pdx.1

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 1 代码 · 共 296 行

.\" SCCSID: @(#)pdx.1	8.1	9/11/90
.TH pdx 1 VAX
.SH Name
pdx \- pascal debugger
.SH Syntax
pdx [\fB\-r\fR] [\|\fIobjfile\fR\|]
.SH Description
.NXR "pdx debugger"
.NXR "Pascal program" "debugging"
.NXA "pc compiler" "pdx debugger"
.NXA "pdx debugger" "pi code translator"
The
.PN pdx
command is a tool for source level debugging and execution of
Pascal programs.
The \fIobjfile\fP is an object file produced by the Pascal translator
.MS pi 1 .
If no \fIobjfile\fP is specified, 
.PN pdx
looks
for a file named ``obj'' in the current directory.
The object file contains a symbol table which includes the name of the
all the source files translated by 
.PN pi
to create it.
These files are available for perusal while using the debugger.
.PP
If the file .pdxinit exists in the current directory, then the
debugger commands in it are executed.
.PP
The \fB\-r\fP option causes
the \fIobjfile\fP to be executed immediately;
if it terminates successfully 
.PN pdx
exits.
Otherwise it reports the reason for termination
and offers the user the option of entering the debugger
or simply letting 
.PN px
continue with a traceback.
If \fB\-r\fP is not specified, 
.PN pdx
just prompts
and waits for a command.
.PP
The commands are:
.TP
\fBrun\fP [\fIargs\fP] [\fB<\fP \fIfilename\fP] [\fB>\fP \fIfilename\fP]
.NXR "run command (pdx)"
Start executing \fIobjfile\fP, passing 
\fIargs\fP as command line arguments;
\fB<\fP or \fB>\fP can be used
to redirect input or output in the usual manner.
.TP
\fBtrace\fP [\fBin\fP \fIprocedure/function\fP] [\fBif\fP \fIcondition\fP]
.ns
.TP
\fBtrace\fP \fIsource-line-number\fP [\fBif\fP \fIcondition\fP]
.ns
.TP
\fBtrace\fP \fIprocedure/function\fP [\fBin\fP \fIprocedure/function\fP] [\fBif\fP \fIcondition\fP]
.ns
.TP
\fBtrace\fP \fIexpression\fP \fBat\fP \fIsource-line-number\fP [\fBif\fP \fIcondition\fP]
.ns
.TP
\fBtrace\fP \fIvariable\fP [\fBin\fP \fIprocedure/function\fP] [\fBif\fP \fIcondition\fP]
.NXR "trace command (pdx)"
Have tracing information printed when the program is executed.
A number is associated with the command that is used
to turn the tracing off (see the \fBdelete\fP command).
.sp 1
The first argument describes what is to be traced.
If it is a \fIsource-line-number\fP, then the line is printed
immediately prior to being executed.
Source line numbers in a file other than the current one
must be preceded by the name of the file and a colon, for example,
``mumble.p:17''.
.sp 1
If the argument is a procedure or function name then
every time it is called, information is printed telling
what routine called it, from what source line it was called,
and what parameters were passed to it.
In addition, its return is noted, and if it's a function
then the value it is returning is also printed.
.sp 1
If the argument is an \fIexpression\fP with an \fBat\fP clause
then the value of the expression is printed whenever the
identified source line is reached.
.sp 1
If the argument is a variable then the name and value of the variable
is printed whenever it changes.
Execution is substantially slower during this form of tracing.
.sp 1
If no argument is specified then all source lines are printed
before they are executed.
Execution is substantially slower during this form of tracing.
.sp 1
The clause ``\fBin\fP \fIprocedure/function\fP'' restricts tracing information
to be printed only while executing inside the given procedure
or function.
.sp 1
\fICondition\fP is a Pascal boolean expression and is
evaluated prior to printing the tracing information;
if it is false then the information is not printed.
.sp 1
There is no restriction on the amount of information
that can be traced.
.br
.ne 10
.IP "\fBstop\fP \fBif\fP \fIcondition\fP"
.ns
.IP "\fBstop\fP \fBat\fP \fIsource-line-number\fP [\fBif\fP \fIcondition\fP]"
.ns
.IP "\fBstop\fP \fBin\fP \fIprocedure/function\fP [\fBif\fP \fIcondition\fP]"
.ns
.IP "\fBstop\fP \fIvariable\fP [\fBif\fP \fIcondition\fP]"
.NXR "stop command (pdx)"
Stop execution when the given line is reached, procedure or function
called, variable changed, or condition true.
.IP "\fBdelete\fP \fIcommand-number\fP"
.NXR "delete command (pdx)"
The trace or stop corresponding to the given number is removed.
The numbers associated with traces and stops are printed by
the \fBstatus\fP command.
.IP "\fBstatus\fP [\fB>\fP \fIfilename\fP]"
.NXR "status command (pdx)"
Print out
the currently active \fBtrace\fP and \fBstop\fP commands.
.IP \fBcont\fP
.NXR "cont command (pdx)"
Continue execution from where it stopped.
This can only be
done when the program was stopped by an interrupt
or through use of the \fBstop\fP command.
.IP \fBstep\fP
.NXR "step command (pdx)"
Execute one source line.
.IP \fBnext\fP
.NXR "next command (pdx)"
Execute up to the next source line.
The difference between this and \fBstep\fP is that
if the line contains a call to a procedure or function
the \fBstep\fP command will stop at the beginning of that
block, while the \fBnext\fP command will not.
.IP "\fBprint\fP \fIexpression\fP [\fB,\fP \fIexpression\fP ...]"
