commit 2a1e2edb60c3b2145d71ba746c3983ac0687c331
author Chris Lattner <sabre@nondot.org> Fri Apr 11 07:00:53 2008 +0000
committer Chris Lattner <sabre@nondot.org> Fri Apr 11 07:00:53 2008 +0000
tree c013e6e8a1beec7434a336c79420958f8d0cfa41
parent e536215fa6f1d6e487fe25d2d7742f62525e89be

Switch sema to maintaining its own scope chain information for variable
shadowing, instead of threading it through the AST.  This patch contributed
by Argiris Kirtzidis!



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@49520 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Sema/SemaDecl.cpp

diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 157700f..a7f8bad 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -65,23 +65,9 @@
     IdentifierInfo *II = D->getIdentifier();
     if (!II) continue;
     
-    // Unlink this decl from the identifier.  Because the scope contains decls
-    // in an unordered collection, and because we have multiple identifier
-    // namespaces (e.g. tag, normal, label),the decl may not be the first entry.
-    if (II->getFETokenInfo<Decl>() == D) {
-      // Normal case, no multiple decls in different namespaces.
-      II->setFETokenInfo(D->getNext());
-    } else {
-      // Scan ahead.  There are only three namespaces in C, so this loop can
-      // never execute more than 3 times.
-      ScopedDecl *SomeDecl = II->getFETokenInfo<ScopedDecl>();
-      while (SomeDecl->getNext() != D) {
-        SomeDecl = SomeDecl->getNext();
-        assert(SomeDecl && "Didn't find this decl on its identifier's chain!");
-      }
-      SomeDecl->setNext(D->getNext());
-    }
-    
+    // Unlink this decl from the identifier.
+    IdResolver.RemoveDecl(D);
+
     // This will have to be revisited for C++: there we want to nest stuff in
     // namespace decls etc.  Even for C, we might want a top-level translation
     // unit decl or something.
@@ -111,14 +97,13 @@
                        Scope *S, bool enableLazyBuiltinCreation) {
   if (II == 0) return 0;
   Decl::IdentifierNamespace NS = (Decl::IdentifierNamespace)NSI;
-  
+
   // Scan up the scope chain looking for a decl that matches this identifier
   // that is in the appropriate namespace.  This search should not take long, as
   // shadowing of names is uncommon, and deep shadowing is extremely uncommon.
-  for (ScopedDecl *D = II->getFETokenInfo<ScopedDecl>(); D; D = D->getNext())
-    if (D->getIdentifierNamespace() == NS)
-      return D;
-  
+  NamedDecl *ND = IdResolver.Lookup(II, NS);
+  if (ND) return ND;
+
   // If we didn't find a use of this identifier, and if the identifier
   // corresponds to a compiler builtin, create the decl object for the builtin
   // now, injecting it into translation unit scope, and return it.
@@ -171,23 +156,12 @@
                                            SourceLocation(), II, R,
                                            FunctionDecl::Extern, false, 0);
   
-  // Find translation-unit scope to insert this function into.
-  if (Scope *FnS = S->getFnParent())
-    S = FnS->getParent();   // Skip all scopes in a function at once.
-  while (S->getParent())
-    S = S->getParent();
-  S->AddDecl(New);
+  // TUScope is the translation-unit scope to insert this function into.
+  TUScope->AddDecl(New);
   
   // Add this decl to the end of the identifier info.
-  if (ScopedDecl *LastDecl = II->getFETokenInfo<ScopedDecl>()) {
-    // Scan until we find the last (outermost) decl in the id chain. 
-    while (LastDecl->getNext())
-      LastDecl = LastDecl->getNext();
-    // Insert before (outside) it.
-    LastDecl->setNext(New);
-  } else {
-    II->setFETokenInfo(New);
-  }    
+  IdResolver.AddGlobalDecl(New);
+
   return New;
 }
 
@@ -456,8 +430,7 @@
   ParmVarDecl *New = ParmVarDecl::Create(Context, CurContext, IdLoc, Id, Type, 
                                          VarDecl::None, 0, 0);
   if (Id) {
-    New->setNext(Id->getFETokenInfo<ScopedDecl>());
-    Id->setFETokenInfo(New);
+    IdResolver.AddDecl(New, S);
     S->AddDecl(New);
   }
 
@@ -924,8 +897,7 @@
   
   // If this has an identifier, add it to the scope stack.
   if (II) {
-    New->setNext(II->getFETokenInfo<ScopedDecl>());
-    II->setFETokenInfo(New);
+    IdResolver.AddDecl(New, S);
     S->AddDecl(New);
   }
   // If any semantic error occurred, mark the decl as invalid.
@@ -1146,8 +1118,7 @@
     New->setInvalidDecl();
     
   if (II) {
-    New->setNext(II->getFETokenInfo<ScopedDecl>());
-    II->setFETokenInfo(New);
+    IdResolver.AddDecl(New, S);
     S->AddDecl(New);
   }
 
@@ -1213,9 +1184,8 @@
   for (unsigned p = 0, NumParams = FD->getNumParams(); p < NumParams; ++p) {
     ParmVarDecl *Param = FD->getParamDecl(p);
     // If this has an identifier, add it to the scope stack.
-    if (IdentifierInfo *II = Param->getIdentifier()) {
-      Param->setNext(II->getFETokenInfo<ScopedDecl>());
-      II->setFETokenInfo(Param);
+    if (Param->getIdentifier()) {
+      IdResolver.AddDecl(Param, FnBodyScope);
       FnBodyScope->AddDecl(Param);
     }
   }
@@ -1408,8 +1378,7 @@
       S = S->getParent();
     
     // Add it to the decl chain.
-    New->setNext(Name->getFETokenInfo<ScopedDecl>());
-    Name->setFETokenInfo(New);
+    IdResolver.AddDecl(New, S);
     S->AddDecl(New);
   }
   
@@ -1752,8 +1721,7 @@
                              LastEnumConst);
   
   // Register this decl in the current scope stack.
-  New->setNext(Id->getFETokenInfo<ScopedDecl>());
-  Id->setFETokenInfo(New);
+  IdResolver.AddDecl(New, S);
   S->AddDecl(New);
   return New;
 }