1#!/usr/bin/env python
2
3#----------------------------------------------------------------------
4# Be sure to add the python path that points to the LLDB shared library.
5#
6# # To use this in the embedded python interpreter using "lldb" just
7# import it with the full path using the "command script import"
8# command
9#   (lldb) command script import /path/to/clandiag.py
10#----------------------------------------------------------------------
11
12from __future__ import absolute_import, division, print_function
13import lldb
14import argparse
15import shlex
16import os
17import re
18import subprocess
19
20class MyParser(argparse.ArgumentParser):
21    def format_help(self):
22        return '''     Commands for managing clang diagnostic breakpoints
23
24Syntax: clangdiag enable [<warning>|<diag-name>]
25        clangdiag disable
26        clangdiag diagtool [<path>|reset]
27
28The following subcommands are supported:
29
30      enable   -- Enable clang diagnostic breakpoints.
31      disable  -- Disable all clang diagnostic breakpoints.
32      diagtool -- Return, set, or reset diagtool path.
33
34This command sets breakpoints in clang, and clang based tools, that
35emit diagnostics.  When a diagnostic is emitted, and clangdiag is
36enabled, it will use the appropriate diagtool application to determine
37the name of the DiagID, and set breakpoints in all locations that
38'diag::name' appears in the source.  Since the new breakpoints are set
39after they are encountered, users will need to launch the executable a
40second time in order to hit the new breakpoints.
41
42For in-tree builds, the diagtool application, used to map DiagID's to
43names, is found automatically in the same directory as the target
44executable.  However, out-or-tree builds must use the 'diagtool'
45subcommand to set the appropriate path for diagtool in the clang debug
46bin directory.  Since this mapping is created at build-time, it's
47important for users to use the same version that was generated when
48clang was compiled, or else the id's won't match.
49
50Notes:
51- Substrings can be passed for both <warning> and <diag-name>.
52- If <warning> is passed, only enable the DiagID(s) for that warning.
53- If <diag-name> is passed, only enable that DiagID.
54- Rerunning enable clears existing breakpoints.
55- diagtool is used in breakpoint callbacks, so it can be changed
56  without the need to rerun enable.
57- Adding this to your ~.lldbinit file makes clangdiag available at startup:
58  "command script import /path/to/clangdiag.py"
59
60'''
61
62def create_diag_options():
63    parser = MyParser(prog='clangdiag')
64    subparsers = parser.add_subparsers(
65        title='subcommands',
66        dest='subcommands',
67        metavar='')
68    disable_parser = subparsers.add_parser('disable')
69    enable_parser = subparsers.add_parser('enable')
70    enable_parser.add_argument('id', nargs='?')
71    diagtool_parser = subparsers.add_parser('diagtool')
72    diagtool_parser.add_argument('path', nargs='?')
73    return parser
74
75def getDiagtool(target, diagtool = None):
76    id = target.GetProcess().GetProcessID()
77    if 'diagtool' not in getDiagtool.__dict__:
78        getDiagtool.diagtool = {}
79    if diagtool:
80        if diagtool == 'reset':
81            getDiagtool.diagtool[id] = None
82        elif os.path.exists(diagtool):
83            getDiagtool.diagtool[id] = diagtool
84        else:
85            print('clangdiag: %s not found.' % diagtool)
86    if not id in getDiagtool.diagtool or not getDiagtool.diagtool[id]:
87        getDiagtool.diagtool[id] = None
88        exe = target.GetExecutable()
89        if not exe.Exists():
90            print('clangdiag: Target (%s) not set.' % exe.GetFilename())
91        else:
92            diagtool = os.path.join(exe.GetDirectory(), 'diagtool')
93            if os.path.exists(diagtool):
94                getDiagtool.diagtool[id] = diagtool
95            else:
96                print('clangdiag: diagtool not found along side %s' % exe)
97
98    return getDiagtool.diagtool[id]
99
100def setDiagBreakpoint(frame, bp_loc, dict):
101    id = frame.FindVariable("DiagID").GetValue()
102    if id is None:
103        print('clangdiag: id is None')
104        return False
105
106    # Don't need to test this time, since we did that in enable.
