VS: Compute project GUIDs deterministically

Compute deterministic GUIDs that are unique to the build tree by
hashing the path to the build tree with the GUID logical name.
Avoid storing them in the cache, but honor any found there.
This will allow project GUIDs to be reproduced in a fresh build
tree so long as its path is the same as the original, which may
be useful for incremental builds.

8 files changed, 22 insertions, 71 deletions

diff --git a/Source/cmGlobalGenerator.h b/Source/cmGlobalGenerator.h
index 979e971..598f6ad 100644
--- a/Source/cmGlobalGenerator.h
+++ b/Source/cmGlobalGenerator.h
@@ -310,8 +310,6 @@ public:
     {
     return this->BinaryDirectories.insert(dir).second;
     }
-  /** Supported systems creates a GUID for the given name */
-  virtual void CreateGUID(const std::string&) {}
 
   /** Return true if the generated build tree may contain multiple builds.
       i.e. "Can I build Debug and Release in the same tree?" */
diff --git a/Source/cmGlobalVisualStudio7Generator.cxx b/Source/cmGlobalVisualStudio7Generator.cxx
index 4dd54d0..a242046 100644
--- a/Source/cmGlobalVisualStudio7Generator.cxx
+++ b/Source/cmGlobalVisualStudio7Generator.cxx
@@ -513,8 +513,6 @@ void cmGlobalVisualStudio7Generator::WriteTargetsToSolution(
 
             cumulativePath = cumulativePath + "/" + *iter;
             }
-
-          this->CreateGUID(cumulativePath.c_str());
           }
 
         if (!cumulativePath.empty())
@@ -899,7 +897,6 @@ cmGlobalVisualStudio7Generator::WriteUtilityDepend(cmTarget const* target)
   fname += ".vcproj";
   cmGeneratedFileStream fout(fname.c_str());
   fout.SetCopyIfDifferent(true);
-  this->CreateGUID(pname.c_str());
   std::string guid = this->GetGUID(pname.c_str());
 
   fout <<
@@ -943,41 +940,28 @@ cmGlobalVisualStudio7Generator::WriteUtilityDepend(cmTarget const* target)
   return pname;
 }
 
-std::string cmGlobalVisualStudio7Generator::GetGUID(const std::string& name)
+//----------------------------------------------------------------------------
+std::string cmGlobalVisualStudio7Generator::GetGUID(std::string const& name)
 {
-  std::string guidStoreName = name;
-  guidStoreName += "_GUID_CMAKE";
-  const char* storedGUID =
-    this->CMakeInstance->GetCacheDefinition(guidStoreName.c_str());
-  if(storedGUID)
+  std::string const& guidStoreName = name + "_GUID_CMAKE";
+  if (const char* storedGUID =
+      this->CMakeInstance->GetCacheDefinition(guidStoreName.c_str()))
     {
     return std::string(storedGUID);
     }
-  cmSystemTools::Error("Unknown Target referenced : ",
-                       name.c_str());
-  return "";
-}
-
-
-void cmGlobalVisualStudio7Generator::CreateGUID(const std::string& name)
-{
-  std::string guidStoreName = name;
-  guidStoreName += "_GUID_CMAKE";
-  if(this->CMakeInstance->GetCacheDefinition(guidStoreName.c_str()))
-    {
-    return;
-    }
-  std::string ret;
-  UUID uid;
-  unsigned short *uidstr;
-  UuidCreate(&uid);
-  UuidToStringW(&uid,&uidstr);
-  ret = cmsys::Encoding::ToNarrow(reinterpret_cast<wchar_t*>(uidstr));
-  RpcStringFreeW(&uidstr);
-  ret = cmSystemTools::UpperCase(ret);
-  this->CMakeInstance->AddCacheEntry(guidStoreName.c_str(),
-                                     ret.c_str(), "Stored GUID",
-                                     cmState::INTERNAL);
+  // Compute a GUID that is deterministic but unique to the build tree.
+  std::string input = this->CMakeInstance->GetState()->GetBinaryDirectory();
+  input += "|";
+  input += name;
+  std::string md5 = cmSystemTools::ComputeStringMD5(input);
+  assert(md5.length() == 32);
+  std::string const& guid =
+    (md5.substr( 0,8)+"-"+
+     md5.substr( 8,4)+"-"+
+     md5.substr(12,4)+"-"+
+     md5.substr(16,4)+"-"+
+     md5.substr(20,12));
+  return cmSystemTools::UpperCase(guid);
 }
 
