Source/DebuggerBackEnd.m

   1 /*
   2  * MacGDBp
   3  * Copyright (c) 2007 - 2011, Blue Static <http://www.bluestatic.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it under the terms of the GNU
   6  * General Public License as published by the Free Software Foundation; either version 2 of the
   7  * License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
  10  * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with this program; if not,
  14  * write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
  15  */
  16
  17 #import "DebuggerBackEnd.h"
  18
  19 #import "AppDelegate.h"
  20 #import "Breakpoint.h"
  21 #import "DebuggerModel.h"
  22 #import "NSXMLElementAdditions.h"
  23 #import "StackFrame.h"
  24
  25 @implementation DebuggerBackEnd {
  26   // The connection to the debugger engine.
  27   uint16_t _port;
  28   ProtocolClient* _client;
  29 }
  30
  31 - (instancetype)initWithPort:(NSUInteger)aPort autoAttach:(BOOL)doAttach
  32 {
  33   if (self = [super init]) {
  34     _port = aPort;
  35     _client = [[ProtocolClient alloc] initWithDelegate:self];
  36
  37     _autoAttach = doAttach;
  38     if (doAttach)
  39       [_client connectOnPort:_port];
  40   }
  41   return self;
  42 }
  43
  44 - (void)dealloc {
  45   [_client release];
  46   [super dealloc];
  47 }
  48
  49 // Getters /////////////////////////////////////////////////////////////////////
  50 #pragma mark Getters
  51
  52 /**
  53  * Gets the port number
  54  */
  55 - (uint16_t)port {
  56   return _port;
  57 }
  58
  59 /**
  60  * Sets the attached state of the debugger. This will open and close the
  61  * connection as appropriate.
  62  */
  63 - (void)setAutoAttach:(BOOL)flag {
  64   if (flag == _autoAttach)
  65     return;
  66
  67   if (_autoAttach)
  68     [_client disconnect];
  69   else
  70     [_client connectOnPort:_port];
  71
  72   _autoAttach = flag;
  73 }
  74
  75 // Commands ////////////////////////////////////////////////////////////////////
  76 #pragma mark Commands
  77
  78 /**
  79  * Tells the debugger to continue running the script. Returns the current stack frame.
  80  */
  81 - (void)run {
  82   [_client sendCommandWithFormat:@"run" handler:^(NSXMLDocument* message) {
  83     [self debuggerStep:message];
  84   }];
  85 }
  86
  87 /**
  88  * Tells the debugger to step into the current command.
  89  */
  90 - (void)stepIn {
  91   [_client sendCommandWithFormat:@"step_into" handler:^(NSXMLDocument* message) {
  92     [self debuggerStep:message];
  93   }];
  94 }
  95
  96 /**
  97  * Tells the debugger to step out of the current context
  98  */
  99 - (void)stepOut {
 100   [_client sendCommandWithFormat:@"step_out" handler:^(NSXMLDocument* message) {
 101     [self debuggerStep:message];
 102   }];
 103 }
 104
 105 /**
 106  * Tells the debugger to step over the current function
 107  */
 108 - (void)stepOver {
 109   [_client sendCommandWithFormat:@"step_over" handler:^(NSXMLDocument* message) {
 110     [self debuggerStep:message];
 111   }];
 112 }
 113
 114 /**
 115  * Halts execution of the script.
 116  */
 117 - (void)stop {
 118   [_client disconnect];
 119   self.model.status = @"Stopped";
 120 }
 121
 122 /**
 123  * Ends the current debugging session.
 124  */
 125 - (void)detach {
 126   [_client sendCommandWithFormat:@"detach"];
 127   self.model.status = @"Stopped";
 128 }
 129
 130 - (void)loadStackFrame:(StackFrame*)frame {
 131   if (frame.loaded)
 132     return;
 133
 134   // Get the source code of the file. Escape % in URL chars.
 135   if ([frame.filename length]) {
 136     ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 137       frame.source = [[message rootElement] base64DecodedValue];
 138     };
 139     [_client sendCommandWithFormat:@"source -f %@" handler:handler, frame.filename];
 140   }
 141
 142   // Get the names of all the contexts.
 143   ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 144     [self loadContexts:message forFrame:frame];
 145   };
 146   [_client sendCommandWithFormat:@"context_names -d %d" handler:handler, frame.index];
 147
 148   // This frame will be fully loaded.
