Name: ________________________________________________
ID Number: ___________________
Please write your answers in the space provided! Make sure your name is in the same form as it appears on your University ID card! Illegible and excessively long answers will be penalized! This exam is open-book, open-notes, closed neighbor! This exam is worth 1/5 of the final grade (10 points; allocate 4 minutes per point).
For a bit more credit, circle the line numbers of the lines that cannot be properly processed on the first pass of a two pass assembler. (0.5 points)line hexadecimal source number location value text 1 ________ ________ B 22 symbol table symbol value 2 ________ ________ X: B #22 ________ ________ 3 ________ ________ B X ________ ________ 4 ________ ________ ; Commentary ________ ________ 5 ________ ________ B Y ________ ________ 6 ________ ________ B Z 7 ________ ________ Y = 10 8 ________ ________ Z:
(1.2 points)#define twice(x) x * 2 #define next(x) x + 1 int i = twice(next(4));
a) What is the actual parameter to next? __________
b) What is the actual parameter to twice? __________
c) What does twice(next(4)) get replaced with? _______________
c) What is the initial value of i ? __________
For a bit more credit, for each symbol in the above symbol table, indicate whether it would be absolute or relocatable. (0.5 points)line hexadecimal source number location value text 1 ________ ________ B X 2 ________ ________ Z: symbol table symbol value abs/rel 3 ________ ________ . = .+1 ________ ________ ____ 4 ________ ________ X: B 15 ________ ________ ____ 5 ________ ________ Y: B 15 ________ ________ ____ 6 ________ ________ . = Z ________ ________ ____ 7 ________ ________ B Y 8 ________ ________ . = Y+1
Fill in the blanks in the following C code fragment to complete the skeleton for a parser for this fragment. (2 points)<s-expr> ::= <atom> | ( [ <s-expr> { <s-expr> } [ . <s-expr> ] ] )
void parse_s_exper() { if (lex_this != '(') { _________________________________ } else { lex_scan(); if ( ) { _________________________________ parse_s_expr(); while (( ) _________________________________ && (lex_this != ')')) { ; _________________________________ } if (lex_this == '.') { ; _________________________________ parse_s_expr(); } } if (lex_this != ')') EXCEPT_RAISE( parse_error ); lex_scan(); } }
MACRO X I 0000: _________ IF I > 0 B I 0001: _________ X (I-1) ENDIF 0002: _________ ENDMAC 0003: _________ X 0 X 1 0004: _________ X 2 X 3 0005: _________