 //----------------------------------------------------------------------------
diff --git a/Source/cmGlobalVisualStudio7Generator.h b/Source/cmGlobalVisualStudio7Generator.h
index c98d269..931ac9c 100644
--- a/Source/cmGlobalVisualStudio7Generator.h
+++ b/Source/cmGlobalVisualStudio7Generator.h
@@ -80,9 +80,8 @@ public:
    */
   virtual void OutputSLNFile();
 
-  ///! Create a GUID or get an existing one.
-  void CreateGUID(const std::string& name);
-  std::string GetGUID(const std::string& name);
+  ///! Lookup a stored GUID or compute one deterministically.
+  std::string GetGUID(std::string const& name);
 
   /** Append the subdirectory for the given configuration.  */
   virtual void AppendDirectoryForConfig(const std::string& prefix,
diff --git a/Source/cmGlobalVisualStudio8Generator.cxx b/Source/cmGlobalVisualStudio8Generator.cxx
index a3ebc61..d24066f 100644
--- a/Source/cmGlobalVisualStudio8Generator.cxx
+++ b/Source/cmGlobalVisualStudio8Generator.cxx
@@ -185,7 +185,6 @@ void cmGlobalVisualStudio8Generator
 void cmGlobalVisualStudio8Generator::Configure()
 {
   this->cmGlobalVisualStudio7Generator::Configure();
-  this->CreateGUID(CMAKE_CHECK_BUILD_SYSTEM_TARGET);
 }
 
 //----------------------------------------------------------------------------
diff --git a/Source/cmLocalVisualStudio10Generator.cxx b/Source/cmLocalVisualStudio10Generator.cxx
index ad6a020..9ded83a 100644
--- a/Source/cmLocalVisualStudio10Generator.cxx
+++ b/Source/cmLocalVisualStudio10Generator.cxx
@@ -107,10 +107,9 @@ void cmLocalVisualStudio10Generator
   cmVS10XMLParser parser;
   parser.ParseFile(path);
 
-  // if we can not find a GUID then create one
+  // if we can not find a GUID then we will generate one later
   if(parser.GUID.empty())
     {
-    this->GlobalGenerator->CreateGUID(name);
     return;
     }
 
diff --git a/Source/cmLocalVisualStudio7Generator.cxx b/Source/cmLocalVisualStudio7Generator.cxx
index 9c031cf..28a74cb 100644
--- a/Source/cmLocalVisualStudio7Generator.cxx
+++ b/Source/cmLocalVisualStudio7Generator.cxx
@@ -82,8 +82,6 @@ void cmLocalVisualStudio7Generator::AddHelperCommands()
   // Now create GUIDs for targets
   cmTargets &tgts = this->Makefile->GetTargets();
 
-  cmGlobalVisualStudio7Generator* gg =
-    static_cast<cmGlobalVisualStudio7Generator *>(this->GlobalGenerator);
   for(cmTargets::iterator l = tgts.begin(); l != tgts.end(); l++)
     {
     if(l->second.GetType() == cmTarget::INTERFACE_LIBRARY)
@@ -96,10 +94,6 @@ void cmLocalVisualStudio7Generator::AddHelperCommands()
       this->ReadAndStoreExternalGUID(
         l->second.GetName().c_str(), path);
       }
-    else
-      {
-      gg->CreateGUID(l->first.c_str());
-      }
     }
 
