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Axel Heider
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cmake: Improve CPIO creation
- improve maintainability with explicit helper files - sanitize intermediate file names - improve comments - support using a directory in output name also Signed-off-by: Axel Heider <[email protected]>
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Lines changed: 78 additions & 34 deletions

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‎cmake-tool/helpers/cpio.cmake‎

Lines changed: 78 additions & 34 deletions
Original file line numberDiff line numberDiff line change
@@ -39,57 +39,101 @@ function(MakeCPIO output_name input_files)
3939
if(NOT "${MAKE_CPIO_UNPARSED_ARGUMENTS}" STREQUAL "")
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message(FATAL_ERROR "Unknown arguments to MakeCPIO")
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endif()
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set(archive_symbol "_cpio_archive")
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if(NOT "${MAKE_CPIO_CPIO_SYMBOL}" STREQUAL "")
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set(archive_symbol ${MAKE_CPIO_CPIO_SYMBOL})
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endif()
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# intermediate files
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set(cpio_archive "archive.${output_name}.cpio")
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set(cpio_archive_s "${output_name}.S")
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set(cpio_archive "${output_name}.cpio")
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# CMake wants absolute paths when calling file(WRITE ...)
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get_filename_component(
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output_name_abs
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"${output_name}"
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ABSOLUTE
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BASE_DIR
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"${CMAKE_CURRENT_BINARY_DIR}"
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)
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51-
# Check that the reproducible flag is available. Don't use it if it isn't.
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# Create a script that prepares CPIO archive contents in a tmp folder and
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# then builds the archive. Some cpio versions support the paramter
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# "--reproducible" to create the archive with consistent inodes and device
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# numbering. In addition, we set each file's the 'modified time' to the
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# epoch (ie 0, but simply using 'touch -d @0' is a GNU extension of the
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# POSIX standard), and the user/group values to 0:0.
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# Since some application access the archive contents by index and not by
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# name, the files must be put into the archive in exactly the same order as
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# they are listen in 'input_files'. Using simply "ls | cpio ...." instead of
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# "printf '%s\\n' \${@##*/} | cpio ..." does not guarantee preserving the
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# order.
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CheckCPIOArgument(cpio_reproducible_flag "--reproducible")
53-
set(
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cpio_cmd
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"cpio ${cpio_reproducible_flag} --quiet --create --format=newc --file=${CMAKE_CURRENT_BINARY_DIR}/${cpio_archive}"
71+
set(cpio_archive_creator "${output_name_abs}.sh")
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file(
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WRITE
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"${cpio_archive_creator}"
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# content
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"#!/bin/sh\n"
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"# auto-generated file from MakeCPIO(), do not edit\n"
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"set -e\n"
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"TMP_DIR=${cpio_archive}.files\n"
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"mkdir -p \${TMP_DIR}\n"
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"cp -a \"$@\" \${TMP_DIR}/\n"
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"touch -d 1970-01-01T00:00:00Z \${TMP_DIR}/*\n"
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"(\n"
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" cd \${TMP_DIR}\n"
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" printf '%s\\n' \${@##*/} | cpio ${cpio_reproducible_flag} --quiet --create --format=newc --owner=+0:+0\n"
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") > ${cpio_archive}\n"
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"rm -rf \${TMP_DIR}\n"
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)
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58-
set(tmp_dir "temp_${output_name}")
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set(commands "bash;-c;${cpio_cmd};&&")
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foreach(file IN LISTS input_files)
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# Try and generate reproducible cpio meta-data as we do this:
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# - touch -d @0 file sets the modified time to 0
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# - --owner=root:root sets user and group values to 0:0
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# - --reproducible creates reproducible archives with consistent inodes and device numbering
65-
list(
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APPEND
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commands
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"bash;-c; mkdir -p ${tmp_dir} && cd ${tmp_dir} && cp -a ${file} . && touch -d 1970-01-01T00:00:00Z `basename ${file}` && echo `basename ${file}` | ${cpio_cmd} --append --owner=+0:+0 && rm `basename ${file}` && cd ../ && rmdir ${tmp_dir};&&"
69-
)
70-
endforeach()
71-
list(APPEND commands "true")
90+
# Create a "program" that makes the compiler generate and object file that
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# contains the cpio archive.
92+
# CMake wants the absolute name when creating files
93+
set(cpio_archive_s "${output_name_abs}.S")
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file(
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WRITE
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"${cpio_archive_s}"
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# content
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"# auto-generated file from MakeCPIO(), do not edit\n"
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".section ._archive_cpio, \"aw\"\n"
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".globl ${archive_symbol}, ${archive_symbol}_end\n"
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"${archive_symbol}:\n"
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".incbin \"${cpio_archive}\"\n"
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"${archive_symbol}_end:\n"
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)
105+
106+
# Re-run CMake configuration in case 'cpio_archive_creator' or
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# 'cpio_archive_s' is deleted.
108+
set_property(
109+
DIRECTORY
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APPEND
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PROPERTY CMAKE_CONFIGURE_DEPENDS "${cpio_archive_creator}" "${cpio_archive_s}"
112+
)
113+
114+
# The 'cpio_archive' is no explicit parameter for the command, because it is
115+
# hard-coded already in the specific script we have generated above. The
116+
# 'input_files' are explicit here, because they are a CMake list that
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# will be converted to parameters for the invokation,
118+
add_custom_command(
119+
OUTPUT ${cpio_archive}
120+
COMMAND bash "${cpio_archive_creator}" ${input_files}
121+
DEPENDS "${cpio_archive_creator}" ${input_files} ${MAKE_CPIO_DEPENDS}
122+
COMMENT "Generate CPIO archive ${cpio_archive}"
123+
)
72124

73125
separate_arguments(cmake_c_flags_sep NATIVE_COMMAND "${CMAKE_C_FLAGS}")
74126
if(CMAKE_C_COMPILER_ID STREQUAL "Clang")
75127
list(APPEND cmake_c_flags_sep "${CMAKE_C_COMPILE_OPTIONS_TARGET}${CMAKE_C_COMPILER_TARGET}")
76128
endif()
77-
129+
# The 'cpio_archive' is no explicit parameter for the command, because it is
130+
# hard-coded already in the specific 'cpio_archive_s' file we have generated
131+
# above.
78132
add_custom_command(
79133
OUTPUT ${output_name}
80-
COMMAND rm -f ${cpio_archive}
81-
COMMAND ${commands}
82-
COMMAND
83-
sh -c
84-
"echo 'X.section ._archive_cpio,\"aw\"X.globl ${archive_symbol}, ${archive_symbol}_endX${archive_symbol}:X.incbin \"${cpio_archive}\"X${archive_symbol}_end:X' | tr X '\\n'"
85-
> "${cpio_archive_s}"
86134
COMMAND
87-
${CMAKE_C_COMPILER} ${cmake_c_flags_sep} -c -o ${output_name} "${cpio_archive_s}"
88-
DEPENDS ${input_files} ${MAKE_CPIO_DEPENDS}
89-
VERBATIM
90-
BYPRODUCTS
91-
"${cpio_archive}"
92-
"${cpio_archive_s}"
135+
${CMAKE_C_COMPILER} ${cmake_c_flags_sep} -c -o "${output_name}" "${cpio_archive_s}"
136+
DEPENDS "${cpio_archive_creator}" "${cpio_archive_s}" "${cpio_archive}"
93137
COMMENT "Generate CPIO archive ${output_name}"
94138
)
95139
endfunction(MakeCPIO)

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