Skip gap blocks early to avoid stdout flooding in verbose mode, and

syzygy/instrument/transforms/afl_transform.cc

 // Copyright 2017 Google Inc. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 183 matching lines @@
 }
 
 bool AFLTransform::OnBlock(const TransformPolicyInterface* policy,
                            BlockGraph* block_graph,
                            BlockGraph::Block* block) {
   total_blocks_++;
 
   if (block->type() != BlockGraph::CODE_BLOCK)
     return true;
 
+  // We exclude gap blocks early to not bias the percentage of instrumentation.
+  // Some binaries have a lot of them and give the impression of a poor
+  // instrumentation ratio when it is actually not the case.
+  // It also avoids to have stdout flooded when using the verbose mode and
+  // not forcing decomposition (as the PE policy rejects gap blocks).
+  if (block->attributes() & BlockGraph::GAP_BLOCK)
+    return true;
+
   total_code_blocks_++;
 
   // Use the policy to skip blocks that aren't eligible for basic block
   // decomposition. Let the user be able to override it though.
   if (!force_decompose_) {
     if (!policy->BlockIsSafeToBasicBlockDecompose(block)) {
       VLOG(1) << "Not instrumenting " << block->name();
       return true;
     }
   }
@@ skipping 118 matching lines @@
     } else {
       bb_ranges_.push_back(source_range);
     }
   }
 
   return true;
 }
 
 }  // namespace transforms
 }  // namespace instrument