Circle CI: Reduce build_hermes_macos Hermes SDK cache size by 75% (#34886)

Summary:
Pull Request resolved: #34886

## Reduced cache size

The `build_hermes_macos` job can spend over 20 minutes restoring cached build artifacts (over 5 GB), when only `build_macosx` and `destroot` are required to be cached: `build_macosx` as it may contain a pre-built `hermesc` from previous builds, and `destroot` which contains the artifacts for previous iOS/macOS builds.

This is the `build_hermes_macos` Restore Cache step, before the changes in this diff:

```
Found a cache from build 308044 at v1-hermes-build_hermes_macos-debug-PEiMHp9XQ13KtYFQMKoT27DmHkkoxOi_PJUyW7PacZE=
Size: 5.2 GiB
Cached paths:
  * /Users/distiller/react-native/sdks/hermes/build_host_hermesc
  * /Users/distiller/react-native/sdks/hermes/build_iphoneos
  * /Users/distiller/react-native/sdks/hermes/build_catalyst
  * /Users/distiller/react-native/sdks/hermes/build_iphonesimulator
  * /Users/distiller/react-native/sdks/hermes/build_macosx
  * /Users/distiller/react-native/sdks/hermes/destroot

Downloading cache archive...
Unarchiving cache...
```

Size: 5.2 GiB
Time to restore cache: 183s

This is the `build_hermes_macos` Restore Cache step, after the changes in this diff:

```
Found a cache from build 310128 at v2-hermes-build_hermes_macos-debug-e7WmoA0+mfveXq1zsMYpgR6BYqVuuDjmVeLLyjqPJWk=
Size: 1.3 GiB
Cached paths:
  * /Users/distiller/react-native/sdks/hermes/build_macosx
  * /Users/distiller/react-native/sdks/hermes/destroot

Downloading cache archive...
Unarchiving cache...
```

Size: 1.3 GiB
Time to restore cache: 42s

**This is a size reduction of 75%, and execution time reduction of 77%.**

This savings will apply to every workflow that runs afterwards until the Hermes cache is invalidated due to a new commit landing in `facebook/hermes`.

## Added `export_hermesc`

As part of the work mentioned above, a reusable `export_hermesc` command was added, which will export hermesc for use in downstream steps. Either of the macOS or iOS build scripts will generate this binary. As we now only cache the macOS build dir, that version is loaded from cache by default if available:
- If the cache contains hermesc, both the macOS and iOS builds will use it.
- If the cache does not contain hermesc, then the iOS job will use the hermesc that was built by the macOS job previously.
- The `export_hermesc` command will work regardless of the order of the Hermes build scripts

## Refactoring of magic strings into reusable yaml references

Some additional changes to the Circle CI config were done in order to reduce repetition of artifacts/cache paths that are re-used across workflows.

Changelog: [Internal]

Reviewed By: cipolleschi

Differential Revision: D40153737

fbshipit-source-id: b9f07302ccc9bac1ce72a09b944d3210e6db2ec1

Author: hramos

.circleci/config.yml

@@ -28,6 +28,8 @@ references:
     /tmp/hermes
   hermes_tarball_artifacts_dir: &hermes_tarball_artifacts_dir
     /tmp/hermes/hermes-runtime-darwin
+  hermes_osxbin_artifacts_dir: &hermes_osxbin_artifacts_dir
+    /tmp/hermes/osx-bin
   attach_hermes_workspace: &attach_hermes_workspace
     attach_workspace:
       at: *hermes_workspace_root
@@ -50,8 +52,8 @@ references:
     gems_cache_key: &gems_cache_key v1-gems-{{ checksum "Gemfile.lock" }}
     gradle_cache_key: &gradle_cache_key v1-gradle-{{ checksum "gradle/wrapper/gradle-wrapper.properties" }}-{{ checksum "ReactAndroid/gradle.properties" }}
     hermes_workspace_cache_key: &hermes_workspace_cache_key v4-hermes-{{ .Environment.CIRCLE_JOB }}-{{ checksum "/tmp/hermes/hermesversion" }}
-    hermes_workspace_debug_cache_key: &hermes_workspace_debug_cache_key v1-hermes-{{ .Environment.CIRCLE_JOB }}-debug-{{ checksum "/tmp/hermes/hermesversion" }}
-    hermes_workspace_release_cache_key: &hermes_workspace_release_cache_key v1-hermes-{{ .Environment.CIRCLE_JOB }}-release-{{ checksum "/tmp/hermes/hermesversion" }}
+    hermes_workspace_debug_cache_key: &hermes_workspace_debug_cache_key v2-hermes-{{ .Environment.CIRCLE_JOB }}-debug-{{ checksum "/tmp/hermes/hermesversion" }}
+    hermes_workspace_release_cache_key: &hermes_workspace_release_cache_key v2-hermes-{{ .Environment.CIRCLE_JOB }}-release-{{ checksum "/tmp/hermes/hermesversion" }}
     hermes_windows_cache_key: &hermes_windows_cache_key v3-hermes-{{ .Environment.CIRCLE_JOB }}-{{ checksum "tmp/hermes/hermesversion" }}
     hermes_tarball_debug_cache_key: &hermes_tarball_debug_cache_key v2-hermes-tarball-debug-{{ checksum "/tmp/hermes/hermesversion" }}
     hermes_tarball_release_cache_key: &hermes_tarball_release_cache_key v1-hermes-tarball-release-{{ checksum "/tmp/hermes/hermesversion" }}
@@ -61,10 +63,6 @@ references:
 
