commit 62f19e700d3126415bb443162501eefe22cf1811
author Richard Smith <richard-llvm@metafoo.co.uk> Sat Jun 25 00:15:56 2016 +0000
committer Richard Smith <richard-llvm@metafoo.co.uk> Sat Jun 25 00:15:56 2016 +0000
tree f099beb58ddd384abd71e64128ae992e87362263
parent b8da3a2bb2b840db6ab7c473190ee6d65dcf3a1e

Implement C++17 P0386R2, inline variables. (The 'inline' specifier gives a
variable weak discardable linkage and partially-ordered initialization, and is
implied for constexpr static data members.)

llvm-svn: 273754

clang/lib/Sema/SemaTemplateInstantiateDecl.cpp

diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 58c0ab0..dbb8c6e 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -3881,11 +3881,12 @@
   Context.setManglingNumber(NewVar, Context.getManglingNumber(OldVar));
   Context.setStaticLocalNumber(NewVar, Context.getStaticLocalNumber(OldVar));
 
-  // Delay instantiation of the initializer for variable templates until a
-  // definition of the variable is needed. We need it right away if the type
-  // contains 'auto'.
+  // Delay instantiation of the initializer for variable templates or inline
+  // static data members until a definition of the variable is needed. We need
+  // it right away if the type contains 'auto'.
   if ((!isa<VarTemplateSpecializationDecl>(NewVar) &&
-       !InstantiatingVarTemplate) ||
+       !InstantiatingVarTemplate &&
+       !(OldVar->isInline() && OldVar->isThisDeclarationADefinition())) ||
       NewVar->getType()->isUndeducedType())
     InstantiateVariableInitializer(NewVar, OldVar, TemplateArgs);
 
@@ -3901,6 +3902,13 @@
 void Sema::InstantiateVariableInitializer(
     VarDecl *Var, VarDecl *OldVar,
     const MultiLevelTemplateArgumentList &TemplateArgs) {
+  // We propagate the 'inline' flag with the initializer, because it
+  // would otherwise imply that the variable is a definition for a
+  // non-static data member.
+  if (OldVar->isInlineSpecified())
+    Var->setInlineSpecified();
+  else if (OldVar->isInline())
+    Var->setImplicitlyInline();
 
   if (Var->getAnyInitializer())
     // We already have an initializer in the class.
@@ -4083,7 +4091,7 @@
 
     assert(PatternDecl && "data member was not instantiated from a template?");
     assert(PatternDecl->isStaticDataMember() && "not a static data member?");
-    Def = PatternDecl->getOutOfLineDefinition();
+    Def = PatternDecl->getDefinition();
   }
 
   // FIXME: Check that the definition is visible before trying to instantiate
@@ -4181,11 +4189,16 @@
   LocalInstantiationScope Local(*this);
 
   VarDecl *OldVar = Var;
-  if (!VarSpec)
+  if (Def->isStaticDataMember() && !Def->isOutOfLine()) {
+    // We're instantiating an inline static data member whose definition was
+    // provided inside the class.
+    // FIXME: Update record?
+    InstantiateVariableInitializer(Var, Def, TemplateArgs);
+  } else if (!VarSpec) {
     Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
                                           TemplateArgs));
-  else if (Var->isStaticDataMember() &&
-           Var->getLexicalDeclContext()->isRecord()) {
+  } else if (Var->isStaticDataMember() &&
+             Var->getLexicalDeclContext()->isRecord()) {
     // We need to instantiate the definition of a static data member template,
     // and all we have is the in-class declaration of it. Instantiate a separate
     // declaration of the definition.