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.

8 files changed, 134 insertions, 22 deletions

diff --git a/source/slang/ir-serialize.cpp b/source/slang/ir-serialize.cpp
index 730f13ca7..a50ed6bd5 100644
--- a/source/slang/ir-serialize.cpp
+++ b/source/slang/ir-serialize.cpp
@@ -1801,7 +1801,7 @@ static int _calcFixSourceLoc(const IRSerialData::DebugSourceInfo& info, SourceVi
             pathInfo.foundPath = debugStringSlices[UInt(srcSourceInfo.m_pathIndex)];
 
             SourceFile* sourceFile = sourceManager->createSourceFileWithSize(pathInfo, srcSourceInfo.m_endSourceLoc - srcSourceInfo.m_startSourceLoc);
-            SourceView* sourceView = sourceManager->createSourceView(sourceFile);
+            SourceView* sourceView = sourceManager->createSourceView(sourceFile, nullptr);
 
             // We need to accumulate all line numbers, for this source file, both adjusted and unadjusted
             List<IRSerialData::DebugLineInfo> lineInfos;
diff --git a/source/slang/preprocessor.cpp b/source/slang/preprocessor.cpp
index 4ccb5d50e..91043bcf9 100644
--- a/source/slang/preprocessor.cpp
+++ b/source/slang/preprocessor.cpp
@@ -842,7 +842,7 @@ top:
         PathInfo pathInfo = PathInfo::makeTokenPaste();
        
         SourceFile* sourceFile = sourceManager->createSourceFileWithString(pathInfo, sb.ProduceString());
-        SourceView* sourceView = sourceManager->createSourceView(sourceFile);
+        SourceView* sourceView = sourceManager->createSourceView(sourceFile, nullptr);
 
         Lexer lexer;
         lexer.initialize(sourceView, GetSink(preprocessor), getNamePool(preprocessor), sourceManager->getMemoryArena());
@@ -1627,6 +1627,9 @@ static void HandleIncludeDirective(PreprocessorDirectiveContext* context)
         return;
     }
 
+    // Simplify the path
+    filePathInfo.foundPath = includeHandler->simplifyPath(filePathInfo.foundPath);
+
     // Push the new file onto our stack of input streams
     // TODO(tfoley): check if we have made our include stack too deep
     auto sourceManager = context->preprocessor->getCompileRequest()->getSourceManager();
@@ -1643,12 +1646,13 @@ static void HandleIncludeDirective(PreprocessorDirectiveContext* context)
             return;
         }
 
+        
         sourceFile = sourceManager->createSourceFileWithBlob(filePathInfo, foundSourceBlob);
         sourceManager->addSourceFile(filePathInfo.uniqueIdentity, sourceFile);
     }
 
     // This is a new parse (even if it's a pre-existing source file), so create a new SourceUnit
-    SourceView* sourceView = sourceManager->createSourceView(sourceFile);
+    SourceView* sourceView = sourceManager->createSourceView(sourceFile, &filePathInfo);
 
     PreprocessorInputStream* inputStream = CreateInputStreamForSource(context->preprocessor, sourceView);
     inputStream->parent = context->preprocessor->inputStream;
@@ -2259,8 +2263,8 @@ static void DefineMacro(
     SourceFile* keyFile = sourceManager->createSourceFileWithString(pathInfo, key);
     SourceFile* valueFile = sourceManager->createSourceFileWithString(pathInfo, value);
 
-    SourceView* keyView = sourceManager->createSourceView(keyFile);
-    SourceView* valueView = sourceManager->createSourceView(valueFile);
+    SourceView* keyView = sourceManager->createSourceView(keyFile, nullptr);
+    SourceView* valueView = sourceManager->createSourceView(valueFile, nullptr);
 
     // Use existing `Lexer` to generate a token stream.
     Lexer lexer;
@@ -2319,7 +2323,7 @@ TokenList preprocessSource(
 
     SourceManager* sourceManager = translationUnit->compileRequest->getSourceManager();
 
-    SourceView* sourceView = sourceManager->createSourceView(file);
+    SourceView* sourceView = sourceManager->createSourceView(file, nullptr);
 
     // create an initial input stream based on the provided buffer
     preprocessor.inputStream = CreateInputStreamForSource(&preprocessor, sourceView);
diff --git a/source/slang/preprocessor.h b/source/slang/preprocessor.h
index 42a3b25f4..4d02cb50b 100644
--- a/source/slang/preprocessor.h
+++ b/source/slang/preprocessor.h
@@ -22,6 +22,8 @@ struct IncludeHandler
 
     virtual SlangResult readFile(const String& path, 
         ISlangBlob** blobOut) = 0;        
+
+    virtual String simplifyPath(const String& path) = 0;
 };
 
