Move aom_ports build commands into aom_ports/aom_ports.cmake.

- Stop abuse of the aom_util target to expose aom_ports includes
  to IDEs.
- Create aom_ports target only on appropriate platforms.
- Otherwise add the include only sources to the libaom target (aka abuse
  the libaom target instead of the aom_util target).

BUG=https://bugs.chromium.org/p/aomedia/issues/detail?id=76

Change-Id: I82a27a0fc2d6ab13ea273726a4777e21ebdbd247

CMakeLists.txt

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3381389..13d2ccd 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -18,6 +18,7 @@
 include("${AOM_ROOT}/build/cmake/aom_optimization.cmake")
 include("${AOM_ROOT}/aom_dsp/aom_dsp.cmake")
 include("${AOM_ROOT}/aom_mem/aom_mem.cmake")
+include("${AOM_ROOT}/aom_ports/aom_ports.cmake")
 include("${AOM_ROOT}/av1/av1.cmake")
 include("${AOM_ROOT}/test/test.cmake")
 
@@ -106,15 +107,6 @@
     "${AOM_ROOT}/aom_scale/yv12config.h")
 
 set(AOM_UTIL_SOURCES
-    "${AOM_ROOT}/aom_ports/aom_once.h"
-    "${AOM_ROOT}/aom_ports/aom_timer.h"
-    "${AOM_ROOT}/aom_ports/bitops.h"
-    "${AOM_ROOT}/aom_ports/emmintrin_compat.h"
-    "${AOM_ROOT}/aom_ports/mem.h"
-    "${AOM_ROOT}/aom_ports/mem_ops.h"
-    "${AOM_ROOT}/aom_ports/mem_ops_aligned.h"
-    "${AOM_ROOT}/aom_ports/msvc.h"
-    "${AOM_ROOT}/aom_ports/system_state.h"
     "${AOM_ROOT}/aom_util/aom_thread.c"
     "${AOM_ROOT}/aom_util/aom_thread.h"
     "${AOM_ROOT}/aom_util/endian_inl.h")
@@ -161,11 +153,6 @@
     "${AOM_ROOT}/webmenc.cc"
     "${AOM_ROOT}/webmenc.h")
 
-set(AOM_PORTS_ASM_X86 "${AOM_ROOT}/aom_ports/x86_abi_support.asm")
-set(AOM_PORTS_ASM_MMX "${AOM_ROOT}/aom_ports/emms.asm")
-
-
-
 include_directories(${AOM_ROOT} ${AOM_CONFIG_DIR})
 
 # Targets
@@ -197,19 +184,10 @@
 set(AOM_LIB_TARGETS ${AOM_LIB_TARGETS} aom_rtcd aom_util aom_encoder_stats
     aom_mem aom_scale aom)
 
-#
-# Assembly and intrinsic targets.
-#
-if ("${AOM_TARGET_CPU}" STREQUAL "x86" OR "${AOM_TARGET_CPU}" STREQUAL "x86_64")
-  add_asm_library("aom_util_x86" "AOM_PORTS_ASM_X86" "aom")
-endif ()
-
-if (HAVE_MMX)
-  add_asm_library("aom_util_mmx" "AOM_PORTS_ASM_MMX" "aom")
-endif ()
-
+# Setup dependencies.
 setup_aom_dsp_targets()
 setup_aom_mem_targets()
+setup_aom_ports_targets()
 setup_av1_targets()
 
 # Make all library targets depend on aom_rtcd to make sure it builds first.

aom_ports/aom_ports.cmake

diff --git a/aom_ports/aom_ports.cmake b/aom_ports/aom_ports.cmake
new file mode 100644
index 0000000..5f67eab
--- /dev/null
+++ b/aom_ports/aom_ports.cmake
@@ -0,0 +1,57 @@
+##
+## Copyright (c) 2017, Alliance for Open Media. All rights reserved
+##
+## This source code is subject to the terms of the BSD 2 Clause License and
+## the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+## was not distributed with this source code in the LICENSE file, you can
+## obtain it at www.aomedia.org/license/software. If the Alliance for Open
+## Media Patent License 1.0 was not distributed with this source code in the
+## PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+##
+set(AOM_PORTS_INCLUDES
+    "${AOM_ROOT}/aom_ports/aom_once.h"
+    "${AOM_ROOT}/aom_ports/aom_timer.h"
+    "${AOM_ROOT}/aom_ports/bitops.h"
+    "${AOM_ROOT}/aom_ports/emmintrin_compat.h"
+    "${AOM_ROOT}/aom_ports/mem.h"
+    "${AOM_ROOT}/aom_ports/mem_ops.h"
+    "${AOM_ROOT}/aom_ports/mem_ops_aligned.h"
+    "${AOM_ROOT}/aom_ports/msvc.h"
+    "${AOM_ROOT}/aom_ports/system_state.h")
+
+set(AOM_PORTS_INCLUDES_X86
+    "${AOM_ROOT}/aom_ports/x86_abi_support.asm")
+
+set(AOM_PORTS_ASM_MMX "${AOM_ROOT}/aom_ports/emms.asm")
+
+# For targets where HAVE_MMX is true:
+#   Creates the aom_ports build target, adds the includes in aom_ports to the
+#   target, and makes libaom depend on it.
+# Otherwise:
+#   Adds the includes in aom_ports to the libaom target.
+# For all target platforms:
+#   The libaom target must exist before this function is called.
+function (setup_aom_ports_targets)
+  if (HAVE_MMX)
+    add_asm_library("aom_ports" "AOM_PORTS_ASM_MMX" "aom")
+    set(aom_ports_has_symbols 1)
+  endif ()
+
+  if (aom_ports_has_symbols)
+    target_sources(aom_ports PUBLIC ${AOM_PORTS_INCLUDES})
+
+    if ("${AOM_TARGET_CPU}" STREQUAL "x86" OR
+        "${AOM_TARGET_CPU}" STREQUAL "x86_64")
+      target_sources(aom_ports PUBLIC ${AOM_PORTS_INCLUDES_X86})
+    endif ()
+
+    set(AOM_LIB_TARGETS ${AOM_LIB_TARGETS} PARENT_SCOPE)
+  else ()
+    target_sources(aom PUBLIC ${AOM_PORTS_INCLUDES})
+
+    if ("${AOM_TARGET_CPU}" STREQUAL "x86" OR
+        "${AOM_TARGET_CPU}" STREQUAL "x86_64")
+      target_sources(aom PUBLIC ${AOM_PORTS_INCLUDES_X86})
+    endif ()
+  endif ()
+endfunction ()