[tools][system-analyzer] Add support for apkEmbeddedLibrary and targetRootFS

The system analyzer relies on server-side processing to symbolize C++
addresses, using lws-middleware.js:

    ws --stack system-analyzer/lws-middleware.js lws-static cors

This does not work on Android however, given the log file refers to the
stripped apk file rather than the unstripped libchrome.so binary. This
CL adds the --apk-embedded-library option to the middleware script to
make this work:

    ws --stack system-analyzer/lws-middleware.js lws-static cors  \
        --apk-embedded-library=/path/to/out/android/lib.unstripped/libchrome.so

Also, for completeness, add the --target option to set targetRootFS.

Bug: v8:10644
Change-Id: I7bb73adf49e3af8eaa88a5e2c81ec913023ac1a9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3823133
Commit-Queue: Pierre Langlois <pierre.langlois@arm.com>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82359}

tools/system-analyzer/lws-middleware.js

@@ -19,13 +19,35 @@ class Symbolizer {
     this.objdumpExec = 'objdump';
   }
 
+  optionDefinitions() {
+    return [
+      {
+        name: 'apk-embedded-library',
+        type: String,
+        description:
+            'Specify the path of the embedded library for Android traces',
+      },
+      {
+        name: 'target',
+        type: String,
+        description: 'Specify the target root directory for cross environment',
+      }
+    ]
+  }
+
   middleware(config) {
     return async (ctx, next) => {
       if (ctx.path == '/v8/loadVMSymbols') {
         await this.parseVMSymbols(ctx)
       } else if (ctx.path == '/v8/info/platform') {
-        ctx.response.type = 'text';
-        ctx.response.body = process.platform;
+        ctx.response.type = 'json';
+        ctx.response.body = JSON.stringify({
+          'name': process.platform,
+          'nmExec': this.nmExec,
+          'objdumpExec': this.objdumpExec,
+          'targetRootFS': config.target,
+          'apkEmbeddedLibrary': config.apkEmbeddedLibrary
+        });
       }
       await next();
     }

tools/system-analyzer/processor.mjs

@@ -325,19 +325,25 @@ export class Processor extends LogReader {
   async _setupCppEntriesProvider() {
     // Probe the local symbol server for the platform:
     const url = new URL('http://localhost:8000/v8/info/platform')
-    let platform = 'linux'
+    let platform = {name: 'linux'};
     try {
       const response = await fetch(url, {timeout: 1});
-      platform = await response.text();
+      if (response.status == 404) {
+        throw new Error(
+            `Local symbol server returned 404: ${await response.text()}`);
+      }
+      platform = await response.json();
     } catch (e) {
       console.warn(`Local symbol server is not running on ${url}`);
       console.warn(e);
     }
-    if (platform === 'darwin') {
-      this._cppEntriesProvider = new RemoteMacOSCppEntriesProvider();
-    } else {
-      this._cppEntriesProvider = new RemoteLinuxCppEntriesProvider();
+    let CppEntriesProvider = RemoteLinuxCppEntriesProvider;
+    if (platform.name === 'darwin') {
+      CppEntriesProvider = RemoteMacOSCppEntriesProvider;
     }
+    this._cppEntriesProvider = new CppEntriesProvider(
+        platform.nmExec, platform.objdumpExec, platform.targetRootFS,
+        platform.apkEmbeddedLibrary);
   }
 
   processCodeCreation(