55 lines
1.5 KiB
C
55 lines
1.5 KiB
C
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/* This file is part of the sample code and exercises
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* used by the class "Advanced Programming in the UNIX
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* Environment" taught by Jan Schaumann
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* <jschauma@netmeister.org> at Stevens Institute of
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* Technology.
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*
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* This file is in the public domain.
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*
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* You don't have to, but if you feel like
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* acknowledging where you got this code, you may
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* reference me by name, email address, or point
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* people to the course website:
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* https://stevens.netmeister.org/631/
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*/
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/* A very simple program to illustrate the different stages in the
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* compilation process. First, use cpp(1) to pre-process the file; repeat
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* with FOOD defined to a different value. Compare output, illustrate
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* that code is pulled in by the preprocessor and macros expanded. Then,
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* compile hello.i to hello.s and show the resulting assembly output
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* before using as(1) to generate object code. Use objdump(1) (or
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* similar) to disassemble the object code. Finally, use ld(1) to create
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* an executable.
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*
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* To illustrate compiler optimization, compile with
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* '-O0 -S' and once with '-O4 -S' and compare the
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* output. You should notice that the calls to func1
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* and func2 are eliminated when optimization is
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* turned on.
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*
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* The file 'dump' includes the traced output of the compiler invocation.
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* Show the different stages again.
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*/
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#include <stdio.h>
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#ifndef FOOD
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#define FOOD "Avocado"
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#endif
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void
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func2(void) {
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printf("%s: great on anything.\n", FOOD);
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}
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void
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func1(void) {
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func2();
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}
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int
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main() {
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func1();
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return 0;
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}
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