From 75517dc4f44ec5bbbee00d2569a7870ea9833065 Mon Sep 17 00:00:00 2001
From: ringabout <43030857+ringabout@users.noreply.github.com>
Date: Wed, 10 Sep 2025 23:11:20 +0800
Subject: [PATCH] use an auxiliary map

---
 compiler/importer.nim | 9 +++++----
 compiler/lookups.nim  | 4 ++--
 compiler/semdata.nim  | 3 ++-
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/compiler/importer.nim b/compiler/importer.nim
index 318176a297..14d01a0f71 100644
--- a/compiler/importer.nim
+++ b/compiler/importer.nim
@@ -14,6 +14,7 @@ import
   semdata, modulepaths, sigmatch, lineinfos,
   modulegraphs, wordrecg
 from std/strutils import `%`, startsWith
+from std/sequtils import addUnique
 import std/[sets, tables, intsets]
 
 when defined(nimPreviewSlimSystem):
@@ -255,7 +256,7 @@ proc importModuleAs(c: PContext; n: PNode, realModule: PSym, importHidden, track
   if trackUnusedImport:
     c.unusedImports.add((result, result.info))
   c.importModuleMap[result.id] = realModule.id
-  c.importModuleLookup.mgetOrPut(result.name.id, @[]).addUniqueModule(realModule.id, result.info)
+  c.importModuleLookup.mgetOrPut(result.name.id, @[]).addUnique realModule.id
 
 proc transformImportAs(c: PContext; n: PNode): tuple[node: PNode, importHidden: bool] =
   result = (nil, false)
@@ -339,13 +340,13 @@ proc afterImport(c: PContext, m: PSym) =
 
 proc impMod(c: PContext; it: PNode; importStmtResult: PNode) =
   var it = it
-  var oldImportModuleMap = c.importModuleLookup
   let m = myImportModule(c, it, importStmtResult)
   if m != nil:
     # ``addDecl`` needs to be done before ``importAllSymbols``!
-    swap oldImportModuleMap, c.importModuleLookup
     addDecl(c, m) # add symbol to symbol table of module
-    swap oldImportModuleMap, c.importModuleLookup
+
+    let realModuleId = c.importModuleMap[m.id]
+    c.importModuleLookupInfo.mgetOrPut(m.name.id, @[]).addUniqueModule(realModuleId, m.info)
     importAllSymbols(c, m)
     #importForwarded(c, m.ast, emptySet, m)
     afterImport(c, m)
diff --git a/compiler/lookups.nim b/compiler/lookups.nim
index c73f4d0aff..5631724459 100644
--- a/compiler/lookups.nim
+++ b/compiler/lookups.nim
@@ -397,8 +397,8 @@ proc addDeclAt*(c: PContext; scope: PScope, sym: PSym, info: TLineInfo) =
         localError(c.config, info, hintDuplicateModuleImport,
           "duplicate import of '$1'; previous import here: $2" %
           [sym.name.s, c.config $ conflict.info])
-      else:
-        for (module, prevInfo) in c.importModuleLookup[sym.name.id]:
+      elif sym.name.id in c.importModuleLookupInfo:
+        for (module, prevInfo) in c.importModuleLookupInfo[sym.name.id]:
           if c.importModuleMap[sym.id] == module:
             localError(c.config, info, hintDuplicateModuleImport,
               "duplicate import of '$1'; previous import here: $2" %
diff --git a/compiler/semdata.nim b/compiler/semdata.nim
index c9ad9b1041..b2b849c2cb 100644
--- a/compiler/semdata.nim
+++ b/compiler/semdata.nim
@@ -171,7 +171,8 @@ type
     lastTLineInfo*: TLineInfo
     sideEffects*: Table[int, seq[(TLineInfo, PSym)]] # symbol.id index
     inUncheckedAssignSection*: int
-    importModuleLookup*: Table[int, seq[(int, TLineInfo)]] # (module.ident.id, [module.id])
+    importModuleLookup*: Table[int, seq[int]] # (module.ident.id, [module.id])
+    importModuleLookupInfo*: Table[int, seq[(int, TLineInfo)]] # (module.ident.id, [module.id])
     forwardTypeUpdates*: seq[(PType, PNode)]
       # types that need to be updated in a type section
       # due to containing forward types, and their corresponding nodes