 149   frame.loaded = YES;
 150 }
 151
 152 - (void)loadVariableNode:(VariableNode*)variable
 153            forStackFrame:(StackFrame*)frame {
 154   if (variable.children.count == variable.childCount)
 155     return;
 156
 157   [self loadVariableNode:variable forStackFrame:frame dataPage:0 loadedData:@[]];
 158 }
 159
 160 - (void)loadVariableNode:(VariableNode*)variable
 161            forStackFrame:(StackFrame*)frame
 162                 dataPage:(unsigned int)dataPage
 163               loadedData:(NSArray*)loadedData {
 164   ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 165     /*
 166      <response>
 167        <property> <!-- this is the one we requested -->
 168          <property ... /> <!-- these are what we want -->
 169        </property>
 170      </repsonse>
 171      */
 172
 173     // Detach all the children so we can insert them into another document.
 174     NSXMLElement* parent = (NSXMLElement*)[[message rootElement] childAtIndex:0];
 175     NSArray* children = [parent children];
 176     [parent setChildren:nil];
 177
 178     // Check to see if there are more children to load.
 179     NSArray* newLoadedData = [loadedData arrayByAddingObjectsFromArray:children];
 180
 181     unsigned int totalChildren = [[[parent attributeForName:@"numchildren"] stringValue] integerValue];
 182     if ([newLoadedData count] < totalChildren) {
 183       [self loadVariableNode:variable
 184                forStackFrame:frame
 185                     dataPage:dataPage + 1
 186                   loadedData:newLoadedData];
 187     } else {
 188       [variable setChildrenFromXMLChildren:newLoadedData];
 189     }
 190   };
 191   [_client sendCommandWithFormat:@"property_get -d %d -n %@ -p %u" handler:handler, frame.index, variable.fullName, dataPage];
 192 }
 193
 194 // Breakpoint Management ///////////////////////////////////////////////////////
 195 #pragma mark Breakpoints
 196
 197 /**
 198  * Send an add breakpoint command
 199  */
 200 - (void)addBreakpoint:(Breakpoint*)bp {
 201   if (!self.model.connected)
 202     return;
 203
 204   NSString* file = [ProtocolClient escapedFilePathURI:[bp transformedPath]];
 205   ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 206     [bp setDebuggerId:[[[[message rootElement] attributeForName:@"id"] stringValue] intValue]];
 207   };
 208   [_client sendCommandWithFormat:@"breakpoint_set -t line -f %@ -n %i" handler:handler, file, [bp line]];
 209 }
 210
 211 /**
 212  * Removes a breakpoint
 213  */
 214 - (void)removeBreakpoint:(Breakpoint*)bp {
 215   if (!self.model.connected)
 216     return;
 217
 218   [_client sendCommandWithFormat:@"breakpoint_remove -d %i", [bp debuggerId]];
 219 }
 220
 221 /**
 222  * Sends a string to be evaluated by the engine.
 223  */
 224 - (void)evalScript:(NSString*)str callback:(void (^)(NSString*))callback {
 225   if (!self.model.connected)
 226     return;
 227
 228   NSData* stringData = [str dataUsingEncoding:NSUTF8StringEncoding];
 229   ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 230     NSXMLElement* parent = (NSXMLElement*)[[message rootElement] childAtIndex:0];
 231     NSString* value = [parent base64DecodedValue];
 232     callback(value);
 233   };
 234   [_client sendCustomCommandWithFormat:@"eval -i {txn} -- %@" handler:handler, [stringData base64Encoding]];
 235 }
 236
 237 // Protocol Client Delegate ////////////////////////////////////////////////////
 238 #pragma mark Protocol Client Delegate
 239
 240 - (void)debuggerEngineConnected:(ProtocolClient*)client {
 241   [_model onNewConnection];
 242 }
 243
 244 /**
 245  * Called when the connection is finally closed. This will reopen the listening
 246  * socket if the debugger remains attached.
 247  */
 248 - (void)debuggerEngineDisconnected:(ProtocolClient*)client {
 249   [_model onDisconnect];
 250
 251   if (self.autoAttach)
 252     [_client connectOnPort:_port];
 253 }
 254
 255 - (void)protocolClient:(ProtocolClient*)client receivedInitialMessage:(NSXMLDocument*)message {
 256   [self handleInitialResponse:message];
 257 }
 258
 259 - (void)protocolClient:(ProtocolClient*)client receivedErrorMessage:(NSXMLDocument*)message {
 260   NSArray* error = [[message rootElement] elementsForName:@"error"];
 261   if ([error count] > 0) {
 262     NSLog(@"Xdebug error: %@", error);
 263     NSString* errorMessage = [[[[error objectAtIndex:0] children] objectAtIndex:0] stringValue];
 264     _model.lastError = errorMessage;
 265   }
 266 }
 267
 268 // Specific Response Handlers //////////////////////////////////////////////////
 269 #pragma mark Response Handlers
 270
 271 /**
 272  * Initial packet received. We've started a brand-new connection to the engine.
