Prototype of modules codegen

First pass at generating weak definitions of inline functions from module files
(& skipping (-O0) or emitting available_externally (optimizations)
definitions where those modules are used).

External functions defined in modules are emitted into the modular
object file as well (this may turn an existing ODR violation (if that
module were imported into multiple translations) into valid/linkable
code).

Internal symbols (static functions, for example) are not correctly
supported yet. The symbol will be produced, internal, in the modular
object - unreferenceable from the users.

Reviewers: rsmith

Differential Revision: https://reviews.llvm.org/D28845

llvm-svn: 293456

1 files changed, 8 insertions, 5 deletions

diff --git a/clang/lib/Lex/ModuleMap.cpp b/clang/lib/Lex/ModuleMap.cpp
index 1488f624da6..1db5becac4b 100644
--- a/clang/lib/Lex/ModuleMap.cpp
+++ b/clang/lib/Lex/ModuleMap.cpp
@@ -91,6 +91,7 @@ ModuleMap::ModuleMap(SourceManager &SourceMgr, DiagnosticsEngine &Diags,
       HeaderInfo(HeaderInfo), BuiltinIncludeDir(nullptr),
       SourceModule(nullptr), NumCreatedModules(0) {
   MMapLangOpts.LineComment = true;
+  MMapLangOpts.ModularCodegen = LangOpts.ModularCodegen;
 }
 
 ModuleMap::~ModuleMap() {
@@ -554,16 +555,17 @@ Module *ModuleMap::lookupModuleQualified(StringRef Name, Module *Context) const{
   return Context->findSubmodule(Name);
 }
 
-std::pair<Module *, bool> 
-ModuleMap::findOrCreateModule(StringRef Name, Module *Parent, bool IsFramework,
-                              bool IsExplicit) {
+std::pair<Module *, bool> ModuleMap::findOrCreateModule(StringRef Name,
+                                                        Module *Parent,
+                                                        bool IsFramework,
+                                                        bool IsExplicit) {
   // Try to find an existing module with this name.
   if (Module *Sub = lookupModuleQualified(Name, Parent))
     return std::make_pair(Sub, false);
   
   // Create a new module with this name.
-  Module *Result = new Module(Name, SourceLocation(), Parent,
-                              IsFramework, IsExplicit, NumCreatedModules++);
+  Module *Result = new Module(Name, SourceLocation(), Parent, IsFramework,
+                              IsExplicit, NumCreatedModules++);
   if (!Parent) {
     if (LangOpts.CurrentModule == Name)
       SourceModule = Result;
@@ -1499,6 +1501,7 @@ void ModuleMapParser::parseModuleDecl() {
       (!ActiveModule->Parent && ModuleName == "Darwin"))
     ActiveModule->NoUndeclaredIncludes = true;
   ActiveModule->Directory = Directory;
+  ActiveModule->WithCodegen = L.getLangOpts().ModularCodegen;
 
   if (!ActiveModule->Parent) {
     StringRef MapFileName(ModuleMapFile->getName());