VSTS: Skip build steps when only docs have changed (GH-8546)

.vsts/docs.yml

@@ -23,21 +23,35 @@ steps:
   clean: true
   fetchDepth: 5
 
+- script: |
+   git fetch -q origin $(system.pullRequest.targetBranch)
+   if ! git diff --name-only HEAD $(git merge-base HEAD FETCH_HEAD) | grep -qE '(\.rst$|^Doc|^Misc)'
+   then
+     echo "No docs were updated, stopping build process."
+     echo "##vso[task.setvariable variable=NoDocs]true"
+     exit
+   fi
+  displayName: Detect doc-only changes
+  condition: and(succeeded(), variables['system.pullRequest.targetBranch'])
+
 - task: UsePythonVersion@0
   displayName: 'Use Python 3.6 or later'
   inputs:
     versionSpec: '>=3.6'
+  condition: and(succeeded(), ne(variables['NoDocs'], 'true'))
 
 - script: python -m pip install sphinx~=1.6.1 blurb python-docs-theme
   displayName: 'Install build dependencies'
+  condition: and(succeeded(), ne(variables['NoDocs'], 'true'))
 
 - script: make check suspicious html PYTHON=python
   workingDirectory: '$(build.sourcesDirectory)/Doc'
   displayName: 'Build documentation'
+  condition: and(succeeded(), ne(variables['NoDocs'], 'true'))
 
 - task: PublishBuildArtifacts@1
   displayName: 'Publish build'
-  condition: and(succeeded(), ne(variables['Build.Reason'], 'PullRequest'))
+  condition: and(and(succeeded(), ne(variables['Build.Reason'], 'PullRequest')), ne(variables['NoDocs'], 'true'))
   inputs:
     PathToPublish: '$(build.sourcesDirectory)/Doc/build'
     ArtifactName: build

.vsts/linux-coverage.yml

@@ -27,12 +27,24 @@ steps:
   clean: true
   fetchDepth: 5
 
+- script: |
+   git fetch -q origin $(system.pullRequest.targetBranch)
+   if ! git diff --name-only HEAD $(git merge-base HEAD FETCH_HEAD) | grep -qvE '(\.rst$|^Doc|^Misc)'
+   then
+     echo "Only docs were updated, stopping build process."
+     echo "##vso[task.setvariable variable=DocOnly]true"
+     exit
+   fi
+  displayName: Detect doc-only changes
+  condition: and(succeeded(), variables['system.pullRequest.targetBranch'])
+
 #- template: linux-deps.yml
 
 # See https://github.com/Microsoft/vsts-agent/blob/master/docs/preview/yamlgettingstarted-templates.md
 # For now, we copy/paste the steps
 - script: echo "deb-src http://archive.ubuntu.com/ubuntu/ xenial main" > /etc/apt/sources.list.d/python.list && sudo apt-get update
   displayName: 'Update apt-get lists'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 
 - script: echo ##vso[task.prependpath]$(OPENSSL_DIR)
   displayName: 'Add $(OPENSSL_DIR) to PATH'
@@ -55,24 +67,32 @@ steps:
     uuid-dev
     xvfb
   displayName: 'Install dependencies'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 - script: python3 Tools/ssl/multissltests.py --steps=library --base-directory $(build.sourcesDirectory)/multissl --openssl $(OPENSSL) --system Linux
   displayName: 'python multissltests.py'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 
 
 - script: ./configure --with-pydebug
   displayName: 'Configure CPython (debug)'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 
 - script: make -s -j4
   displayName: 'Build CPython'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 
 - script: ./python -m venv venv && ./venv/bin/python -m pip install -U coverage
   displayName: 'Set up virtual environment'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 
 - script: ./venv/bin/python -m test.pythoninfo
   displayName: 'Display build info'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 
 - script: xvfb-run ./venv/bin/python -m coverage run --pylib -m test --fail-env-changed -uall,-cpu -x test_multiprocessing_fork -x test_multiprocessing_forkserver -x test_multiprocessing_spawn -x test_concurrent_futures
   displayName: 'Tests with coverage'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 
 - script: source ./venv/bin/activate && bash <(curl -s https://codecov.io/bash)
   displayName: 'Publish code coverage results'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))

