New Go frontend

This PR contains a complete re-write of the Go language frontend based on JNA instead of a pure Go implementation. While this has a slight performance drawback (I am working on providing some numbers), it has infinitly better debugging capabilities. The handlers and most of the frontend itself is written in Kotlin using our classes and we than use a JNA bridge to a C API wrapper around the Go `go/ast` package.

.github/workflows/build.yml

@@ -19,16 +19,10 @@ jobs:
     runs-on: macos-latest
     steps:
       - uses: actions/checkout@v3
-        with:
-          fetch-depth: 0 # Shallow clones should be disabled for a better relevancy of SonarQube analysis
       - name: Setup Go
         uses: actions/setup-go@v4
         with:
-          go-version: 1.18
-      - uses: actions/setup-java@v3
-        with:
-          distribution: "zulu"
-          java-version: "17"
+          go-version: "1.20"
       - name: Build
         run: |
           cd cpg-language-go/src/main/golang

cpg-core/src/main/kotlin/de/fraunhofer/aisec/cpg/graph/declarations/DeclarationSequence.kt

@@ -47,8 +47,9 @@ class DeclarationSequence : Declaration(), DeclarationHolder {
             for (declarationChild in declaration.children) {
                 addIfNotContains(childEdges, declarationChild)
             }
+        } else {
+            addIfNotContains(childEdges, declaration)
         }
-        addIfNotContains(childEdges, declaration)
     }
 
     fun asList(): List<Declaration> {
@@ -62,6 +63,10 @@ class DeclarationSequence : Declaration(), DeclarationHolder {
         return childEdges[0].end
     }
 
+    operator fun plusAssign(declaration: Declaration) {
+        return addDeclaration(declaration)
+    }
+
     override val declarations: List<Declaration>
         get() = children
 }

cpg-core/src/main/kotlin/de/fraunhofer/aisec/cpg/passes/EvaluationOrderGraphPass.kt

@@ -40,6 +40,7 @@ import de.fraunhofer.aisec.cpg.graph.types.Type
 import de.fraunhofer.aisec.cpg.helpers.SubgraphWalker
 import de.fraunhofer.aisec.cpg.helpers.Util
 import de.fraunhofer.aisec.cpg.passes.order.DependsOn
+import de.fraunhofer.aisec.cpg.passes.order.ReplacePass
 import java.util.*
 import org.slf4j.LoggerFactory
 
@@ -290,7 +291,7 @@ open class EvaluationOrderGraphPass(ctx: TranslationContext) : TranslationUnitPa
         pushToEOG(node)
     }
 
-    protected fun handleFunctionDeclaration(node: FunctionDeclaration) {
+    protected open fun handleFunctionDeclaration(node: FunctionDeclaration) {
         // reset EOG
         currentPredecessors.clear()
         var needToLeaveRecord = false
@@ -525,25 +526,43 @@ open class EvaluationOrderGraphPass(ctx: TranslationContext) : TranslationUnitPa
     }
 
     protected fun handleUnaryOperator(node: UnaryOperator) {
+        // TODO(oxisto): These operator codes are highly language specific and might be more suited
+        //  to be handled differently (see https://github.com/Fraunhofer-AISEC/cpg/issues/1161)
+        if (node.operatorCode == "throw") {
+            handleThrowOperator(node)
+        } else {
+            handleUnspecificUnaryOperator(node)
+        }
+    }
+
+    protected fun handleThrowOperator(node: UnaryOperator) {
         val input = node.input
         createEOG(input)
-        if (node.operatorCode == "throw") {
-            val catchingScope =
-                scopeManager.firstScopeOrNull { scope ->
-                    scope is TryScope || scope is FunctionScope
-                }
 
-            val throwType = input.type
-            pushToEOG(node)
-            if (catchingScope is TryScope) {
-                catchingScope.catchesOrRelays[throwType] = ArrayList(currentPredecessors)
-            } else if (catchingScope is FunctionScope) {
-                catchingScope.catchesOrRelays[throwType] = ArrayList(currentPredecessors)
-            }
-            currentPredecessors.clear()
-        } else {
-            pushToEOG(node)
+        val catchingScope =
+            scopeManager.firstScopeOrNull { scope -> scope is TryScope || scope is FunctionScope }
+
+        val throwType = input.type
+        pushToEOG(node)
+        if (catchingScope is TryScope) {
+            catchingScope.catchesOrRelays[throwType] = ArrayList(currentPredecessors)
+        } else if (catchingScope is FunctionScope) {
+            catchingScope.catchesOrRelays[throwType] = ArrayList(currentPredecessors)
         }
+        currentPredecessors.clear()
+    }
+
+    /**
+     * This function handles all regular unary operators that do not receive any special handling
+     * (such as [handleThrowOperator]). This gives language frontends a chance to override this
+     * function using [ReplacePass], handle specific operators on their own and delegate the rest to
+     * this function.
+     */
+    protected open fun handleUnspecificUnaryOperator(node: UnaryOperator) {
+        val input = node.input
+        createEOG(input)
+
+        pushToEOG(node)
     }
 
     protected fun handleCompoundStatementExpression(node: CompoundStatementExpression) {

cpg-language-go/build.gradle.kts

@@ -39,6 +39,10 @@ publishing {
     }
 }
 
+dependencies {
+    implementation("net.java.dev.jna:jna:5.13.0")
+}
+
 if (!project.hasProperty("skipGoBuild")) {
     val compileGolang = tasks.register("compileGolang") {
         doLast {

cpg-language-go/src/main/golang/build.sh

@@ -8,16 +8,9 @@ else
     EXTENSION="so"
 fi
 
-if [ "$JAVA_HOME" == "" ]
-then
-    JAVA_HOME=`/usr/libexec/java_home`
-fi
-
-export CGO_CFLAGS="-I${JAVA_HOME}/include -I/${JAVA_HOME}/include/${ARCH}"
-
 CGO_ENABLED=1 GOARCH=amd64 go build -buildmode=c-shared -o ../resources/libcpgo-amd64.${EXTENSION} lib/cpg/main.go
 
 if [ $ARCH == "darwin" ]
 then
-CGO_ENABLED=1 GOARCH=arm64 go build -buildmode=c-shared -o ../resources/libcpgo-arm64.${EXTENSION} lib/cpg/main.go
+    CGO_ENABLED=1 GOARCH=arm64 go build -buildmode=c-shared -o ../resources/libcpgo-arm64.${EXTENSION} lib/cpg/main.go
 fi