add simple example

1 files changed, 44 insertions, 0 deletions

diff --git a/test/example/find_div0s.cpp b/test/example/find_div0s.cpp
new file mode 100644
index 000000000..77a5d2c61
--- /dev/null
+++ b/test/example/find_div0s.cpp
@@ -0,0 +1,44 @@
+
+#include <ostream>
+#include <wasm.h>
+
+using namespace wasm;
+
+int main() {
+  // A module with a function with a division by zero in the body
+  Module module;
+  Function func;
+  func.name = "func";
+  Binary div;
+  div.op = BinaryOp::DivS;
+  Const left;
+  left.value = 5;
+  Const right;
+  right.value = 0;
+  div.left = &left;
+  div.right = &right;
+  div.finalize();
+  func.body = &div;
+  module.addFunction(&func);
+
+  // Print it out
+  std::cout << module;
+
+  // Search it for divisions by zero: Walk the module, looking for
+  // that operation.
+  struct DivZeroSeeker : public WasmWalker {
+    void visitBinary(Binary* curr) {
+      // In every Binary, look for integer divisions
+      if (curr->op == BinaryOp::DivS || curr->op == BinaryOp::DivU) {
+        // Check if the right operand is a constant, and if it is 0
+        auto right = curr->right->dyn_cast<Const>();
+        if (right && right->value.getInteger() == 0) {
+          std::cout << "We found that " << curr->left << " is divided by zero\n";
+        }
+      }
+    }
+  };
+  DivZeroSeeker seeker;
+  seeker.startWalk(&module);
+}
+