[PATCH v5 8/9] buildtools/chkincs: use a staging directory for headers

[David Marchand <david.marchand@redhat.com>]

A problem with the current headers check is that it relies on
meson dependencies objects that come with their include_directories
directives, and all of those point at the library / driver sources.

This means that we won't detect a public header including a private
(as in, not exported) header, or a driver only header.

To address this issue, a staging directory is added and every header
is copied to it.

Drivers and library headers are staged to two different directories
and the check is updated accordingly.

Signed-off-by: David Marchand <david.marchand@redhat.com>
---
Changes since v4:
- split global_inc (isolating config include path from EAL headers),
- moved all changes under buildtools/chkincs,

Changes since v3:
- removed update of global_inc (which was unneeded, and probably was
  what triggered a Windows clang build issue reported by CI),
- moved all staging operations under a check on check_includes= option,
- moved staging directories under buildtools/chkincs/,
- renamed all variables to reflect those concern the headers check,
- made chkincs binaries depend on staging deps instead of having the
  libraries/drivers depend on them,
- added C++ check for driver headers (missed in v3),

---

 buildtools/chkincs/meson.build                | 67 +++++++++++++++----
 buildtools/chkincs/stage-headers.py           | 32 +++++++++
 .../chkincs/staging/drivers/meson.build       | 12 ++++
 buildtools/chkincs/staging/meson.build        | 30 +++++++++
 meson.build                                   |  6 +-
 5 files changed, 131 insertions(+), 16 deletions(-)
 create mode 100644 buildtools/chkincs/stage-headers.py
 create mode 100644 buildtools/chkincs/staging/drivers/meson.build
 create mode 100644 buildtools/chkincs/staging/meson.build

diff --git a/buildtools/chkincs/meson.build b/buildtools/chkincs/meson.build
index ac7df41304..50cb542f23 100644
--- a/buildtools/chkincs/meson.build
+++ b/buildtools/chkincs/meson.build
@@ -6,6 +6,15 @@ if not get_option('check_includes')
     subdir_done()
 endif
 
+stage_headers_cmd = py3 + files('stage-headers.py')
+
+includes = [config_inc]
+deps = []
+includes_drivers = []
+deps_drivers = []
+
+subdir('staging')
+
 gen_c_file_for_header = find_program('gen_c_file_for_header.py')
 gen_c_files = generator(gen_c_file_for_header,
         output: '@BASENAME@.c',
@@ -18,18 +27,7 @@ endif
 cflags += no_wvla_cflag
 
 sources = files('main.c')
-sources += gen_c_files.process(dpdk_arch_headers + dpdk_headers + dpdk_drivers_headers)
-
-# some driver SDK headers depend on these two buses, which are mandatory in build
-# so we always include them in deps list
-deps = [get_variable('shared_rte_bus_vdev'), get_variable('shared_rte_bus_pci')]
-if dpdk_conf.has('RTE_BUS_VMBUS')
-    deps += get_variable('shared_rte_bus_vmbus')
-endif
-# add the rest of the libs to the dependencies
-foreach l:dpdk_libs_enabled
-    deps += get_variable('shared_rte_' + l)
-endforeach
+sources += gen_c_files.process(dpdk_arch_headers + dpdk_headers)
 
 executable('chkincs', sources,
         c_args: cflags,
@@ -49,6 +47,27 @@ executable('chkincs-all', sources,
         dependencies: deps,
         install: false)
 
+sources_drivers = files('main.c')
+sources_drivers += gen_c_files.process(dpdk_drivers_headers)
+
+executable('chkincs-drv', sources_drivers,
+        c_args: cflags,
+        include_directories: includes + includes_drivers,
+        dependencies: deps + deps_drivers,
+        install: false)
+
+executable('chkincs-drv-exp', sources_drivers,
+        c_args: [cflags, '-DALLOW_EXPERIMENTAL_API'],
+        include_directories: includes + includes_drivers,
+        dependencies: deps + deps_drivers,
+        install: false)
+
+executable('chkincs-drv-all', sources_drivers,
+        c_args: [cflags, '-DALLOW_EXPERIMENTAL_API', '-DALLOW_INTERNAL_API'],
+        include_directories: includes + includes_drivers,
+        dependencies: deps + deps_drivers,
+        install: false)
+
 # run tests for c++ builds also
 if not add_languages('cpp', required: false)
     subdir_done()
@@ -59,7 +78,7 @@ gen_cpp_files = generator(gen_c_file_for_header,
         arguments: ['@INPUT@', '@OUTPUT@'])
 
 cpp_sources = files('main.cpp')
-cpp_sources += gen_cpp_files.process(dpdk_arch_headers + dpdk_headers + dpdk_drivers_headers)
+cpp_sources += gen_cpp_files.process(dpdk_arch_headers + dpdk_headers)
 
