Bridge Parser Diagnostics into the C++ Diagnostic Engine

Author: CodaFi

Sources/SwiftCompilerSupport/ConsistencyCheck.swift

@@ -39,7 +39,9 @@ extension Syntax {
 @_spi(SwiftCompiler)
 public func _parserConsistencyCheck(
   bufferPtr: UnsafePointer<UInt8>, bufferLength: Int,
-  filename: UnsafePointer<UInt8>, flags: CUnsignedInt
+  filename: UnsafePointer<UInt8>, flags: CUnsignedInt,
+  ctx: OpaquePointer,
+  hook: @convention(c) (Int, UnsafePointer<Int8>, OpaquePointer) -> Void
 ) -> CInt {
   let buffer = UnsafeBufferPointer<UInt8>(
     start: bufferPtr, count: bufferLength)
@@ -62,7 +64,9 @@ public func _parserConsistencyCheck(
       var anyDiags = false
 
       let sourceFile = Syntax(raw: rawSourceFile.raw).as(SourceFileSyntax.self)!
+      let fileName = String(cString: filename)
 
+      let converter = SourceLocationConverter(file: fileName, tree: sourceFile)
       let diags = ParseDiagnosticsGenerator.diagnostics(
         for: sourceFile)
       for diag in diags {
@@ -73,7 +77,9 @@ public func _parserConsistencyCheck(
           continue
         }
 
-        print("\(String(cString: filename)): error: \(diag.debugDescription)")
+        diag.debugDescription.withCString { diagText in
+          hook(diag.location(converter: converter).offset, diagText, ctx)
+        }
         anyDiags = true
       }
 

Sources/SwiftCompilerSupport/SwiftCompilerSupport.h

@@ -32,6 +32,10 @@ enum SwiftConsistencyCheckFlags {
   SCC_FoldSequences = 0x04,
 };
 
+/// A callback function that is called once per emitted diagnostic with a
+/// byte offset and message text.
+typedef void (*swift_parser_diagnostic_hook_t)(ptrdiff_t off, const char *text, void *ctx);
+
 /// Entry point for the Swift compiler to use for consistency checking.
 ///
 /// - Parameters:
@@ -43,7 +47,8 @@ enum SwiftConsistencyCheckFlags {
 /// - Returns: 0 if all requested consistency checks passed, nonzero otherwise.
 int swift_parser_consistencyCheck(
   const char *buffer, ptrdiff_t bufferLength, const char *filename,
-  unsigned int flags);
+  unsigned int flags,
+  void *hookCtx, swift_parser_diagnostic_hook_t hook);
 
 #ifdef __cplusplus
 }