[cfe-commits] r139837 - /cfe/trunk/lib/Frontend/CompilerInstance.cpp

[Douglas Gregor]

Author: dgregor
Date: Thu Sep 15 15:53:28 2011
New Revision: 139837

URL: http://llvm.org/viewvc/llvm-project?rev=139837&view=rev
Log:
Comment what's going on when we compile a module

Modified:
    cfe/trunk/lib/Frontend/CompilerInstance.cpp

Modified: cfe/trunk/lib/Frontend/CompilerInstance.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/CompilerInstance.cpp?rev=139837&r1=139836&r2=139837&view=diff
==============================================================================
--- cfe/trunk/lib/Frontend/CompilerInstance.cpp (original)
+++ cfe/trunk/lib/Frontend/CompilerInstance.cpp Thu Sep 15 15:53:28 2011
@@ -658,10 +658,18 @@
   // Construct a compiler invocation for creating this module.
   llvm::IntrusiveRefCntPtr<CompilerInvocation> Invocation
     (new CompilerInvocation(ImportingInstance.getInvocation()));
+  
+  // For any options that aren't intended to affect how a module is built,
+  // reset them to their default values.
   Invocation->getLangOpts().resetNonModularOptions();
   Invocation->getPreprocessorOpts().resetNonModularOptions();
+  
+  // Note that this module is part of the module build path, so that we 
+  // can detect cycles in the module graph.
   Invocation->getPreprocessorOpts().ModuleBuildPath.push_back(ModuleName);
   
+  // Set up the inputs/outputs so that we build the module from its umbrella
+  // header.
   FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
   FrontendOpts.OutputFile = ModuleFileName.str();
   FrontendOpts.DisableFree = false;