Fix exception handling

According to existing tests, exceptions in the semanticdb-kotlinc
plugin should not propagate to the host.

Down to 23 failing tests.

Author: nicolas-guichard

semanticdb-kotlinc/src/main/kotlin/com/sourcegraph/semanticdb_kotlinc/PostAnalysisExtension.kt

@@ -1,12 +1,19 @@
 package com.sourcegraph.semanticdb_kotlinc
 
+import java.io.PrintWriter
+import java.io.Writer
 import java.nio.file.Files
 import java.nio.file.Path
 import java.nio.file.Paths
 import kotlin.contracts.ExperimentalContracts
 import org.jetbrains.kotlin.KtSourceFile
 import org.jetbrains.kotlin.backend.common.extensions.IrGenerationExtension
 import org.jetbrains.kotlin.backend.common.extensions.IrPluginContext
+import org.jetbrains.kotlin.cli.common.messages.CompilerMessageSeverity
+import org.jetbrains.kotlin.cli.common.messages.MessageRenderer
+import org.jetbrains.kotlin.cli.common.messages.PrintingMessageCollector
+import org.jetbrains.kotlin.config.CommonConfigurationKeys
+import org.jetbrains.kotlin.config.CompilerConfiguration
 import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
 
 class PostAnalysisExtension(
@@ -16,12 +23,20 @@ class PostAnalysisExtension(
 ) : IrGenerationExtension {
     @OptIn(ExperimentalContracts::class)
     override fun generate(moduleFragment: IrModuleFragment, pluginContext: IrPluginContext) {
-        for ((ktSourceFile, visitor) in AnalyzerCheckers.visitors) {
-            val document = visitor.build()
-            semanticdbOutPathForFile(ktSourceFile)?.apply {
-                Files.write(this, TextDocuments { addDocuments(document) }.toByteArray())
+        try {
+            for ((ktSourceFile, visitor) in AnalyzerCheckers.visitors) {
+                try {
+                    val document = visitor.build()
+                    semanticdbOutPathForFile(ktSourceFile)?.apply {
+                        Files.write(this, TextDocuments { addDocuments(document) }.toByteArray())
+                    }
+                    callback(document)
+                } catch (e: Exception) {
+                    handleException(e)
+                }
             }
-            callback(document)
+        } catch (e: Exception) {
+            handleException(e)
         }
     }
 
@@ -44,4 +59,31 @@ class PostAnalysisExtension(
             "given file is not under the sourceroot.\n\tSourceroot: $sourceRoot\n\tFile path: ${file.path}\n\tNormalized file path: $normalizedPath")
         return null
     }
+
+    private val messageCollector =
+        CompilerConfiguration()
+            .get(
+                CommonConfigurationKeys.MESSAGE_COLLECTOR_KEY,
+                PrintingMessageCollector(System.err, MessageRenderer.PLAIN_FULL_PATHS, false))
+
+    private fun handleException(e: Exception) {
+        val writer =
+            PrintWriter(
+                object : Writer() {
+                    val buf = StringBuffer()
+                    override fun close() =
+                        messageCollector.report(CompilerMessageSeverity.EXCEPTION, buf.toString())
+
+                    override fun flush() = Unit
+                    override fun write(data: CharArray, offset: Int, len: Int) {
+                        buf.append(data, offset, len)
+                    }
+                },
+                false)
+        writer.println("Exception in semanticdb-kotlin compiler plugin:")
+        e.printStackTrace(writer)
+        writer.println(
+            "Please report a bug to https://github.com/sourcegraph/lsif-kotlin with the stack trace above.")
+        writer.close()
+    }
 }