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Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
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|
1 |
\documentclass{article}
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Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
2 |
\usepackage{../style}
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216
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
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|
3 |
\usepackage{../langs}
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200
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
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|
4 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
5 |
\begin{document}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
6 |
|
354
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
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|
7 |
%https://github.com/Storyyeller/Krakatau
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
8 |
%https://docs.oracle.com/javase/specs/jvms/se7/html/
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
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|
9 |
|
309
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
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|
10 |
\section*{Coursework 4 (Strand 1)}
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200
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
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|
11 |
|
328
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
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|
12 |
\noindent This coursework is worth 10\% and is due on 11
|
309
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
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|
13 |
December at 16:00. You are asked to implement a compiler for
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
14 |
the WHILE language that targets the assembler language
|
358
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
15 |
provided by Jasmin or Krakatau. You can do the implementation
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
16 |
in any programming language you like, but you need to submit
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
17 |
the source code with which you answered the questions,
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
18 |
otherwise a mark of 0\% will be awarded. You should use the
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
19 |
lexer and parser from the previous courseworks.
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
20 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
21 |
\subsection*{Disclaimer}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
22 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
23 |
It should be understood that the work you submit represents
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
24 |
your own effort. You have not copied from anyone else. An
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
25 |
exception is the Scala code I showed during the lectures,
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
26 |
which you can use. You can also use your own code from the
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
27 |
CW~1, CW~2 and CW~3.
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
28 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
29 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
30 |
\subsection*{Assemblers}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
31 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
32 |
The Jasmin assembler is available from
|
201
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
33 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
34 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
35 |
\url{http://jasmin.sourceforge.net}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
36 |
\end{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
37 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
38 |
\noindent
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
39 |
There is a user guide for Jasmin
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
40 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
41 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
42 |
\url{http://jasmin.sourceforge.net/guide.html}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
43 |
\end{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
44 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
45 |
\noindent
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
46 |
and also a description of some of the instructions that the JVM understands
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
47 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
48 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
49 |
\url{http://jasmin.sourceforge.net/instructions.html}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
50 |
\end{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
51 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
52 |
\noindent
|
205
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
53 |
If you generated a correct assembler file for Jasmin, for example
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
54 |
\texttt{loops.j}, you can use
|
200
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
55 |
|
205
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
56 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
57 |
\texttt{java -jar jasmin-2.4/jasmin.jar loops.j}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
58 |
\end{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
59 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
60 |
\noindent
|
210
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
61 |
in order to translate it to Java byte code. The resulting class file can be
|
205
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
62 |
run with
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
63 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
64 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
65 |
\texttt{java loops}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
66 |
\end{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
67 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
68 |
\noindent
|
322
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
69 |
where you might need to give the correct path to the class file.
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
70 |
For example:
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
71 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
72 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
73 |
\texttt{java -cp . loops/loops}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
74 |
\end{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
75 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
76 |
\noindent
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
77 |
There are also other resources about Jasmin on the Internet, for example
|
313
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
78 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
79 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
80 |
\url{http://www.ceng.metu.edu.tr/courses/ceng444/link/f3jasmintutorial.html}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
81 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
82 |
and
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
83 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
84 |
\url{http://www.csc.villanova.edu/~tway/courses/csc8505/s2011/handouts/JVM%20and%20Jasmin.pdf}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
85 |
\end{center}
|
200
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
86 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
87 |
\noindent
|
204
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
88 |
You need to submit a document containing the answers for the two questions
|
200
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
89 |
below. You can do the implementation in any programming language you like, but you need
|
205
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
90 |
to submit the source code with which you answered the questions. Otherwise
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
91 |
the submission will not be counted. However, the coursework
|
200
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
92 |
will \emph{only} be judged according to the answers. You can submit your answers
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
93 |
in a txt-file or as pdf.\bigskip
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
94 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
95 |
|
313
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
96 |
\subsection*{Question 1 (marked with 5\%)}
|
200
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
97 |
|
321
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
98 |
You need to lex and parse WHILE programs, and then generate Java Byte
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
99 |
Code instructions for the Jasmin assembler. As solution you need to
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
100 |
submit the assembler instructions for the Fibonacci and Factorial
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
101 |
programs. Both should be so modified that a user can input on the
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
102 |
console which Fibonacci number and which Factorial should
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
103 |
calculated. The Fibonacci program is given in Figure~\ref{fibs}. You
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
104 |
can write your own program for calculating factorials.
