Add simple fuzz-harness

fuzz/fuzz_layout.cpp

@@ -0,0 +1,50 @@
+#include <fuzzer/FuzzedDataProvider.h>
+#include <yoga/Yoga.h>
+#include <cstdint>
+
+YGFlexDirection fuzzed_flex_direction(FuzzedDataProvider& fdp) {
+  return fdp.PickValueInArray({
+      YGFlexDirectionColumn,
+      YGFlexDirectionColumnReverse,
+      YGFlexDirectionRow,
+      YGFlexDirectionRowReverse,
+  });
+}
+
+void FillFuzzedTree(
+    FuzzedDataProvider& fdp,
+    const YGConfigRef& config,
+    const YGNodeRef& root,
+    size_t depth = 0) {
+  constexpr size_t kMaxDepth = 20;
+  constexpr size_t kMaxChildren = 20;
+
+  if (depth > kMaxDepth) {
+    return;
+  }
+
+  size_t children = fdp.ConsumeIntegralInRange<size_t>(0, kMaxChildren);
+  for (size_t i = 0; i < children; i++) {
+    const YGNodeRef child = YGNodeNewWithConfig(config);
+    YGNodeStyleSetFlexDirection(root, fuzzed_flex_direction(fdp));
+    YGNodeStyleSetWidth(child, fdp.ConsumeFloatingPoint<float>());
+    YGNodeStyleSetGap(
+        child, YGGutterAll, fdp.ConsumeProbability<float>() * 100);
+    YGNodeStyleSetHeight(child, fdp.ConsumeFloatingPoint<float>());
+    YGNodeInsertChild(root, child, i);
+    FillFuzzedTree(fdp, config, child, depth + 1);
+  }
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  FuzzedDataProvider fdp(data, size);
+  const YGConfigRef config = YGConfigNew();
+  const YGNodeRef root = YGNodeNewWithConfig(config);
+  FillFuzzedTree(fdp, config, root);
+
+  YGNodeCalculateLayout(root, YGUndefined, YGUndefined, YGDirectionLTR);
+
+  YGNodeFreeRecursive(root);
+  YGConfigFree(config);
+  return 0;
+}