[Java frontend]Javalib's lambda rewritting is making his way through Infer

Reviewed By: ngorogiannis

Differential Revision: D19970219

fbshipit-source-id: b14bb36a4

Author: davidpichardie

infer/src/IR/Cfg.ml

@@ -128,7 +128,13 @@ let proc_inline_synthetic_methods cfg pdesc : unit =
           let attributes = Procdesc.get_attributes pd in
           let is_synthetic = attributes.is_synthetic_method in
           let is_bridge = attributes.is_bridge_method in
-          if is_access || is_bridge || is_synthetic then
+          let is_generated_for_lambda =
+            String.is_substring ~substring:"$Lambda$" (Procname.get_method pn)
+          in
+          (* this is a temporary hack in order to stop synthetic inlining on
+             methods that are generated for lambda rewritting *)
+          if is_generated_for_lambda then instr
+          else if is_access || is_bridge || is_synthetic then
             inline_synthetic_method ret_id_typ etl pd loc |> Option.value ~default:instr
           else instr
       | exception (Caml.Not_found | Not_found_s _) ->

infer/src/java/jClasspath.ml

@@ -255,17 +255,22 @@ let get_classpath_channel program = program.classpath.channel
 
 let get_models program = program.models
 
+(* this string should characterize the methods we generate for lambda rewriting *)
+let lambda_str = "$Lambda$"
+
 let add_class cn jclass program =
   (* [prefix] must be a fresh class name *)
-  let prefix = JBasics.cn_name cn ^ "$Lambda$" in
+  let prefix = JBasics.cn_name cn ^ lambda_str in
   (* we rewrite each class to replace invokedynamic (closure construction)
      with equivalent old-style Java code that implements a suitable Java interface *)
   let rewritten_jclass, new_classes = Javalib.remove_invokedynamics jclass ~prefix in
   program.classmap <- JBasics.ClassMap.add cn rewritten_jclass program.classmap ;
   (* the rewrite will generate new classes and we add them to the program *)
   JBasics.ClassMap.iter
     (fun cn jcl -> program.classmap <- JBasics.ClassMap.add cn jcl program.classmap)
-    new_classes
+    new_classes ;
+  rewritten_jclass
+
 
 let set_callee_translated program pname = Procname.Hash.replace program.callees pname Translated
 
@@ -286,7 +291,7 @@ let lookup_node cn program =
   with Caml.Not_found -> (
     try
       let jclass = javalib_get_class (get_classpath_channel program) cn in
-      add_class cn jclass program ; Some jclass
+      Some (add_class cn jclass program)
     with
     | JBasics.No_class_found _ ->
         (* TODO T28155039 Figure out when and what to log *)

infer/src/java/jTrans.ml

@@ -217,10 +217,12 @@ let get_bytecode cm =
       L.(die InternalError)
         "native method %s found in %s@." (JBasics.ms_name ms) (JBasics.cn_name cn)
   | Javalib.Java t ->
-      (* Sawja doesn't handle invokedynamic, and it will crash with a Match_failure if we give it
-         bytecode with this instruction. hack around this problem by converting all invokedynamic's
-         to invokestatic's that call a method with the same signature as the lambda on
-         java.lang.Object. this isn't great, but it's a lot better than crashing *)
+      (* Java frontend doesn't know how to translate Sawja invokedynamics, but most
+         of them will be rewritten by Javalib before arriving to Sawja. For the
+         remainings we (still) use this hack that convert an invokedynamic
+         into an invokestatic that calls a method with the same signature as the lambda.
+         But the objective is to never have to do that and hope Javalib rewriting
+         is complete enough *)
       let bytecode = Lazy.force t in
       let c_code =
         Array.map

infer/tests/codetoanalyze/java/infer/InvokeDynamic.java

@@ -9,6 +9,7 @@
 
 import java.util.Collections;
 import java.util.List;
+import java.util.function.Function;
 
