Transcript CPS120: Introduction to Computer Science

CPS120: Introduction to
Computer Science
Compiling Your Programs Using
Visual C++
Compilers
• Engines that work on your behalf to process
instructions and allow you to deal with
various basic rules of the language
– The compiler’s job is to make sure you follow
the rules, to require that you provide enough
information that the compiler can translate you
instructions into languages the components can
understand
Compilers Available
• Products range from freeware compilers to work
environments designed for commercial application
development
–Borland C++ compiler
–CodeWarrior
–IBM Visual Age C++
–Microsoft Visual C++
–GNU freeware
–DJGPP freeware ( www.delorie.com/djgpp/ )
Compilation Process
1. Get the set of instructions from you
2. Review the instructions to see if they violate the
rules (syntax) of the language
3. If all the rules are obeyed, create a working file
in the language of the computer (machine
language)
4. Attach to the working file full instructions for
any shortcuts you may have used (linkage)
5. Assemble a final file in machine language
Compiler Files
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Source code
Linked/Library file
Object file
Executable file
Source Code
• The set of instruction that you will develop
on your own for processing by the compiler
Executable Files
• A machine-language executable file created
when the compilation process is complete
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All that is needed to run the program
Not human-readable
Has the extension .EXE
Stored in binary form
• Copies may be distributed (portable)
– Known as an application
Compiling and Debugging
• Executable code will not be created until
you correct all of the syntax errors in your
source code
• Then the fun (with logic errors) begins
Creating Source Code Files
Actually Compiling a Program
Creating Source Code
• Programmers spend most of their time with
source code files
– Need to be comfortable with an editor that
creates ASCII text files
• 7-bit representation of all keyboard character
– Don’t use a word processor
– If an editor in an environment is available, use
that, it provides more sophisticated tools
Using the Editor
• Save often because there is no autosave in
Visual C++
• The editor will do matching of delimiters
and intelligent indentation
Columns and White Space
• Modern programming languages are free form with
delimiters instead of columns to determine the end
of instructions
–The ; (semi-colon) is the delimiter used in C++
• Use tabs, indents, and blank lines in any manner
that makes code easier to understand
• Many programming instructions become
subordinate to other instructions due to scope and
other restrictions. Formatting code to reflect this
makes it easier to read
Color Coding in Visual C++ Editor
• Comments are green and are ignored by the
compiler
• All ANSI keywords are coded in blue
• Other code is in plain black
– Compiler keywords like cin and cout are also
shown in black
Setting Up a Visual C++ Workspace
1. Left-click START
2. In the program section, select Visual Studio or
Visual C++ (depending on what is installed)
3. Left click on the Visual C++ icon to load the
environment
4. Create a new work area by choosing FILE/NEW
5. Choose FILES tab
6. Click on the C++ Source File to reach the editor
i.
Add a filename and directory before continuing
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e.g. c:/cppFun/myFirstCpp
Setting Up a Visual C++ Workspace
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Create the directory with START / EXPLORE
Double-click the drive letter
Choose FILE, NEW FOLDER
Left click on FOLDER
Change new folder to cppFUN
Close Explorer with the X
Back in Visual C++, type myFirstCpp in the file
box
14. Click OK and get back to the main edit screen
Setting Up a Visual C++ Workspace
15. Enter the source code
16. After entering the program, FILE then
SAVE
Why Create New Subdirectories?
• You should always use subdirectories to store your
files. Visual C++ creates quire a few work files
when it generates the executable file for you
source code, and they will be easy to dispose of if
you keep everything together in one convenient
place.
• Under no circumstances should you use the root
(C:\) directory except on a floppy disk (A:\).
Running the Program
1. Press the REBUILD ALL button. It has
two arrows in a box
2. Press the RUN button. It is a red
exclamation point
Disk Space Issues
• Text files are insignificant in terms of space
• However, six other files are created every
time something is compiled; some get
around 95% full
– Highlighting the disk in are 3 or 4 times larger
than the source
– You can delete anything but the file with the
.cpp suffix; everything else can be recreated
Recompiling
1. Open the file by going the file you stored it in and
double clicking on it
2. Scan the source code for obvious errors before
attempting to compile
3. Attempt to compile using the COMPILE button or
choosing the first option on the BUILD menu
4. Answer Yes to use the default project workspace
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The lower window will be active and the compile will occur
5. Note the number of errors and warnings
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These need to be dealt with before executable code is created