From 049093be6b5d6b5a01251b9cb261a363949eba7e Mon Sep 17 00:00:00 2001
From: Alexandre Poirot <poirot.alex@gmail.com>
Date: Thu, 7 Nov 2024 15:52:03 +0000
Subject: [PATCH] Bug 1929007 - [devtools] Collect console API calls when
 tracing from DevTools. r=dthayer

Because the tracer actor runs in the content process, the preference toggling logic
has to be done in some code running in the parent process: TargetConfiguration.

Differential Revision: https://phabricator.services.mozilla.com/D227833
---
 .../server/actors/target-configuration.js     | 44 +++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/devtools/server/actors/target-configuration.js b/devtools/server/actors/target-configuration.js
index ca1f4ad75027..ca80b9e4d859 100644
--- a/devtools/server/actors/target-configuration.js
+++ b/devtools/server/actors/target-configuration.js
@@ -104,6 +104,9 @@ class TargetConfigurationActor extends Actor {
     this._browsingContext = this.watcherActor.browserElement?.browsingContext;
   }
 
+  // Value of `logging.console` pref, before starting recording JS Traces
+  #consolePrefValue;
+
   form() {
     return {
       actor: this.actorID,
@@ -234,6 +237,11 @@ class TargetConfigurationActor extends Actor {
    * @param {Object} configuration: See `updateConfiguration`
    */
   _updateParentProcessConfiguration(configuration) {
+    // Process "tracerOptions" for all session types, as this isn't specific to tab debugging
+    if ("tracerOptions" in configuration) {
+      this._setTracerOptions(configuration.tracerOptions);
+    }
+
     if (!this._shouldHandleConfigurationInParentProcess()) {
       return;
     }
@@ -290,6 +298,11 @@ class TargetConfigurationActor extends Actor {
   }
 
   _restoreParentProcessConfiguration() {
+    // Always process tracer options as this isn't specific to tab debugging
+    if (this.#consolePrefValue !== undefined) {
+      this._setTracerOptions();
+    }
+
     if (!this._shouldHandleConfigurationInParentProcess()) {
       return;
     }
@@ -495,6 +508,37 @@ class TargetConfigurationActor extends Actor {
     }
     super.destroy();
   }
+
+  /**
+   * Called when the tracer is toggled on/off by the frontend.
+   * Note that when `options` is defined, it is meant to be enabled.
+   * It may not actually be tracing yet depending on the passed options.
+   *
+   * @param {Object} options
+   */
+  _setTracerOptions(options) {
+    if (!options) {
+      if (this.#consolePrefValue === -1) {
+        Services.prefs.clearUserPref("logging.console");
+      } else {
+        Services.prefs.setIntPref("logging.console", this.#consolePrefValue);
+      }
+      this.#consolePrefValue = undefined;
+      return;
+    }
+    // Enable `MOZ_LOG=console:5` via the logging.console so that all console API calls
+    // are stored in the profiler when recording JS Traces via the profiler.
+    //
+    // We do this from here as TargetConfiguration runs in the parent process,
+    // where we can set preferences. Whereas the profiler tracer actor runs in the content process.
+    const LOG_DISABLED = -1;
+    const LOG_VERBOSE = 5;
+    this.#consolePrefValue = Services.prefs.getIntPref(
+      "logging.console",
+      LOG_DISABLED
+    );
+    Services.prefs.setIntPref("logging.console", LOG_VERBOSE);
+  }
 }
 
 exports.TargetConfigurationActor = TargetConfigurationActor;