Distinguish stack overflow from other traps (#388)

WebAssembly · Jan 18, 2017 · 5236d50 · 5236d50
1 parent 0729a93
commit 5236d50
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Showing 12 changed files with 48 additions and 20 deletions.
diff --git a/interpreter/host/js.ml b/interpreter/host/js.ml
@@ -85,6 +85,16 @@ let prefix =
   "  throw new Error(\"Wasm trap expected\");\n" ^
   "}\n" ^
   "\n" ^
+  "let StackOverflow;\n" ^
+  "try { (function f() { 1 + f() })() } catch (e) { StackOverflow = e.constructor }\n" ^
+  "\n" ^
+  "function assert_exhaustion(action) {\n" ^
+  "  try { action() } catch (e) {\n" ^
+  "    if (e instanceof StackOverflow) return;\n" ^
+  "  }\n" ^
+  "  throw new Error(\"Wasm resource exhaustion expected\");\n" ^
+  "}\n" ^
+  "\n" ^
   "function assert_return(action, expected) {\n" ^
   "  let actual = action();\n" ^
   "  if (!Object.is(actual, expected)) {\n" ^
@@ -301,8 +311,9 @@ let of_assertion mods ass =
     of_return_assertion mods act
       (fun act_js -> "assert_return_nan(() => " ^ act_js ^ ")")
       assert_return_nan
-  | AssertTrap (act, _) ->
-    let js act_js = "assert_trap(() => " ^ act_js ^ ")" in
+  | AssertTrap (act, _) | AssertExhaustion (act, _) ->
+    let name = match ass.it with AssertTrap _ -> "trap" | _ -> "exhaustion" in
+    let js act_js = "assert_" ^ name ^ "(() => " ^ act_js ^ ")" in
     match of_action mods act with
     | act_js, None -> js act_js ^ ";"
     | act_js, Some (act_wrapper, ts) ->

diff --git a/interpreter/host/run.ml b/interpreter/host/run.ml
@@ -97,6 +97,7 @@ let input_from get_script run =
   | Import.Unknown (at, msg) -> error at "link failure" msg
   | Eval.Link (at, msg) -> error at "link failure" msg
   | Eval.Trap (at, msg) -> error at "runtime trap" msg
+  | Eval.Exhaustion (at, msg) -> error at "resource exhaustion" msg
   | Eval.Crash (at, msg) -> error at "runtime crash" msg
   | Encode.Code (at, msg) -> error at "encoding error" msg
   | IO (at, msg) -> error at "i/o error" msg
@@ -377,6 +378,14 @@ let run_assertion ass =
     | _ -> Assert.error ass.at "expected runtime error"
     )
 
+  | AssertExhaustion (act, re) ->
+    trace ("Asserting exhaustion...");
+    (match run_action act with
+    | exception Eval.Exhaustion (_, msg) ->
+      assert_message ass.at "exhaustion" msg re
+    | _ -> Assert.error ass.at "expected exhaustion error"
+    )
+
 let rec run_command cmd =
   match cmd.it with
   | Module (x_opt, def) ->

diff --git a/interpreter/spec/eval.ml b/interpreter/spec/eval.ml
@@ -10,10 +10,12 @@ open Source
 module Link = Error.Make ()
 module Trap = Error.Make ()
 module Crash = Error.Make ()
+module Exhaustion = Error.Make ()
 
 exception Link = Link.Error
 exception Trap = Trap.Error
 exception Crash = Crash.Error (* failure that cannot happen in valid code *)
+exception Exhaustion = Exhaustion.Error
 
 let memory_error at = function
   | Memory.Bounds -> "out of bounds memory access"
@@ -281,7 +283,7 @@ let rec step (inst : instance) (c : config) : config =
       vs, [Local (inst', c'.locals, c'.values, c'.instrs) @@ e.at]
 
     | Invoke clos, vs when c.budget = 0 ->
-      vs, [Trapped "call stack exhausted" @@ e.at]
+      Exhaustion.error e.at "call stack exhausted"
 
