First bits of external debugger API

runtime/bin/main.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 
 #include "include/dart_api.h"
+#include "include/dart_debugger_api.h"
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
 #include "bin/file.h"
 #include "bin/globals.h"
 #include "bin/platform.h"
 
 // snapshot_buffer points to a snapshot if we link in a snapshot otherwise
 // it is initialized to NULL.
 extern const uint8_t* snapshot_buffer;
 
 
 // Global state that stores a pointer to the application script file.
 static char* canonical_script_name = NULL;
 
 
 // Global state that indicates whether pprof symbol information is
 // to be generated or not.
 static const char* generate_pprof_symbols_filename = NULL;
 
 
+// Global state that indicates whether there is a debug breakpoint.
+// This pointer points into an argv buffer and does not need to be
+// free'd.
+static const char* breakpoint_at = NULL;
+
+
 static bool IsValidFlag(const char* name,
                         const char* prefix,
                         intptr_t prefix_length) {
   intptr_t name_length = strlen(name);
   return ((name_length > prefix_length) &&
           (strncmp(name, prefix, prefix_length) == 0));
 }
 
 
 static const char* ProcessOption(const char* option, const char* name) {
   const intptr_t length = strlen(name);
   if (strncmp(option, name, length) == 0) {
     return (option + length);
   }
   return NULL;
 }
 
 
 static bool ProcessPprofOption(const char* option) {
   const char* kProfOption = "--generate_pprof_symbols=";
   const char* filename = ProcessOption(option, kProfOption);
   if (filename != NULL) {
     generate_pprof_symbols_filename = filename;
   }
   return filename != NULL;
 }
 
 
+static bool ProcessDebugOption(const char* option) {
+  const char* kDebugOption = "--break_at=";
+  const char* func_name = ProcessOption(option, kDebugOption);
+  if (func_name != NULL) {
+    breakpoint_at = func_name;
+  }
+  return func_name != NULL;
+}
+
+
 // Parse out the command line arguments. Returns -1 if the arguments
 // are incorrect, 0 otherwise.
 static int ParseArguments(int argc,
                           char** argv,
                           CommandLineOptions* vm_options,
                           char** script_name,
                           CommandLineOptions* dart_options) {
   const char* kPrefix = "--";
   const intptr_t kPrefixLen = strlen(kPrefix);
 
   // Skip the binary name.
   int i = 1;
 
   // Parse out the vm options.
   while ((i < argc) && IsValidFlag(argv[i], kPrefix, kPrefixLen)) {
     if (ProcessPprofOption(argv[i])) {
       i += 1;
-      continue;
+    } else if (ProcessDebugOption(argv[i])) {
+      i += 1;
+    } else {
+      vm_options->AddArgument(argv[i]);
+      i += 1;
     }
-    vm_options->AddArgument(argv[i]);
-    i += 1;
   }
   if (generate_pprof_symbols_filename != NULL) {
     Dart_InitPprofSupport();
   }
 
   // Get the script name.
   if (i < argc) {
     *script_name = argv[i];
     i += 1;
   } else {
@@ skipping 232 matching lines @@
   // Create a dart options object that can be accessed from dart code.
   Dart_Handle options_result = SetupRuntimeOptions(&dart_options);
   if (Dart_IsError(options_result)) {
     fprintf(stderr, "%s\n", Dart_GetError(options_result));
     Dart_ExitScope();
     Dart_ShutdownIsolate();
     free(canonical_script_name);
     return 255;  // Indicates we encountered an error.
   }
 
-  // Lookup and invoke the top level main function.
+  // Lookup the library of the main script.
   Dart_Handle script_url = Dart_NewString(canonical_script_name);
   Dart_Handle library = Dart_LookupLibrary(script_url);
   if (Dart_IsError(library)) {
     fprintf(stderr, "%s\n", Dart_GetError(library));
     Dart_ExitScope();
     Dart_ShutdownIsolate();
     free(canonical_script_name);
     return 255;  // Indicates we encountered an error.
   }
+  // Set debug breakpoint if specified on the command line.
+  if (breakpoint_at != NULL) {
+    char* bpt_function = strdup(breakpoint_at);
+    Dart_Handle class_name;
+    Dart_Handle function_name;
+    char* dot = strchr(bpt_function, '.');
+    if (dot == NULL) {
+      class_name = Dart_NewString("");
+      function_name = Dart_NewString(breakpoint_at);
+    } else {
+      *dot = '\0';
+      class_name = Dart_NewString(bpt_function);
+      function_name = Dart_NewString(dot + 1);
+    }
+    free(bpt_function);
+    Dart_Breakpoint bpt;
+    result = Dart_SetBreakpointAtEntry(
+                 library, class_name, function_name, &bpt);
+    if (Dart_IsError(result)) {
+      fprintf(stderr, "Error setting breakpoint at '%s': %s\n",
+          breakpoint_at,
+          Dart_GetError(result));
+      Dart_ExitScope();
+      Dart_ShutdownIsolate();
+      free(canonical_script_name);
+      return 255;  // Indicates we encountered an error.
+    }
+  }
+  // Lookup and invoke the top level main function.
   result = Dart_InvokeStatic(library,
                              Dart_NewString(""),
                              Dart_NewString("main"),
                              0,
                              NULL);
   if (Dart_IsError(result)) {
     fprintf(stderr, "%s\n", Dart_GetError(result));
     Dart_ExitScope();
     Dart_ShutdownIsolate();
     free(canonical_script_name);
     return 255;  // Indicates we encountered an error.
   }
   // Keep handling messages until the last active receive port is closed.
   result = Dart_RunLoop();
   if (Dart_IsError(result)) {
     fprintf(stderr, "%s\n", Dart_GetError(result));
     Dart_ExitScope();
     Dart_ShutdownIsolate();
     free(canonical_script_name);
     return 255;  // Indicates we encountered an error.
   }
   free(canonical_script_name);
   Dart_ExitScope();
   // Dump symbol information for the profiler.
   DumpPprofSymbolInfo();
   // Shutdown the isolate.
   Dart_ShutdownIsolate();
   return 0;
 }