Shared Source CLI Essentials

Chapter 5. Synthesizing Components

In CLI component-based applications, references between types are represented symbolically using names, as we saw in Chapter 4. This chapter investigates how a set of running components can be synthesized just-in-time by following these symbolic names. Just-in-time synthesis customizes component structure and behavior to a local environment. Using this technique, the execution engine can create optimizations and adaptation wrappers for the benefit of the component.

A gap exists between the CLI’s logical representation of a component, expressed as assembly metadata and CIL, and the physical structure and machine instructions needed to execute on an actual microprocessor. To create components and run the behaviors associated with them, the execution engine must bridge this gap and convert the logical representation into data types and instructions that the underlying CPU can understand. CIL must be transformed into opcodes and operands; component metadata must be realized as in-memory data structures that fit both the microprocessor’s conventions and any constraints imposed by the host operating system. In short, the execution engine must play by the rules imposed by the hardware and operating system at runtime.

In a traditional approach to compilation, a compiler frontend parses high-level type descriptions and converts them into an intermediate representation, performing data layout at the same time. The back-end then converts the CIL to a flow ...