libaom: prepare for switch to cmake

The configure scripts, used to generate many of the files in
source/config, have been removed from libaom in favor of cmake scripts.

Modify generate_gni.sh and BUILD.gn to accomodate.

However, the library is not ready to be updated yet, so keep these in
limbo.

Change-Id: I187c7877b3f3a5eadffb3d0055d9e3abf9d17b2a
Reviewed-on: https://chromium-review.googlesource.com/1038437
Commit-Queue: Johann Koenig <johannkoenig@google.com>
Reviewed-by: James Zern <jzern@google.com>
Cr-Commit-Position: refs/heads/master@{#555210}

third_party/libaom/cmake_update.sh

+#!/bin/bash
+#
+# Copyright (c) 2018 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# This script is used to generate .gni files and files in the
+# config/platform directories needed to build libaom.
+#
+# Every time the upstream source code is updated this script must be run.
+#
+# Usage:
+# $ ./cmake_update.sh
+# Requirements:
+# 32bit build environment for cmake. Including but potentially not limited to:
+#  -lib32gcc-7-dev
+#  -lib32stdc++-7-dev
+# Alternatively: treat 32bit builds like Windows and manually tweak aom_config.h
+
+set -e
+
+# sort() consistently.
+export LC_ALL=C
+
+BASE=$(pwd)
+SRC="${BASE}/source/libaom"
+CFG="${BASE}/source/config"
+
+function clean {
+  rm -rf "${TMP}"
+}
+
+if [ $# -ne 0 ]; then
+  echo "Unknown option(s): ${@}"
+  exit 1
+fi
+
+# Missing function:
+# find_duplicates
+# We may have enough targets to avoid re-implementing this.
+
+# Generate libaom.config file for rtcd.pl.
+# $1 - platform/arch
+function print_config {
+  combined_config="$(cat ${CFG}/${1}/aom_config.h | grep -E ' +[01] *$')"
+  combined_config="$(echo "$combined_config" | grep -v DO1STROUNDING)"
+  combined_config="$(echo "$combined_config" | sed 's/[ \t]//g')"
+  combined_config="$(echo "$combined_config" | sed 's/.*define//')"
+  combined_config="$(echo "$combined_config" | sed 's/0$/=no/')"
+  combined_config="$(echo "$combined_config" | sed 's/1$/=yes/')"
+  echo "$combined_config" | sort | uniq
+}
+
+# Generate *_rtcd.h files.
+# $1 - Header file directory.
+# $2 - Architecture.
+# $3 - Optional - additional arguments to pass through to rtcd.pl.
+function gen_rtcd_header {
+  echo "Generate ${1} RTCD files."
+
+  print_config ${1} > "libaom.config"
+
+  ${SRC}/build/make/rtcd.pl \
+    --arch=${2} \
+    --sym=av1_rtcd ${3} \
+    --config=libaom.config \
+    "${SRC}/av1/common/av1_rtcd_defs.pl" \
+    > "${CFG}/${1}/av1_rtcd.h"
+
+  clang-format -i "${CFG}/${1}/av1_rtcd.h"
+
+  ${SRC}/build/make/rtcd.pl \
+    --arch=${2} \
+    --sym=aom_scale_rtcd ${3} \
+    --config=libaom.config \
+    "${SRC}/aom_scale/aom_scale_rtcd.pl" \
+    > "${CFG}/${1}/aom_scale_rtcd.h"
+
+  clang-format -i "${CFG}/${1}/aom_scale_rtcd.h"
+
+  ${SRC}/build/make/rtcd.pl \
+    --arch=${2} \
+    --sym=aom_dsp_rtcd ${3} \
+    --config=libaom.config \
+    "${SRC}/aom_dsp/aom_dsp_rtcd_defs.pl" \
+    > "${CFG}/${1}/aom_dsp_rtcd.h"
+
+  clang-format -i "${CFG}/${1}/aom_dsp_rtcd.h"
+}
+
+# Generate Config files.
+# $1 - Header file directory.
+# $2 - cmake options.
