[interpreter] Add flag for controlling call budget

Author: rossberg

interpreter/exec/eval.ml

@@ -73,7 +73,8 @@ type config =
 }
 
 let frame inst locals = {inst; locals}
-let config inst vs es = {frame = frame inst []; code = vs, es; budget = 300}
+let config inst vs es =
+  {frame = frame inst []; code = vs, es; budget = !Flags.budget}
 
 let plain e = Plain e.it @@ e.at
 

interpreter/main/flags.ml

@@ -5,3 +5,4 @@ let print_sig = ref false
 let dry = ref false
 let width = ref 80
 let harness = ref true
+let budget = ref 256

interpreter/main/main.ml

@@ -24,11 +24,13 @@ let argspec = Arg.align
     " read script from file";
   "-o", Arg.String (fun file -> add_arg ("(output " ^ quote file ^ ")")),
     " write module to file";
+  "-b", Arg.Int (fun n -> Flags.budget := n),
+    " configure call depth budget (default is " ^ string_of_int !Flags.budget ^ ")";
   "-w", Arg.Int (fun n -> Flags.width := n),
-    " configure output width (default is 80)";
+    " configure output width (default is " ^ string_of_int !Flags.width ^ ")";
   "-s", Arg.Set Flags.print_sig, " show module signatures";
   "-u", Arg.Set Flags.unchecked, " unchecked, do not perform validation";
-  "-h", Arg.Clear Flags.harness, " exclude harness for JS conversion";
+  "-j", Arg.Clear Flags.harness, " exclude harness for JS conversion";
   "-d", Arg.Set Flags.dry, " dry, do not run program";
   "-t", Arg.Set Flags.trace, " trace execution";
   "-v", Arg.Unit banner, " show version"

test/build.py

@@ -60,7 +60,7 @@ def ensure_wasm_executable(path_to_wasm):
 def convert_one_wast_file(inputs):
     wast_file, js_file = inputs
     print('Compiling {} to JS...'.format(wast_file))
-    return run(WASM_EXEC, wast_file, '-h', '-o', js_file)
+    return run(WASM_EXEC, wast_file, '-j', '-o', js_file)
 
 def convert_wast_to_js(out_js_dir):
     """Compile all the wast files to JS and store the results in the JS dir."""