From d3816961a68b68b971e7811bbc9df70675cdba1b Mon Sep 17 00:00:00 2001
From: Hubert Plociniczak <hubert.plociniczak@gmail.com>
Date: Tue, 10 Sep 2024 15:24:57 +0100
Subject: [PATCH] Re-compile module if IdMap is present (#11032)

Loading IR caches and IdMap for a module don't play very well. Rather
than complicating logic and introducing yet another re-compilation
request let's not even attempt to deserialize a module if IdMap is
present. The cost of compiling a single module (right now containing the
project itself) is negligble, compared to a possibility of bugs that
we've encountered so far.

(cherry picked from commit 62e15696ec6c58eb38eaea506d5f600c03cd256f)
---
 .../scala/org/enso/compiler/Compiler.scala    | 30 ++++---------------
 1 file changed, 6 insertions(+), 24 deletions(-)

diff --git a/engine/runtime-compiler/src/main/scala/org/enso/compiler/Compiler.scala b/engine/runtime-compiler/src/main/scala/org/enso/compiler/Compiler.scala
index e68b0dac8730..95d96e71399d 100644
--- a/engine/runtime-compiler/src/main/scala/org/enso/compiler/Compiler.scala
+++ b/engine/runtime-compiler/src/main/scala/org/enso/compiler/Compiler.scala
@@ -25,11 +25,7 @@ import org.enso.compiler.core.EnsoParser
 import org.enso.compiler.data.CompilerConfig
 import org.enso.compiler.pass.PassManager
 import org.enso.compiler.pass.analyse._
-import org.enso.compiler.phase.{
-  IdMapProcessor,
-  ImportResolver,
-  ImportResolverAlgorithm
-}
+import org.enso.compiler.phase.{ImportResolver, ImportResolverAlgorithm}
 import org.enso.editions.LibraryName
 import org.enso.pkg.QualifiedName
 import org.enso.common.CompilationStage
@@ -562,25 +558,11 @@ class Compiler(
     )
     context.updateModule(module, _.resetScope())
 
-    if (useCaches) {
-      if (context.deserializeModule(this, module)) {
-        val updatedIr =
-          IdMapProcessor.updateIr(
-            context.getIr(module),
-            context.getIdMap(module)
-          )
-        if (updatedIr != null) {
-          context.updateModule(
-            module,
-            u => {
-              u.resetScope()
-              u.ir(updatedIr)
-              u.compilationStage(CompilationStage.AFTER_PARSING)
-            }
-          )
-        }
-        return
-      }
+    if (
+      useCaches && context.getIdMap(module) == null && context
+        .deserializeModule(this, module)
+    ) {
+      return
     }
 
     uncachedParseModule(module, isGenDocs)