+function gen_config_files {
+  cmake "${SRC}" ${2} &> /dev/null
+
+  case "${1}" in
+    linux*)
+      local ASM_CONV=ads2gas.pl
+      ;;
+    *)
+      local ASM_CONV=ads2gas_apple.pl
+      ;;
+  esac
+
+  case "${1}" in
+    *mips*) ;;
+    nacl) ;;
+    *x64*|*ia32*)
+      egrep "#define [A-Z0-9_]+ [01]" aom_config.h | \
+        awk '{print "%define " $2 " " $3}' > aom_config.asm
+      ;;
+    *)
+      egrep "#define [A-Z0-9_]+ [01]" aom_config.h | \
+        awk '{print $2 " EQU " $3}' | \
+        perl "${SRC}/build/make/${ASM_CONV}" > aom_config.asm
+  esac
+}
+
+function update_readme {
+  local IFS=$'\n'
+  # Split git log output '<date>\n<commit hash>' on the newline to produce 2
+  # array entries.
+  local vals=($(git --no-pager log -1 --format="%cd%n%H" \
+    --date=format:"%A %B %d %Y"))
+  sed -E -i.bak \
+    -e "s/^(Date:)[[:space:]]+.*$/\1 ${vals[0]}/" \
+    -e "s/^(Commit:)[[:space:]]+[a-f0-9]{40}/\1 ${vals[1]}/" \
+    ${BASE}/README.chromium
+  rm ${BASE}/README.chromium.bak
+  cat <<EOF
+
+README.chromium updated with:
+Date: ${vals[0]}
+Commit: ${vals[1]}
+EOF
+}
+
+TMP=$(mktemp -d "${BASE}/build.XXXX")
+cd "${TMP}"
+
+all_platforms="-DCONFIG_SIZE_LIMIT=1"
+all_platforms+=" -DDECODE_HEIGHT_LIMIT=16384 -DDECODE_WIDTH_LIMIT=16384"
+all_platforms+=" -DCONFIG_AV1_ENCODER=0"
+all_platforms+=" -DCONFIG_LOWBITDEPTH=1"
+# avx2 optimizations account for ~0.3mb of the decoder.
+#all_platforms+=" -DENABLE_AVX2=0"
+toolchain="-DCMAKE_TOOLCHAIN_FILE=${SRC}/build/cmake/toolchains"
+
+echo "Generate linux/ia32 config files."
+gen_config_files linux/ia32 "${toolchain}/x86-linux.cmake ${all_platforms}"
+# libaom_srcs.gni and aom_version.h are shared.
+cp libaom_srcs.gni "${BASE}"
+cp aom_version.h "${CFG}"
+rm -f "${CFG}/linux/ia32"/*
+cp aom_config.h aom_config.c aom_config.asm "${CFG}/linux/ia32/"
+gen_rtcd_header linux/ia32 x86 #--disable-avx2
+
+cd ..
+rm -rf "${TMP}"
+mkdir "${TMP}"
+cd "${TMP}"
+
+echo "Generate linux/x64 config files."
+gen_config_files linux/x64 "${all_platforms}"
+rm -f "${CFG}/linux/x64"/*
+cp aom_config.h aom_config.c aom_config.asm "${CFG}/linux/x64/"
+gen_rtcd_header linux/x64 x86_64 #--disable-avx2
+
+# Windows looks like linux but with some minor tweaks. Cmake doesn't generate VS
+# project files on linux otherwise we would not resort to these hacks.
+
+echo "Generate win/x64 config files"
+rm -f "${CFG}/win/x64"/*
+cp "${CFG}/linux/x64"/* "${CFG}/win/x64/"
+sed -i.bak \
+  -e 's/\(#define[[:space:]]INLINE[[:space:]]*\)inline/#define INLINE __inline/' \
+  -e 's/\(#define[[:space:]]HAVE_PTHREAD_H[[:space:]]*\)1/#define HAVE_PTHREAD_H 0/' \
+  -e 's/\(#define[[:space:]]HAVE_UNISTD_H[[:space:]]*\)1/#define HAVE_UNISTD_H 0/' \
+  -e 's/\(#define[[:space:]]CONFIG_GCC[[:space:]]*\)1/#define CONFIG_GCC 0/' \
+  -e 's/\(#define[[:space:]]CONFIG_MSVS[[:space:]]*\)0/#define CONFIG_MSVS 1/' \
+  "${CFG}/win/x64/aom_config.h"
+rm "${CFG}/win/x64/aom_config.h.bak"
+egrep "#define [A-Z0-9_]+ [01]" "${CFG}/win/x64/aom_config.h" \
+  | awk '{print "%define " $2 " " $3}' > "${CFG}/win/x64/aom_config.asm"
+
+clean