.NXR "print command (pdx)"
Print out the values of the Pascal expressions.
Variables declared in an outer block but having
the same identifier as one in the current block may be
referenced as ``\fIblock-name\fP\ \fB.\fP\ \fIvariable\fP''.
.IP "\fBwhatis\fP \fIidentifier\fP"
.NXR "whatis command (pdx)"
Print the declaration of the given identifier.
.IP "\fBwhich\fP \fIidentifier\fP"
.NXR "which command (pdx)"
Print the full qualification of the given identifier, that is
the outer blocks that the identifier is associated with.
.IP "\fBassign\fP \fIvariable\fP \fIexpression\fP"
.NXR "assign command (pdx)"
Assign the value of the expression to the variable.
.IP "\fBcall\fP \fIprocedure(parameters)\fP"
.NXR "call command (pdx)"
Execute the object code associated with the named procedure or function.
.IP \fBhelp\fP
.NXR "help command (pdx)"
Print out a synopsis of 
.PN pdx
commands.
.IP \fBgripe\fP
.NXR "gripe command (pdx)"
Invokes a mail program to send a message to the person in charge of 
.PN pdx .
.IP \fBwhere\fP
.NXR "where command (pdx)"
Print out
a list of the active procedures and functions and the respective source
line where they are called.
.TP
\fBsource\fP \fIfilename\fP
.NXR "source command (pdx)"
Read 
.PN pdx
commands from the given \fIfilename\fP.
Especially useful when the \fIfilename\fP has been created by redirecting
a \fBstatus\fP command from an earlier debugging session.
.IP "\fBdump\fP [\fB>\fP \fIfilename\fP]"
.NXR "dump command (pdx)"
Print the names and values of all active
data.
.IP "\fBlist\fP [\fIsource-line-number\fP [\fB,\fP \fIsource-line-number\fP]]"
.ns
.IP "\fBlist\fP \fIprocedure/function\fP"
.NXR "list command (pdx)"
List the lines in the current source file from the first line number to
the second inclusive.
As in the editor
``$'' can be used to refer to the last line.
If no lines are specified, the entire file is listed.
If the name of a procedure or function is given
lines \fIn-k\fP to \fIn+k\fP are listed where \fIn\fP is the first statement
in the procedure or function and \fIk\fP is small.
.IP "\fBfile\fP [\fIfilename\fP]"
.NXR "file command (pdx)"
Change the current source file name to \fIfilename\fP.
If none is specified then the current source file name is printed.
.IP "\fBedit\fP [\fIfilename\fP]"
.ns
.IP "\fBedit\fP \fIprocedure/function-name\fP"
.NXR "edit command (pdx)"
Invoke an editor on \fIfilename\fP or the current source file if none
is specified.
If a \fIprocedure\fP or \fIfunction\fP name is specified,
the editor is invoked on the file that contains it.
Which editor is invoked by default depends on the installation.
The default can be overridden by setting the environment variable
EDITOR to the name of the desired editor.
.IP \fBpi\fP
.NXR "pi command (pdx)"
Recompile the program and read in the new symbol table information.
.IP "\fBsh\fP \fIcommand-line\fP"
.NXR "sh command (pdx)"
Pass the command line to the shell for execution.
The SHELL environment variable determines which shell is used.
.IP "\fBalias\fP \fInew-command-name\fP \fIold-command-name\fP"
.NXR "alias command (pdx)"
This command makes 
.PN pdx
respond to \fInew-command-name\fP
the way it used to respond to \fIold-command-name\fP.
.IP "\fBquit\fP"
.NXR "quit command (pdx)"
Exit 
.PN pdx .
.PP
The following commands deal with the program at the \fIpx\fP instruction
level rather than source level.
.NXR "pdx debugger" "instructor-level commands"
They are not intended for general use.
.TP
\fBtracei\fP [\fIaddress\fP] [\fBif\fP \fIcond\fP]
.NXR "tracei command (pdx)"
.ns
.TP
\fBtracei\fP [\fIvariable\fP] [\fBat\fP \fIaddress\fP] [\fBif\fP \fIcond\fP]
.ns
.TP
\fBstopi\fP [\fIaddress\fP] [\fBif\fP \fIcond\fP]
.NXR "stopi command (pdx)"
.ns
.TP
\fBstopi\fP [\fBat\fP] [\fIaddress\fP] [\fBif\fP \fIcond\fP]
Turn on tracing or set a stop using a \fIpx\fP machine
instruction addresses.
.TP
\fBxi\fP \fIaddress\fP [\fB,\fP \fIaddress\fP]
.NXR "xi command (pdx)"
Print the instructions starting at the first \fIaddress\fP.
Instructions up to
the second \fIaddress\fP are printed.
.TP
\fBxd\fP \fIaddress\fP [\fB,\fP \fIaddress\fP]
.NXR "xd command (pdx)"
Print in octal the specified data location(s).
.SH Options
.NXR "pdx debugger" "option"
.IP \fB\-r\fR 5
Causes
.PN obifile
to be executed immediately.  Normally
.PN pdx
prompts and waits for a command.
.SH Restrictions
.NXR "pdx debugger" "restricted"
The
.PN pdx
command does not understand sets,
and provides no information about files.
.PP
The 
.PN whatis
command doesn't quite work for variant records.
.PP
Unexpected results occur if a procedure invoked with
the \fBcall\fP command does a non-local goto.
.SH Files
.TP 10
.PN obj
Pascal object file
.TP
.PN \&.pdxinit 
.PN pdx 
initialization file
.SH See Also
pi(1), px(1)