Asyncify verbose option (#3022)

This logs out the decisions made about instrumenting functions, which
can help figure out why a function is instrumented, or to get a list of
what might need to be.

As the test shows, it can print things like this:

[asyncify] import is an import that can change the state
[asyncify] calls-import can change the state due to import
[asyncify] calls-calls-import can change the state due to calls-import
[asyncify] calls-calls-calls-import can change the state due to calls-calls-import

(the test has calls-calls-calls-import => calls-calls-import => calls-import -> import).

1 files changed, 8 insertions, 3 deletions

diff --git a/src/ir/module-utils.h b/src/ir/module-utils.h
index ab23649f7..8f89c780f 100644
--- a/src/ir/module-utils.h
+++ b/src/ir/module-utils.h
@@ -349,9 +349,14 @@ template<typename T> struct CallGraphPropertyAnalysis {
   enum IndirectCalls { IgnoreIndirectCalls, IndirectCallsHaveProperty };
 
   // Propagate a property from a function to those that call it.
+  //
+  // hasProperty() - Check if the property is present.
+  // canHaveProperty() - Check if the property could be present.
+  // addProperty() - Adds the property. This receives a second parameter which
+  //                 is the function due to which we are adding the property.
   void propagateBack(std::function<bool(const T&)> hasProperty,
                      std::function<bool(const T&)> canHaveProperty,
-                     std::function<void(T&)> addProperty,
+                     std::function<void(T&, Function*)> addProperty,
                      IndirectCalls indirectCalls) {
     // The work queue contains items we just learned can change the state.
     UniqueDeferredQueue<Function*> work;
@@ -359,7 +364,7 @@ template<typename T> struct CallGraphPropertyAnalysis {
       if (hasProperty(map[func.get()]) ||
           (indirectCalls == IndirectCallsHaveProperty &&
            map[func.get()].hasIndirectCall)) {
-        addProperty(map[func.get()]);
+        addProperty(map[func.get()], func.get());
         work.push(func.get());
       }
     }
@@ -369,7 +374,7 @@ template<typename T> struct CallGraphPropertyAnalysis {
         // If we don't already have the property, and we are not forbidden
         // from getting it, then it propagates back to us now.
         if (!hasProperty(map[caller]) && canHaveProperty(map[caller])) {
-          addProperty(map[caller]);
+          addProperty(map[caller], func);
           work.push(caller);
         }
       }