Analyzer

The role of the analyzer is to provide a facade over objects and methods to create a simple interface for lexical and semantic processing (analysis) of a single HLASM source file. The output of the analysis is the basic input of the LSP server.

After the analyzer is constructed, it analyzes the provided source file. As a result, it updates HLASM context tables and provides a list of diagnostics linked to the file, highlighting, a list of symbol definitions, etc.

Overview

The analyzer is composed of several sub-components, all required to properly process the file.

• The LSP data collector collects and retrieves all LSP information created while processing the file.
• HLASM context tables hold information about the context of the processed HLASM source code.
• Lexer–Parser sub-components simplify the processing interface and ease the use of this component. They are needed to create a source file parser.
• The processing manager executes the main loop where the file is processed.

The LSP data collector is required by the Lexer-Parser sub-components. They are composed into the parser object required by the processing manager. HLASM context tables are used by the manager and the sub-components as well.

The components together contribute to the proper functionality of the method analyze. It processes a provided file and fills the LSP data collector, from which LSP information can be further retrieved.

Construction

In order to parse a HLASM file, the analyzer class is constructed with the following parameters:

• Name and content of the file.

• Parse library provider – an object responsible for resolving source file dependencies. The dependencies are only discovered during the analysis, so it is not possible to provide the files beforehand.

• Processing tracer (see macro tracer).

When this constructor is used, the analyzer creates HLASM context tables and processes the provided source as an open-code. The analyzer has owner semantics; it is the owner of the context tables.

The analyzer provides reference semantics as well (holding just a reference of the context tables). The provided source is not treated as an open-code, rather as an external file dependency. The constructor of an analyzer with reference semantics adds the following two parameters to the previous one:

• HLASM context tables reference — belongs to the owning open-code analyzer.

• Library data — states how the dependency file should be treated (see Processing manager).

This constructor is called within the open-code analyzer by its sub-components when they use the Parse library provider.

The components of the analyzer are further described in the following pages:

1. LSP data collector
2. Processing manager
3. Instruction format validation
4. Lexer
5. Parser
6. HLASM context tables