Ignore .tundra2 files in glob signature checking

Use consistent exclusion rules in globbing and dag generation.

src/DagGenerator.cpp

@@ -855,14 +855,22 @@ static bool CompileDag(const JsonObjectValue* root, BinaryWriter* writer, MemAll
 
         for (size_t i = 0, count = subdirs->m_Count; i < count; ++i)
         {
-          HashAddPath(&h, subdirs->m_Values[i]->GetString());
-          HashAddSeparator(&h);
+          const char* path = subdirs->m_Values[i]->GetString();
+          if (!ShouldFilter(path))
+          {
+            HashAddPath(&h, path);
+            HashAddSeparator(&h);
+          }
         }
 
         for (size_t i = 0, count = files->m_Count; i < count; ++i)
         {
-          HashAddPath(&h, files->m_Values[i]->GetString());
-          HashAddSeparator(&h);
+          const char* path = files->m_Values[i]->GetString();
+          if (!ShouldFilter(path))
+          {
+            HashAddPath(&h, path);
+            HashAddSeparator(&h);
+          }
         }
 
         HashDigest digest;
@@ -1018,10 +1026,10 @@ static bool RunExternalTool(const char* options, ...)
     char cmdline[1024];
     snprintf(cmdline, sizeof cmdline, "%s%s%s %s", quotes, dag_gen_path, quotes, option_str);
     cmdline[sizeof(cmdline)-1] = '\0';
-    
+
     cmdline_to_use = cmdline;
   }
-  
+
   const bool echo = (GetLogFlags() & kDebug) ? true : false;
 
   ExecResult result = ExecuteProcess(cmdline_to_use, 1, &env_var, 0, echo, nullptr);

src/Driver.cpp

@@ -308,7 +308,7 @@ static bool DriverCheckDagSignatures(Driver* self)
     qsort(ctx.m_Dirs.m_Storage, ctx.m_Dirs.m_Size, sizeof(const char*), IterContext::SortStringPtrs);
     qsort(ctx.m_Files.m_Storage, ctx.m_Files.m_Size, sizeof(const char*), IterContext::SortStringPtrs);
 
-    // Compute digest
+    // Compute digest - note that this has to match DagGenerator.cpp
     HashState h;
     HashInit(&h);
     for (const char* p : ctx.m_Dirs)

src/FileInfo.cpp

@@ -69,7 +69,12 @@ FileInfo GetFileInfo(const char* path)
   return result;
 }
 
-static bool ShouldFilter(const char* name, size_t len)
+bool ShouldFilter(const char* name)
+{
+  return ShouldFilter(name, strlen(name));
+}
+
+bool ShouldFilter(const char* name, size_t len)
 {
   // Filter out some common noise entries that only serve to cause DAG regeneration.
 
@@ -83,6 +88,12 @@ static bool ShouldFilter(const char* name, size_t len)
   if (len >= 4 && name[0] == '.' && 0 == memcmp(name + len - 4, ".swp", 4))
     return true;
 
+  // Weed out '.tundra2.*' files too, as the .json file gets removed in between
+  // regenerating, messing up glob signatures.
+  static const char t2_prefix[] = ".tundra2.";
+  if (len >= (sizeof t2_prefix) - 1 && 0 == memcmp(name, t2_prefix, (sizeof t2_prefix) - 1))
+    return true;
+
   // Emacs foo~ files
   if (len > 1 && name[len-1] == '~')
     return true;

src/FileInfo.hpp

@@ -28,6 +28,9 @@ struct FileInfo
 
 FileInfo GetFileInfo(const char* path);
 
+bool ShouldFilter(const char* name);
+bool ShouldFilter(const char* name, size_t len);
+
 void ListDirectory(
     const char* dir,
     void* user_data,