   cache_paths:
     hermes_workspace_macos_cache_paths: &hermes_workspace_macos_cache_paths
-      - ~/react-native/sdks/hermes/build_host_hermesc
-      - ~/react-native/sdks/hermes/build_iphoneos
-      - ~/react-native/sdks/hermes/build_catalyst
-      - ~/react-native/sdks/hermes/build_iphonesimulator
       - ~/react-native/sdks/hermes/build_macosx
       - ~/react-native/sdks/hermes/destroot
     hermes_tarball_cache_paths: &hermes_tarball_cache_paths
@@ -335,6 +333,51 @@ commands:
                 key: *hermes_tarball_release_cache_key
                 paths: *hermes_tarball_cache_paths
 
+  with_hermesc_span:
+    description: "Makes hermesc available to the provided steps, if hermesc is present."
+    parameters:
+      steps:
+        type: steps
+    steps:
+      - export_hermesc
+      - steps: << parameters.steps >>
+      - export_hermesc
+
+  export_hermesc:
+    description: "Configures hermesc for use in Hermes builds when possible. The binary is built by either of the macOS or iOS builds, and may be cached by previous builds."
+    parameters:
+      artifacts_dir:
+        type: string
+        default: *hermes_osxbin_artifacts_dir
+    steps:
+      - run:
+          name: "Export HermesC if available"
+          command: |
+            hermesc_artifacts_path=<< parameters.artifacts_dir >>/hermesc
+            hermesc_bin_path=bin/hermesc
+            hermes_build_dir_macos=$(pwd)/sdks/hermes/build_macosx
+            hermes_build_dir_ios=$(pwd)/sdks/hermes/build_iphoneos
+
+            function export_hermesc_cmake_path {
+              build_dir=$1
+              hermesc_bin=$build_dir/$hermesc_bin_path
+              cmake_path=$build_dir/ImportHermesc.cmake
+
+              if [[ -f $cmake_path ]]; then
+                echo "export HERMES_OVERRIDE_HERMESC_PATH=$cmake_path" >> $BASH_ENV
+              fi
+
+              if [[ ! -f $hermesc_artifacts_path ]]; then
+                cp $hermesc_bin $hermesc_artifacts_path
+              fi
+            }
+
+            if [[ -f $hermes_build_dir_macos/$hermesc_bin_path ]]; then
+              export_hermesc_cmake_path $hermes_build_dir_macos
+            elif [[ -f $hermes_build_dir_ios/$hermesc_bin_path ]]; then
+              export_hermesc_cmake_path $hermes_build_dir_ios
+            fi
+
 # -------------------------
 #          JOBS
 # -------------------------
@@ -994,7 +1037,7 @@ jobs:
           path: ~/react-native/coverage/
 
