1 files changed, 45 insertions, 0 deletions
diff --git a/instrumentation/afl-llvm-common.cc b/instrumentation/afl-llvm-common.cc
index 8e9e7800..ed9268dc 100644
--- a/instrumentation/afl-llvm-common.cc
+++ b/instrumentation/afl-llvm-common.cc
@@ -26,6 +26,51 @@ static std::list<std::string> allowListFunctions;
 static std::list<std::string> denyListFiles;
 static std::list<std::string> denyListFunctions;
 
+unsigned int calcCyclomaticComplexity(llvm::Function *F) {
+
+  unsigned int numBlocks = 0;
+  unsigned int numEdges = 0;
+  unsigned int numCalls = 0;
+
+  // Iterate through each basic block in the function
+  for (BasicBlock &BB : *F) {
+
+    // count all nodes == basic blocks
+    numBlocks++;
+    // Count the number of successors (outgoing edges)
+    for (BasicBlock *Succ : successors(&BB)) {
+
+      // count edges for CC
+      numEdges++;
+      (void)(Succ);
+
+    }
+
+    for (Instruction &I : BB) {
+
+      // every call is also an edge, so we need to count the calls too
+      if (isa<CallInst>(&I) || isa<InvokeInst>(&I)) { numCalls++; }
+
+    }
+
+  }
+
+  // Cyclomatic Complexity V(G) = E - N + 2P
+  // For a single function, P (number of connected components) is 1
+  // Calls are considered to be an edge
+  unsigned int CC = 2 + numCalls + numEdges - numBlocks;
+
+  // if (debug) {
+
+  fprintf(stderr, "CyclomaticComplexity for %s: %u\n",
+          F->getName().str().c_str(), CC);
+
+  //}
+
+  return CC;
+
+}
+
 char *getBBName(const llvm::BasicBlock *BB) {
 
   static char *name;