ARROW-6052: [C++] Split up arrow/array.h/cc into multiple files under…

… arrow/array/, move ArrayData to separate header, make ArrayData::dictionary ArrayData

One meaningful change in this patch was to change `ArrayData::dictionary` to be `shared_ptr<ArrayData>`, which was not difficult.

Otherwise, this allows some files that only need ArrayData or just Array to not include a bunch of unnecessary header code. The increase in number of lines of code is pretty much all due to license headers.

I did a modest amount of IWYU cleaning, there are plenty of still usages of "arrow/array.h" that might be better replaced by more specific headers.

As part of this patch I disabled `build/include_what_you_use` in cpplint per ARROW-8994. If we're going to spend time doing IWYU cleaning (which IMHO is overall worthwhile) we should rely on its output rather than having IWYU checks by two different tools.

Closes #7310 from wesm/cpp-split-array-h

Authored-by: Wes McKinney <wesm+git@apache.org>
Signed-off-by: Wes McKinney <wesm+git@apache.org>

cpp/build-support/iwyu/iwyu.sh

@@ -25,11 +25,13 @@ IWYU_LOG=$(mktemp -t arrow-cpp-iwyu.XXXXXX)
 trap "rm -f $IWYU_LOG" EXIT
 
 IWYU_MAPPINGS_PATH="$ROOT/cpp/build-support/iwyu/mappings"
-IWYU_ARGS="--mapping_file=$IWYU_MAPPINGS_PATH/boost-all.imp \
+IWYU_ARGS="--no_fwd_decls \
+    --mapping_file=$IWYU_MAPPINGS_PATH/boost-all.imp \
     --mapping_file=$IWYU_MAPPINGS_PATH/boost-all-private.imp \
     --mapping_file=$IWYU_MAPPINGS_PATH/boost-extra.imp \
     --mapping_file=$IWYU_MAPPINGS_PATH/gflags.imp \
     --mapping_file=$IWYU_MAPPINGS_PATH/glog.imp \
+    --mapping_file=$IWYU_MAPPINGS_PATH/gmock.imp \
     --mapping_file=$IWYU_MAPPINGS_PATH/gtest.imp \
     --mapping_file=$IWYU_MAPPINGS_PATH/arrow-misc.imp"
 

cpp/build-support/iwyu/mappings/arrow-misc.imp

@@ -32,6 +32,8 @@
   { include: ["<bits/stdint-uintn.h>", private, "<cstdint>", public ] },
   { include: ["<bits/shared_ptr.h>", private, "<memory>", public ] },
   { include: ["<initializer_list>", public, "<vector>", public ] },
+  { include: ["<stdint.h>", public, "<cstdint>", public ] },
+  { include: ["<string.h>", public, "<cstring>", public ] },
   { symbol: ["bool", private, "<cstdint>", public ] },
   { symbol: ["false", private, "<cstdint>", public ] },
   { symbol: ["true", private, "<cstdint>", public ] },
@@ -45,7 +47,7 @@
   { symbol: ["uint64_t", private, "<cstdint>", public ] },
   { symbol: ["size_t", private, "<cstddef>", public ] },
   { symbol: ["variant", private, "\"arrow/compute/kernel.h\"", public ] },
-  { symbol: ["Array", private, "\"arrow/type_fwd.h\"", public ] },
+  { symbol: ["default_memory_pool", private, "\"arrow/type_fwd.h\"", public ] },
   { symbol: ["make_shared", private, "<memory>", public ] },
   { symbol: ["shared_ptr", private, "<memory>", public ] },
   { symbol: ["_Node_const_iterator", private, "<flatbuffers/flatbuffers.h>", public ] },

cpp/build-support/iwyu/mappings/gmock.imp

@@ -0,0 +1,23 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#include
+#include
+
+[
+  { include: [ "<gmock/gmock-generated-matchers.h>", private, "<gmock/gmock.h>", public ] },
+  { include: [ "<gmock/gmock-matchers.h>", private, "<gmock/gmock.h>", public ] }
+]

cpp/build-support/run_cpplint.py

@@ -38,6 +38,7 @@
 -readability/alt_tokens
 -build/header_guard
 -build/c++11
+-build/include_what_you_use
 -runtime/references
 -build/include_order
 '''.split()

cpp/src/arrow/CMakeLists.txt

@@ -120,7 +120,12 @@ function(ADD_ARROW_BENCHMARK REL_TEST_NAME)
 endfunction()
 
 set(ARROW_SRCS
-    array.cc
+    array/array_base.cc
+    array/array_binary.cc
+    array/array_decimal.cc
+    array/array_dict.cc
+    array/array_nested.cc
+    array/array_primitive.cc
     array/builder_adaptive.cc
     array/builder_base.cc
     array/builder_binary.cc
@@ -130,8 +135,9 @@ set(ARROW_SRCS
     array/builder_primitive.cc
     array/builder_union.cc
     array/concatenate.cc
-    array/dict_internal.cc
+    array/data.cc
     array/diff.cc
+    array/util.cc
     array/validate.cc
     builder.cc
     buffer.cc
@@ -511,18 +517,18 @@ install(FILES ${CMAKE_CURRENT_SOURCE_DIR}/arrow-config.cmake
 #
 # Unit tests
 #
-
 add_arrow_test(array_test
                SOURCES
-               array_test.cc
-               array_binary_test.cc
-               array_dict_test.cc
-               array_list_test.cc
-               array_struct_test.cc
-               array_union_test.cc
-               array_view_test.cc
+               array/array_test.cc
+               array/array_binary_test.cc
+               array/array_dict_test.cc
+               array/array_list_test.cc
+               array/array_struct_test.cc
+               array/array_union_test.cc
+               array/array_view_test.cc
                PRECOMPILED_HEADERS
                "$<$<COMPILE_LANGUAGE:CXX>:arrow/testing/pch.h>")
+
 add_arrow_test(buffer_test)
 
 if(ARROW_IPC)