From b7d70ff17846877418ff5d6cf92c53f84a6661d6 Mon Sep 17 00:00:00 2001
From: Martino Luca <martinoluca@fb.com>
Date: Tue, 9 Aug 2016 03:10:22 -0700
Subject: [PATCH] Add support for extra cases of BAD_POINTER_COMPARISON warning

Reviewed By: akotulski

Differential Revision: D3674896

fbshipit-source-id: 48d10bf
---
 infer/src/clang/cFrontend_checkers.ml         | 23 +++--
 .../codetoanalyze/objc/linters/badpointer.m   | 90 +++++++++++++++++++
 .../endtoend/objc/linters/NSNumber2Test.java  |  2 +-
 3 files changed, 101 insertions(+), 14 deletions(-)

diff --git a/infer/src/clang/cFrontend_checkers.ml b/infer/src/clang/cFrontend_checkers.ml
index 5d35088ea..152e20487 100644
--- a/infer/src/clang/cFrontend_checkers.ml
+++ b/infer/src/clang/cFrontend_checkers.ml
@@ -277,23 +277,20 @@ let captured_cxx_ref_in_objc_block_warning _ stmt_info captured_vars =
 let bad_pointer_comparison_warning _ stmt_info stmts =
   let rec condition stmts =
     let condition_aux stmt =
-      match stmt with
-      | Clang_ast_t.CallExpr _
-      | Clang_ast_t.CXXMemberCallExpr _
-      | Clang_ast_t.CXXOperatorCallExpr _
-      | Clang_ast_t.ObjCMessageExpr _ -> false
-      | Clang_ast_t.BinaryOperator (_, _, _, boi)
-        when (boi.boi_kind = `NE) || (boi.boi_kind = `EQ) -> false
-      | Clang_ast_t.UnaryOperator (_, stmts, _, uoi) when uoi.uoi_kind = `LNot ->
+      match (stmt: Clang_ast_t.stmt) with
+      | BinaryOperator (_, _, _, boi) when
+          (boi.boi_kind = `EQ) || (boi.boi_kind = `NE) -> false
+      | BinaryOperator (_, stmts, _, _) -> condition stmts
+      | UnaryOperator (_, stmts, _, uoi) when uoi.uoi_kind = `LNot ->
+          condition stmts
+      | ImplicitCastExpr (_, stmts, _, _)
+      | ExprWithCleanups (_, stmts, _, _) ->
           condition stmts
       | stmt ->
           match Clang_ast_proj.get_expr_tuple stmt with
-          | Some (_, stmts, expr_info) ->
+          | Some (_, _, expr_info) ->
               let typ = CFrontend_utils.Ast_utils.get_desugared_type expr_info.ei_type_ptr in
-              if CFrontend_utils.Ast_utils.is_ptr_to_objc_class typ "NSNumber" then
-                true
-              else
-                condition stmts
+              CFrontend_utils.Ast_utils.is_ptr_to_objc_class typ "NSNumber"
           | _ -> false in
     IList.exists condition_aux stmts in
   if condition stmts then
diff --git a/infer/tests/codetoanalyze/objc/linters/badpointer.m b/infer/tests/codetoanalyze/objc/linters/badpointer.m
index 42c34b488..868bc01dc 100644
--- a/infer/tests/codetoanalyze/objc/linters/badpointer.m
+++ b/infer/tests/codetoanalyze/objc/linters/badpointer.m
@@ -53,3 +53,93 @@ void good2() {
     i = 0;
   }
 }
+
+int good3(NSNumber* number) {
+  if (number.doubleValue) {
+    return 0;
+  }
+  return 1;
+}
+
+//---
+
+@interface Simple : NSObject
+
+@property(strong, atomic) NSNumber* number;
+
+- (NSNumber*)fooWithCondition:(BOOL)number andNumber:(NSNumber*)number;
+
+@end
+
+@implementation Simple
+
+- (NSNumber*)fooWithCondition:(BOOL)condition andNumber:(NSNumber*)number {
+  return number;
+}
+
+@end
+
+//---
+
+int bad4(NSNumber* number, Simple* simple) {
+  if ([simple fooWithCondition:true andNumber:number] < 19) {
+    return 0;
+  }
+  return 1;
+}
+
+int good4(NSNumber* number, Simple* simple) {
+  if ([simple fooWithCondition:true andNumber:number].doubleValue) {
+    return 0;
+  }
+  return 1;
+}
+
+int bad5(NSNumber* number, Simple* simple) {
+  if ([simple fooWithCondition:(number ? 1 : 2) andNumber:number] != nil) {
+    return 0;
+  }
+  return 1;
+}
+
+int bad6(NSNumber* number, Simple* simple) {
+  if ([simple fooWithCondition:(number == nil ? 1 : 2) andNumber:number]) {
+    return 0;
+  }
+  return 1;
+}
+
+int good5(NSNumber* number, Simple* simple) {
+  if ([simple fooWithCondition:(number == nil ? 1 : 2) andNumber:number] !=
+      nil) {
+    return 0;
+  }
+  return 1;
+}
+
+int bad7(NSNumber* number) {
+  if (number < 0) {
+    return 0;
+  }
+  return 1;
+}
+
+int bad8(NSNumber* number) {
+  if (number) {
+    return 0;
+  }
+  return 1;
+}
+
+int bad9(NSNumber* number, Simple* simple) {
+  simple.number = simple.number ? simple.number : number;
+}
+
+int bad10(NSNumber* number, Simple* simple) {
+  if ([simple fooWithCondition:true andNumber:number]) {
+    return 1;
+  }
+  return 0;
+}
+
+int good6(NSNumber* number) { return (number.integerValue > 5 ? 1 : 0); }
diff --git a/infer/tests/endtoend/objc/linters/NSNumber2Test.java b/infer/tests/endtoend/objc/linters/NSNumber2Test.java
index 9c2229b29..274c559b7 100644
--- a/infer/tests/endtoend/objc/linters/NSNumber2Test.java
+++ b/infer/tests/endtoend/objc/linters/NSNumber2Test.java
@@ -51,7 +51,7 @@ public class NSNumber2Test {
     assertThat(
         "Results should contain " + BAD_POINTER_COMPARISON,
         inferResults,
-        containsOnlyLines(new int[]{17, 26, 33}));
+        containsOnlyLines(new int[]{17, 26, 33, 85, 99, 106, 121, 128, 135, 139}));
   }
 
 }