     | Invoke clos, vs ->
       let FuncType (ins, out) = func_type_of clos in
@@ -322,7 +324,7 @@ let invoke (clos : closure) (vs : value list) : value list =
   let inst = instance (empty_module @@ at) in
   let c = config (List.rev vs) [Invoke clos @@ at] in
   try List.rev (eval inst c)
-  with Stack_overflow -> Trap.error at "call stack exhausted"
+  with Stack_overflow -> Exhaustion.error at "call stack exhausted"
 
 let eval_const (inst : instance) (const : const) : value =
   let c = config [] (List.map plain const.it) in

diff --git a/interpreter/spec/eval.mli b/interpreter/spec/eval.mli
@@ -4,6 +4,7 @@ open Instance
 exception Link of Source.region * string
 exception Trap of Source.region * string
 exception Crash of Source.region * string
+exception Exhaustion of Source.region * string
 
 val init : Ast.module_ -> extern list -> instance
 val invoke : closure -> value list -> value list (* raises Trap *)
diff --git a/interpreter/test/call.wast b/interpreter/test/call.wast
@@ -141,8 +141,8 @@
 (assert_return (invoke "odd" (i64.const 200)) (i32.const 99))
 (assert_return (invoke "odd" (i64.const 77)) (i32.const 44))
 
-(assert_trap (invoke "runaway") "call stack exhausted")
-(assert_trap (invoke "mutual-runaway") "call stack exhausted")
+(assert_exhaustion (invoke "runaway") "call stack exhausted")
+(assert_exhaustion (invoke "mutual-runaway") "call stack exhausted")
 
 
 ;; Invalid typing

diff --git a/interpreter/test/call_indirect.wast b/interpreter/test/call_indirect.wast
@@ -219,8 +219,8 @@
 (assert_return (invoke "odd" (i32.const 200)) (i32.const 99))
 (assert_return (invoke "odd" (i32.const 77)) (i32.const 44))
 
-(assert_trap (invoke "runaway") "call stack exhausted")
-(assert_trap (invoke "mutual-runaway") "call stack exhausted")
+(assert_exhaustion (invoke "runaway") "call stack exhausted")
+(assert_exhaustion (invoke "mutual-runaway") "call stack exhausted")
 
 
 ;; Invalid typing

diff --git a/interpreter/test/fac.wast b/interpreter/test/fac.wast
@@ -82,4 +82,4 @@
 (assert_return (invoke "fac-rec-named" (i64.const 25)) (i64.const 7034535277573963776))
 (assert_return (invoke "fac-iter-named" (i64.const 25)) (i64.const 7034535277573963776))
 (assert_return (invoke "fac-opt" (i64.const 25)) (i64.const 7034535277573963776))
-(assert_trap (invoke "fac-rec" (i64.const 1073741824)) "call stack exhausted")
+(assert_exhaustion (invoke "fac-rec" (i64.const 1073741824)) "call stack exhausted")
diff --git a/interpreter/test/skip-stack-guard-page.wast b/interpreter/test/skip-stack-guard-page.wast
@@ -2272,13 +2272,13 @@
   )
 )
 
