Type Checking - Introduction to Compiler Construction in a Java World - page 145

}
//Declaretheparameters
for(JFormalParameterparam:params){
this.context.addEntry(param.line(),param.name(),
newLocalVariableDefn(param.type(),this.context
.nextOffset(),null));
}
if(body!=null){
body=body.analyze(this.context);
}
returnthis;
}
The code for analyzing a JBlock is even simpler; it performs just two steps:
1. It creates a new LocalContext , whose surroundingContext points back to the pre-
vious MethodContext (or LocalContext in the case of nested blocks). Its nextOffset
value is copied from the previous context.
2. It analyzes each of the body's statements. Any JVariableDeclaration s declare their
variables in the LocalContext created in step 1. Any nested JBlock simply invokes
this two-step process recursively, creating yet another LocalContext for the nested
block.
Again, the code is straightforward:
publicJBlockanalyze(Contextcontext){
//{...}definesanewlevelofscope.
this.context=newLocalContext(context);
for(inti=0;i<statements.size();i++){
statements.set(i,(JStatement)statements.get(i).analyze(
this.context));
}
returnthis;
}
For example, the steps in adding the contexts to the symbol table for the analysis of method
foo() are illustrated in Figure 4.7. In the contexts, the names should map to objects of
type LocalVariableDefn , which define the variables and their stack frame offsets. In the
figures, the arrows point to the offsets in parentheses.