Replace resource embedder with cmake function

Currently cross compilation fails as it is built for the target
architecture, but then runs on the host architecture. This solves that
problem and also

* moves the function to retrieve data inside the adm namespace
* moves the data inside an implementation file
* allows embedding of non-text data

This is the same change as recently applied to libear

Author: rsjbailey

CMakeLists.txt

@@ -61,7 +61,6 @@ configure_file(
 # add targets
 ############################################################
 add_subdirectory(src)
-add_subdirectory(tools)
 if(ADM_EXAMPLES)
   add_subdirectory(examples)
 endif()

cmake/embed_resource.cmake

@@ -0,0 +1,70 @@
+set(current_dir ${CMAKE_CURRENT_LIST_DIR})
+function(embed_resource)
+  # parse function arguments
+  set(options "")
+  set(oneValueArguments NAMESPACE BASE_NAME)
+  set(multiValueArguments RESOURCE_FILES)
+  cmake_parse_arguments(EMBED "${options}" "${oneValueArguments}"
+                        "${multiValueArguments}" ${ARGN})
+  foreach(arg ${oneValueArguments} ${multiValueArguments})
+    if(NOT EMBED_${arg})
+      message(WARNING "Argument ${arg} not defined in call to embed_resource")
+    endif()
+  endforeach()
+
+  set_property(
+    DIRECTORY
+    APPEND
+    PROPERTY CMAKE_CONFIGURE_DEPENDS ${EMBED_RESOURCE_FILES})
+
+  set(byte_array_template
+      "const char file_@FILE_COUNT@[] = { @FILE_BYTE_ARRAY@ }")
+  set(lookup_template
+      "if (fileName == \"@FILE_NAME@\") { stream.write(file_@FILE_COUNT@, @ARRAY_SIZE@)\; return true\; }"
+  )
+
+  set(FILE_COUNT 1)
+  foreach(file_path ${EMBED_RESOURCE_FILES})
+    # read resource file as hex with no byte separator
+    file(READ ${file_path} file_contents HEX)
+    # split into 2 char hex bytes
+    string(REGEX MATCHALL "(..)" file_bytes ${file_contents})
+    # need length for call to ostream.write()
+    list(LENGTH file_bytes ARRAY_SIZE)
+
+    # add 0x prefix and , separator TRANSFORM only valid in cmake 3.14+ or we
+    # could just do list(TRANSFORM file_bytes PREPEND "0x") list(JOIN file_bytes
+    # "," FILE_BYTE_ARRAY)
+    list(POP_FRONT file_bytes first_byte)
+    string(PREPEND first_byte "0x")
+    list(PREPEND file_bytes ${first_byte})
+    list(JOIN file_bytes ",0x" FILE_BYTE_ARRAY)
+
+    # strip path from data file, leaving name
+    get_filename_component(FILE_NAME "${file_path}" NAME)
+    # generate single byte array from template
+    string(CONFIGURE ${byte_array_template} byte_array @ONLY)
+    # add the trailing semicolon here as it gets interpreted as a list seperator
+    # if in template
+    list(APPEND byte_arrays "${byte_array}\;")
+    # generate single lookup entry
+    string(CONFIGURE "${lookup_template}" lookup @ONLY)
+    list(APPEND lookups "${lookup}")
+    math(EXPR FILE_COUNT "${FILE_COUNT} + 1")
+  endforeach()
+
+  # join entries with newline for readability
+  if(WIN32)
+    set(line_end "\n\r")
+  else()
+    set(line_end "\n")
+  endif()
+  list(JOIN byte_arrays "${line_end}" EMBED_BYTE_ARRAYS)
+  list(JOIN lookups "${line_end}" EMBED_LOOKUPS)
+
+  # generate files
+  configure_file("${current_dir}/embedded_resource.hpp.in"
+                 "${CMAKE_CURRENT_BINARY_DIR}/${EMBED_BASE_NAME}.hpp" @ONLY)
+  configure_file("${current_dir}/embedded_resource.cpp.in"
+                 "${CMAKE_CURRENT_BINARY_DIR}/${EMBED_BASE_NAME}.cpp" @ONLY)
+endfunction()

cmake/embedded_resource.cpp.in

@@ -0,0 +1,13 @@
+// WARNING This file is auto-generated during configuration by the cmake
+// function embed_resource(). Do not manually edit as changes will be lost
+
+#include "@[email protected]"
+
+namespace {
+@EMBED_BYTE_ARRAYS@
+}
+
+bool @EMBED_NAMESPACE@::getEmbeddedFile(std::string const& fileName, std::ostream& stream) {
+@EMBED_LOOKUPS@
+  return false;
+}

cmake/embedded_resource.hpp.in

@@ -0,0 +1,10 @@
+// WARNING This file is auto-generated during configuration by the cmake
+// function embed_resource(). Do not manually edit as changes will be lost
+
+#pragma once
+#include <string>
+#include <ostream>
+
+namespace @EMBED_NAMESPACE@ {
+    bool getEmbeddedFile(std::string const& fileName, std::ostream& stream);
+}

format.sh

@@ -1,5 +1,5 @@
 #!/bin/bash
-DIRS="examples include src tests tools"
+DIRS="examples include src tests"
 
 IGNORE="
 src/elements/time.cpp

src/CMakeLists.txt

@@ -2,14 +2,11 @@
 
 include(${PROJECT_SOURCE_DIR}/submodules/rapidxml.cmake)
 
-add_custom_command(
-  OUTPUT ${PROJECT_BINARY_DIR}/resources.hpp
-  COMMAND resource_embedder common_definitions.xml > ${PROJECT_BINARY_DIR}/resources.hpp
-  WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}/resources
-  DEPENDS resource_embedder ${PROJECT_SOURCE_DIR}/resources/common_definitions.xml
-  COMMENT "Running resource embedder."
-  VERBATIM
-)
+include(embed_resource)
+embed_resource(
+        NAMESPACE adm
+        BASE_NAME resources
+        RESOURCE_FILES ${PROJECT_SOURCE_DIR}/resources/common_definitions.xml)
 
 add_library(adm
   document.cpp
@@ -66,10 +63,13 @@ add_library(adm
   detail/id_assigner.cpp
   parse.cpp
   write.cpp
-  ${PROJECT_BINARY_DIR}/resources.hpp
+  ${CMAKE_CURRENT_BINARY_DIR}/resources.hpp
+  ${CMAKE_CURRENT_BINARY_DIR}/resources.cpp
 )
 
 target_include_directories(adm
+  PRIVATE
+    $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}> # resources.hpp
   PUBLIC
   # Headers used from source/build location:
     $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>