Add --print-flow-graph-filter to allow filtering debugging output.

runtime/vm/il_printer.cc

 // Copyright (c) 2012, 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 "vm/il_printer.h"
 
 #include "vm/flow_graph_range_analysis.h"
 #include "vm/intermediate_language.h"
 #include "vm/os.h"
 #include "vm/parser.h"
 
 namespace dart {
 
 DEFINE_FLAG(bool, print_environments, false, "Print SSA environments.");
-
+DEFINE_FLAG(charp, print_flow_graph_filter, NULL,
+    "Print only IR of functions with matching names");
 
 void BufferFormatter::Print(const char* format, ...) {
   va_list args;
   va_start(args, format);
   VPrint(format, args);
   va_end(args);
 }
 
 
 void BufferFormatter::VPrint(const char* format, va_list args) {
   intptr_t available = size_ - position_;
   if (available <= 0) return;
   intptr_t written =
       OS::VSNPrint(buffer_ + position_, available, format, args);
   if (written >= 0) {
     position_ += (available <= written) ? available : written;
   }
 }
 
 
+// Checks whether function's name matches the given filter, which is
+// a comma-separated list of strings.
+bool FlowGraphPrinter::PassesFilter(const char* filter,
+                                    const Function& function) {
+  if (filter == NULL) {
+    return true;
+  }
+
+  char* save_ptr;  // Needed for strtok_r.
+  const char* function_name = function.ToFullyQualifiedCString();
+  intptr_t function_name_len = strlen(function_name);
+
+  intptr_t len = strlen(filter) + 1;  // Length with \0.
+  char* filter_buffer = new char[len];
+  strncpy(filter_buffer, filter, len);  // strtok modifies arg 1.
+  char* token = strtok_r(filter_buffer, ",", &save_ptr);
+  bool found = false;
+  while (token != NULL) {
+    if (strstr(function_name, token) != NULL) {
+      found = true;
+      break;
+    }
+    const intptr_t token_len = strlen(token);
+    if (token[token_len - 1] == '%') {
+      if (function_name_len > token_len) {
+        const char* suffix = function_name +
+            (function_name_len - token_len + 1);
+        if (strncmp(suffix, token, token_len - 1) == 0) {
+          found = true;
+          break;
+        }
+      }
+    }
+    token = strtok_r(NULL, ",", &save_ptr);
+  }
+  delete[] filter_buffer;
+
+  return found;
+}
+
+
+bool FlowGraphPrinter::ShouldPrint(const Function& function) {
+  return PassesFilter(FLAG_print_flow_graph_filter, function);
+}
+
+
 void FlowGraphPrinter::PrintGraph(const char* phase, FlowGraph* flow_graph) {
   OS::Print("*** BEGIN CFG\n%s\n", phase);
   FlowGraphPrinter printer(*flow_graph);
   printer.PrintBlocks();
   OS::Print("*** END CFG\n");
   fflush(stdout);
 }
 
 
 void FlowGraphPrinter::PrintBlock(BlockEntryInstr* block,
@@ skipping 1113 matching lines @@
 }
 
 const char* Environment::ToCString() const {
   char buffer[1024];
   BufferFormatter bf(buffer, 1024);
   PrintTo(&bf);
   return Isolate::Current()->current_zone()->MakeCopyOfString(buffer);
 }
 
 }  // namespace dart