PR27513: When determining which declaration to put into an exported lookup

table for a module / PCH, never map from a normal declaration of a class to an
injected-class-name declaration (or vice versa). Those declarations live in
distinct lookup tables and should not be confused.

We really shouldn't be using a CXXRecordDecl to represent an
injected-class-name in the first place; I've filed PR27532 so we don't forget.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@267632 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Serialization/ASTWriter.cpp

@@ -3107,11 +3107,20 @@ static NamedDecl *getDeclForLocalLookup(const LangOptions &LangOpts,
   if (Decl *Redecl = D->getPreviousDecl()) {
     // For Redeclarable decls, a prior declaration might be local.
     for (; Redecl; Redecl = Redecl->getPreviousDecl()) {
-      if (!Redecl->isFromASTFile())
+      // If we find a local decl, we're done.
+      if (!Redecl->isFromASTFile()) {
+        // Exception: in very rare cases (for injected-class-names), not all
+        // redeclarations are in the same semantic context. Skip ones in a
+        // different context. They don't go in this lookup table at all.
+        if (!Redecl->getDeclContext()->getRedeclContext()->Equals(
+                D->getDeclContext()->getRedeclContext()))
+          continue;
         return cast<NamedDecl>(Redecl);
+      }
+
       // If we find a decl from a (chained-)PCH stop since we won't find a
       // local one.
-      if (D->getOwningModuleID() == 0)
+      if (Redecl->getOwningModuleID() == 0)
         break;
     }
   } else if (Decl *First = D->getCanonicalDecl()) {

test/Modules/Inputs/PR27513/a.h

@@ -0,0 +1,5 @@
+#include "b.h"
+
+inline void f() { basic_string<char> s; }
+
+#include "c.h"

test/Modules/Inputs/PR27513/b.h

@@ -0,0 +1,3 @@
+#include "mystring.h"
+#include "b1.h"
+#include "b2.h"

test/Modules/Inputs/PR27513/b1.h

@@ -0,0 +1 @@
+#include "b11.h"

test/Modules/Inputs/PR27513/b11.h

@@ -0,0 +1,2 @@
+#include "mystring.h"
+#include "b111.h"

test/Modules/Inputs/PR27513/b111.h

@@ -0,0 +1,3 @@
+#include "mystring.h"
+#include "b1111.h"
+#include "b1112.h"

test/Modules/Inputs/PR27513/b1111.h

@@ -0,0 +1 @@
+#include "mystring.h"

test/Modules/Inputs/PR27513/b1112.h

@@ -0,0 +1 @@
+#include "mystring.h"

test/Modules/Inputs/PR27513/b2.h

@@ -0,0 +1 @@
+#include "mystring.h"

test/Modules/Inputs/PR27513/c.h

@@ -0,0 +1 @@
+#include "mystring.h"

test/Modules/Inputs/PR27513/module.modulemap

@@ -0,0 +1,7 @@
+module "c.h" {header "c.h" export *}
+module "b2.h" { header "b2.h" export *}
+module "b.h" {header "b.h" export *}
+module "b111.h" { header "b111.h" export *}
+module "b11.h" { header "b11.h" export *}
+module "b1111.h" { header "b1111.h" export *}
+module "b1112.h" { header "b1112.h" export *}

test/Modules/Inputs/PR27513/mystring.h

@@ -0,0 +1,8 @@
+#ifndef _GLIBCXX_STRING
+#define _GLIBCXX_STRING
+template<typename> struct basic_string {
+  struct _Alloc_hider {} _M_dataplus;
+  ~basic_string() { _Alloc_hider h; } 
+};
+extern template class basic_string<char>;
+#endif

test/Modules/pr27513.cpp

@@ -0,0 +1,7 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -std=c++11 -I%S/Inputs/PR27513 -verify %s
+// RUN: %clang_cc1 -std=c++11 -fmodules -fmodule-map-file=%S/Inputs/PR27513/module.modulemap -fmodules-cache-path=%t -I%S/Inputs/PR27513 -verify %s
+
+#include "Inputs/PR27513/a.h"
+
+//expected-no-diagnostics