Modern compiler design [PDF]

Chapter 7
Semantic Analysis in C
Chapter Overview
7.1 Types in simpleJava
7.1.1 Built-in Types
7.1.2 Array Types
7.1.3 Class Types
7.2Implementing Environments in C
7.3 Writing a Suite of Functions for Semantic Analysis
7.3.1 Analyzing a simpleJava Program
7.3.2 Analyzing simpleJava Expressions in C
7.3.2 Analyzing Variables Expressions in C
7.3.3 Analyzing simpleJava Statements in C
7.4 Semantic Analyzer Project in C
7.4.1 Project Definition
7.4.1 Type Rules For Statements
7.4.1 Type Rules For Expressions
7.4.2 Project Difficulty
7.4.3 Project “Gotcha”s
7.4.4 Provided Files
7.1 Types in simpleJava
First, we will consider the implementation of types for simpleJava in C. A header file that defines the internal
representation of types is in Figure 7.1.
7.1.1 Built-in Types
For the build-in types integer and boolean, we do not need to keep track of any extra information. The
constructors for the base types are thus extremely simple – just IntegerType(), BooleanType(), and Void-
Type(). To make our life a little easier, multiple calls to each of these constructors will always return the
same pointer, so we can use pointer comparisons to check for type equivalence. That is, in the following
code:
type t1,t2;
t1 = IntegerType();
t2 = IntegerType();
if (t1 == t2) {
...
}
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