 // Take a string of source code and preprocess it into a list of tokens.
diff --git a/source/slang/slang-file-system.cpp b/source/slang/slang-file-system.cpp
index b3ba692bd..d52ea1157 100644
--- a/source/slang/slang-file-system.cpp
+++ b/source/slang/slang-file-system.cpp
@@ -76,6 +76,13 @@ SlangResult OSFileSystem::getCanonicalPath(const char* path, ISlangBlob** outCan
     return SLANG_OK;
 }
 
+SlangResult OSFileSystem::getSimplifiedPath(const char* pathIn, ISlangBlob** outSimplifiedPath)
+{
+    String simplifiedPath = Path::Simplify(_fixPathDelimiters(pathIn));
+    *outSimplifiedPath = StringUtil::createStringBlob(simplifiedPath).detach();
+    return SLANG_OK;
+}
+
 SlangResult OSFileSystem::calcCombinedPath(SlangPathType fromPathType, const char* fromPath, const char* path, ISlangBlob** pathOut)
 {
     // Don't need to fix delimiters - because combine path handles both path delimiter types
@@ -143,9 +150,10 @@ ISlangUnknown* CacheFileSystem::getInterface(const Guid& guid)
     return _getInterface(this, guid);
 }
 
-CacheFileSystem::CacheFileSystem(ISlangFileSystem* fileSystem, UniqueIdentityMode uniqueIdentityMode) :
+CacheFileSystem::CacheFileSystem(ISlangFileSystem* fileSystem, UniqueIdentityMode uniqueIdentityMode, PathStyle pathStyle) :
     m_fileSystem(fileSystem),
-    m_uniqueIdentityMode(uniqueIdentityMode)
+    m_uniqueIdentityMode(uniqueIdentityMode),
+    m_pathStyle(pathStyle)
 {
     // Try to get the more sophisticated interface
     fileSystem->queryInterface(IID_ISlangFileSystemExt, (void**)m_fileSystemExt.writeRef());
@@ -162,6 +170,17 @@ CacheFileSystem::CacheFileSystem(ISlangFileSystem* fileSystem, UniqueIdentityMod
         default: break;
     }
 
+    if (m_fileSystemExt)
+    {
+        // We just defer to the m_fileSystem, so we mark as unknown 
+        m_pathStyle = PathStyle::Unknown;
+    }
+    else if (m_pathStyle == PathStyle::Default)
+    {
+        // We'll assume it's simplify-able 
+        m_pathStyle = PathStyle::Simplifiable;
+    }
+
     // It can't be default
     SLANG_ASSERT(m_uniqueIdentityMode != UniqueIdentityMode::Default);
 }
@@ -286,7 +305,7 @@ CacheFileSystem::PathInfo* CacheFileSystem::_resolveUniqueIdentityCacheInfo(cons
     // At this point they must have same uniqueIdentity
     SLANG_ASSERT(pathInfo->getUniqueIdentity() == uniqueIdentity);
 
-    // If we have the file contents (because of calcing uniqueIdentity), and there isn't a read fileblob already
+    // If we have the file contents (because of calc-ing uniqueIdentity), and there isn't a read file blob already
     // store the data as if read, so doesn't get read again
     if (fileContents && !pathInfo->m_fileBlob)
     {
@@ -414,6 +433,29 @@ SlangResult CacheFileSystem::getPathType(const char* pathIn, SlangPathType* path
     return toResult(info->m_getPathTypeResult);
 }
 
+SlangResult CacheFileSystem::getSimplifiedPath(const char* path, ISlangBlob** outSimplifiedPath)
+{
+    // If we have a ISlangFileSystemExt we can just pass on the request to it
+    if (m_fileSystemExt)
+    {
+        return m_fileSystemExt->getSimplifiedPath(path, outSimplifiedPath);
+    }
+    else
+    {
+        // Use the path style to see what we can do with it
+        switch (m_pathStyle)
+        {
+            case PathStyle::Simplifiable:
+            {
+                String simplifiedPath = Path::Simplify(_fixPathDelimiters(path));
+                *outSimplifiedPath = StringUtil::createStringBlob(simplifiedPath).detach();
+                return SLANG_OK;
+            }
+            default: return SLANG_E_NOT_IMPLEMENTED;
+        }
+    }
+}
+
 SlangResult CacheFileSystem::getCanonicalPath(const char* path, ISlangBlob** outCanonicalPath)
 {
     // If we don't have a backing full file system, we can't produce a canonical path with just ISlangFileSystem::loadFile
diff --git a/source/slang/slang-file-system.h b/source/slang/slang-file-system.h
index e341bf649..a9e92dc1e 100644
--- a/source/slang/slang-file-system.h
+++ b/source/slang/slang-file-system.h
@@ -40,9 +40,13 @@ public:
         const char* path,
         SlangPathType* pathTypeOut) SLANG_OVERRIDE;
 
