[inferbo] Do not report duplicate issues

Summary: Merge safety conditions that are exactly the same, keep the earliest location.

Reviewed By: jvillard

Differential Revision: D5953981

fbshipit-source-id: 874eee1

infer/src/bufferoverrun/bufferOverrunProofObligations.ml

@@ -20,6 +20,8 @@ module Condition = struct
 
   let get_symbols c = ItvPure.get_symbols c.idx @ ItvPure.get_symbols c.size
 
+  let eq c1 c2 = ItvPure.equal c1.idx c2.idx && ItvPure.equal c1.size c2.size
+
   let set_size_pos : t -> t =
     fun c ->
       let size' = ItvPure.make_positive c.size in
@@ -162,9 +164,37 @@ module ConditionSet = struct
 
   type t = condition_with_trace list
 
+  (* invariant: add_one of one of the elements should return the original list *)
+
   let empty = []
 
-  let join condset1 condset2 = condset1 @ condset2
+  let compare_by_location cwt1 cwt2 =
+    Location.compare (ConditionTrace.get_location cwt1.trace)
+      (ConditionTrace.get_location cwt2.trace)
+
+  let try_merge ~existing ~new_ =
+    if Condition.eq existing.cond new_.cond then
+      (* keep the first one in the code *)
+      if compare_by_location existing new_ <= 0 then `KeepExistingAndStop
+      else `RemoveExistingAddNewAndStop
+    else `KeepGoingFinallyAddNew
+
+  let add_one condset new_ =
+    let rec aux ~new_ acc = function
+      | []
+       -> new_ :: condset
+      | existing :: rest ->
+        match try_merge ~existing ~new_ with
+        | `KeepExistingAndStop
+         -> condset
+        | `RemoveExistingAddNewAndStop
+         -> new_ :: List.rev_append acc rest
+        | `KeepGoingFinallyAddNew
+         -> aux ~new_ (existing :: acc) rest
+    in
+    aux ~new_ [] condset
+
+  let join condset1 condset2 = List.fold_left ~f:add_one condset1 ~init:condset2
 
   let add_bo_safety pname loc id ~idx ~size val_traces condset =
     match Condition.make ~idx ~size with

infer/src/bufferoverrun/itv.ml

@@ -633,6 +633,8 @@ module ItvPure = struct
 
   type t = astate
 
+  let equal = [%compare.equal : astate]
+
   let initial : t = (Bound.initial, Bound.initial)
 
   let lb : t -> Bound.t = fst

infer/tests/codetoanalyze/c/bufferoverrun/issues.exp

@@ -6,13 +6,10 @@ codetoanalyze/c/bufferoverrun/break_continue_return.c, break_continue_return, 13
 codetoanalyze/c/bufferoverrun/break_continue_return.c, break_continue_return, 16, BUFFER_OVERRUN, [ArrayDeclaration,Assignment,ArrayAccess: Offset: [0, 10] Size: [10, 10]]
 codetoanalyze/c/bufferoverrun/cast.c, cast2_Good_FP, 2, BUFFER_OVERRUN, [ArrayDeclaration,ArrayAccess: Offset: [4, 4] Size: [4, 4]]
 codetoanalyze/c/bufferoverrun/do_while.c, do_while, 2, BUFFER_OVERRUN, [ArrayDeclaration,Assignment,Call,Assignment,ArrayAccess: Offset: [0, +oo] Size: [10, 10] @ codetoanalyze/c/bufferoverrun/do_while.c:18:5 by call `do_while_sub()` ]
-codetoanalyze/c/bufferoverrun/do_while.c, do_while, 3, BUFFER_OVERRUN, [ArrayDeclaration,Assignment,Call,Assignment,ArrayAccess: Offset: [0, +oo] Size: [10, 10] @ codetoanalyze/c/bufferoverrun/do_while.c:18:5 by call `do_while_sub()` ]
 codetoanalyze/c/bufferoverrun/duplicates.c, one_alarm_is_enough, 2, BUFFER_OVERRUN, [ArrayDeclaration,Call,ArrayAccess: Offset: [1, 1] Size: [1, 1] @ codetoanalyze/c/bufferoverrun/duplicates.c:11:7 by call `two_accesses()` ]
-codetoanalyze/c/bufferoverrun/duplicates.c, one_alarm_is_enough, 2, BUFFER_OVERRUN, [ArrayDeclaration,Call,ArrayAccess: Offset: [1, 1] Size: [1, 1] @ codetoanalyze/c/bufferoverrun/duplicates.c:12:5 by call `two_accesses()` ]
 codetoanalyze/c/bufferoverrun/external.c, extern_bad, 4, BUFFER_OVERRUN, [ArrayDeclaration,ArrayAccess: Offset: [10, 10] Size: [10, 10]]
 codetoanalyze/c/bufferoverrun/external.c, extern_bad, 5, BUFFER_OVERRUN, [Assignment,ArrayAccess: Offset: [-oo, +oo] Size: [0, +oo]]
 codetoanalyze/c/bufferoverrun/external.c, extern_bad, 7, BUFFER_OVERRUN, [ArrayDeclaration,ArrayAccess: Offset: [20, 20] Size: [10, 10]]
-codetoanalyze/c/bufferoverrun/external.c, extern_bad, 8, BUFFER_OVERRUN, [Assignment,ArrayAccess: Offset: [-oo, +oo] Size: [0, +oo]]
 codetoanalyze/c/bufferoverrun/external.c, extern_bad, 10, BUFFER_OVERRUN, [ArrayDeclaration,ArrayAccess: Offset: [30, 30] Size: [10, 10]]
 codetoanalyze/c/bufferoverrun/for_loop.c, for_loop, 10, BUFFER_OVERRUN, [Call,ArrayDeclaration,Assignment,Assignment,Return,Assignment,Assignment,ArrayAccess: Offset: [0, 9] Size: [5, 10]]
 codetoanalyze/c/bufferoverrun/for_loop.c, safealloc, 10, UNREACHABLE_CODE, []