107    target = frame.GetThread().GetProcess().GetTarget()
108    diagtool = getDiagtool(target)
109    name = subprocess.check_output([diagtool, "find-diagnostic-id", id]).rstrip();
110    # Make sure we only consider errors, warnings, and extensions.
111    # FIXME: Make this configurable?
112    prefixes = ['err_', 'warn_', 'exp_']
113    if len([prefix for prefix in prefixes+[''] if name.startswith(prefix)][0]):
114        bp = target.BreakpointCreateBySourceRegex(name, lldb.SBFileSpec())
115        bp.AddName("clang::Diagnostic")
116
117    return False
118
119def enable(exe_ctx, args):
120    # Always disable existing breakpoints
121    disable(exe_ctx)
122
123    target = exe_ctx.GetTarget()
124    numOfBreakpoints = target.GetNumBreakpoints()
125
126    if args.id:
127        # Make sure we only consider errors, warnings, and extensions.
128        # FIXME: Make this configurable?
129        prefixes = ['err_', 'warn_', 'exp_']
130        if len([prefix for prefix in prefixes+[''] if args.id.startswith(prefix)][0]):
131            bp = target.BreakpointCreateBySourceRegex(args.id, lldb.SBFileSpec())
132            bp.AddName("clang::Diagnostic")
133        else:
134            diagtool = getDiagtool(target)
135            list = subprocess.check_output([diagtool, "list-warnings"]).rstrip();
136            for line in list.splitlines(True):
137                m = re.search(r' *(.*) .*\[\-W' + re.escape(args.id) + r'.*].*', line)
138                # Make sure we only consider warnings.
139                if m and m.group(1).startswith('warn_'):
140                    bp = target.BreakpointCreateBySourceRegex(m.group(1), lldb.SBFileSpec())
141                    bp.AddName("clang::Diagnostic")
142    else:
143        print('Adding callbacks.')
144        bp = target.BreakpointCreateByName('DiagnosticsEngine::Report')
145        bp.SetScriptCallbackFunction('clangdiag.setDiagBreakpoint')
146        bp.AddName("clang::Diagnostic")
147
148    count = target.GetNumBreakpoints() - numOfBreakpoints
149    print('%i breakpoint%s added.' % (count, "s"[count==1:]))
150
151    return
152
153def disable(exe_ctx):
154    target = exe_ctx.GetTarget()
155    # Remove all diag breakpoints.
156    bkpts = lldb.SBBreakpointList(target)
157    target.FindBreakpointsByName("clang::Diagnostic", bkpts)
158    for i in range(bkpts.GetSize()):
159        target.BreakpointDelete(bkpts.GetBreakpointAtIndex(i).GetID())
160
161    return
162
163def the_diag_command(debugger, command, exe_ctx, result, dict):
164    # Use the Shell Lexer to properly parse up command options just like a
165    # shell would
166    command_args = shlex.split(command)
167    parser = create_diag_options()
168    try:
169        args = parser.parse_args(command_args)
170    except:
171        return
172
173    if args.subcommands == 'enable':
174        enable(exe_ctx, args)
175    elif args.subcommands == 'disable':
176        disable(exe_ctx)
177    else:
178        diagtool = getDiagtool(exe_ctx.GetTarget(), args.path)
179        print('diagtool = %s' % diagtool)
180
181    return
182
183def __lldb_init_module(debugger, dict):
184    # This initializer is being run from LLDB in the embedded command interpreter
185    # Make the options so we can generate the help text for the new LLDB
186    # command line command prior to registering it with LLDB below
187    parser = create_diag_options()
188    the_diag_command.__doc__ = parser.format_help()
189    # Add any commands contained in this module to LLDB
190    debugger.HandleCommand(
191        'command script add -f clangdiag.the_diag_command clangdiag')
192    print('The "clangdiag" command has been installed, type "help clangdiag" or "clangdiag --help" for detailed help.')
193