Auto enable -XX:+ShowCodeDetailsInExceptionMessages for java 14 apps (#828)

Signed-off-by: Jinbo Wang <[email protected]>

Author: testforstephen

src/configurationProvider.ts

@@ -11,7 +11,7 @@ import * as anchor from "./anchor";
 import { buildWorkspace } from "./build";
 import * as commands from "./commands";
 import * as lsPlugin from "./languageServerPlugin";
-import { detectLaunchCommandStyle, validateRuntime } from "./launchCommand";
+import { addMoreHelpfulVMArgs, detectLaunchCommandStyle, validateRuntime } from "./launchCommand";
 import { logger, Type } from "./logger";
 import { resolveProcessId } from "./processPicker";
 import * as utility from "./utility";
@@ -222,6 +222,9 @@ export class JavaDebugConfigurationProvider implements vscode.DebugConfiguration
                     validateRuntime(config);
                 }
 
+                // Add more helpful vmArgs.
+                await addMoreHelpfulVMArgs(config);
+
                 if (!config.shortenCommandLine || config.shortenCommandLine === "auto") {
                     config.shortenCommandLine = await detectLaunchCommandStyle(config);
                 }

src/launchCommand.ts

@@ -15,6 +15,8 @@ enum shortenApproach {
     argfile = "argfile",
 }
 
+const HELPFUL_NPE_VMARGS = "-XX:+ShowCodeDetailsInExceptionMessages";
+
 export async function detectLaunchCommandStyle(config: vscode.DebugConfiguration): Promise<shortenApproach> {
     const javaExec: string = config.javaExec || path.join(await getJavaHome(), "bin", "java");
     const javaVersion = await checkJavaVersion(javaExec);
@@ -40,6 +42,23 @@ export async function validateRuntime(config: vscode.DebugConfiguration) {
     }
 }
 
+export async function addMoreHelpfulVMArgs(config: vscode.DebugConfiguration) {
+    try {
+        const javaExec = config.javaExec || path.join(await getJavaHome(), "bin", "java");
+        const version = await checkJavaVersion(javaExec);
+        if (version >= 14) {
+            // JEP-358: https://openjdk.java.net/jeps/358
+            if (config.vmArgs && config.vmArgs.indexOf(HELPFUL_NPE_VMARGS) >= 0) {
+                return;
+            }
+
+            config.vmArgs = (config.vmArgs || "") + " " + HELPFUL_NPE_VMARGS;
+        }
+    } catch (error) {
+        // do nothing.
+    }
+}
+
 function checkJavaVersion(javaExec: string): Promise<number> {
     return new Promise((resolve, reject) => {
         cp.execFile(javaExec, ["-version"], {}, (error, stdout, stderr) => {