* M2 Operators:: Built-in operators
* Built-In Func/Proc:: Built-in functions and procedures
* M2 Constants:: Modula-2 constants
+* M2 Types:: Modula-2 types
* M2 Defaults:: Default settings for Modula-2
* Deviations:: Deviations from standard Modula-2
* M2 Checks:: Modula-2 type and range checks
@end table
@quotation
-@emph{Warning:} Sets and their operations are not yet supported, so @value{GDBN}
+@emph{Warning:} Set expressions and their operations are not yet supported, so @value{GDBN}
treats the use of the operator @code{IN}, or the use of operators
@code{+}, @code{-}, @code{*}, @code{/}, @code{=}, , @code{<>}, @code{#},
@code{<=}, and @code{>=} on sets as an error.
Set constants are not yet supported.
@end itemize
+@node M2 Types
+@subsubsection Modula-2 Types
+@cindex Modula-2 types
+
+Currently @value{GDBN} can print the following data types in Modula-2
+syntax: array types, record types, set types, pointer types, procedure
+types, enumerated types, subrange types and base types. You can also
+print the contents of variables declared using these type.
+This section gives a number of simple source code examples together with
+sample @value{GDBN} sessions.
+
+The first example contains the following section of code:
+
+@smallexample
+VAR
+ s: SET OF CHAR ;
+ r: [20..40] ;
+@end smallexample
+
+@noindent
+and you can request @value{GDBN} to interrogate the type and value of
+@code{r} and @code{s}.
+
+@smallexample
+(@value{GDBP}) print s
+@{'A'..'C', 'Z'@}
+(@value{GDBP}) ptype s
+SET OF CHAR
+(@value{GDBP}) print r
+21
+(@value{GDBP}) ptype r
+[20..40]
+@end smallexample
+
+@noindent
+Likewise if your source code declares @code{s} as:
+
+@smallexample
+VAR
+ s: SET ['A'..'Z'] ;
+@end smallexample
+
+@noindent
+then you may query the type of @code{s} by:
+
+@smallexample
+(@value{GDBP}) ptype s
+type = SET ['A'..'Z']
+@end smallexample
+
+@noindent
+Note that at present you cannot interactively manipulate set
+expressions using the debugger.
+
+The following example shows how you might declare an array in Modula-2
+and how you can interact with @value{GDBN} to print its type and contents:
+
+@smallexample
+VAR
+ s: ARRAY [-10..10] OF CHAR ;
+@end smallexample
+
+@smallexample
+(@value{GDBP}) ptype s
+ARRAY [-10..10] OF CHAR
+@end smallexample
+
+Note that the array handling is not yet complete and although the type
+is printed correctly, expression handling still assumes that all
+arrays have a lower bound of zero and not @code{-10} as in the example
+above. Unbounded arrays are also not yet recognized in @value{GDBN}.
+
+Here are some more type related Modula-2 examples:
+
+@smallexample
+TYPE
+ colour = (blue, red, yellow, green) ;
+ t = [blue..yellow] ;
+VAR
+ s: t ;
+BEGIN
+ s := blue ;
+@end smallexample
+
+@noindent
+The @value{GDBN} interaction shows how you can query the data type
+and value of a variable.
+
+@smallexample
+(@value{GDBP}) print s
+$1 = blue
+(@value{GDBP}) ptype t
+type = [blue..yellow]
+@end smallexample
+
+@noindent
+In this example a Modula-2 array is declared and its contents
+displayed. Observe that the contents are written in the same way as
+their @code{C} counterparts.
+
+@smallexample
+VAR
+ s: ARRAY [1..5] OF CARDINAL ;
+BEGIN
+ s[1] := 1 ;
+@end smallexample
+
+@smallexample
+(@value{GDBP}) print s
+$1 = @{1, 0, 0, 0, 0@}
+(@value{GDBP}) ptype s
+type = ARRAY [1..5] OF CARDINAL
+@end smallexample
+
+The Modula-2 language interface to @value{GDBN} also understands
+pointer types as shown in this example:
+
+@smallexample
+VAR
+ s: POINTER TO ARRAY [1..5] OF CARDINAL ;
+BEGIN
+ NEW(s) ;
+ s^[1] := 1 ;
+@end smallexample
+
+@noindent
+and you can request that @value{GDBN} describes the type of @code{s}.
+
+@smallexample
+(@value{GDBP}) ptype s
+type = POINTER TO ARRAY [1..5] OF CARDINAL
+@end smallexample
+
+@value{GDBN} handles compound types as we can see in this example.
