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, 5 insertions, 4 deletions

diff --git a/src/passes/PostEmscripten.cpp b/src/passes/PostEmscripten.cpp
index 00fb30b51..2397284c3 100644
--- a/src/passes/PostEmscripten.cpp
+++ b/src/passes/PostEmscripten.cpp
@@ -175,10 +175,11 @@ struct PostEmscripten : public Pass {
       });
 
     // Assume an indirect call might throw.
-    analyzer.propagateBack([](const Info& info) { return info.canThrow; },
-                           [](const Info& info) { return true; },
-                           [](Info& info) { info.canThrow = true; },
-                           analyzer.IndirectCallsHaveProperty);
+    analyzer.propagateBack(
+      [](const Info& info) { return info.canThrow; },
+      [](const Info& info) { return true; },
+      [](Info& info, Function* reason) { info.canThrow = true; },
+      analyzer.IndirectCallsHaveProperty);
 
     // Apply the information.
     struct OptimizeInvokes : public WalkerPass<PostWalker<OptimizeInvokes>> {