##SPA Introduction##
A Static Program Analyzer(SPA) is an interactive tool that automatically answers queries about programs.
##SPA Requirements##
####SIMPLE Language####
####Program Design Abstraction#### Calls, Calls*, Modifies, Modifies*, Uses, Uses*,
Follows, Follows*, Parent, Parent*, Next, Next*, Affects, Affects*
####Program Query Language (PQL)#### e.g. Select p such that Calls (p, q) with q.procName = “Third”
####Abstract Syntax Tree (AST)####
##SPA Architecture##
-SPA Front-End
-Parser: extracts design abstractions including:
Uses, Modifies, ProcTable, VarTable, AST, Parent, Follows, Calls.
-Design Extractor: extracts remaining design abstractions
-Program Knowledge Base(PKB)
-data structures: AST, Calls, CFG, Follows, Parent, Modifies, Uses, ProcTable, VarTable.
-Query Processor
-Query Preprocessor
-*Query Validator*: Checks if passed query is syntactically and semantically correct.
-*Query Tree Creator*: Creates a query tree for the query.
-Query Evaluator: Evaluates the query using the query tree and fetches the relevant data from the PKB.
-Query Projector: Formats the results of the Query Evaluator into a user-friendly form.