[C++] Don't ignore header files passed in --changed-files-index

Summary:
Whenever header file is in changed-files-index, it should be captured and analyzed on demand.
It was already being captured, but ondemand analysis wasn't triggered for code in header file. This diff does it.
Use hacky header->source mapping to go from header to source (cluster) and then analyze everything in that cluster (inlucing code coming from header)

Reviewed By: jberdine

Differential Revision: D4265495

fbshipit-source-id: 61606f4

infer/src/base/DB.ml

@@ -158,7 +158,14 @@ let changed_source_files_set =
   Option.map_default read_file None Config.changed_files_index |>
   Option.map (
     IList.fold_left
-      (fun changed_files line -> SourceFileSet.add (create_source_file line) changed_files)
+      (fun changed_files line ->
+         let source_file = create_source_file line in
+         let changed_files' = SourceFileSet.add source_file changed_files in
+         (* Add source corresponding to changed header if it exists *)
+         match source_file_of_header source_file with
+         | Some src -> SourceFileSet.add src changed_files'
+         | None -> changed_files'
+      )
       SourceFileSet.empty
   )
 

infer/src/base/DB.mli

@@ -126,7 +126,9 @@ val source_file_is_under_project_root : source_file -> bool
     file exists. returns None otherwise *)
 val source_file_of_header : source_file -> source_file option
 
-(** Set of files read from --changed-files-index file, None if option not specified *)
+(** Set of files read from --changed-files-index file, None if option not specified
+    NOTE: it may include extra source_files if --changed-files-index contains paths to
+          header files *)
 val changed_source_files_set : SourceFileSet.t option
 
 (** {2 Source Dirs} *)

infer/src/integration/CaptureCompilationDatabase.ml

@@ -25,13 +25,7 @@ let should_capture_file_from_index () =
            Process.print_error_and_exit "Error reading the changed files index %s.\n%!" index
        | None -> function _ -> true)
   | Some files_set ->
-      function source_file ->
-        DB.SourceFileSet.mem source_file files_set ||
-        (* as fallback try to capture corresponding source file for headers *)
-        Option.map_default
-          (fun src -> DB.SourceFileSet.mem src files_set)
-          false
-          (DB.source_file_of_header source_file)
+      function source_file -> DB.SourceFileSet.mem source_file files_set
 
 (** The buck targets are assumed to start with //, aliases are not supported. *)
 let check_args_for_targets args =

infer/tests/build_systems/clang_compilation_db/Makefile

@@ -12,7 +12,7 @@ CMAKE_BUILD_DIR = $(CMAKE_DIR)/_build
 
 ANALYZER = infer
 CLEAN_EXTRA = $(CMAKE_BUILD_DIR)
-INFER_OPTIONS = --report-custom-error --developer-mode --project-root $(CMAKE_DIR)
+INFER_OPTIONS = --cxx --report-custom-error --developer-mode --project-root $(CMAKE_DIR)
 SOURCES = $(CMAKE_DIR)/hello.cpp
 OBJECTS = $(CMAKE_BUILD_DIR)/compile_commands.json
 INFERPRINT_OPTIONS = --issues-tests

infer/tests/build_systems/clang_compilation_db/issues.exp

@@ -1,5 +1,7 @@
 hello.cpp, test0, 2, NULL_DEREFERENCE, [start of procedure test0()]
 hello.cpp, test1, 2, NULL_DEREFERENCE, [start of procedure test1(),start of procedure deref1()]
+lib3.h, test, 1, NULL_DEREFERENCE, [start of procedure test(),start of procedure deref3()]
 hello.cpp, test0, 2, NULL_DEREFERENCE, [start of procedure test0()]
 hello.cpp, test1, 2, NULL_DEREFERENCE, [start of procedure test1(),start of procedure deref1()]
 hello.cpp, test2, 2, NULL_DEREFERENCE, [start of procedure test2(),start of procedure deref2()]
+lib3.h, test, 1, NULL_DEREFERENCE, [start of procedure test(),start of procedure deref3()]

infer/tests/build_systems/codetoanalyze/clang_compilation_database/CMakeLists.txt

@@ -1,4 +1,4 @@
 cmake_minimum_required (VERSION 3.1)
 set(CMAKE_CXX_STANDARD 11)
 project (HELLO)
-add_library (Hello hello.cpp lib1.cpp lib2.cpp)
+add_library (Hello hello.cpp lib1.cpp lib2.cpp lib3.cpp)

infer/tests/build_systems/codetoanalyze/clang_compilation_database/index.txt

@@ -1,2 +1,3 @@
 hello.cpp
 lib1.cpp
+lib3.h

infer/tests/build_systems/codetoanalyze/clang_compilation_database/lib3.cpp

@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) 2016 - 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.
+ */
+#include "lib3.h"
+
+int deref3(int* p) { return *p; }
+

infer/tests/build_systems/codetoanalyze/clang_compilation_database/lib3.h

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2016 - 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 deref3(int* p);
+
+int test() {
+  return deref3(nullptr);
+}