Add API Baseline checking to the build

BUILDING.md

@@ -57,6 +57,10 @@ replace. To do that run with the `baseline-compare-and-replace` profile.
 
 Requires verify phase of maven to run, i.e. will not run with `mvn package` even if profile is specified.
 
+#### api-baseline-check
+
+`api-baseline-check` checks the API of CDT matches the [API policy](https://github.com/eclipse-cdt/cdt/blob/main/POLICY.md#api)
+
 #### production
 
 Runs the production steps of the build. This profile can only be run on the CDT CI machines

Jenkinsfile

@@ -42,6 +42,7 @@ pipeline {
                       -Dmaven.test.failure.ignore=true \
                       -DexcludedGroups=flakyTest,slowTest \
                       -P baseline-compare-and-replace \
+                      -P api-baseline-check \
                       -Ddsf.gdb.tests.timeout.multiplier=50 \
                       -Dindexer.timeout=300 \
                       -P production \

pom.xml

@@ -45,6 +45,8 @@
 		<!-- Some old tests, like CDescriptorOldTests, fail due to reflection access. Therefore we add-opens to make that pass -->
 		<base.test.vmargs>-Xms256m -Xmx512m -ea --add-opens=java.xml/com.sun.org.apache.xerces.internal.dom=ALL-UNNAMED</base.test.vmargs>
 		<comparator.repo>https://download.eclipse.org/tools/cdt/releases/11.2/cdt-11.2.0/</comparator.repo>
+		<api-baseline.repo>https://download.eclipse.org/tools/cdt/releases/latest/</api-baseline.repo>
+		<api-baseline.repo.simrel>https://download.eclipse.org/releases/latest/</api-baseline.repo.simrel>
 		<!-- these parameters are to control baseline replace and compare. On a local build you want
 		     to avoid baseline replace and compare, especially if you have different versions of Java than
 			 the baseline was built with. This is the default.
@@ -549,6 +551,41 @@
 				<replace-version-with-baselines.replace>all</replace-version-with-baselines.replace>
 			</properties>
 		</profile>
+		<profile>
+			<id>api-baseline-check</id>
+			<build>
+				<plugins>
+					<plugin>
+						<groupId>org.eclipse.tycho</groupId>
+						<artifactId>tycho-apitools-plugin</artifactId>
+						<version>${tycho-version}</version>
+						<configuration>
+							<skipIfReplaced>false</skipIfReplaced>
+							<baselines>
+								<repository>
+									<url>${api-baseline.repo}</url>
+									<url>${api-baseline.repo.simrel}</url>
+								</repository>
+							</baselines>
+						</configuration>
+						<executions>
+							<execution>
+								<id>generate</id>
+								<goals>
+									<goal>generate</goal>
+								</goals>
+							</execution>
+							<execution>
+								<id>verify</id>
+								<goals>
+									<goal>verify</goal>
+								</goals>
+							</execution>
+						</executions>
+					</plugin>
+				</plugins>
+			</build>
+		</profile>
 		<profile>
 			<id>production</id>
 			<build>

releng/scripts/check_bundle_versions.sh

@@ -29,6 +29,7 @@ ${MVN:-mvn} \
         -DskipDoc=true \
         -DskipTests=true \
         -P baseline-compare-and-replace \
+        -P api-baseline-check \
          2>&1 | tee ${logfile}
 
 if [ $? -eq 0 ]; then

releng/scripts/check_bundle_versions_report.sh

@@ -23,6 +23,7 @@ fi
 logfile=baseline-compare-and-replace.log
 bundles_only_qualifier_changed=$(grep "Only qualifier changed" ${logfile} | sed -e 's/^.*Only qualifier changed for .//' -e 's@/.*@@' | sort)
 if [ -n "$bundles_only_qualifier_changed" ]; then
+    echo
     echo "The following bundles are missing a service segment version bump:"
     for bundle in $bundles_only_qualifier_changed; do
         echo "  - $bundle"
@@ -35,6 +36,7 @@ fi
 
 bundles_same_version_different_content=$(grep "baseline and build artifacts have same version but different contents" ${logfile} | sed -e 's/^.* on project //' -e 's@: baseline.*@@' | sort)
 if [ -n "$bundles_same_version_different_content" ]; then
+    echo
     echo "The following bundles have same version as baseline, but different contents:"
     for bundle in $bundles_same_version_different_content; do
         echo "  - $bundle"
@@ -49,6 +51,21 @@ if [ -n "$bundles_same_version_different_content" ]; then
     echo
 fi
 
+api_errors=$(grep "API ERROR" ${logfile} | grep -v "0 API ERRORS" || true)
+if [ -n "$api_errors" ]; then
+    echo
+    echo "API Errors were detected when running the build:"
+    grep "API ERROR" ${logfile} | grep -v "0 API ERRORS" || true
+    major_version=$(grep "The major version should be incremented" ${logfile})
+    if [ -n "$major_version" ]; then
+        echo "WARNING: some of the API errors report as 'major version should be incremented'. Incrementing the"
+        echo "major version is only allowed on major new versions of CDT. This error indicates that API has been"
+        echo "broken in some incompatible way. An project committer can help explain what to do if the (lengthy)"
+        echo "documentation below needs interpreting for this use case.".
+    fi
+    echo "See https://github.com/eclipse-cdt/cdt/blob/main/POLICY.md#api for details"
+fi
+
 success=$(grep "SUCCESS - Maven check all versions have been bumped appropriately appears to have completed successfully" ${logfile})
 if [ -n "$success" ]; then
     echo "Maven check all versions have been bumped appropriately appears to have completed successfully"