Miscellaneous topics in Compiler design GATE CS PYQs

Consider the following ANSI C program: 
 

int main () {
    Integer x;
    return 0;
}

Which one of the following phases in a seven-phase C compiler will throw an error?
 

Consider the program given below, in a block-structured pseudo-language with lexical scoping and nesting of procedures permitted.

Program main;
  Var ...
  
    Procedure A1;
     Var ...
     Call A2;
    End A1
    
    Procedure A2;
      Var ...
  
      Procedure A21;
        Var ...
        Call A1;
        End A21
        
    Call A21;
  End A21
  
    Call A1;
  End main.

Consider the calling chain : Main->A1->A2->A21->A1 The correct set of activation records along with their access links is given by :

Consider a program P that consists of two source modules M1 and M2 contained in two different files. If M1 contains a reference to a function defined in M2, the reference will be resolved at

Match all items in Group 1 with correct options from those given in Group 2.

Group 1                          Group 2
P. Regular expression        1. Syntax analysis
Q. Pushdown automata         2. Code generation
R. Dataflow analysis         3. Lexical analysis
S. Register allocation       4. Code optimization

Let pA be a problem that belongs to the class NP. Then which one of the following is TRUE?

A variable x is said to be live at a statement Si in a program if the following three conditions hold simultaneously:

1. There exists a statement Sj that uses x
2. There is a path from Si to Sj in the flow
   graph corresponding to the program
3. The path has no intervening assignment to x 
   including at Si and Sj

The variables which are live both at the statement in basic block 2 and at the statement in basic block 3 of the above control flow graph are

Which of the following statements are CORRECT?

1) Static allocation of all data areas by a compiler
   makes it impossible to implement recursion.
2) Automatic garbage collection is essential 
   to implement recursion.
3) Dynamic allocation of activation records is 
   essential to implement recursion.
4) Both heap and stack are essential to implement
   recursion.

Which one of the following is NOT performed during compilation?

Consider the basic block given below.

  a = b + c
  c = a + d
  d = b + c
  e = d - b
  a = e + b 

The minimum number of nodes and edges present in the DAG representation of the above basic block respectively are

Match the following:

(P) Lexical analysis       (i) Leftmost derivation
(Q) Top down parsing       (ii) Type checking
(R) Semantic analysis      (iii) Regular expressions
(S) Runtime environments   (iv) Activation records