From 15fbf707ca77fc68f4b59ef3b556e0b95132e43a Mon Sep 17 00:00:00 2001
From: Carles Cufi <carles.cufi@nordicsemi.no>
Date: Thu, 6 Dec 2018 12:21:48 +0100
Subject: [PATCH] doc: revert to copy files with extract_content.py directly

Adding ninja targets based on the files that are to be copied into the
build folder doesn't seem to speed up the build, so simplify the CMake
script by relying on extract_content.py to do the copy.

Numbers on my machine:

* master
  clean: 6m45.541s, 6m8.113s
  incremental: 1m24.233s, 1m32.720s

* revert
  clean: 6m25.221s, 6m19.751s
  incremental:1m20.893s, 1m20.337s

Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
---
 doc/CMakeLists.txt | 52 ++++++----------------------------------------
 1 file changed, 6 insertions(+), 46 deletions(-)

diff --git a/doc/CMakeLists.txt b/doc/CMakeLists.txt
index eaeefb180c2..54d27e1e60a 100644
--- a/doc/CMakeLists.txt
+++ b/doc/CMakeLists.txt
@@ -74,27 +74,17 @@ set(CONTENT_OUTPUTS ${CMAKE_CURRENT_BINARY_DIR}/extracted-content.txt)
 
 configure_file(${DOXYFILE_IN} ${DOXYFILE_OUT} @ONLY)
 
-# This command is used to find all documentation source files so they
-# can be copied into the build directory, and the copies can be
-# properly tracked by CMake as built files.
+# This command is used to copy all documentation source files into the build
+# directory,
 #
 # We need to make copies because Sphinx requires a single
 # documentation root directory, but Zephyr's documentation is
 # scattered around the tree in samples/, boards/, and doc/. Putting
 # them into a single rooted tree in the build directory is a
 # workaround for this limitation.
-#
-# This command does NOT cause the content files to be copied; we leave
-# that up to an add_custom_command() below. (Ninja will copy them during
-# the first build regardless of if they exist already or not, so
-# --just-outputs means the copy only happens once. The build system
-# has to know about the relationship between sources and copies to
-# track dependencies properly, for the "clean" target, etc.)
 set(EXTRACT_CONTENT_COMMAND
   ${CMAKE_COMMAND} -E env
   ${PYTHON_EXECUTABLE} scripts/extract_content.py
-  # Just save the outputs for processing by this list file.
-  --outputs ${CONTENT_OUTPUTS} --just-outputs
   # Ignore any files in the output directory.
   --ignore ${CMAKE_CURRENT_BINARY_DIR}
   # Copy all files in doc to the rst folder.
@@ -112,42 +102,12 @@ set(EXTRACT_CONTENT_COMMAND
   "*.rst:samples:${RST_OUT}" "*.rst:boards:${RST_OUT}"
   "*.rst:samples:${RST_OUT}/doc" "*.rst:boards:${RST_OUT}/doc")
 
-# Run the content extraction command at configure time in order to
-# produce lists of input and output files, which are respectively its
-# dependencies and outputs.
-execute_process(
+add_custom_target(
+  content
+  # Copy all files in doc/ to the rst folder
   COMMAND ${EXTRACT_CONTENT_COMMAND}
   WORKING_DIRECTORY ${CMAKE_CURRENT_LIST_DIR}
-  RESULT_VARIABLE RET)
-
-if (NOT RET EQUAL 0)
-  message(FATAL_ERROR "Cannot prepare documentation content extraction")
-endif()
-
-# Load the outputs listing from extract_content.py. This is a file
-# where each pair of lines is a source file in the Zephyr tree and a
-# destination file in the build directory.
-file(STRINGS ${CONTENT_OUTPUTS} EXTRACT_CONTENT_RAW)
-
-# Build up a list of output files for later use in target/command
-# DEPENDS. Make sure each output file gets updated if the
-# corresponding input file changes.
-set(EXTRACT_CONTENT_OUTPUTS)
-while(EXTRACT_CONTENT_RAW)
-  list(GET EXTRACT_CONTENT_RAW 0 SRC)
-  list(GET EXTRACT_CONTENT_RAW 1 DST)
-
-  add_custom_command(
-    COMMAND ${CMAKE_COMMAND} -E copy ${SRC} ${DST}
-    DEPENDS ${SRC}
-    OUTPUT ${DST}
-    )
-
-  list(REMOVE_AT EXTRACT_CONTENT_RAW 0 1)
-  list(APPEND EXTRACT_CONTENT_OUTPUTS ${DST})
-endwhile()
-
-add_custom_target(content DEPENDS ${EXTRACT_CONTENT_OUTPUTS})
+)
 
 set(ARGS ${DOXYFILE_OUT})