|
200
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
105 |
|
313
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
106 |
\begin{figure}[t]
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
107 |
\lstinputlisting[language=while]{../progs/fib.while}
|
320
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
108 |
\caption{The Fibonacci program in the WHILE language.\label{fibs}}
|
313
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
109 |
\end{figure}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
110 |
|
333
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
111 |
\subsection*{Question 2 (marked with 4\%)}
|
201
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
112 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
113 |
Extend the syntax of you language so that it contains also \texttt{for}-loops, like
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
114 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
115 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
116 |
\texttt{for} \;\textit{Id} \texttt{:=} \textit{AExp}\; \texttt{upto} \;\textit{AExp}\; \texttt{do} \textit{Block}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
117 |
\end{center}
|
200
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
118 |
|
202
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
119 |
\noindent
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
120 |
The intended meaning is to first assign the variable \textit{Id} the value of the first arithmetic
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
121 |
expression, then go through the loop, at the end increase the value of the variable by 1,
|
210
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
122 |
and finally test wether the value is not less or equal to the value of the second
|
202
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
123 |
arithmetic expression. For example the following instance of a \texttt{for}-loop
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
124 |
is supposed to print out the numbers \texttt{2}, \texttt{3}, \texttt{4}.
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
125 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
126 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
127 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
128 |
\begin{minipage}{6cm}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
129 |
\begin{lstlisting}[language=While,basicstyle=\ttfamily, numbers=none]
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
130 |
for i := 2 upto 4 do {
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
131 |
write i
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
132 |
}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
133 |
\end{lstlisting}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
134 |
\end{minipage}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
135 |
\end{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
136 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
137 |
\noindent
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
138 |
There are two ways how this can be implemented: one is to adapt the code generation
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
139 |
part of the compiler and generate specific code for \texttt{for}-loops; the other is to
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
140 |
translate the abstract syntax tree of \texttt{for}-loops into an abstract syntax tree using
|
203
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
141 |
existing language constructs. For example the loop above could be translated
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
142 |
to the following \texttt{while}-loop:
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
143 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
144 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
145 |
\begin{minipage}{6cm}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
146 |
\begin{lstlisting}[language=While,basicstyle=\ttfamily, numbers=none]
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
147 |
i := 2;
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
148 |
while (i <= 4) do {
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
149 |
write i;
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
150 |
i := i + 1;
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
151 |
}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
152 |
\end{lstlisting}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
153 |
\end{minipage}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
154 |
\end{center}
|
202
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
155 |
|
333
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
156 |
\subsection*{Question 3 (marked with 1\%)}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
157 |
|
205
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
158 |
\noindent
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
159 |
In this question you are supposed to give the assembler instructions for the
|
214
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
160 |
program
|
205
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
161 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
162 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
163 |
\begin{minipage}{6cm}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
164 |
\begin{lstlisting}[language=While,basicstyle=\ttfamily, numbers=none]
|
333
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
165 |
for i := 1 upto 10 do {
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
166 |
for i := 1 upto 10 do {
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
167 |
write i
|
205
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
168 |
}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
169 |
}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
170 |
\end{lstlisting}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
171 |
\end{minipage}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
172 |
\end{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
173 |
|
313
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
174 |
\noindent
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
175 |
Note that in this program the variable \pcode{i} is used
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
176 |
twice. You need to make a decision how it should be compiled?
|
333
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
177 |
Explain you decision and indicate what this program would
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
178 |
print out.