 public class InvokeDynamic {
 
@@ -32,7 +33,8 @@ void npeInLambdaBad(List<String> list) {
         });
   }
 
-  // we won't get this one because we don't actually translate the invocation of the lambda
+  // we still don't get this one (even with Javalib lambda rewriting)
+  // because Collections.sort is skipped
   void FN_npeViaCaptureBad(List<String> list) {
     String s = null;
     Collections.sort(
@@ -41,4 +43,15 @@ void FN_npeViaCaptureBad(List<String> list) {
           return s.compareTo(a);
         });
   }
+
+  Integer npeViaSimpleCapture() {
+    String s = null;
+    Function<String, Integer> f = (s1) -> s.length();
+    return f.apply(null);
+  }
+
+  Integer npeViaSimpleParamPassing() {
+    Function<String, Integer> f = (s) -> s.length();
+    return f.apply(null);
+  }
 }

infer/tests/codetoanalyze/java/infer/issues.exp

@@ -100,6 +100,8 @@ codetoanalyze/java/infer/HashMapExample.java, codetoanalyze.java.infer.HashMapEx
 codetoanalyze/java/infer/IntegerExample.java, codetoanalyze.java.infer.IntegerExample.testIntegerEqualsBad():void, 5, NULL_DEREFERENCE, B1, ERROR, [start of procedure testIntegerEqualsBad(),Taking true branch]
 codetoanalyze/java/infer/InvokeDynamic.java, codetoanalyze.java.infer.InvokeDynamic.invokeDynamicThenNpeBad(java.util.List):void, 6, NULL_DEREFERENCE, B1, ERROR, [start of procedure invokeDynamicThenNpeBad(...),start of procedure callsite_codetoanalyze.java.infer.InvokeDynamic$Lambda$_3_3(),return from a call to Comparator InvokeDynamic.callsite_codetoanalyze.java.infer.InvokeDynamic$Lambda$_3_3(),Skipping sort(...): unknown method]
 codetoanalyze/java/infer/InvokeDynamic.java, codetoanalyze.java.infer.InvokeDynamic.lambda$npeInLambdaBad$1(java.lang.String,java.lang.String):int, 1, NULL_DEREFERENCE, B1, ERROR, [start of procedure lambda$npeInLambdaBad$1(...)]
+codetoanalyze/java/infer/InvokeDynamic.java, codetoanalyze.java.infer.InvokeDynamic.npeViaSimpleCapture():java.lang.Integer, 2, PRECONDITION_NOT_MET, no_bucket, WARNING, [start of procedure npeViaSimpleCapture(),start of procedure callsite_codetoanalyze.java.infer.InvokeDynamic$Lambda$_10_3(...),return from a call to Function InvokeDynamic.callsite_codetoanalyze.java.infer.InvokeDynamic$Lambda$_10_3(String)]
+codetoanalyze/java/infer/InvokeDynamic.java, codetoanalyze.java.infer.InvokeDynamic.npeViaSimpleParamPassing():java.lang.Integer, 1, PRECONDITION_NOT_MET, no_bucket, WARNING, [start of procedure npeViaSimpleParamPassing(),start of procedure callsite_codetoanalyze.java.infer.InvokeDynamic$Lambda$_11_0(),return from a call to Function InvokeDynamic.callsite_codetoanalyze.java.infer.InvokeDynamic$Lambda$_11_0()]
 codetoanalyze/java/infer/JunitAssertion.java, codetoanalyze.java.infer.JunitAssertion.consistentAssertion(codetoanalyze.java.infer.JunitAssertion$A):void, 0, PRECONDITION_NOT_MET, no_bucket, WARNING, [start of procedure consistentAssertion(...),Taking false branch]
 codetoanalyze/java/infer/JunitAssertion.java, codetoanalyze.java.infer.JunitAssertion.inconsistentAssertion(codetoanalyze.java.infer.JunitAssertion$A):void, 1, NULL_DEREFERENCE, B5, ERROR, [start of procedure inconsistentAssertion(...),Taking false branch]
 codetoanalyze/java/infer/Lists.java, codetoanalyze.java.infer.Lists.clearCausesEmptinessNPE(java.util.List,int):void, 4, NULL_DEREFERENCE, B1, ERROR, [start of procedure clearCausesEmptinessNPE(...),Taking true branch,Taking true branch]