-(assert_trap (invoke "test-guard-page-skip" (i32.const 0)) "call stack exhausted")
-(assert_trap (invoke "test-guard-page-skip" (i32.const 100)) "call stack exhausted")
-(assert_trap (invoke "test-guard-page-skip" (i32.const 200)) "call stack exhausted")
-(assert_trap (invoke "test-guard-page-skip" (i32.const 300)) "call stack exhausted")
-(assert_trap (invoke "test-guard-page-skip" (i32.const 400)) "call stack exhausted")
-(assert_trap (invoke "test-guard-page-skip" (i32.const 500)) "call stack exhausted")
-(assert_trap (invoke "test-guard-page-skip" (i32.const 600)) "call stack exhausted")
-(assert_trap (invoke "test-guard-page-skip" (i32.const 700)) "call stack exhausted")
-(assert_trap (invoke "test-guard-page-skip" (i32.const 800)) "call stack exhausted")
-(assert_trap (invoke "test-guard-page-skip" (i32.const 900)) "call stack exhausted")
+(assert_exhaustion (invoke "test-guard-page-skip" (i32.const 0)) "call stack exhausted")
+(assert_exhaustion (invoke "test-guard-page-skip" (i32.const 100)) "call stack exhausted")
+(assert_exhaustion (invoke "test-guard-page-skip" (i32.const 200)) "call stack exhausted")
+(assert_exhaustion (invoke "test-guard-page-skip" (i32.const 300)) "call stack exhausted")
+(assert_exhaustion (invoke "test-guard-page-skip" (i32.const 400)) "call stack exhausted")
+(assert_exhaustion (invoke "test-guard-page-skip" (i32.const 500)) "call stack exhausted")
+(assert_exhaustion (invoke "test-guard-page-skip" (i32.const 600)) "call stack exhausted")
+(assert_exhaustion (invoke "test-guard-page-skip" (i32.const 700)) "call stack exhausted")
+(assert_exhaustion (invoke "test-guard-page-skip" (i32.const 800)) "call stack exhausted")
+(assert_exhaustion (invoke "test-guard-page-skip" (i32.const 900)) "call stack exhausted")
diff --git a/interpreter/text/arrange.ml b/interpreter/text/arrange.ml
@@ -422,6 +422,8 @@ let assertion mode ass =
     Node ("assert_return_nan", [action act])
   | AssertTrap (act, re) ->
     Node ("assert_trap", [action act; Atom (string re)])
+  | AssertExhaustion (act, re) ->
+    Node ("assert_exhaustion", [action act; Atom (string re)])
 
 let command mode cmd =
   match cmd.it with

diff --git a/interpreter/text/lexer.mll b/interpreter/text/lexer.mll
@@ -311,6 +311,7 @@ rule token = parse
   | "assert_return" { ASSERT_RETURN }
   | "assert_return_nan" { ASSERT_RETURN_NAN }
   | "assert_trap" { ASSERT_TRAP }
+  | "assert_exhaustion" { ASSERT_EXHAUSTION }
   | "input" { INPUT }
   | "output" { OUTPUT }
 

diff --git a/interpreter/text/parser.mly b/interpreter/text/parser.mly
@@ -157,7 +157,7 @@ let inline_type (c : context) ty at =
 %token MODULE TABLE ELEM MEMORY DATA OFFSET IMPORT EXPORT TABLE
 %token SCRIPT REGISTER INVOKE GET
 %token ASSERT_MALFORMED ASSERT_INVALID ASSERT_SOFT_INVALID ASSERT_UNLINKABLE
-%token ASSERT_RETURN ASSERT_RETURN_NAN ASSERT_TRAP
+%token ASSERT_RETURN ASSERT_RETURN_NAN ASSERT_TRAP ASSERT_EXHAUSTION
 %token INPUT OUTPUT
 %token EOF
 
@@ -665,6 +665,7 @@ assertion :
   | LPAR ASSERT_RETURN action const_list RPAR { AssertReturn ($3, $4) @@ at () }
   | LPAR ASSERT_RETURN_NAN action RPAR { AssertReturnNaN $3 @@ at () }
   | LPAR ASSERT_TRAP action TEXT RPAR { AssertTrap ($3, $4) @@ at () }
+  | LPAR ASSERT_EXHAUSTION action TEXT RPAR { AssertExhaustion ($3, $4) @@ at () }
 
 cmd :
   | action { Action $1 @@ at () }

diff --git a/interpreter/text/script.ml b/interpreter/text/script.ml
@@ -20,6 +20,7 @@ and assertion' =
   | AssertReturn of action * Ast.literal list
   | AssertReturnNaN of action
   | AssertTrap of action * string
+  | AssertExhaustion of action * string
 
 type command = command' Source.phrase
 and command' =