|
202
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
179 |
|
204
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
180 |
\subsection*{Further Information}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
181 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
182 |
The Java infrastructure unfortunately does not contain an assembler out-of-the-box
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
183 |
(therefore
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
184 |
you need to download the additional package Jasmin---see above). But it does contain a
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
185 |
disassembler, called \texttt{javap}. A dissembler does the ``opposite'' of an assembler: it
|
210
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
186 |
generates readable assembler code from Java byte code. Have a look at the
|
214
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
187 |
following example: Compile using the usual Java compiler the simple Hello World
|
210
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
188 |
program below:
|
204
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
189 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
190 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
191 |
\begin{minipage}{10cm}
|
313
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
192 |
\begin{lstlisting}[language=Java,numbers=none]
|
204
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
193 |
class HelloWorld {
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
194 |
public static void main(String[] args) {
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
195 |
System.out.println("Hello World!");
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
196 |
}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
197 |
}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
198 |
\end{lstlisting}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
199 |
\end{minipage}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
200 |
\end{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
201 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
202 |
\noindent
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
203 |
You can use the command
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
204 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
205 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
206 |
\texttt{javap -v HelloWorld}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
207 |
\end{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
208 |
|
313
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
209 |
\noindent to see the assembler instructions of the Java byte
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
210 |
code that has been generated for this program. You can compare
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
211 |
this with the code generated for the Scala version of Hello
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
212 |
World.
|
204
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
213 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
214 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
215 |
\begin{minipage}{10cm}
|
313
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
216 |
\begin{lstlisting}[language=Scala,numbers=none]
|
204
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
217 |
object HelloWorld {
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
218 |
def main(args: Array[String]) {
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
219 |
println("Hello World!")
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
220 |
}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
221 |
}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
222 |
\end{lstlisting}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
223 |
\end{minipage}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
224 |
\end{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
225 |
|
222
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
226 |
|
210
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
227 |
\subsection*{Library Functions}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
228 |
|
313
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
229 |
You need to generate code for the commands \texttt{write} and
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
230 |
\texttt{read}. This will require the addition of some
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
231 |
``library'' functions to your generated code. The first
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
232 |
command even needs two versions, because you need to write out
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
233 |
an integer and string. The Java byte code will need two
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
234 |
separate functions for this. For writing out an integer, you
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
235 |
can use the assembler code
|
210
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
236 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
237 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
238 |
\begin{minipage}{12cm}
|
313
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
239 |
\begin{lstlisting}[language=JVMIS, numbers=none]
|
210
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
240 |
.method public static write(I)V
|
373
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
241 |
.limit locals 1
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
242 |
.limit stack 2
|
210
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
243 |
getstatic java/lang/System/out Ljava/io/PrintStream;
|
373
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
244 |
iload 0
|
210
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
245 |
invokevirtual java/io/PrintStream/println(I)V
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
246 |
return
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
247 |
.end method
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
248 |
\end{lstlisting}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
249 |
\end{minipage}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
250 |
\end{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
251 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
252 |
\noindent
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
253 |
This function will invoke Java's \texttt{println} function for integers. Then if you need
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
254 |
to generate code for \texttt{write x} where \texttt{x} is an integer variable, you can generate
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
255 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
256 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
257 |
\begin{minipage}{8cm}
|
313
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
258 |
\begin{lstlisting}[language=JVMIS, numbers=none]
|
210
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
259 |
iload n
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
260 |
invokestatic XXX/XXX/write(I)V
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
261 |
\end{lstlisting}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
262 |
\end{minipage}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
263 |
\end{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
264 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
265 |
\noindent
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
266 |
where \texttt{n} is the index where the value of the variable \texttt{x} is
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
267 |
stored. The \texttt{XXX/XXX} needs to be replaced with the class name
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
268 |
which you use to generate the code (for example \texttt{fib/fib} in case
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
269 |
of the Fibonacci numbers).
