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INTEGRATED DEVELOPMENT ENVIRONMENT.
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The Turbo C integrated development environment (IDE) includes not only a
fast compiler, but also an editor, debugger, linker and Make utility. The
compiler converts source code (a file with a .C extension) to an object file
(a machine code file with an .OBJ extension). The editor is used to create
and edit the source file, and includes the use of 'Wordstar-like' key
commands. The debugger is used to locate semantic and logic errors in the
program (after compilation) with trace and watch facilities, which allow the
programmer to trace through the program one line at a time whilst certain
critical values are checked in a 'watch' window. The linker copies into the
object file certain functions from the standard run-time library files to
convert the object file to an executable file with a .EXE extension. The
Make utility combines both compilation and linking to create an executable
(.EXE) file directly.
The integrated development environment is described in detail in chapter 5
of the User's Guide to which reference should be made. This note highlights
some of the more frequently used facilities of the IDE. When turbo C is
initiated from the DOS prompt by typing tc and pressing the Enter key, the
main TC screen appears. At the top of this TC screen the Main Menu line
appears:
File Edit Run Compile Project Options Debug Break/watch
Below this is the edit window, which has a status line at the top:
Line 1 Col 1 Insert Indent Tab Fill Unindent C:NONAME.C
Below the edit window there is a smaller Message window and below that is a
Quick-Ref line:
F1-Help F5-Zoom F6-Switch F7-Trace F8-Step F9-Make F10-Menu
This line can be changed by holding the ALT key down for a few seconds to
display the action of various keys when the ALT key is held down, as shown
below:
Alt: F1-Last help F3-Pick F6-Swap F7/F8-Prev/Next error F9-Compile
These two Quick-Ref lines define the function of some of the Turbo C Hot
Keys. Further details are given on pages 84-5 of the User's Guide. As
illustrations, pressing the function key F1 will create a Help window on the
screen with context sensitive information, whilst F10 toggles between the
menus and the active window.
The various choices on the Main Menu can also be selected by means of Hot
Keys. Pressing the ALT key with the initial letter of the main menu item
will pull down a sub-menu window. For example, ALT-F will produce the
options:
Load F3
Pick Alt-F3
New
Save F2
Write to
Directory
Change dir
OS shell
Quit Alt-X
These sub-menu options are mostly self explanatory, as are the four hot key
options shown. Each option can also be selected by simply pressing the key
for the initial letter of that option. For example, L will select the Load
option and a window then appears for entry of the name of the file to be
loaded. Alternatively a mask using wildcards (* and ?) can be used to
display all files to the mask specification and selection made by use of the
arrow keys. In either case the file is then loaded as soon as the Enter key
is pressed.
Pressing S from the file sub-menu or F2 from anywhere in the system will
save the current file in the editor with the existing name, which is shown
at the right of the status line. Alternatively, if a new name is required,
then W for 'Write to' will display a New Name prompt box, which allows the
entry of the new pathname.
Pressing O for the OS Shell temporarily returns to DOS for any necessary
operations before returning from DOS by typing EXIT and pressing ENTER.
These and the other file menu options are fully described on pages 100-102
of the User's Guide.
The Edit option of the Main Menu is automatically selected when a file is
loaded and this option has no sub-menu. Any edit is facilitated by use of
the Wordstar-like keys, such as CTRL-K B and CTRL-K K to mark the beginning
and end of a block respectively and CTRL-K V to move the block to the
cursor.
The Run sub-menu is selected by Alt-R and is shown on page 103 of the User's
Guide, together with a description of the options on pages 103-106. The
most important option is:
Run Ctrl-F9 - this runs the program with any arguments passed via
Options/Arguments. If the source code has been modified
the program is recompiled and linked, otherwise the
program runs directly.
Other options include:
Program reset Ctrl-F2 - cancels current debugging session, releases
memory and closes files.
Trace into F7 - this runs the next statement in the current function.
User screen Alt-F5 - This option switches to the User Screen, which
contains any output, from the main TC screen, which
is displayed after the program is run.
The Compile sub-menu is selected by pressing Alt-C and is shown on page 107
of the User's Guide. The options include Compile to an .OBJ file, Make an
.EXE file, Link an .EXE file and each can be selected by means of the
initial letter shown in capitals.