.vsts/linux-pr.yml

@@ -27,15 +27,29 @@ steps:
   clean: true
   fetchDepth: 5
 
+- script: |
+   git fetch -q origin $(system.pullRequest.targetBranch)
+   if ! git diff --name-only HEAD $(git merge-base HEAD FETCH_HEAD) | grep -qvE '(\.rst$|^Doc|^Misc)'
+   then
+     echo "Only docs were updated, stopping build process."
+     echo "##vso[task.setvariable variable=DocOnly]true"
+     exit
+   fi
+  displayName: Detect doc-only changes
+  condition: and(succeeded(), variables['system.pullRequest.targetBranch'])
+
 #- template: linux-deps.yml
 
 # See https://github.com/Microsoft/vsts-agent/blob/master/docs/preview/yamlgettingstarted-templates.md
 # For now, we copy/paste the steps
 - script: echo "deb-src http://archive.ubuntu.com/ubuntu/ xenial main" > /etc/apt/sources.list.d/python.list && sudo apt-get update
   displayName: 'Update apt-get lists'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 
 - script: echo ##vso[task.prependpath]$(OPENSSL_DIR)
   displayName: 'Add $(OPENSSL_DIR) to PATH'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
+
 - script: >
     sudo apt-get -yq install
     build-essential
@@ -55,22 +69,30 @@ steps:
     uuid-dev
     xvfb
   displayName: 'Install dependencies'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
+
 - script: python3 Tools/ssl/multissltests.py --steps=library --base-directory $(build.sourcesDirectory)/multissl --openssl $(OPENSSL) --system Linux
   displayName: 'python multissltests.py'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 
 
 - script: ./configure --with-pydebug
   displayName: 'Configure CPython (debug)'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 
 - script: make -s -j4
   displayName: 'Build CPython'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 
 - script: make pythoninfo
   displayName: 'Display build info'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 
 # Run patchcheck and fail if anything is discovered
 - script: ./python Tools/scripts/patchcheck.py --travis true
   displayName: 'Run patchcheck.py'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 
 - script: xvfb-run make buildbottest TESTOPTS="-j4 -uall,-cpu"
   displayName: 'Tests'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))

.vsts/macos-pr.yml

@@ -24,14 +24,32 @@ steps:
   clean: true
   fetchDepth: 5
 
+- script: |
+   git fetch -q origin $(system.pullRequest.targetBranch)
+   changes = $(git diff --name-only HEAD $(git merge-base HEAD FETCH_HEAD))
+   echo "Files changed:"
+   echo "$changes"
+   if ! echo "$changes" | grep -qvE '(\.rst$)|(^Doc)|(^Misc)'
+   then
+     echo "Only docs were updated, stopping build process."
+     echo "##vso[task.setvariable variable=DocOnly]true"
+     exit
+   fi
+  displayName: Detect doc-only changes
+  condition: and(succeeded(), variables['system.pullRequest.targetBranch'])
+
 - script: ./configure --with-pydebug --with-openssl=/usr/local/opt/openssl --prefix=/opt/python-vsts
   displayName: 'Configure CPython (debug)'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 
 - script: make -s -j4
   displayName: 'Build CPython'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 
 - script: make pythoninfo
   displayName: 'Display build info'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 
 - script: make buildbottest TESTOPTS="-j4 -uall,-cpu"
   displayName: 'Tests'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))

.vsts/windows-pr.yml

@@ -37,13 +37,25 @@ steps:
   clean: true
   fetchDepth: 5
 
+- powershell: |
+   git fetch -q origin $(System.PullRequest.TargetBranch)
+   if (-not (git diff --name-only HEAD (git merge-base HEAD FETCH_HEAD) | sls -NotMatch '(\.rst$)|(^Doc)|(^Misc)')) {
+      Write-Host 'Only docs were updated. Skipping build'
+      Write-Host '##vso[task.setvariable variable=DocOnly]true'
+   }
+  displayName: Detect doc-only changes
+  condition: and(succeeded(), variables['System.PullRequest.TargetBranch'])
+
 - script: PCbuild\build.bat -e $(buildOpt)
   displayName: 'Build CPython'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 
 - script: python.bat -m test.pythoninfo
   displayName: 'Display build info'
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))
 
 - script: PCbuild\rt.bat -q -uall -u-cpu -rwW --slowest --timeout=1200 -j0
   displayName: 'Tests'
   env:
     PREFIX: $(Py_OutDir)\$(outDirSuffix)
+  condition: and(succeeded(), ne(variables['DocOnly'], 'true'))