 executable('chkincs-cpp', cpp_sources,
         cpp_args: ['-include', 'rte_config.h', cflags],
@@ -79,3 +98,25 @@ executable('chkincs-cpp-all', cpp_sources,
         include_directories: includes,
         dependencies: deps,
         install: false)
+
+cpp_sources_drivers = files('main.cpp')
+cpp_sources_drivers += gen_cpp_files.process(dpdk_drivers_headers)
+
+executable('chkincs-drv-cpp', cpp_sources_drivers,
+        cpp_args: ['-include', 'rte_config.h', cflags],
+        include_directories: includes + includes_drivers,
+        dependencies: deps + deps_drivers,
+        install: false)
+
+executable('chkincs-drv-cpp-exp', cpp_sources_drivers,
+        cpp_args: ['-include', 'rte_config.h', cflags, '-DALLOW_EXPERIMENTAL_API'],
+        include_directories: includes + includes_drivers,
+        dependencies: deps + deps_drivers,
+        install: false)
+
+executable('chkincs-drv-cpp-all', cpp_sources_drivers,
+        cpp_args: ['-include', 'rte_config.h', cflags, '-DALLOW_EXPERIMENTAL_API',
+                   '-DALLOW_INTERNAL_API'],
+        include_directories: includes + includes_drivers,
+        dependencies: deps + deps_drivers,
+        install: false)
diff --git a/buildtools/chkincs/stage-headers.py b/buildtools/chkincs/stage-headers.py
new file mode 100644
index 0000000000..3057c6a26f
--- /dev/null
+++ b/buildtools/chkincs/stage-headers.py
@@ -0,0 +1,32 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright (c) 2025 Red Hat, Inc.
+
+"""
+Headers staging script for DPDK build system.
+"""
+
+import sys
+import os
+import shutil
+from pathlib import Path
+
+def main():
+    if len(sys.argv) < 4:
+        print("Usage: stage-headers.py <staging_dir> <meson_stamp> [headers...]")
+        sys.exit(1)
+
+    staging_dir = Path(sys.argv[1])
+    meson_stamp = Path(sys.argv[2])
+    headers = sys.argv[3:]
+
+    staging_dir.mkdir(parents=True, exist_ok=True)
+
+    for header in headers:
+        file = Path(header)
+        shutil.copy2(file, staging_dir / file.name)
+
+    meson_stamp.touch()
+
+if __name__ == "__main__":
+    main()
diff --git a/buildtools/chkincs/staging/drivers/meson.build b/buildtools/chkincs/staging/drivers/meson.build
new file mode 100644
index 0000000000..c89fe8529a
--- /dev/null
+++ b/buildtools/chkincs/staging/drivers/meson.build
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright (c) 2025 Red Hat, Inc.
+
+includes += include_directories('.')
+deps += declare_dependency(sources:
+    custom_target('drivers_headers_staging',
+            output: 'drivers_headers_staging.stamp',
+            command: [stage_headers_cmd, meson.current_build_dir(), '@OUTPUT@',
+                dpdk_drivers_headers],
+            install: false,
+    )
+)
diff --git a/buildtools/chkincs/staging/meson.build b/buildtools/chkincs/staging/meson.build
new file mode 100644
index 0000000000..c66cce4831
--- /dev/null
+++ b/buildtools/chkincs/staging/meson.build
@@ -0,0 +1,30 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright (c) 2025 Red Hat, Inc.
+
+subdir('drivers')
+
+includes += include_directories('.')
+deps += declare_dependency(sources:
+    custom_target('arch_headers_staging',
+            output: 'arch_headers_staging.stamp',
+            command: [stage_headers_cmd, meson.current_build_dir(), '@OUTPUT@',
+                dpdk_arch_headers + dpdk_arch_indirect_headers],
+            install: false,
+    )
+)
+deps += declare_dependency(sources:
+    custom_target('headers_staging',
+            output: 'headers_staging.stamp',
+            command: [stage_headers_cmd, meson.current_build_dir(), '@OUTPUT@',
+                dpdk_headers + dpdk_indirect_headers],
+            install: false,
+    )
+)
+deps += declare_dependency(sources:
+    custom_target('generic_headers_staging',
+            output: 'generic_headers_staging.stamp',
+            command: [stage_headers_cmd, join_paths(meson.current_build_dir(), 'generic'),
+                '@OUTPUT@', dpdk_generic_headers],
+            install: false,
+    )
+)
diff --git a/meson.build b/meson.build
index 9f0b06179b..7f90d3bdc3 100644
--- a/meson.build
+++ b/meson.build
@@ -69,9 +69,9 @@ elif host_machine.cpu_family().startswith('riscv')
 endif
 
 # configure the build, and make sure configs here and in config folder are
-# able to be included in any file. We also store a global array of include dirs
-# for passing to pmdinfogen scripts
-global_inc = [include_directories('.', 'config',
+# able to be included in any file
+config_inc = [include_directories('.', 'config')]
+global_inc = [config_inc, include_directories(
     'lib/eal/include',
     'lib/eal/@0@/include'.format(host_machine.system()),
     'lib/eal/@0@/include'.format(arch_subdir),
-- 
2.51.0