   # -------------------------
-  #      JOBS: Build hermesc
+  #      JOBS: Build Hermes
   # -------------------------
   prepare_hermes_workspace:
     docker:
@@ -1100,6 +1143,7 @@ jobs:
     environment:
       - HERMES_WS_DIR: *hermes_workspace_root
       - HERMES_TARBALL_ARTIFACTS_DIR: *hermes_tarball_artifacts_dir
+      - HERMES_OSXBIN_ARTIFACTS_DIR: *hermes_osxbin_artifacts_dir
     steps:
       - checkout_code_with_cache
       - run_yarn
@@ -1121,25 +1165,27 @@ jobs:
       - run:
           name: Set up workspace
           command: |
-            mkdir -p /tmp/hermes/osx-bin
-            mkdir -p ~/react-native/sdks/hermes
-            cp -r $HERMES_WS_DIR/hermes/* ~/react-native/sdks/hermes/.
+            mkdir -p $HERMES_OSXBIN_ARTIFACTS_DIR ./sdks/hermes
+            cp -r $HERMES_WS_DIR/hermes/* ./sdks/hermes/.
       - brew_install:
           package: cmake
       - with_hermes_tarball_cache_span:
           flavor: << parameters.flavor >>
           steps:
-            - run:
-                name: Build the Hermes iOS frameworks
-                command: |
-                  cd ~/react-native/sdks/hermes
-                  BUILD_TYPE="<< parameters.flavor >>" ./utils/build-ios-framework.sh
-            - run:
-                name: Build the Hermes Mac frameworks
-                command: |
-                  cd ~/react-native/sdks/hermes
-                  BUILD_TYPE="<< parameters.flavor >>" ./utils/build-mac-framework.sh
-                  cp build_macosx/bin/hermesc /tmp/hermes/osx-bin/.
+            - with_hermesc_span:
+                steps:
+                  - run:
+                      name: Build the Hermes Mac frameworks
+                      command: |
+                        cd ./sdks/hermes || exit 1
+                        BUILD_TYPE="<< parameters.flavor >>" ./utils/build-mac-framework.sh
+            - with_hermesc_span:
+                steps:
+                  - run:
+                      name: Build the Hermes iOS frameworks
+                      command: |
+                        cd ./sdks/hermes || exit 1
+                        BUILD_TYPE="<< parameters.flavor >>" ./utils/build-ios-framework.sh
             - run:
                 name: Package the Hermes Apple frameworks
                 command: |
@@ -1149,35 +1195,34 @@ jobs:
                   TARBALL_OUTPUT_DIR=$(mktemp -d /tmp/hermes-tarball-output-XXXXXXXX)
 
                   # get_release_version() is defined in build-apple-framework.sh
-                  cd ~/react-native/sdks/hermes
-                  BUILD_TYPE=$BUILD_TYPE source ./utils/build-apple-framework.sh
-                  RELEASE_VERSION=$(get_release_version)
-
-                  cd ~/react-native
+                  pushd ./sdks/hermes || exit 1
+                    BUILD_TYPE=$BUILD_TYPE source ./utils/build-apple-framework.sh
+                    RELEASE_VERSION=$(get_release_version)
+                  popd
 
                   TARBALL_FILENAME=$(node ./scripts/hermes/get-tarball-name.js --buildType "$BUILD_TYPE" --releaseVersion "$RELEASE_VERSION")
 
                   echo "Packaging Hermes Apple frameworks for $BUILD_TYPE build type"
 
                   TARBALL_OUTPUT_PATH=$(node ./scripts/hermes/create-tarball.js \
-                    --inputDir ~/react-native/sdks/hermes \
+                    --inputDir ./sdks/hermes \
                     --buildType "$BUILD_TYPE" \
                     --releaseVersion "$RELEASE_VERSION" \
-                    --outputDir "$TARBALL_OUTPUT_DIR")
+                    --outputDir $TARBALL_OUTPUT_DIR)
 
                   echo "Hermes tarball saved to $TARBALL_OUTPUT_PATH"
 
-                  mkdir -p "$HERMES_TARBALL_ARTIFACTS_DIR"
-                  cp "$TARBALL_OUTPUT_PATH" "$HERMES_TARBALL_ARTIFACTS_DIR/."
+                  mkdir -p $HERMES_TARBALL_ARTIFACTS_DIR
+                  cp $TARBALL_OUTPUT_PATH $HERMES_TARBALL_ARTIFACTS_DIR/.
 
                   # Make a copy of the debug tarball and use the old filename.
                   # This is necessary to support patch releases in versions of
                   # React Native that expect a single tarball.
                   # TODO: Remove once 0.70.x and 0.69.x are no longer being patched.
                   if [[ $BUILD_TYPE == "Debug" ]]; then
                     OLD_TARBALL_FILENAME="hermes-runtime-darwin-v$RELEASE_VERSION.tar.gz"
-                    cp "$HERMES_TARBALL_ARTIFACTS_DIR/$TARBALL_FILENAME" "$HERMES_TARBALL_ARTIFACTS_DIR/$OLD_TARBALL_FILENAME"
-                    echo "$OLD_TARBALL_FILENAME is a copy of $TARBALL_FILENAME, provided for backward compatibility." >> "$HERMES_TARBALL_ARTIFACTS_DIR/README.txt"
+                    cp $HERMES_TARBALL_ARTIFACTS_DIR/$TARBALL_FILENAME $HERMES_TARBALL_ARTIFACTS_DIR/$OLD_TARBALL_FILENAME
+                    echo "$OLD_TARBALL_FILENAME is a copy of $TARBALL_FILENAME, provided for backward compatibility." >> $HERMES_TARBALL_ARTIFACTS_DIR/README.txt
                   fi
             - when:
                 condition:
@@ -1196,7 +1241,7 @@ jobs:
             - store_artifacts:
                 path: *hermes_tarball_artifacts_dir
             - store_artifacts:
-                path: /tmp/hermes/osx-bin/
+                path: *hermes_osxbin_artifacts_dir
             - persist_to_workspace:
                 root: /tmp/hermes/
                 paths: