For modules, use a hash of the compiler version, language options, and

target triple to separate modules built under different
conditions. The hash is used to create a subdirectory in the module
cache path where other invocations of the compiler (with the same
version, language options, etc.) can find the precompiled modules.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@139662 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 96 insertions, 14 deletions

diff --git a/lib/Frontend/CompilerInstance.cpp b/lib/Frontend/CompilerInstance.cpp
index ece9cd8406..720f7bb582 100644
--- a/lib/Frontend/CompilerInstance.cpp
+++ b/lib/Frontend/CompilerInstance.cpp
@@ -221,6 +221,15 @@ void CompilerInstance::createPreprocessor() {
   
   InitializePreprocessor(*PP, PPOpts, getHeaderSearchOpts(), getFrontendOpts());
   
+  // Set up the module path, including the hash for the
+  // module-creation options.
+  llvm::SmallString<256> SpecificModuleCache(
+                           getHeaderSearchOpts().ModuleCachePath);
+  if (!getHeaderSearchOpts().DisableModuleHash)
+    llvm::sys::path::append(SpecificModuleCache, 
+                            getInvocation().getModuleHash());
+  PP->getHeaderSearchInfo().setModuleCachePath(SpecificModuleCache);
+  
   // Handle generating dependencies, if requested.
   const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
   if (!DepOpts.OutputFile.empty())
@@ -644,13 +653,8 @@ static InputKind getSourceInputKindFromOptions(const LangOptions &LangOpts) {
 /// instance.
 static void compileModule(CompilerInstance &ImportingInstance,
                           StringRef ModuleName,
+                          StringRef ModuleFileName,
                           StringRef UmbrellaHeader) {
-  // Determine the file that we'll be writing to.
-  llvm::SmallString<128> ModuleFile;
-  ModuleFile += 
-    ImportingInstance.getInvocation().getHeaderSearchOpts().ModuleCachePath;
-  llvm::sys::path::append(ModuleFile, ModuleName + ".pcm");
-  
   // Construct a compiler invocation for creating this module.
   llvm::IntrusiveRefCntPtr<CompilerInvocation> Invocation
     (new CompilerInvocation(ImportingInstance.getInvocation()));
@@ -658,7 +662,7 @@ static void compileModule(CompilerInstance &ImportingInstance,
   Invocation->getPreprocessorOpts().resetNonModularOptions();
   
   FrontendOptions &FrontendOpts = Invocation->getFrontendOpts();
-  FrontendOpts.OutputFile = ModuleFile.str();
+  FrontendOpts.OutputFile = ModuleFileName.str();
   FrontendOpts.DisableFree = false;
   FrontendOpts.Inputs.clear();
   FrontendOpts.Inputs.push_back(
@@ -686,10 +690,6 @@ static void compileModule(CompilerInstance &ImportingInstance,
   // FIXME: Need to synchronize when multiple processes do this.
   Instance.ExecuteAction(CreateModuleAction);
   
-  // Tell the importing instance's file manager to forget about the module
-  // file, since we've just created it.
-  ImportingInstance.getFileManager().forgetFile(ModuleFile);
-  
   // Tell the diagnostic client that it's (re-)starting to process a source
   // file.
   ImportingInstance.getDiagnosticClient()
@@ -710,8 +710,10 @@ ModuleKey CompilerInstance::loadModule(SourceLocation ImportLoc,
 
   // Search for a module with the given name.
   std::string UmbrellaHeader;
+  std::string ModuleFileName;
   const FileEntry *ModuleFile
     = PP->getHeaderSearchInfo().lookupModule(ModuleName.getName(),
+                                             &ModuleFileName,
                                              &UmbrellaHeader);
   
   bool BuildingModule = false;
@@ -720,7 +722,7 @@ ModuleKey CompilerInstance::loadModule(SourceLocation ImportLoc,
     // can be used to create the module file. Create a separate compilation
     // module to do so.
     BuildingModule = true;
-    compileModule(*this, ModuleName.getName(), UmbrellaHeader);
+    compileModule(*this, ModuleName.getName(), ModuleFileName, UmbrellaHeader);
     ModuleFile = PP->getHeaderSearchInfo().lookupModule(ModuleName.getName());
   }
   
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 6c999caf24..6c47d7b114 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -1383,6 +1383,7 @@ static void ParseHeaderSearchArgs(HeaderSearchOptions &Opts, ArgList &Args) {
     Opts.UseLibcxx = (strcmp(A->getValue(Args), "libc++") == 0);
   Opts.ResourceDir = Args.getLastArgValue(OPT_resource_dir);
   Opts.ModuleCachePath = Args.getLastArgValue(OPT_fmodule_cache_path);
+  Opts.DisableModuleHash = Args.hasArg(OPT_fdisable_module_hash);
   
   // Add -I..., -F..., and -index-header-map options in order.
   bool IsIndexHeaderMap = false;
@@ -1914,3 +1915,84 @@ void CompilerInvocation::CreateFromArgs(CompilerInvocation &Res,
   ParsePreprocessorOutputArgs(Res.getPreprocessorOutputOpts(), *Args);
   ParseTargetArgs(Res.getTargetOpts(), *Args);
 }
+
+namespace {
+
+  class ModuleSignature {
+    llvm::SmallVector<uint64_t, 16> Data;
+    unsigned CurBit;
+    uint64_t CurValue;
+    
+  public:
+    ModuleSignature() : CurBit(0), CurValue(0) { }
+    
+    void add(uint64_t Value, unsigned Bits);
+    void add(StringRef Value);
+    void flush();
+    
+    llvm::APInt getAsInteger() const;
+  };
+}
+
+void ModuleSignature::add(uint64_t Value, unsigned int NumBits) {
+  CurValue |= Value << CurBit;
+  if (CurBit + NumBits < 64) {
+    CurBit += NumBits;
+    return;
+  }
+  
+  // Add the current word.
+  Data.push_back(CurValue);
+  
+  if (CurBit)
+    CurValue = Value >> (64-CurBit);
+  else
+    CurValue = 0;
+  CurBit = (CurBit+NumBits) & 63;
+}
+
+void ModuleSignature::flush() {
+  if (CurBit == 0)
+    return;
+  
+  Data.push_back(CurValue);
+  CurBit = 0;
+  CurValue = 0;
+}
+
+void ModuleSignature::add(StringRef Value) {
+  for (StringRef::iterator I = Value.begin(), IEnd = Value.end(); I != IEnd;++I)
+    add(*I, 8);
+}
+
+llvm::APInt ModuleSignature::getAsInteger() const {
+  return llvm::APInt(Data.size() * 64, Data);
+}
+
+std::string CompilerInvocation::getModuleHash() const {
+  ModuleSignature Signature;
+  
+  // Start the signature with the compiler version.
+  Signature.add(getClangFullRepositoryVersion());
+  
+  // Extend the signature with the language options
+#define LANGOPT(Name, Bits, Default, Description) \
+  Signature.add(LangOpts.Name, Bits);
+#define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
+  Signature.add(static_cast<unsigned>(LangOpts.get##Name()), Bits);
+#define BENIGN_LANGOPT(Name, Bits, Default, Description)
+#define BENIGN_ENUM_LANGOPT(Name, Type, Bits, Default, Description)
+#include "clang/Basic/LangOptions.def"
+  
+  // Extend the signature with the target triple
+  llvm::Triple T(TargetOpts.Triple);
+  Signature.add((unsigned)T.getArch(), 5);
+  Signature.add((unsigned)T.getVendor(), 4);
+  Signature.add((unsigned)T.getOS(), 5);
+  Signature.add((unsigned)T.getEnvironment(), 4);
+
+  // We've generated the signature. Treat it as one large APInt that we'll
+  // encode as hex and return.
+  Signature.flush();
+  return Signature.getAsInteger().toString(16, /*Signed=*/false);
+}
diff --git a/lib/Frontend/InitHeaderSearch.cpp b/lib/Frontend/InitHeaderSearch.cpp
index 05152a77b2..08af532267 100644
--- a/lib/Frontend/InitHeaderSearch.cpp
+++ b/lib/Frontend/InitHeaderSearch.cpp
@@ -1161,7 +1161,5 @@ void clang::ApplyHeaderSearchOptions(HeaderSearch &HS,
   if (HSOpts.UseStandardIncludes)
     Init.AddDefaultSystemIncludePaths(Lang, Triple, HSOpts);
 
-  HS.setModuleCachePath(HSOpts.ModuleCachePath);
-  
   Init.Realize(Lang);
 }