+Here we combine array types, record types, pointer types and subrange
+types:
+
+@smallexample
+TYPE
+ foo = RECORD
+ f1: CARDINAL ;
+ f2: CHAR ;
+ f3: myarray ;
+ END ;
+
+ myarray = ARRAY myrange OF CARDINAL ;
+ myrange = [-2..2] ;
+VAR
+ s: POINTER TO ARRAY myrange OF foo ;
+@end smallexample
+
+@noindent
+and you can ask @value{GDBN} to describe the type of @code{s} as shown
+below.
+
+@smallexample
+(@value{GDBP}) ptype s
+type = POINTER TO ARRAY [-2..2] OF foo = RECORD
+ f1 : CARDINAL;
+ f2 : CHAR;
+ f3 : ARRAY [-2..2] OF CARDINAL;
+END
+@end smallexample
+
@node M2 Defaults
@subsubsection Modula-2 defaults
@cindex Modula-2 defaults
This command loads symbols from a dll similarly to
add-sym command but without the need to specify a base address.
+@kindex set cygwin-exceptions
+@cindex debugging the Cygwin DLL
+@cindex Cygwin DLL, debugging
+@item set cygwin-exceptions @var{mode}
+If @var{mode} is @code{on}, @value{GDBN} will break on exceptions that
+happen inside the Cygwin DLL. If @var{mode} is @code{off},
+@value{GDBN} will delay recognition of exceptions, and may ignore some
+exceptions which seem to be caused by internal Cygwin DLL
+``bookkeeping''. This option is meant primarily for debugging the
+Cygwin DLL itself; the default value is @code{off} to avoid annoying
+@value{GDBN} users with false @code{SIGSEGV} signals.
+
+@kindex show cygwin-exceptions
+@item show cygwin-exceptions
+Displays whether @value{GDBN} will break on exceptions that happen
+inside the Cygwin DLL itself.
+
@kindex set new-console
@item set new-console @var{mode}
If @var{mode} is @code{on} the debuggee will
@c inc-hist.texinfo
@c Use -I with makeinfo to point to the appropriate directory,
@c environment var TEXINPUTS with TeX.
-@include rluser.texinfo
+@include rluser.texi
@include inc-hist.texinfo
foos) or @samp{Qacme.bar} (for setting bars).
@end itemize
-A query or set packet may optionally be followed by a @samp{,} or
-@samp{;} separated list. Stubs must be careful to match the full
-packet name, in case packet names have common prefixes.
+The name of a query or set packet should be separated from any
+parameters by a @samp{:}; the parameters themselves should be
+separated by @samp{,} or @samp{;}. Stubs must be careful to match the
+full packet name, and check for a separator or the end of the packet,
+in case two packet names share a common prefix. New packets should not begin
+with @samp{qC}, @samp{qP}, or @samp{qL}@footnote{The @samp{qP} and @samp{qL}
+packets predate these conventions, and have arguments without any terminator
+for the packet name; we suspect they are in widespread use in places that
+are difficult to upgrade. The @samp{qC} packet has no arguments, but some
+existing stubs (e.g.@: RedBoot) are known to not check for the end of the
+packet.}.
Like the descriptions of the other packets, each description here
has a template showing the packet's overall syntax, followed by an
Returns information on @var{threadid}. Where: @var{mode} is a hex
encoded 32 bit mode; @var{threadid} is a hex encoded 64 bit thread ID.
+Don't use this packet; use the @samp{qThreadExtraInfo} query instead
+(see below).
+
Reply: see @code{remote.c:remote_unpack_thread_info_response()}.
@item qPart:@var{object}:read:@var{annex}:@var{offset},@var{length}
encoding of @var{annex} is specific to the object; it can supply
additional details about what data to access.
+Since this packet is ambiguous with the older @code{qP} packet, we
+plan to rename it.
+
Here are the specific requests of this form defined so far. All
@samp{qPart:@var{object}:read:@dots{}} requests use the same reply
formats, listed below.
An empty reply indicates that @samp{qRcmd} is not recognized.
@end table
+(Note that the @code{qRcmd} packet's name is separated from the
+command by a @samp{,}, not a @samp{:}, contrary to the naming
+conventions above. Please don't use this packet as a model for new
+packets.)
+
@item qSymbol::
@cindex symbol lookup, remote request
@cindex @samp{qSymbol} packet
the thread's attributes.
@end table
+(Note that the @code{qThreadExtraInfo} packet's name is separated from
+the command by a @samp{,}, not a @samp{:}, contrary to the naming
+conventions above. Please don't use this packet as a model for new
+packets.)
+
@item QTStart
@itemx QTStop
@itemx QTinit
projects / deliverable / binutils-gdb.git / blobdiff