Add a parserSourceFile function that takes a file path directly

This avoids adding boilerplate around the SourceMgr on the client.

PiperOrigin-RevId: 239918122

mlir/include/mlir/Parser.h

@@ -37,6 +37,11 @@ class MLIRContext;
 /// the error handler registered in the context, and a null pointer is returned.
 Module *parseSourceFile(const llvm::SourceMgr &sourceMgr, MLIRContext *context);
 
+/// This parses the file specified by the indicated filename and returns an
+/// MLIR module if it was valid.  If not, the error message is emitted through
+/// the error handler registered in the context, and a null pointer is returned.
+Module *parseSourceFile(llvm::StringRef filename, MLIRContext *context);
+
 /// This parses the module string to a MLIR module if it was valid.  If not, the
 /// error message is emitted through / the error handler registered in the
 /// context, and a null pointer is returned.

mlir/lib/Parser/Parser.cpp

@@ -3743,6 +3743,23 @@ Module *mlir::parseSourceFile(const llvm::SourceMgr &sourceMgr,
   return module.release();
 }
 
+/// This parses the file specified by the indicated filename and returns an
+/// MLIR module if it was valid.  If not, the error message is emitted through
+/// the error handler registered in the context, and a null pointer is returned.
+Module *parseSourceFile(StringRef filename, MLIRContext *context) {
+  auto file_or_err = llvm::MemoryBuffer::getFile(filename);
+  if (std::error_code error = file_or_err.getError()) {
+    context->emitError(mlir::UnknownLoc::get(context),
+                       "Could not open input file " + filename);
+    return nullptr;
+  }
+
+  // Load the MLIR module.
+  llvm::SourceMgr source_mgr;
+  source_mgr.AddNewSourceBuffer(std::move(*file_or_err), llvm::SMLoc());
+  return parseSourceFile(source_mgr, context);
+}
+
 /// This parses the program string to a MLIR module if it was valid. If not,
 /// it emits diagnostics and returns null.
 Module *mlir::parseSourceString(StringRef moduleStr, MLIRContext *context) {