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
270 |
|
214
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
271 |
Writing out a string is similar. The corresponding library function uses strings
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
272 |
instead of integers:
|
210
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
273 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
274 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
275 |
\begin{minipage}{12cm}
|
313
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
276 |
\begin{lstlisting}[language=JVMIS, numbers=none]
|
210
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
277 |
.method public static writes(Ljava/lang/String;)V
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
278 |
.limit stack 2
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
279 |
.limit locals 2
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
280 |
getstatic java/lang/System/out Ljava/io/PrintStream;
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
281 |
aload 0
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
282 |
invokevirtual java/io/PrintStream/println(Ljava/lang/String;)V
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
283 |
return
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
284 |
.end method
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
285 |
\end{lstlisting}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
286 |
\end{minipage}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
287 |
\end{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
288 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
289 |
\noindent
|
313
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
290 |
The code that needs to be generated for \code{write "some_string"} commands
|
210
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
291 |
is
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
292 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
293 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
294 |
\begin{minipage}{8cm}
|
313
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
295 |
\begin{lstlisting}[language=JVMIS,numbers=none]
|
210
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
296 |
ldc "some_string"
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
297 |
invokestatic XXX/XXX/writes(Ljava/lang/String;)V
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
298 |
\end{lstlisting}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
299 |
\end{minipage}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
300 |
\end{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
301 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
302 |
\noindent
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
303 |
Again you need to adjust the \texttt{XXX/XXX} part in each call.
|
202
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
304 |
|
214
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
305 |
The code for \texttt{read} is more complicated. The reason is that inputting a string
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
306 |
will need to be transformed into an integer. The code in Figure~\ref{read} does this.
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
307 |
It can be called with
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
308 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
309 |
\begin{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
310 |
\begin{minipage}{8cm}
|
313
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
311 |
\begin{lstlisting}[language=JVMIS,numbers=none]
|
214
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
312 |
invokestatic XXX/XXX/read()I
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
313 |
istore n
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
314 |
\end{lstlisting}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
315 |
\end{minipage}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
316 |
\end{center}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
317 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
318 |
\noindent
|
321
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
319 |
where \texttt{n} is the index of the variable that requires an input. If you
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
320 |
use Windows you need to take into account that a ``return'' is not just a newline,
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
321 |
\code{'\\10'}, but \code{'\\13\\10'}. This means you need to change line~12 in
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
322 |
Figure~\ref{read} to \pcode{ldc 13}.
|
214
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
323 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
324 |
|
321
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
325 |
\begin{figure}[t]\small
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
326 |
\begin{lstlisting}[language=JVMIS]
|
214
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
327 |
.method public static read()I
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
328 |
.limit locals 10
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
329 |
.limit stack 10
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
330 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
331 |
ldc 0
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
332 |
istore 1 ; this will hold our final integer
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
333 |
Label1:
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
334 |
getstatic java/lang/System/in Ljava/io/InputStream;
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
335 |
invokevirtual java/io/InputStream/read()I
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
336 |
istore 2
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
337 |
iload 2
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
338 |
ldc 10 ; the newline delimiter
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
339 |
isub
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
340 |
ifeq Label2
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
341 |
iload 2
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
342 |
ldc 32 ; the space delimiter
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
343 |
isub
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
344 |
ifeq Label2
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
345 |
iload 2
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
346 |
ldc 48 ; we have our digit in ASCII, have to subtract it from 48
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
347 |
isub
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
348 |
ldc 10
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
349 |
iload 1
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
350 |
imul
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
351 |
iadd
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
352 |
istore 1
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
353 |
goto Label1
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
354 |
Label2:
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
355 |
;when we come here we have our integer computed in Local Variable 1
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
356 |
iload 1
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
357 |
ireturn
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
358 |
.end method
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
359 |
\end{lstlisting}\normalsize
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
360 |
\caption{Assembler code for reading an integer from the console.\label{read}}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
361 |
\end{figure}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
diff
changeset
|
362 |
|
200
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
363 |
\end{document}
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
364 |
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
365 |
%%% Local Variables:
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
366 |
%%% mode: latex
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
367 |
%%% TeX-master: t
|
Christian Urban <christian dot urban at kcl dot ac dot uk>
parents:
diff
changeset
|
368 |
%%% End:
|