Tema 070218

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Formal Languages and Compilers Proff. Breveglieri, Morzenti Written exam1: laboratory question 07/02/2018 SURNAME: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NAME: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Student ID:. . . . . . . . . . . . . . . . Course: ◦ Laurea Specialistica ◦ V. O. ◦ Laurea Triennale ◦ Other: . . . . . . . . . . . . . Instructor: ◦ Prof. Breveglieri ◦ Prof Morzenti The laboratory question must be answered taking into account the implementation of the Acse compiler given with the exam text. Modify the specification of the lexical analyser ( flex input) and the syntactic analyser (bison input) and any other source file required to extend the Lance language with the new array reduction construct. The array reduction construct is constituted of the red keyword, followed by a variable name enclosed in round braces. The implementation must check that the said variable is an array. The behaviour of the construct is the computation of the sum of all the elements in the array. An example is provided in the following. int v[2], a; a = 0; v[0] = 3; v[1] = 2; a=red(v); while( red(v) ){ v[0] = v[0]-1; v[1] = v[0]; } 1Time 60’. Textbooks and notes can be used. Pencil writing is allowed. Write your name on any additional sheet. 1 1. Define the tokens (and the related declarations in Acse.lex and Acse.y). (3 points) 2. Define the syntactic rules or the modifications required to the existing ones. (4 points) 3. Define the semantic actions needed to implement the required functionality. (18 points) The solution is in the attached patch. 2 3 4. Given the following Lance code snippet: a[5] = 3 + b; write down the…