+    virtual SLANG_NO_THROW SlangResult SLANG_MCALL getSimplifiedPath(
+        const char* path,
+        ISlangBlob** outSimplifiedPath) SLANG_OVERRIDE;
+
     virtual SLANG_NO_THROW SlangResult SLANG_MCALL getCanonicalPath(
         const char* path,
-        ISlangBlob** outCanonicalPath);
+        ISlangBlob** outCanonicalPath) SLANG_OVERRIDE;
 
     virtual SLANG_NO_THROW void SLANG_MCALL clearCache() {}
 
@@ -71,6 +75,13 @@ class CacheFileSystem: public ISlangFileSystemExt, public RefObject
 {
     public:
 
+    enum class PathStyle
+    {
+        Default,                    ///< Pass to say use the default 
+        Unknown,                    ///< It's an unknown type of path
+        Simplifiable,               ///< It can be simplified by Path::Simplify
+    };
+
     enum UniqueIdentityMode
     {
         Default,                    ///< If passed, will default to the others depending on what kind of ISlangFileSystem is passed in
@@ -115,6 +126,10 @@ class CacheFileSystem: public ISlangFileSystemExt, public RefObject
         const char* path,
         SlangPathType* outPathType) SLANG_OVERRIDE;
 
+    virtual SLANG_NO_THROW SlangResult SLANG_MCALL getSimplifiedPath(
+        const char* path,
+        ISlangBlob** outSimplifiedPath) SLANG_OVERRIDE;
+
     virtual SLANG_NO_THROW SlangResult SLANG_MCALL getCanonicalPath(
         const char* path,
         ISlangBlob** outCanonicalPath);
@@ -122,7 +137,7 @@ class CacheFileSystem: public ISlangFileSystemExt, public RefObject
     virtual SLANG_NO_THROW void SLANG_MCALL clearCache();
 
         /// Ctor
-    CacheFileSystem(ISlangFileSystem* fileSystem, UniqueIdentityMode uniqueIdentityMode = UniqueIdentityMode::Default);
+    CacheFileSystem(ISlangFileSystem* fileSystem, UniqueIdentityMode uniqueIdentityMode = UniqueIdentityMode::Default, PathStyle pathStyle = PathStyle::Default);
         /// Dtor
     virtual ~CacheFileSystem();
 
@@ -178,6 +193,7 @@ protected:
     Dictionary<String, PathInfo*> m_uniqueIdentityMap;  ///< Maps a unique identity for a file to its contents. This OWNs the PathInfo.
 
     UniqueIdentityMode m_uniqueIdentityMode;            ///< Determines how the 'uniqueIdentity' is produced. Cannot be Default in usage.
+    PathStyle m_pathStyle;                              ///< Style of paths
 
     ComPtr<ISlangFileSystem> m_fileSystem;              ///< Must always be set
     ComPtr<ISlangFileSystemExt> m_fileSystemExt;        ///< Optionally set -> if nullptr will fall back on the m_fileSystem and emulate all the other methods of ISlangFileSystemExt
diff --git a/source/slang/slang.cpp b/source/slang/slang.cpp
index e332ef588..16dfe8618 100644
--- a/source/slang/slang.cpp
+++ b/source/slang/slang.cpp
@@ -176,6 +176,17 @@ struct IncludeHandlerImpl : IncludeHandler
         return SLANG_OK;
     }
 
+    virtual String simplifyPath(const String& path) override
+    {
+        ISlangFileSystemExt* fileSystemExt = _getFileSystemExt();
+        ComPtr<ISlangBlob> simplifiedPath;
+        if (SLANG_FAILED(fileSystemExt->getSimplifiedPath(path.Buffer(), simplifiedPath.writeRef())))
+        {
+            return path;
+        }
+        return StringUtil::getString(simplifiedPath);
+    }
+
 };
 
 //
diff --git a/source/slang/source-loc.cpp b/source/slang/source-loc.cpp
index 6507ea4b7..00b6d3be4 100644
--- a/source/slang/source-loc.cpp
+++ b/source/slang/source-loc.cpp
@@ -150,16 +150,30 @@ HumaneSourceLoc SourceView::getHumaneLoc(SourceLoc loc, SourceLocType type)
         pathHandle = entry.m_pathHandle;
     }
 
-    humaneLoc.pathInfo = _getPathInfo(pathHandle);
+    humaneLoc.pathInfo = _getPathInfoFromHandle(pathHandle);
     return humaneLoc;
 }
 