When compile is selected, a window displays the results, including the
number of errors and warnings. On 'pressing any key', the IDE moves to the
message window and highlights the first error, if there are any errros.
Otherwise the compilation window, which indicates success, is removed.
Make invokes Project-Make to make an .EXE file (see below for an
explanation of the project sub-menu).
Link takes the current .OBJ and .LIB files and links them to produce a new
.EXE file.
The other compile options are:
Build all - rebuilds all files in the Project regardless of whether they are
out of date.
Primary C file - when errors occur in compilation, the file containing the
error (.C or .H) is automatically loaded into the editor.
Get Info - provides information about the name and size of the current file
and size of available memory.
The Project sub-menu is shown on page 110 of the User's Guide and is
selected by Alt-P. The first option is Project name, which chooses a
project file containing the names of the files to be compiled and/or linked.
The project name is given to the .EXE and .MAP files when they are created.
A typical project file has the extension .PRJ.
For many programs which consist of one .C file, which may have associated .H
files included, this Project option is not used. Pages 109-112 of the
User's Guide should be consulted when necessary.
The Options sub-menu, selected by Alt-O, is shown on page 112 of the User's
Guide and has several further sub-menus as can be seen from page 87 of the
Guide. These options contain settings that determine how the integrated
development environment works. All the necessary details are given on pages
112- 130 of the User's guide. The 7 sub-menu options produce a set of 95
options, some of which are 3 sub-menus removed from this first sub-menu.
Generally the default settings will be satisfactory.
A few of the options are briefly mentioned for illustration:
The 'Compiler/Model' option selects the memory model and hence the method of
memory addressing. The default is 'Small'. The option 'Compiler/Code
generation/Instruction set' toggles between 8088/8086 and 80x86 code. the
option 'Compiler/Optimization/Optimize for' toggles between size and speed.
The option 'Compiler/Errors/Errors : stop after 25' (default) can be reset
to any value between 0 and 255.
The option 'Linker/Graphics library', when toggled 'on', will allow
automatic search of the BGI graphics library.
The 'Environment/Tab size' option allows tab sizes between 2 and 16, with a
default of 8.
The option 'Directories/Include directories:' allows the user to specify
the directories that contain the standard include files.
The 'Arguments' option allows the inclusion of command line arguments
exactly as if they had been typed on the DOS command line.
The 'Save' option saves all the other chosen options in a configuration
file, with a default name TCCONFIG.TC
The 'Retrieve' option loads a configuration file previously saved as above.
The Debug sub-menu, selected by Alt-D, contains the commands which control
the features of the integrated debugger, other than breakpoints and watch
expressions, which are on the Break/Watch menu. The options are shown on
page 130 of the User's Guide and described on pages 130-135.
The 'Evaluate' option evaluates a variable or expression, displays its value
and, if appropriate, allows modification of the value. A pop-up window
contains three fields: Evaluate, Result and New Value.
The other options are: Call stack, Find function, Refresh display, Display
swapping, Source debugging.
The Break/Watch sub-menu, selected by Alt-B, offers options to control
breakpoints and watch expressions. A 'breakpoint' is a location in a
program where execution should halt, to allow examination of the value of
critical variables and expressions. It is shown by a breakpoint highlight.
A 'watch' expression is one whose value is displayed in the Watch window and
is evaluated whenever the program halts. The various options are:
Add watch - prompts for the entry of a watch expression in a pop-up window.
Delete watch - deletes the current expression from the Watch window.
Edit watch - permits an edit of the current watch expression.
Remove all watches - deletes all expressions from the Watch window.
Toggle breakpoint - sets or clears a breakpoint at the cursor position.
Clear all breakpoints - removes all breakpoints from the program.
View next breakpoint - moves the cursor to the next breakpoint, in the order
in which they were set (not program order).
Those programmers, familiar with the integrated development environment in
Turbo Pascal, will find that the only difference in the Main Menu is the
inclusion of the Project sub-menu. Most of the other sub-menus are very
similar, except for the Options sub-menu, which is significantly different.
The integrated development environment can be used intuitively and because
of the multiplicity of options available, is probably best understood after
'trial and error' experimentation, with reference to the User's Guide for
the finer details.