Module use declarations (II)

Review: http://llvm-reviews.chandlerc.com/D1546.

I have picked up this patch form Lawrence
(http://llvm-reviews.chandlerc.com/D1063) and did a few changes.

From the original change description (updated as appropriate):
This patch adds a check that ensures that modules only use modules they
have so declared. To this end, it adds a statement on intended module
use to the module.map grammar:

  use module-id

A module can then only use headers from other modules if it 'uses' them.
This enforcement is off by default, but may be turned on with the new
option -fmodules-decluse.

When enforcing the module semantics, we also need to consider a source
file part of a module. This is achieved with a compiler option

-fmodule-name=<module-id>.

The compiler at present only applies restrictions to the module directly
being built.

llvm-svn: 191283

1 files changed, 63 insertions, 1 deletions

diff --git a/clang/lib/Lex/ModuleMap.cpp b/clang/lib/Lex/ModuleMap.cpp
index df80a93e4db..0f12af361a4 100644
--- a/clang/lib/Lex/ModuleMap.cpp
+++ b/clang/lib/Lex/ModuleMap.cpp
@@ -387,6 +387,10 @@ ModuleMap::findOrCreateModule(StringRef Name, Module *Parent, bool IsFramework,
   // Create a new module with this name.
   Module *Result = new Module(Name, SourceLocation(), Parent, IsFramework, 
                               IsExplicit);
+  if (LangOpts.CurrentModule == Name) {
+    SourceModule = Result;
+    SourceModuleName = Name;
+  }
   if (!Parent) {
     Modules[Name] = Result;
     if (!LangOpts.CurrentModule.empty() && !CompilingModule &&
@@ -518,6 +522,10 @@ ModuleMap::inferFrameworkModule(StringRef ModuleName,
   
   Module *Result = new Module(ModuleName, SourceLocation(), Parent,
                               /*IsFramework=*/true, /*IsExplicit=*/false);
+  if (LangOpts.CurrentModule == ModuleName) {
+    SourceModule = Result;
+    SourceModuleName = ModuleName;
+  }
   if (IsSystem)
     Result->IsSystem = IsSystem;
   
@@ -653,6 +661,20 @@ bool ModuleMap::resolveExports(Module *Mod, bool Complain) {
   return HadError;
 }
 
+bool ModuleMap::resolveUses(Module *Mod, bool Complain) {
+  bool HadError = false;
+  for (unsigned I = 0, N = Mod->UnresolvedDirectUses.size(); I != N; ++I) {
+    Module *DirectUse =
+        resolveModuleId(Mod->UnresolvedDirectUses[I], Mod, Complain);
+    if (DirectUse)
+      Mod->DirectUses.push_back(DirectUse);
+    else
+      HadError = true;
+  }
+  Mod->UnresolvedDirectUses.clear();
+  return HadError;
+}
+
 bool ModuleMap::resolveConflicts(Module *Mod, bool Complain) {
   bool HadError = false;
   for (unsigned I = 0, N = Mod->UnresolvedConflicts.size(); I != N; ++I) {
@@ -727,6 +749,7 @@ namespace clang {
       Period,
       PrivateKeyword,
       UmbrellaKeyword,
+      UseKeyword,
       RequiresKeyword,
       Star,
       StringLiteral,
@@ -819,6 +842,7 @@ namespace clang {
                          SourceLocation LeadingLoc);
     void parseUmbrellaDirDecl(SourceLocation UmbrellaLoc);
     void parseExportDecl();
+    void parseUseDecl();
     void parseLinkDecl();
     void parseConfigMacros();
     void parseConflict();
@@ -873,6 +897,7 @@ retry:
                  .Case("private", MMToken::PrivateKeyword)
                  .Case("requires", MMToken::RequiresKeyword)
                  .Case("umbrella", MMToken::UmbrellaKeyword)
+                 .Case("use", MMToken::UseKeyword)
                  .Default(MMToken::Identifier);
     break;
 
@@ -1209,6 +1234,10 @@ void ModuleMapParser::parseModuleDecl() {
     case MMToken::ExportKeyword:
       parseExportDecl();
       break;
+
+    case MMToken::UseKeyword:
+      parseUseDecl();
+      break;
         
     case MMToken::RequiresKeyword:
       parseRequiresDecl();
@@ -1593,7 +1622,7 @@ void ModuleMapParser::parseExportDecl() {
       break;
     }
     
-    Diags.Report(Tok.getLocation(), diag::err_mmap_export_module_id);
+    Diags.Report(Tok.getLocation(), diag::err_mmap_module_id);
     HadError = true;
     return;
   } while (true);
@@ -1604,6 +1633,38 @@ void ModuleMapParser::parseExportDecl() {
   ActiveModule->UnresolvedExports.push_back(Unresolved);
 }
 
+/// \brief Parse a module uses declaration.
+///
+///   uses-declaration:
+///     'uses' wildcard-module-id
+void ModuleMapParser::parseUseDecl() {
+  assert(Tok.is(MMToken::UseKeyword));
+  consumeToken();
+  // Parse the module-id.
+  ModuleId ParsedModuleId;
+
+  do {
+    if (Tok.is(MMToken::Identifier)) {
+      ParsedModuleId.push_back(
+          std::make_pair(Tok.getString(), Tok.getLocation()));
+      consumeToken();
+
+      if (Tok.is(MMToken::Period)) {
+        consumeToken();
+        continue;
+      }
+
+      break;
+    }
+
+    Diags.Report(Tok.getLocation(), diag::err_mmap_module_id);
+    HadError = true;
+    return;
+  } while (true);
+
+  ActiveModule->UnresolvedDirectUses.push_back(ParsedModuleId);
+}
+
 /// \brief Parse a link declaration.
 ///
 ///   module-declaration:
@@ -2001,6 +2062,7 @@ bool ModuleMapParser::parseModuleMapFile() {
     case MMToken::Star:
     case MMToken::StringLiteral:
     case MMToken::UmbrellaKeyword:
+    case MMToken::UseKeyword:
       Diags.Report(Tok.getLocation(), diag::err_mmap_expected_module);
       HadError = true;
       consumeToken();