 273  */
 274 - (void)handleInitialResponse:(NSXMLDocument*)response {
 275   if (!self.autoAttach) {
 276     [_client sendCommandWithFormat:@"detach"];
 277     return;
 278   }
 279
 280   // Register any breakpoints that exist offline.
 281   for (Breakpoint* bp in self.model.breakpointManager.breakpoints)
 282     [self addBreakpoint:bp];
 283
 284   // TODO: update the status.
 285 }
 286
 287 /**
 288  * Receiver for status updates. This just freshens up the UI.
 289  */
 290 - (void)updateStatus:(NSXMLDocument*)response {
 291   NSString* status = [[[[response rootElement] attributeForName:@"status"] stringValue] capitalizedString];
 292   self.model.status = status;
 293   if (!status || [status isEqualToString:@"Stopped"]) {
 294     [_model onDisconnect];
 295   } else if ([status isEqualToString:@"Stopping"]) {
 296     [_client sendCommandWithFormat:@"stop"];
 297   }
 298 }
 299
 300 /**
 301  * Step in/out/over and run all take this path. We first get the status of the
 302  * debugger and then request fresh stack information.
 303  */
 304 - (void)debuggerStep:(NSXMLDocument*)response {
 305   [self updateStatus:response];
 306   if (!self.model.connected)
 307     return;
 308
 309   [_client sendCommandWithFormat:@"stack_depth" handler:^(NSXMLDocument* message) {
 310     [self rebuildStack:message];
 311   }];
 312 }
 313
 314 /**
 315  * We ask for the stack_depth and now we clobber the stack and start rebuilding
 316  * it.
 317  */
 318 - (void)rebuildStack:(NSXMLDocument*)response {
 319   NSUInteger depth = [[[[response rootElement] attributeForName:@"depth"] stringValue] intValue];
 320
 321   // Send a request to get each frame of the stack, which will be added to this
 322   // array. When the final frame arrives, the |tempStack| is released.
 323   __block NSMutableArray* tempStack = [[NSMutableArray alloc] init];
 324
 325   for (NSUInteger i = 0; i < depth; ++i) {
 326     ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 327       [tempStack addObject:[self transformXMLToStackFrame:message]];
 328       if (i == depth - 1) {
 329         [self.model updateStack:[tempStack autorelease]];
 330       }
 331     };
 332     [_client sendCommandWithFormat:@"stack_get -d %d" handler:handler, i];
 333   }
 334 }
 335
 336 /**
 337  * Creates a StackFrame object from an NSXMLDocument response from the "stack_get"
 338  * command.
 339  */
 340 - (StackFrame*)transformXMLToStackFrame:(NSXMLDocument*)response {
 341   NSXMLElement* xmlframe = (NSXMLElement*)[[[response rootElement] children] objectAtIndex:0];
 342   StackFrame* frame = [[[StackFrame alloc] init] autorelease];
 343   frame.index = [[[xmlframe attributeForName:@"level"] stringValue] intValue];
 344   frame.filename = [[xmlframe attributeForName:@"filename"] stringValue];
 345   frame.lineNumber = [[[xmlframe attributeForName:@"lineno"] stringValue] intValue];
 346   frame.function = [[xmlframe attributeForName:@"where"] stringValue];
 347   return frame;
 348 }
 349
 350 /**
 351  * Enumerates all the contexts of a given stack frame. We then in turn get the
 352  * contents of each one of these contexts.
 353  */
 354 - (void)loadContexts:(NSXMLDocument*)response forFrame:(StackFrame*)frame {
 355   NSXMLElement* contextNames = [response rootElement];
 356   for (NSXMLElement* context in [contextNames children]) {
 357     NSInteger cid = [[[context attributeForName:@"id"] stringValue] intValue];
 358
 359     // Fetch each context's variables.
 360     ProtocolClientMessageHandler handler = ^(NSXMLDocument* message) {
 361       NSMutableArray* variables = [NSMutableArray array];
 362
 363       // Merge the frame's existing variables.
 364       if (frame.variables)
 365         [variables addObjectsFromArray:frame.variables];
 366
 367       // Add these new variables.
 368       NSArray* addVariables = [[message rootElement] children];
 369       if (addVariables) {
 370         for (NSXMLElement* elm in addVariables) {
 371           VariableNode* node = [[VariableNode alloc] initWithXMLNode:elm];
 372           [variables addObject:[node autorelease]];
 373         }
 374       }
 375
 376       frame.variables = variables;
 377     };
 378     [_client sendCommandWithFormat:@"context_get -d %d -c %d" handler:handler, frame.index, cid];
 379   }
 380 }
 381
 382 @end