Discuss syntax analysis in compiler with example.

Syntax analysis, also known as parsing, is the second stage of the compilation process. It takes the tokens produced during the lexical analysis stage and generates a parse tree (or syntax tree). This tree is a representation of the syntactic structure of the source code according to the formal grammar of the programming language.

The syntax analyzer checks the source code for correct syntax and reports any errors it finds. It also handles operator precedence and associativity rules, ensuring that expressions are evaluated in the correct order.

For example, consider the simple arithmetic expression "3 + 4 * 5". According to the rules of operator precedence, the multiplication should be performed before the addition. A syntax analyzer would generate a parse tree that reflects this, like so:

  +
 / \
3   *
   / \
  4   5

In this tree, the multiplication node is a child of the addition node, indicating that it should be evaluated first. The numbers 3, 4, and 5 are leaf nodes, representing the operands of the operations.

If the syntax analyzer encounters an error, such as a missing parenthesis in an expression like "(3 + 4 * 5", it will generate an error message and halt the compilation process.