[infer][backend] Perform deep match in Sil.exp_replace_exp

Reviewed By: jberdine

Differential Revision: D5353364

fbshipit-source-id: 10149d1

infer/src/IR/Sil.re

@@ -2248,8 +2248,53 @@ let hpred_sub subst => {
 
 
 /** {2 Functions for replacing occurrences of expressions.} */
-let exp_replace_exp epairs e =>
+let rec exp_replace_exp epairs e =>
-  List.find f::(fun (e1, _) => Exp.equal e e1) epairs |> Option.value_map f::snd default::e;
+  /* First we check if there is an exact match */
+  switch (List.find f::(fun (e1, _) => Exp.equal e e1) epairs) {
+  | Some (_, e2) => e2
+  | None =>
+    /* If e is a compound expression, we need to check for its subexpressions as well */
+    switch e {
+    | Exp.UnOp op e0 ty =>
+      let e0' = exp_replace_exp epairs e0;
+      if (phys_equal e0 e0') {
+        e
+      } else {
+        Exp.UnOp op e0' ty
+      }
+    | Exp.BinOp op lhs rhs =>
+      let lhs' = exp_replace_exp epairs lhs;
+      let rhs' = exp_replace_exp epairs rhs;
+      if (phys_equal lhs lhs' && phys_equal rhs rhs') {
+        e
+      } else {
+        Exp.BinOp op lhs' rhs'
+      }
+    | Exp.Cast ty e0 =>
+      let e0' = exp_replace_exp epairs e0;
+      if (phys_equal e0 e0') {
+        e
+      } else {
+        Exp.Cast ty e0'
+      }
+    | Exp.Lfield e0 fname ty =>
+      let e0' = exp_replace_exp epairs e0;
+      if (phys_equal e0 e0') {
+        e
+      } else {
+        Exp.Lfield e0' fname ty
+      }
+    | Exp.Lindex base index =>
+      let base' = exp_replace_exp epairs base;
+      let index' = exp_replace_exp epairs index;
+      if (phys_equal base base' && phys_equal index index') {
+        e
+      } else {
+        Exp.Lindex base' index'
+      }
+    | _ => e
+    }
+  };
 
 let atom_replace_exp epairs atom => atom_expmap (fun e => exp_replace_exp epairs e) atom;
 

infer/tests/codetoanalyze/cpp/errors/Makefile

@@ -61,6 +61,7 @@ SOURCES = \
   shared/types/struct_pass_by_value.cpp \
   shared/types/typeid_expr.cpp \
   $(wildcard smart_ptr/*.cpp) \
+	$(wildcard stack_escape/*.cpp) \
 	$(wildcard static_local/*.cpp) \
   $(wildcard subtyping/*.cpp) \
   $(wildcard vector/*.cpp) \

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

@@ -122,6 +122,9 @@ codetoanalyze/cpp/errors/smart_ptr/unique_ptr_deref.cpp, unique_ptr::unique_ptr_
 codetoanalyze/cpp/errors/smart_ptr/unique_ptr_deref.cpp, unique_ptr::unique_ptr_move_null_deref, 3, NULL_DEREFERENCE, [start of procedure unique_ptr::unique_ptr_move_null_deref()]
 codetoanalyze/cpp/errors/smart_ptr/unique_ptr_deref.cpp, unique_ptr::unique_ptr_move_ok_deref, 3, UNINITIALIZED_VALUE, [start of procedure unique_ptr::unique_ptr_move_ok_deref()]
 codetoanalyze/cpp/errors/smart_ptr/unique_ptr_deref.cpp, unique_ptr::unique_ptr_move_ok_deref, 4, MEMORY_LEAK, [start of procedure unique_ptr::unique_ptr_move_ok_deref(),return from a call to unique_ptr::unique_ptr_move_ok_deref]
+codetoanalyze/cpp/errors/stack_escape/basic.cpp, basic_escape_local_bad, 3, STACK_VARIABLE_ADDRESS_ESCAPE, [start of procedure basic_escape_local_bad(),return from a call to basic_escape_local_bad]
+codetoanalyze/cpp/errors/stack_escape/basic.cpp, basic_escape_param_bad, 0, STACK_VARIABLE_ADDRESS_ESCAPE, [start of procedure basic_escape_param_bad(),return from a call to basic_escape_param_bad]
+codetoanalyze/cpp/errors/stack_escape/basic.cpp, escape_local_struct_member_bad, 3, STACK_VARIABLE_ADDRESS_ESCAPE, [start of procedure escape_local_struct_member_bad(),start of procedure EscapeTest,return from a call to EscapeTest_EscapeTest,return from a call to escape_local_struct_member_bad]
 codetoanalyze/cpp/errors/static_local/nonstatic_local_bad.cpp, nonstatic_local_bad, 3, STACK_VARIABLE_ADDRESS_ESCAPE, [start of procedure nonstatic_local_bad(),return from a call to nonstatic_local_bad]
 codetoanalyze/cpp/errors/static_local/nonstatic_local_bad.cpp, nonstatic_local_caller, 2, DANGLING_POINTER_DEREFERENCE, [start of procedure nonstatic_local_caller(),start of procedure nonstatic_local_bad(),return from a call to nonstatic_local_bad]
 codetoanalyze/cpp/errors/subtyping/cast_with_enforce.cpp, cast_with_enforce::cast_with_npe, 3, NULL_DEREFERENCE, [start of procedure cast_with_enforce::cast_with_npe(),start of procedure Base,return from a call to cast_with_enforce::Base_Base]

infer/tests/codetoanalyze/cpp/errors/stack_escape/basic.cpp

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2017 - present Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+int* basic_escape_local_bad() {
+  int a;
+  return &a;
+}
+
+int* basic_escape_param_bad(int a) { return &a; }
+
+struct EscapeTest {
+  int x;
+};
+int* escape_local_struct_member_bad() {
+  EscapeTest esc;
+  return &(esc.x);
+}