binutils-gdb/gdb/testsuite/lib/ton.tcl
Tom Tromey de7d7cb58e Initial implementation of Debugger Adapter Protocol
The Debugger Adapter Protocol is a JSON-RPC protocol that IDEs can use
to communicate with debuggers.  You can find more information here:

    https://microsoft.github.io/debug-adapter-protocol/

Frequently this is implemented as a shim, but it seemed to me that GDB
could implement it directly, via the Python API.  This patch is the
initial implementation.

DAP is implemented as a new "interp".  This is slightly weird, because
it doesn't act like an ordinary interpreter -- for example it doesn't
implement a command syntax, and doesn't use GDB's ordinary event loop.
However, this seemed like the best approach overall.

To run GDB in this mode, use:

    gdb -i=dap

The DAP code will accept JSON-RPC messages on stdin and print
responses to stdout.  GDB redirects the inferior's stdout to a new
pipe so that output can be encapsulated by the protocol.

The Python code uses multiple threads to do its work.  Separate
threads are used for reading JSON from the client and for writing JSON
to the client.  All GDB work is done in the main thread.  (The first
implementation used asyncio, but this had some limitations, and so I
rewrote it to use threads instead.)

This is not a complete implementation of the protocol, but it does
implement enough to demonstrate that the overall approach works.

There is a rudimentary test suite.  It uses a JSON parser written in
pure Tcl.  This parser is under the same license as Tcl itself, so I
felt it was acceptable to simply import it into the tree.

There is also a bit of documentation -- just documenting the new
interpreter name.
2023-01-02 09:49:37 -07:00

