Commit Graph
4 Commits
Author SHA1 Message Date
Niels Lohmann 57371b0977 Avoid //include in Meson-generated CMake target for prefix /
As CMake's generated targets file does, reset _IMPORT_PREFIX to an empty
string when it resolves to "/".

Reported by @heitbaum in #5587.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-10-01 13:07:17 +02:00
Niels Lohmann 9cbe62efb0 Fix the Meson CMake target for includedir or datadir outside the prefix
nlohmann_jsonTargets.cmake always prepended the prefix computed from the
file's location to includedir. With an absolute includedir outside the
prefix (as Nix passes for packages with a separate dev output), this gave
"<prefix>//abs/include"; with an absolute datadir outside the prefix, the
number of ".." was derived from the absolute path and the prefix resolved
to "/". In both cases find_package(nlohmann_json) failed with "Imported
target includes non-existent path". Use the absolute include directory in
these cases, as CMake's install(EXPORT) does, and check it in CI.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-27 18:23:27 +02:00
Niels Lohmann cc9fafa0e1 Complete the Meson options and match CMake's compile definitions
Finish the Meson changes from #4452:

- Offer all eight options that change the CMake target, named like the
  CMake options without the JSON_ prefix. MultipleHeaders defaults to
  false so that existing Meson users keep the single header.
- Add a compile definition only for an option that differs from its
  default, exactly as target_compile_definitions does. Before, the
  GlobalUDLs and ImplicitConversions definitions were inverted and were
  also added in the default configuration.
- Keep the nlohmann_json_multiple_headers dependency that earlier
  versions of meson.build provided.
- Put the definitions into the pkg-config file and the Meson-generated
  nlohmann_jsonTargets.cmake, and install the pkg-config file into
  <datadir>/pkgconfig like CMake does.
- Ship meson_options.txt in include.zip, since meson.build now reads
  options and the zip is documented as a Meson subproject.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-27 14:50:10 +02:00
Niels Lohmann 0d2240ad1e Install CMake package config files with Meson
A Meson installation only provided the headers and a pkg-config file, so
consumers using find_package(nlohmann_json) could not find the library.
Meson now also installs nlohmann_jsonConfig.cmake and
nlohmann_jsonConfigVersion.cmake from the existing templates, plus a
static nlohmann_jsonTargets.cmake that defines the header-only imported
target with a relocatable include path.

A new CI job installs with Meson and builds tests/cmake_import/project
against the result.

Closes #3885

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
2026-09-27 14:25:10 +02:00