Checker and emitter changes to report errors on inaccessibility of symbols when writing types in declaration file

Author: sheetalkamat

src/compiler/checker.ts

@@ -645,7 +645,7 @@ module ts {
                 }
 
                 // If symbol is directly available by its name in the symbol table
-                if (isAccessible(symbols[symbol.name])) {
+                if (hasProperty(symbols, symbol.name) && isAccessible(symbols[symbol.name])) {
                     return symbol;
                 }
 
@@ -668,7 +668,7 @@ module ts {
             var qualify = false;
             forEachSymbolTableInScope(enclosingDeclaration, symbolTable => {
                 // If symbol of this name is not available in the symbol table we are ok
-                if (!symbolTable[symbol.name]) {
+                if (!hasProperty(symbolTable, symbol.name)) {
                     // Continue to the next symbol table
                     return false;
                 }
@@ -693,8 +693,36 @@ module ts {
             return qualify
         }
 
-        function isSymbolAccessible(symbol: Symbol, enclosingDeclaration: Node, meaning: SymbolFlags): boolean {
-            // TODO(shkamat): Actual implementation
+        function isSymbolAccessible(symbol: Symbol, enclosingDeclaration: Node, meaning: SymbolFlags): SymbolAccessiblityResult {
+            if (symbol && enclosingDeclaration && !(symbol.flags & SymbolFlags.TypeParameter)) {
+                var initialSymbol = symbol;
+                var meaningToLook = meaning;
+                while (symbol) {
+                    // Symbol is accessible if it by itself is accessible
+                    var accessibleSymbol = getAccessibleSymbol(symbol, enclosingDeclaration, meaningToLook);
+                    if (accessibleSymbol) {
+                        if (forEach(accessibleSymbol.declarations, declaration => !isDeclarationVisible(declaration))) {
+                            return {
+                                accessibility: SymbolAccessibility.NotAccessible,
+                                errorSymbolName: symbolToString(initialSymbol, enclosingDeclaration, meaning),
+                                errorModuleName: symbol !== initialSymbol ? symbolToString(symbol, enclosingDeclaration, SymbolFlags.Namespace) : undefined
+                            };
+                        }
+                        return { accessibility: SymbolAccessibility.Accessible };
+                    }
+
+                    meaningToLook = SymbolFlags.Namespace;
+                    symbol = symbol.parent;
+                }
+
+                // This is a local symbol that cannot be named
+                return {
+                    accessibility: SymbolAccessibility.CannotBeNamed,
+                    errorSymbolName: symbolToString(initialSymbol, enclosingDeclaration, meaning),
+                };
+            }
+
+            return { accessibility: SymbolAccessibility.Accessible };
         }
 
         // Enclosing declaration is optional when we dont want to get qualified name in the enclosing declaration scope

src/compiler/emitter.ts

@@ -1854,10 +1854,30 @@ module ts {
             var decreaseIndent = writer.decreaseIndent;
 
             var enclosingDeclaration: Node;
+            var reportedDeclarationError = false;
+
+            var getSymbolVisibilityDiagnosticMessage: (symbolAccesibilityResult: SymbolAccessiblityResult) => {
+                errorNode: Node;
+                diagnosticMessage: DiagnosticMessage;
+                typeName: Identifier
+            }
 
             function writeSymbol(symbol: Symbol, enclosingDeclaration?: Node, meaning?: SymbolFlags) {
-                // TODO(shkamat): Report error if the symbol is not accessible
-                resolver.writeSymbol(symbol, enclosingDeclaration, meaning, writer);
+                var symbolAccesibilityResult = resolver.isSymbolAccessible(symbol, enclosingDeclaration, meaning);
+                    // TODO(shkamat): Since we dont have error reporting for all the cases as yet we have this check on handler being present
+                if (!getSymbolVisibilityDiagnosticMessage || symbolAccesibilityResult.accessibility === SymbolAccessibility.Accessible) {
+                    resolver.writeSymbol(symbol, enclosingDeclaration, meaning, writer);
+                }
+                else {
+                    // Report error
+                    reportedDeclarationError = true;
+                    var errorInfo = getSymbolVisibilityDiagnosticMessage(symbolAccesibilityResult);
+                    diagnostics.push(createDiagnosticForNode(errorInfo.errorNode,
+                        errorInfo.diagnosticMessage,
+                        getSourceTextOfLocalNode(errorInfo.typeName),
+                        symbolAccesibilityResult.errorSymbolName,
+                        symbolAccesibilityResult.errorModuleName));
+                }
             }
 
             function emitLines(nodes: Node[]) {
@@ -2296,7 +2316,11 @@ module ts {
                 });
             }
 
-            writeFile(getModuleNameFromFilename(jsFilePath) + ".d.ts", referencePathsOutput + writer.getText());
+            // TODO(shkamat): Should we not write any declaration file if any of them can produce error, 
+            // or should we just not write this file like we are doing now
+            if (!reportedDeclarationError) {
+                writeFile(getModuleNameFromFilename(jsFilePath) + ".d.ts", referencePathsOutput + writer.getText());
+            }
         }
 
         var shouldEmitDeclarations = resolver.shouldEmitDeclarations();

src/compiler/types.ts

@@ -611,6 +611,18 @@ module ts {
         WriteArrayAsGenericType     = 0x00000001,  // Declarations
     }
 
+    export enum SymbolAccessibility {
+        Accessible,
+        NotAccessible,
+        CannotBeNamed
+    }
+
+    export interface SymbolAccessiblityResult {
+        accessibility: SymbolAccessibility;
+        errorSymbolName?: string // Optional symbol name that results in error
+        errorModuleName?: string // If the symbol is not visibile from module, module's name
+    }
+
     export interface EmitResolver {
         getProgram(): Program;
         getModuleObjectName(node: ModuleDeclaration): string;
@@ -627,7 +639,7 @@ module ts {
         writeTypeAtLocation(location: Node, enclosingDeclaration: Node, flags: TypeFormatFlags, writer: TextWriter): void;
         writeReturnTypeOfSignatureDeclaration(signatureDeclaration: SignatureDeclaration, enclosingDeclaration: Node, flags: TypeFormatFlags, writer: TextWriter): void;
         writeSymbol(symbol: Symbol, enclosingDeclaration: Node, meaning: SymbolFlags, writer: TextWriter): void;
-        isSymbolAccessible(symbol: Symbol, enclosingDeclaration: Node, meaning: SymbolFlags): boolean;
+        isSymbolAccessible(symbol: Symbol, enclosingDeclaration: Node, meaning: SymbolFlags): SymbolAccessiblityResult;
     }
 
     export enum SymbolFlags {