Feature/file unique identity (#789)

* * Fix memory bug around expanding va_args - needed buffer to have space for terminating 0
* Fix problem with FileWriter defaults being globals, as memory they allocate, will only be freed after return from main - work around by making StdWriters RefObject derived, and kept in scope such the writers are destroyed before checks for leaks is found
* Added SimplifyPathAndHash mode for CacheFileSystem - will simplify the path and see if simplified path is in cache before reading file (limiting amout of underlying file requests)

* * Added calcReplaceChar
* Renamed DefaultFileSystem to OSFileSystem
* Made OSFileSystem convert windows \ to / on linux

* Simplified logic for caching in CacheFileSystem.

* Added pragma-once-c to add extra test, but also so there is an 'include' directory in preprocessor tests.

* Small fixes in pragma once test.

* Simplified cache handling path, so that paths/simplified paths area always added.

* Improve naming of methods for different caches.

* Removed references to 'canonicalPath' and made 'uniqueIdentity'

* * Re-add support for canonicalPath to ISlangFileSystem -> not for uniqueIdentifier but as a way to display 'canonicalPath'
* Added peliminary support for being able to display verbose paths in a diagnostic
* Added 'clearCache' support
* Added verbose path support to SourceManager (now needs a ISlangFileSystemExt to do this)

* Added support for '-verbose-path' option to slangc and slang-test.

1 files changed, 13 insertions, 2 deletions

diff --git a/source/slang/diagnostics.h b/source/slang/diagnostics.h
index 8e5bbcb64..fed492bc7 100644
--- a/source/slang/diagnostics.h
+++ b/source/slang/diagnostics.h
@@ -141,12 +141,23 @@ namespace Slang
         // The source manager to use when mapping source locations to file+line info
         SourceManager*  sourceManager;
 
+        struct Flag 
+        {
+            enum Enum: uint32_t
+            {
+                VerbosePath = 0x1,              ///< Will try and display a 
+            };
+        };
+        typedef uint32_t Flags;
+
         StringBuilder outputBuffer;
 //            List<Diagnostic> diagnostics;
         int errorCount = 0;
 
-        ISlangWriter* writer                        = nullptr;
 
+        ISlangWriter* writer                        = nullptr;
+        Flags flags                                 = 0;
+        
 /*
         void Error(int id, const String & msg, const SourceLoc & pos)
         {
@@ -163,7 +174,7 @@ namespace Slang
 
         void diagnoseDispatch(SourceLoc const& pos, DiagnosticInfo const& info)
         {
-            diagnoseImpl(pos, info, 0, NULL);
+            diagnoseImpl(pos, info, 0, nullptr);
         }
 
         void diagnoseDispatch(SourceLoc const& pos, DiagnosticInfo const& info, DiagnosticArg const& arg0)