-PathInfo SourceView::_getPathInfo(StringSlicePool::Handle pathHandle) const
+PathInfo SourceView::_getPathInfo() const
+{
+    if (m_viewPath.Length())
+    {
+        PathInfo pathInfo(m_sourceFile->getPathInfo());
+        pathInfo.foundPath = m_viewPath;
+        return pathInfo;
+    }
+    else
+    {
+        return m_sourceFile->getPathInfo();
+    }
+}
+
+PathInfo SourceView::_getPathInfoFromHandle(StringSlicePool::Handle pathHandle) const
 {
     // If there is no override path, then just the source files path
     if (pathHandle == StringSlicePool::Handle(0))
     {
-        return m_sourceFile->getPathInfo();
+        return _getPathInfo();
     }
     else
     {
@@ -171,11 +185,11 @@ PathInfo SourceView::getPathInfo(SourceLoc loc, SourceLocType type)
 {
     if (type == SourceLocType::Actual)
     {
-        return m_sourceFile->getPathInfo();
+        return _getPathInfo();
     }
 
     const int entryIndex = findEntryIndex(loc);
-    return _getPathInfo((entryIndex >= 0) ? m_entries[entryIndex].m_pathHandle : StringSlicePool::Handle(0));
+    return _getPathInfoFromHandle((entryIndex >= 0) ? m_entries[entryIndex].m_pathHandle : StringSlicePool::Handle(0));
 }
 
 /* !!!!!!!!!!!!!!!!!!!!!!! SourceFile !!!!!!!!!!!!!!!!!!!!!!!!!!!! */
@@ -418,10 +432,21 @@ SourceFile* SourceManager::createSourceFileWithBlob(const PathInfo& pathInfo, IS
     return sourceFile;
 }
 
-SourceView* SourceManager::createSourceView(SourceFile* sourceFile)
+SourceView* SourceManager::createSourceView(SourceFile* sourceFile, const PathInfo* pathInfo)
 {
     SourceRange range = allocateSourceRange(sourceFile->getContentSize());
-    SourceView* sourceView = new SourceView(sourceFile, range);
+
+    SourceView* sourceView = nullptr;
+    if (pathInfo &&
+        (pathInfo->foundPath.Length() && sourceFile->getPathInfo().foundPath != pathInfo->foundPath))
+    {
+        sourceView = new SourceView(sourceFile, range, &pathInfo->foundPath);
+    }
+    else
+    {
+        sourceView = new SourceView(sourceFile, range, nullptr);
+    }
+
     m_sourceViews.Add(sourceView);
 
     return sourceView;
diff --git a/source/slang/source-loc.h b/source/slang/source-loc.h
index aa0623e3d..ad0453d0e 100644
--- a/source/slang/source-loc.h
+++ b/source/slang/source-loc.h
@@ -194,7 +194,7 @@ public:
 
     protected:
 
-    SourceManager * m_sourceManager;       ///< The source manager this belongs to
+    SourceManager* m_sourceManager;       ///< The source manager this belongs to
     PathInfo m_pathInfo;                  ///< The path The logical file path to report for locations inside this span.
     ComPtr<ISlangBlob> m_contentBlob;     ///< A blob that owns the storage for the file contents. If nullptr, there is no contents
     UnownedStringSlice m_content;         ///< The actual contents of the file.
@@ -281,14 +281,24 @@ class SourceView
     PathInfo getPathInfo(SourceLoc loc, SourceLocType type = SourceLocType::Nominal);
 
         /// Ctor
-    SourceView(SourceFile* sourceFile, SourceRange range):
+    SourceView(SourceFile* sourceFile, SourceRange range, const String* viewPath):
         m_range(range),
         m_sourceFile(sourceFile)
     {
+        if (viewPath)
+        {
+            m_viewPath = *viewPath;
+        }
     }
 
     protected:
-    PathInfo _getPathInfo(StringSlicePool::Handle pathHandle) const;
+        /// Get the pathInfo from a string handle. If it's 0, it will return the _getPathInfo
+    PathInfo _getPathInfoFromHandle(StringSlicePool::Handle pathHandle) const;
+        /// Gets the pathInfo for this view. It may be different from the m_sourceFile's if the path has been
+        /// overridden by m_viewPath
+    PathInfo _getPathInfo() const;
+
+    String m_viewPath;                      ///< Path to this view. If empty the path is the path to the SourceView
 
     SourceRange m_range;                ///< The range that this SourceView applies to
     SourceFile* m_sourceFile;           ///< The source file. Can hold the line breaks
@@ -315,7 +325,9 @@ struct SourceManager
     PathInfo getPathInfo(SourceLoc loc, SourceLocType type = SourceLocType::Nominal);
 
         /// Create a new source view from a file
-    SourceView* createSourceView(SourceFile* sourceFile);
+        /// @param sourceFile is the source file that contains the source
+        /// @param pathInfo is path used to read the file from
+    SourceView* createSourceView(SourceFile* sourceFile, const PathInfo* pathInfo);
 
         /// Find a view by a source file location. 
         /// If not found in this manager will look in the parent SourceManager