[modules] Remove redundant import of lexical decls when building a lookup table

for a DeclContext, and fix propagation of exception specifications along
redeclaration chains.

This reverts r232905, r232907, and r232907, which reverted r232793, r232853,
and r232853.

One additional change is present here to resolve issues with LLDB: distinguish
between whether lexical decls missing from the lookup table are local or are
provided by the external AST source, and still look in the external source if
that's where they came from.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@232928 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 38 insertions, 10 deletions

diff --git a/lib/Sema/IdentifierResolver.cpp b/lib/Sema/IdentifierResolver.cpp
index a6efe96573..53263bac54 100644
--- a/lib/Sema/IdentifierResolver.cpp
+++ b/lib/Sema/IdentifierResolver.cpp
@@ -98,7 +98,7 @@ bool IdentifierResolver::isDeclInScope(Decl *D, DeclContext *Ctx, Scope *S,
                                        bool AllowInlineNamespace) const {
   Ctx = Ctx->getRedeclContext();
 
-  if (Ctx->isFunctionOrMethod() || S->isFunctionPrototypeScope()) {
+  if (Ctx->isFunctionOrMethod() || (S && S->isFunctionPrototypeScope())) {
     // Ignore the scopes associated within transparent declaration contexts.
     while (S->getEntity() && S->getEntity()->isTransparentContext())
       S = S->getParent();
diff --git a/lib/Sema/SemaExceptionSpec.cpp b/lib/Sema/SemaExceptionSpec.cpp
index 41abd49627..51d6acebad 100644
--- a/lib/Sema/SemaExceptionSpec.cpp
+++ b/lib/Sema/SemaExceptionSpec.cpp
@@ -167,13 +167,13 @@ Sema::ResolveExceptionSpec(SourceLocation Loc, const FunctionProtoType *FPT) {
 void
 Sema::UpdateExceptionSpec(FunctionDecl *FD,
                           const FunctionProtoType::ExceptionSpecInfo &ESI) {
-  for (auto *Redecl : FD->redecls())
-    Context.adjustExceptionSpec(cast<FunctionDecl>(Redecl), ESI);
-
   // If we've fully resolved the exception specification, notify listeners.
   if (!isUnresolvedExceptionSpec(ESI.Type))
     if (auto *Listener = getASTMutationListener())
       Listener->ResolvedExceptionSpec(FD);
+
+  for (auto *Redecl : FD->redecls())
+    Context.adjustExceptionSpec(cast<FunctionDecl>(Redecl), ESI);
 }
 
 /// Determine whether a function has an implicitly-generated exception
diff --git a/lib/Sema/SemaLookup.cpp b/lib/Sema/SemaLookup.cpp
index e15e532be1..0b40618405 100644
--- a/lib/Sema/SemaLookup.cpp
+++ b/lib/Sema/SemaLookup.cpp
@@ -3021,17 +3021,45 @@ static void LookupVisibleDecls(DeclContext *Ctx, LookupResult &Result,
   if (Visited.visitedContext(Ctx->getPrimaryContext()))
     return;
 
+  // Outside C++, lookup results for the TU live on identifiers.
+  if (isa<TranslationUnitDecl>(Ctx) &&
+      !Result.getSema().getLangOpts().CPlusPlus) {
+    auto &S = Result.getSema();
+    auto &Idents = S.Context.Idents;
+
+    // Ensure all external identifiers are in the identifier table.
+    if (IdentifierInfoLookup *External = Idents.getExternalIdentifierLookup()) {
+      std::unique_ptr<IdentifierIterator> Iter(External->getIdentifiers());
+      for (StringRef Name = Iter->Next(); !Name.empty(); Name = Iter->Next())
+        Idents.get(Name);
+    }
+
+    // Walk all lookup results in the TU for each identifier.
+    for (const auto &Ident : Idents) {
+      for (auto I = S.IdResolver.begin(Ident.getValue()),
+                E = S.IdResolver.end();
+           I != E; ++I) {
+        if (S.IdResolver.isDeclInScope(*I, Ctx)) {
+          if (NamedDecl *ND = Result.getAcceptableDecl(*I)) {
+            Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
+            Visited.add(ND);
+          }
+        }
+      }
+    }
+
+    return;
+  }
+
   if (CXXRecordDecl *Class = dyn_cast<CXXRecordDecl>(Ctx))
     Result.getSema().ForceDeclarationOfImplicitMembers(Class);
 
   // Enumerate all of the results in this context.
   for (const auto &R : Ctx->lookups()) {
-    for (auto *I : R) {
-      if (NamedDecl *ND = dyn_cast<NamedDecl>(I)) {
-        if ((ND = Result.getAcceptableDecl(ND))) {
-          Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
-          Visited.add(ND);
-        }
+    for (auto *D : R) {
+      if (auto *ND = Result.getAcceptableDecl(D)) {
+        Consumer.FoundDecl(ND, Visited.checkHidden(ND), Ctx, InBaseClass);
+        Visited.add(ND);
       }
     }
   }