Feature/view path (#824)

* Use 'is' over 'as' where appropriate.

* dynamic_cast -> dynamicCast

* Replace 'dynamicCast' with 'as' where has no change in behavior/ambiguity.

* Replace dynamicCast with as where doesn't change behavior/non ambiguous.

* Keep a per view path to the file loaded - such that diagnostic messages always display the path to the requested file.

* Add simplifyPath to ISlangFileSystemExt
Simplify (if possible) paths that are set on SourceFile and SourcView - doing so makes reading paths simpler.

* Fix small typo.

* Improve documentation in source for getFileUniqueIdentity

* Fix override warning.

1 files changed, 28 insertions, 7 deletions

diff --git a/slang.h b/slang.h
index 9a1880536..7abaebfe1 100644
--- a/slang.h
+++ b/slang.h
@@ -780,8 +780,15 @@ extern "C"
     public:
         /** Get a uniqueIdentity which uniquely identifies an object of the file system.
            
-        Given a path, returns a 'uniqueIdentity' path will return the same value for the same file/directory on the file system. 
-        The uniqueIdentity is used to compare if two includes are the same file. 
+        Given a path, returns a 'uniqueIdentity' which ideally is the same value for the same file on the file system.
+
+        The uniqueIdentity is used to compare if files are the same - which allows slang to cache source contents internally. It is also used
+        for #pragma once functionality.
+
+        A *requirement* is for any implementation is that two paths can only return the same uniqueIdentity if the
+        contents of the two files are *identical*. If an implementation breaks this constraint it can produce incorrect compilation.
+        If an implementation cannot *strictly* identify *the same* files, this will only have an effect on #pragma once behavior.
+
         The string for the uniqueIdentity is held zero terminated in the ISlangBlob of outUniqueIdentity.
    
         Note that there are many ways a uniqueIdentity may be generated for a file. For example it could be the
@@ -823,18 +830,32 @@ extern "C"
             const char* path, 
             SlangPathType* pathTypeOut) = 0;
 
+        /** Get a simplified path. 
+        Given a path, returns a simplified version of that path - typically removing '..' and/or '.'. A simplified
+        path must point to the same object as the original. 
+       
+        This method is optional, if not implemented return SLANG_E_NOT_IMPLEMENTED.
+
+        @param path
+        @param outSimplifiedPath
+        @returns SLANG_OK if successfully simplified the path (SLANG_E_NOT_IMPLEMENTED if not implemented, or some other error code)
+        */
+        virtual SLANG_NO_THROW SlangResult SLANG_MCALL getSimplifiedPath(
+            const char* path,
+            ISlangBlob** outSimplifiedPath) = 0;
+
         /** Get a canonical path identifies an object of the file system.
 
-        Given a path, returns a 'canonicalPath' the file. This may be a file system 'canonical path' to
-        show where a file was read from. Also though if the filesystem is say a zip file - it might include the path to the zip
+        Given a path, returns a 'canonicalPath' to the file. This may be a file system 'canonical path' to
+        show where a file was read from. If the file system is say a zip file - it might include the path to the zip
         container as well as the absolute path to the specific file. The main purpose of the method is to be able
-        to display to users unambiguously where a file was read from in diagnostics.
+        to display to uses unambiguously where a file was read from.
 
-        This method is optional and if not implemented will display 'found paths'. If not implemented return SLANG_E_NOT_IMPLEMENTED. 
+        This method is optional, if not implemented return SLANG_E_NOT_IMPLEMENTED.
 
         @param path
         @param outCanonicalPath
-        @returns A `SlangResult`
+        @returns SLANG_OK if successfully canonicalized the path (SLANG_E_NOT_IMPLEMENTED if not implemented, or some other error code)
         */
         virtual SLANG_NO_THROW SlangResult SLANG_MCALL getCanonicalPath(
             const char* path,