create mode 100644 build/build-clang/skip-stage-1.json

diff --git a/build/build-clang/1stage.json b/build/build-clang/1stage.json
new file mode 100644
index 000000000000..5fd0aaf1653a
--- /dev/null
+++ b/build/build-clang/1stage.json
@@ -0,0 +1,4 @@
+{
+    "stages": "1",
+    "pgo": false
+}
diff --git a/build/build-clang/skip-stage-1.json b/build/build-clang/skip-stage-1.json
new file mode 100644
index 000000000000..aa1101b13b67
--- /dev/null
+++ b/build/build-clang/skip-stage-1.json
@@ -0,0 +1,6 @@
+{
+    "skip_stages": "1",
+    "cc": "{MOZ_FETCHES_DIR}/clang/bin/clang",
+    "cxx": "{MOZ_FETCHES_DIR}/clang/bin/clang++",
+    "as": "{MOZ_FETCHES_DIR}/clang/bin/clang"
+}
diff --git a/taskcluster/ci/toolchain/clang.yml b/taskcluster/ci/toolchain/clang.yml
index bef43f9620da..13f12cca60cc 100644
--- a/taskcluster/ci/toolchain/clang.yml
+++ b/taskcluster/ci/toolchain/clang.yml
@@ -101,6 +101,29 @@ linux64-clang-trunk:
             - linux64-toolchain-sysroot
             - wasm32-wasi-compiler-rt
 
+linux64-clang-13-stage1:
+    description: "Clang 13 toolchain build"
+    treeherder:
+        symbol: TL(clang13-stage1)
+    run-on-projects: [trunk]
+    run:
+        using: toolchain-script
+        script: build-clang.sh
+        arguments:
+            - 'build/build-clang/linux64.json'
+            - 'build/build-clang/clang-13.json'
+            - 'build/build-clang/1stage.json'
+        resources:
+            - 'build/build-clang/linux64.json'
+            - 'build/build-clang/clang-13.json'
+            - 'build/build-clang/1stage.json'
+        toolchain-alias:
+            - linux64-clang-toolchain
+        toolchain-artifact: public/build/clang.tar.zst
+    fetches:
+        fetch:
+            - clang-13
+
 linux64-clang-13:
     description: "Clang 13 toolchain build"
     attributes:
@@ -114,17 +137,19 @@ linux64-clang-13:
         arguments:
             - 'build/build-clang/linux64.json'
             - 'build/build-clang/clang-13.json'
+            - 'build/build-clang/skip-stage-1.json'
         resources:
             - 'build/build-clang/linux64.json'
             - 'build/build-clang/clang-13.json'
+            - 'build/build-clang/skip-stage-1.json'
         toolchain-alias:
             - linux64-clang
-            - linux64-clang-toolchain
         toolchain-artifact: public/build/clang.tar.zst
     fetches:
         fetch:
             - clang-13
         toolchain:
+            - linux64-clang-13-stage1
             - linux64-toolchain-sysroot
             - wasm32-wasi-compiler-rt-13
 
diff --git a/taskcluster/ci/toolchain/compiler-rt.yml b/taskcluster/ci/toolchain/compiler-rt.yml
index 444872d40449..0fd200bad7bf 100644
--- a/taskcluster/ci/toolchain/compiler-rt.yml
+++ b/taskcluster/ci/toolchain/compiler-rt.yml
@@ -25,7 +25,7 @@ android-aarch64-compiler-rt-13:
         fetch:
             - clang-13
         toolchain:
-            - linux64-clang-13
+            - linux64-clang-13-stage1
             - linux64-android-ndk-linux-repack
 
 android-arm-compiler-rt-13:
@@ -42,7 +42,7 @@ android-arm-compiler-rt-13:
         fetch:
             - clang-13
         toolchain:
-            - linux64-clang-13
+            - linux64-clang-13-stage1
             - linux64-android-ndk-linux-repack
 
 android-x86-compiler-rt-13:
@@ -59,7 +59,7 @@ android-x86-compiler-rt-13:
         fetch:
             - clang-13
         toolchain:
-            - linux64-clang-13
+            - linux64-clang-13-stage1
             - linux64-android-ndk-linux-repack
 
 android-x64-compiler-rt-13:
@@ -76,7 +76,7 @@ android-x64-compiler-rt-13:
         fetch:
             - clang-13
         toolchain:
-            - linux64-clang-13
+            - linux64-clang-13-stage1
             - linux64-android-ndk-linux-repack
 
 linux64-aarch64-compiler-rt-13:
@@ -94,7 +94,7 @@ linux64-aarch64-compiler-rt-13:
             - clang-13
         toolchain:
             - linux64-binutils
-            - linux64-clang-13
+            - linux64-clang-13-stage1
             - sysroot-aarch64-linux-gnu
 
 macosx64-x64-compiler-rt-13:
@@ -109,7 +109,7 @@ macosx64-x64-compiler-rt-13:
             - clang-13
         toolchain:
             - linux64-cctools-port-clang-13
-            - linux64-clang-13
+            - linux64-clang-13-stage1
             - macosx64-sdk-11.0
 
 macosx64-aarch64-compiler-rt-13:
@@ -124,7 +124,7 @@ macosx64-aarch64-compiler-rt-13:
             - clang-13
         toolchain:
             - linux64-cctools-port-clang-13
-            - linux64-clang-13
+            - linux64-clang-13-stage1
             - macosx64-sdk-11.0
 
 wasm32-wasi-compiler-rt-13:
diff --git a/taskcluster/docker/toolchain-build/Dockerfile b/taskcluster/docker/toolchain-build/Dockerfile
index 846926c26918..0c0375e815d8 100644
--- a/taskcluster/docker/toolchain-build/Dockerfile
+++ b/taskcluster/docker/toolchain-build/Dockerfile
@@ -30,6 +30,7 @@ RUN apt-get update && \
       libssl-dev \
       libtool \
       libucl-dev \
+      libxml2-dev \
       ninja-build \
       openssh-client \
       p7zip-full \