303 lines
8.7 KiB
Tcl

# This was imported into gdb from:
# https://github.com/jorge-leon/ton
# This software is copyrighted by Georg Lehner <jorge@at.anteris.net>.
# The following terms apply to all files associated with the software
# unless explicitly disclaimed in individual files.
# The authors hereby grant permission to use, copy, modify, distribute,
# and license this software and its documentation for any purpose,
# provided that existing copyright notices are retained in all copies
# and that this notice is included verbatim in any distributions. No
# written agreement, license, or royalty fee is required for any of the
# authorized uses. Modifications to this software may be copyrighted by
# their authors and need not follow the licensing terms described here,
# provided that the new terms are clearly indicated on the first page of
# each file where they apply.
# IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY
# FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
# ARISING OUT OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION, OR ANY
# DERIVATIVES THEREOF, EVEN IF THE AUTHORS HAVE BEEN ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
# THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES,
# INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, AND
# NON-INFRINGEMENT. THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, AND
# THE AUTHORS AND DISTRIBUTORS HAVE NO OBLIGATION TO PROVIDE
# MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
# GOVERNMENT USE: If you are acquiring this software on behalf of the
# U.S. government, the Government shall have only "Restricted Rights" in
# the software and related documentation as defined in the Federal
# Acquisition Regulations (FARs) in Clause 52.227.19 (c) (2). If you
# are acquiring the software on behalf of the Department of Defense, the
# software shall be classified as "Commercial Computer Software" and the
# Government shall have only "Restricted Rights" as defined in Clause
# 252.227-7013 (c) (1) of DFARs. Notwithstanding the foregoing, the
# authors grant the U.S. Government and others acting in its behalf
# permission to use and distribute the software in accordance with the
# terms specified in this license.
# leg20180331: ton / TON - Tcl Object Notation
#
# This package provides manipulation functionality for TON - a data
# serialization format with a direct mapping to JSON.
#
# In its essence, a JSON parser is provided, which can convert a JSON
# string into a Tcllib json style dictionary (dicts and arrays mixed),
# into a jimhttp style dictionary (only dicts) or into a nested, typed
# Tcl list.
#
# Finally, TON can be converted into (unformatted) JSON.
namespace eval ton {
namespace export json2ton
variable version 0.4
}
proc ton::json2ton json {
# Parse JSON string json
#
# return: TON
set i [trr $json [string length $json]]
if {!$i} {return ""}
lassign [jscan $json $i] i ton
if {[set i [trr $json $i]]} {
error "json string invalid:[incr i -1]: left over characters."
}
return $ton
}
proc ton::trr {s i} {
# Trim righthand whitespace on the first i characters of s.
# return: number of remaining characters in s
while {[set j $i] &&
([string is space [set c [string index $s [incr i -1]]]]
|| $c eq "\n")} {}
return $j
}
proc ton::jscan {json i {d :}} {
# Scan JSON in first i characters of string json.
# d is the default delimiter list for the next token.
#
# return list of
# - remaining characters in json
# - TON
#
# The string must already be whitespace trimmed from the right.
incr i -1
if {[set c [string index $json $i]] eq "\""} {
str $json [incr i -1]
} elseif {$c eq "\}"} {
obj $json $i
} elseif {$c eq "\]"} {
arr $json $i
} elseif {$c in {e l}} {
lit $json $i
} elseif {[string match {[0-9.]} $c]} {
num $json $i $c $d
} else {
error "json string end invalid:$i: ..[string range $json $i-10 $i].."
}
}
proc ton::num {json i c d} {
# Parse number from position i in string json to the left.
# c .. character at position i
# d .. delimiter on which to stop
#
# return list:
# - remaining string length
# - TON of number
set float [expr {$c eq "."}]
for {set j $i} {$i} {incr i -1} {
if {[string match $d [set c [string index $json $i-1]]]} break
set float [expr {$float || [string match "\[eE.]" $c]}]
}
set num [string trimleft [string range $json $i $j]]
if {!$float && [string is entier $num]} {
list $i "i $num"
} elseif {$float && [string is double $num]} {
list $i "d $num"
} else {
error "number invalid:$i: $num."
}
}
proc ton::lit {json i} {
# Parse literal from position i in string json to the left
# return list:
# - remaining string length
# - TON of literal
if {[set c [string index $json $i-1]] eq "u"} {
list [incr i -3] "l true"
} elseif {$c eq "s"} {
list [incr i -4] "l false"
} elseif {$c eq "l"} {
list [incr i -3] "l null"
} else {
set e [string range $json $i-3 $i]
error "literal invalid:[incr i -1]: ..$e."
}
}
proc ton::str {json i} {
# Parse string from position i in string json to the left
# return list:
# - remaining string length
# - TON of string
for {set j $i} {$i} {incr i -1} {
set i [string last \" $json $i]
if {[string index $json $i-1] ne "\\"} break
}
if {$i==-1} {
error "json string start invalid:$i: exhausted while parsing string."
}
list $i "s [list [string range $json $i+1 $j]]"
}
proc ton::arr {json i} {
# Parse array from i characters in string json
# return list:
# - remaining string length
# - TON of array
set i [trr $json $i]
if {!$i} {
error "json string invalid:0: exhausted while parsing array."
}
if {[string index $json $i-1] eq "\["} {
return [list [incr i -1] a]
}
set r {}
while {$i} {
lassign [jscan $json $i "\[,\[]"] i v
lappend r \[$v\]
set i [trr $json $i]
incr i -1
if {[set c [string index $json $i]] eq ","} {
set i [trr $json $i]
continue
} elseif {$c eq "\["} break
error "json string invalid:$i: parsing array."
}
lappend r a
return [list $i [join [lreverse $r]]]
}
proc ton::obj {json i} {
# Parse array from i character in string json
# return list:
# - remaining string length
# - TON of object
set i [trr $json $i]
if {!$i} {
error "json string invalid:0: exhausted while parsing object."
}
if {[string index $json $i-1] eq "\{"} {
return [list [incr i -1] o]
}
set r {}
while {$i} {
lassign [jscan $json $i] i v
set i [trr $json $i]
incr i -1
if {[string index $json $i] ne ":"} {
error "json string invalid:$i: parsing key in object."
}
set i [trr $json $i]
lassign [jscan $json $i] i k
lassign $k type k
if {$type ne "s"} {
error "json string invalid:[incr i -1]: key not a string."
}
lappend r \[$v\] [list $k]
set i [trr $json $i]
incr i -1
if {[set c [string index $json $i]] eq ","} {
set i [trr $json $i]
continue
} elseif {$c eq "\{"} break
error "json string invalid:$i: parsing object."
}
lappend r o
return [list $i [join [lreverse $r]]]
}
# TON decoders
namespace eval ton::2list {
proc atom {type v} {list $type $v}
foreach type {i d s l} {
interp alias {} $type {} [namespace current]::atom $type
}
proc a args {
set r a
foreach v $args {lappend r $v}
return $r
}
proc o args {
set r o
foreach {k v} $args {lappend r $k $v}
return $r
}
# There is plenty of room for validation in get
# array index bounds
# object key existence
proc get {l args} {
foreach k $args {
switch [lindex $l 0] {
o {set l [dict get [lrange $l 1 end] $k]}
a {set l [lindex $l [incr k]]}
default {
error "error: key $k to long, or wrong data: [lindex $l 0]"
}
}
}
return $l
}
}
namespace eval ton::2dict {
proc atom v {return $v}
foreach type {i d l s} {
interp alias {} $type {} [namespace current]::atom
}
proc a args {return $args}
proc o args {return $args}
}
namespace eval ton::a2dict {
proc atom v {return $v}
foreach type {i d l s} {
interp alias {} $type {} [namespace current]::atom
}
proc a args {
set i -1
set r {}
foreach v $args {
lappend r [incr i] $v
}
return $r
}
proc o args {return $args}
}
namespace eval ton::2json {
proc atom v {return $v}
foreach type {i d l} {
interp alias {} $type {} [namespace current]::atom
}
proc a args {
return "\[[join $args {, }]]"
}
proc o args {
set r {}
foreach {k v} $args {lappend r "\"$k\": $v"}
return "{[join $r {, }]}"
}
proc s s {return "\"$s\""}
}
package provide ton $ton::version