infer/tests/codetoanalyze/cpp/bufferoverrun/issues.exp

@@ -3,7 +3,6 @@ codetoanalyze/cpp/bufferoverrun/class.cpp, my_class_access_Bad, 2, BUFFER_OVERRU
 codetoanalyze/cpp/bufferoverrun/external.cpp, extern_bad, 4, BUFFER_OVERRUN, [ArrayDeclaration,ArrayAccess: Offset: [10, 10] Size: [10, 10]]
 codetoanalyze/cpp/bufferoverrun/external.cpp, extern_bad, 5, BUFFER_OVERRUN, [Assignment,ArrayAccess: Offset: [-oo, +oo] Size: [0, +oo]]
 codetoanalyze/cpp/bufferoverrun/external.cpp, extern_bad, 7, BUFFER_OVERRUN, [ArrayDeclaration,ArrayAccess: Offset: [20, 20] Size: [10, 10]]
-codetoanalyze/cpp/bufferoverrun/external.cpp, extern_bad, 8, BUFFER_OVERRUN, [Assignment,ArrayAccess: Offset: [-oo, +oo] Size: [0, +oo]]
 codetoanalyze/cpp/bufferoverrun/external.cpp, extern_bad, 10, BUFFER_OVERRUN, [ArrayDeclaration,ArrayAccess: Offset: [30, 30] Size: [10, 10]]
 codetoanalyze/cpp/bufferoverrun/function_call.cpp, call_by_ref_bad, 4, BUFFER_OVERRUN, [ArrayDeclaration,Call,Assignment,ArrayAccess: Offset: [-1, -1] Size: [10, 10]]
 codetoanalyze/cpp/bufferoverrun/remove_temps.cpp, C_foo_Bad, 1, CONDITION_ALWAYS_TRUE, []
@@ -17,7 +16,6 @@ codetoanalyze/cpp/bufferoverrun/trivial.cpp, trivial, 2, BUFFER_OVERRUN, [ArrayD
 codetoanalyze/cpp/bufferoverrun/vector.cpp, call_safe_access4_Good_FP, 2, BUFFER_OVERRUN, [Call,Call,Assignment,Call,Call,Assignment,Return,Call,Assignment,Call,Call,Call,Call,ArrayDeclaration,Assignment,ArrayAccess: Offset: [0, 0] Size: [0, 0]]
 codetoanalyze/cpp/bufferoverrun/vector.cpp, just_test_model_FP, 11, BUFFER_OVERRUN, [Call,Assignment,Call,Call,Call,Call,Call,Assignment,Call,Call,Call,Call,Call,Assignment,Call,Call,Call,Call,Call,Assignment,Call,Call,Call,Call,Call,Assignment,Call,Call,ArrayDeclaration,Assignment,ArrayAccess: Offset: [0, 0] Size: [0, +oo]]
 codetoanalyze/cpp/bufferoverrun/vector.cpp, just_test_model_FP, 16, BUFFER_OVERRUN, [Call,ArrayAccess: Offset: [-oo, +oo] Size: [0, +oo]]
-codetoanalyze/cpp/bufferoverrun/vector.cpp, just_test_model_FP, 17, BUFFER_OVERRUN, [Call,Call,Call,Assignment,Call,Call,ArrayDeclaration,Assignment,ArrayAccess: Offset: [0, 0] Size: [0, +oo]]
 codetoanalyze/cpp/bufferoverrun/vector.cpp, just_test_model_FP, 18, BUFFER_OVERRUN, [Call,Call,Call,Assignment,Call,Call,Call,Call,Call,ArrayDeclaration,Assignment,ArrayAccess: Offset: [1, 1] Size: [0, +oo]]
 codetoanalyze/cpp/bufferoverrun/vector.cpp, out_of_bound_Bad, 2, BUFFER_OVERRUN, [Call,Call,Call,ArrayDeclaration,Assignment,ArrayAccess: Offset: [max(0, s$12), s$13] Size: [max(0, s$12), s$13]]
 codetoanalyze/cpp/bufferoverrun/vector.cpp, push_back_Bad, 3, BUFFER_OVERRUN, [Call,Call,Assignment,Call,Assignment,Call,Call,ArrayDeclaration,Assignment,ArrayAccess: Offset: [1, 1] Size: [1, 1]]