[cost] add a mode to compute exclusive cost

Summary: Add a flag `is-inclusive-cost` (`true` by default) which computes inclusive cost for each function. Setting the flag to `false` computes exclusive cost of the function where the cost of the callees are assumed to be `0`.

Reviewed By: skcho

Differential Revision: D20558275

fbshipit-source-id: 6b5798916

Makefile

@@ -168,6 +168,7 @@ DIRECT_TESTS += \
   java_infer \
   java_litho-required-props \
   java_performance \
+  java_performance-exclusive \
   java_purity \
   java_quandary \
   java_racerd \

infer/man/man1/infer-full.txt

@@ -1402,6 +1402,10 @@ INTERNAL OPTIONS
        --icfg-dotty-outfile-reset
            Cancel the effect of --icfg-dotty-outfile.
 
+       --no-inclusive-cost
+           Deactivates: Computes the inclusive cost (Conversely:
+           --inclusive-cost)
+
        --incremental-analysis
            Activates: [EXPERIMENTAL] Use incremental analysis for changed
            files. Not compatible with --reanalyze and --continue-analysis.

infer/src/base/Config.ml

@@ -1402,6 +1402,10 @@ and icfg_dotty_outfile =
      options that would generate icfg file otherwise"
 
 
+and inclusive_cost =
+  CLOpt.mk_bool ~long:"inclusive-cost" ~default:true "Computes the inclusive cost"
+
+
 and iphoneos_target_sdk_version =
   CLOpt.mk_string_opt ~long:"iphoneos-target-sdk-version"
     ~in_help:InferCommand.[(Capture, manual_clang_linters)]
@@ -2752,6 +2756,8 @@ and hoisting_report_only_expensive = !hoisting_report_only_expensive
 
 and icfg_dotty_outfile = !icfg_dotty_outfile
 
+and inclusive_cost = !inclusive_cost
+
 and iphoneos_target_sdk_version = !iphoneos_target_sdk_version
 
 and iphoneos_target_sdk_version_path_regex =

infer/src/base/Config.mli

@@ -373,6 +373,8 @@ val infer_is_javac : bool
 
 val implicit_sdk_root : string option
 
+val inclusive_cost : bool
+
 val inferconfig_file : string option
 
 val inferconfig_dir : string option

infer/src/cost/cost.ml

@@ -60,7 +60,8 @@ module InstrBasicCost = struct
 
   let get_instr_cost_record tenv extras instr_node instr =
     match instr with
-    | Sil.Call (ret, Exp.Const (Const.Cfun callee_pname), params, _, _) ->
+    | Sil.Call (ret, Exp.Const (Const.Cfun callee_pname), params, _, _) when Config.inclusive_cost
+      ->
         let {inferbo_invariant_map; integer_type_widths; get_callee_summary_and_formals} = extras in
         let operation_cost =
           match
@@ -94,6 +95,8 @@ module InstrBasicCost = struct
         if is_allocation_function callee_pname then
           CostDomain.plus CostDomain.unit_cost_allocation operation_cost
         else operation_cost
+    | Sil.Call (_, Exp.Const (Const.Cfun _), _, _, _) ->
+        CostDomain.zero_record
     | Sil.Load {id= lhs_id} when Ident.is_none lhs_id ->
         (* dummy deref inserted by frontend--don't count as a step. In
            JDK 11, dummy deref disappears and causes cost differences

infer/tests/codetoanalyze/java/performance-exclusive/ExclusiveTest.java

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+class ExclusiveTest {
+
+  void linear(int x) {
+    for (int i = 0; i < x; i++) {}
+  }
+
+  void call_linear_exclusive_constant(int x) {
+    linear(x);
+  }
+
+  void call_linear_exclusive_linear(int x) {
+    for (int i = 0; i < x; i++) {
+      linear(i);
+    }
+  }
+}

infer/tests/codetoanalyze/java/performance-exclusive/Makefile

@@ -0,0 +1,12 @@
+# Copyright (c) Facebook, Inc. and its affiliates.
+#
+# This source code is licensed under the MIT license found in the
+# LICENSE file in the root directory of this source tree.
+
+TESTS_DIR = ../../..
+
+INFER_OPTIONS = --cost-only --no-inclusive-cost --bufferoverrun --debug-exceptions --use-cost-threshold
+INFERPRINT_OPTIONS = --issues-tests
+SOURCES = $(wildcard *.java)
+
+include $(TESTS_DIR)/javac.make

infer/tests/codetoanalyze/java/performance-exclusive/issues.exp

@@ -0,0 +1,2 @@
+codetoanalyze/java/performance-exclusive/ExclusiveTest.java, ExclusiveTest.call_linear_exclusive_linear(int):void, 0, EXPENSIVE_EXECUTION_TIME, no_bucket, ERROR, [with estimated cost 2 + 7 ⋅ x, O(x), degree = 1,{x},Loop at line 18]
+codetoanalyze/java/performance-exclusive/ExclusiveTest.java, ExclusiveTest.linear(int):void, 0, EXPENSIVE_EXECUTION_TIME, no_bucket, ERROR, [with estimated cost 2 + 5 ⋅ x, O(x), degree = 1,{x},Loop at line 10]