We have mentioned some of the semantics errors that the semantic analyzer is expected to recognize: The following tasks should be performed in semantic analysis: These rules are set by the grammar of the language and evaluated in semantic analysis. Should not issue an error in lexical and syntax analysis phase, as it is lexically and structurally correct, but it should generate a semantic error as the type of the assignment differs. CFG + semantic rules = Syntax Directed Definitions
Semantic analysis judges whether the syntax structure constructed in the source program derives any meaning or not. Semantics help interpret symbols, their types, and their relations with each other. Semantics of a language provide meaning to its constructs, like tokens and syntax structure. The above CFG production has no semantic rule associated with it, and it cannot help in making any sense of the production.
#WHAT IS SYNTAX ANALYSIS IN COMPILER DESIGN HOW TO#
The productions of context-free grammar, which makes the rules of the language, do not accommodate how to interpret them. The plain parse-tree constructed in that phase is generally of no use for a compiler, as it does not carry any information of how to evaluate the tree. We have learnt how a parser constructs parse trees in the syntax analysis phase.
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