Test: Syntax Directed Translation- 1 - Computer Science Engineering (CSE) MCQ

A linker or link editor is a computer program that takes one or more object files generated by a compiler and combines then into single executable file, library file or another object file.

Generation of intermediate code based on an abstract machine model is useful in compilers because it makes implementation of lexical analysis and syntax analysis easier

Creating syntax tree for

Therefore  is left associative.

Creating syntax tree for 

Therefore,  is right associative.

Every S(Synthesized) - attributed definition is L- attributed. For implementing inherited attributed during bottom-up parsing, extends to some, but not LR grammars. Consider the following example

In the example above the nonterminal L in L → E inherits the count of the number of 1 ’s generated by S. Since the production L → E is the first that a bottom- up parser would reduce by, the translator at the time can't know the number of 1 ’s in the input. So in a bottom-up evaluation of a syntax directed definition, inherits attributes can’t be evaluated if the definition is L-attributed in the given example. So we can say. that L-attributed definition is based on simple LR(1) grammar, but it can’t be implemented always but inherit attributes can be evaluated only if the definition has synthesized attributes.

For the input ‘9 + 5 + 2’ the translation scheme is 95 + 2 + shown below:

To optimize the solution evaluate the expression E₂. Then we can calculate E₁ and finally E₁ will be one of operands that will be in register and we can perform subtraction directly. But if we follow the opposite then we have to make move and store operations.