 
@@ -2312,12 +2306,9 @@ void cmLocalVisualStudio7Generator::ReadAndStoreExternalGUID(
 {
   cmVS7XMLParser parser;
   parser.ParseFile(path);
-  // if we can not find a GUID then create one
+  // if we can not find a GUID then we will generate one later
   if(parser.GUID.size() == 0)
     {
-    cmGlobalVisualStudio7Generator* gg =
-      static_cast<cmGlobalVisualStudio7Generator *>(this->GlobalGenerator);
-    gg->CreateGUID(name);
     return;
     }
   std::string guidStoreName = name;
diff --git a/Source/cmMakefile.cxx b/Source/cmMakefile.cxx
index 7c74a0f..137c28b 100644
--- a/Source/cmMakefile.cxx
+++ b/Source/cmMakefile.cxx
@@ -2116,25 +2116,10 @@ void cmMakefile::AddSourceGroup(const std::vector<std::string>& name,
     return;
     }
   // build the whole source group path
-  const char* fullname = sg->GetFullName();
-  cmGlobalGenerator* gg = this->GetGlobalGenerator();
-  if(strlen(fullname))
-    {
-    std::string guidName = "SG_Filter_";
-    guidName += fullname;
-    gg->CreateGUID(guidName);
-    }
   for(++i; i<=lastElement; ++i)
     {
     sg->AddChild(cmSourceGroup(name[i].c_str(), 0, sg->GetFullName()));
     sg = sg->LookupChild(name[i].c_str());
-    fullname = sg->GetFullName();
-    if(strlen(fullname))
-      {
-      std::string guidName = "SG_Filter_";
-      guidName += fullname;
-      gg->CreateGUID(guidName);
-      }
     }
 
   sg->SetGroupRegex(regex);
diff --git a/Source/cmVisualStudio10TargetGenerator.cxx b/Source/cmVisualStudio10TargetGenerator.cxx
index 5dfdb14..0be1335 100644
--- a/Source/cmVisualStudio10TargetGenerator.cxx
+++ b/Source/cmVisualStudio10TargetGenerator.cxx
@@ -178,7 +178,6 @@ cmVisualStudio10TargetGenerator(cmTarget* target,
     (cmLocalVisualStudio7Generator*)
     this->Makefile->GetLocalGenerator();
   this->Name = this->Target->GetName();
-  this->GlobalGenerator->CreateGUID(this->Name.c_str());
   this->GUID = this->GlobalGenerator->GetGUID(this->Name.c_str());
   this->Platform = gg->GetPlatformName();
   this->NsightTegra = gg->IsNsightTegra();
@@ -1084,7 +1083,6 @@ void cmVisualStudio10TargetGenerator::WriteGroups()
       (*this->BuildFileStream) << name << "\">\n";
       std::string guidName = "SG_Filter_";
       guidName += name;
-      this->GlobalGenerator->CreateGUID(guidName.c_str());
       this->WriteString("<UniqueIdentifier>", 3);
       std::string guid
         = this->GlobalGenerator->GetGUID(guidName.c_str());
@@ -1099,7 +1097,6 @@ void cmVisualStudio10TargetGenerator::WriteGroups()
     {
     this->WriteString("<Filter Include=\"Object Libraries\">\n", 2);
     std::string guidName = "SG_Filter_Object Libraries";
-    this->GlobalGenerator->CreateGUID(guidName.c_str());
     this->WriteString("<UniqueIdentifier>", 3);
     std::string guid =
       this->GlobalGenerator->GetGUID(guidName.c_str());
@@ -1112,7 +1109,6 @@ void cmVisualStudio10TargetGenerator::WriteGroups()
     {
     this->WriteString("<Filter Include=\"Resource Files\">\n", 2);
     std::string guidName = "SG_Filter_Resource Files";
-    this->GlobalGenerator->CreateGUID(guidName.c_str());
     this->WriteString("<UniqueIdentifier>", 3);
     std::string guid =
       this->GlobalGenerator->GetGUID(guidName.c_str());