Symbol table: major inherited attribute and major data structure in a compiler Principal operations: – Insert: store the information provided by name declarations when processing these declarations – Lookup: retrieve the information associated to a name when that name is used in the associated code
A stack-based environment will result in a dangling reference when the procedure is exited if a local variable in a procedure can be returned to the caller The simplest example:
The idea of Recursive-Descent Parsing Viewing the grammar rule for a non-terminal A as a definition for a procedure to recognize an A The right-hand side of the grammar for A specifies the structure of the code for this procedure The Expression Grammar:
A bottom-up parser uses an explicit stack to perform a parse – The parsing stack contains tokens, nonterminals as well as some extra state information – The stack is empty at the beginning of a bottom-up parse, and will contain the start symbol at the end of a successful parse
