cmake: clear package version after `pkg-config` detection

`pkg_check_modules()` seems to leave `<PACKAGE>_VERSION` defined with an
empty value, if the package is not found.

When

cmake: clear package version after `pkg-config` detection

`pkg_check_modules()` seems to leave `<PACKAGE>_VERSION` defined with an
empty value, if the package is not found.

When the package is also not found in the fallback branch,
`find_package_handle_standard_args()` logs and error message. In this
message it includes the bogus empty value as: `(found version "")`:
```
Could NOT find Libssh2 (missing: LIBSSH2_INCLUDE_DIR LIBSSH2_LIBRARY) (found version "")
```
https://github.com/curl/curl/actions/runs/11509727553/job/32040378958?pr=15408#step:31:99

Clear the version number to avoid the confusion:
```
Could NOT find Libssh2 (missing: LIBSSH2_INCLUDE_DIR LIBSSH2_LIBRARY)
```
https://github.com/curl/curl/actions/runs/11510022503/job/32041149129?pr=15408#step:31:99

Seen with CMake v3.30.5.

Follow-up to 7bab201abe3915a0167c002f9308950cb8a06e4b #15193
Closes #15409

show more ...

cmake: document `-D` and env build options

Extend `INSTALL-CMAKE` document with the list of available options,
a short description and default values.

The list may not be 100% c

cmake: document `-D` and env build options

Extend `INSTALL-CMAKE` document with the list of available options,
a short description and default values.

The list may not be 100% complete.

There are no component boundaries in CMake, so the line is blurry
between curl options, CMake options, CMake Find modules options.
I included certain CMake options that seemed useful, and/or have
dedicated use withing curl's CMake source. But, all CMake built-in
options are usable, as documented upstream in CMake.

The naming of the options has a heritage and the inconsistencies with
it, including a lack of clear namespace. This may be subject to future
updates, also after figuring out which name has special meaning within
CMake and/or CMake projects out of unwritten convention or something
more tangible.

CMake allows to initialize any internal variable via `-D`. This may be
useful to pre-initialize/override feature check results. The list
doesn't contain these, and they remain officially undocumented.

Also:
- make adjustments to keep the spellchecker happy.
- retrofit description changes to the cmake sources.
- stop documenting deprecated `Find*` variables.

Reported-by: Daniel Stenberg
Fixes https://github.com/curl/curl/discussions/14885
Closes #15388

show more ...

cmake: add native `pkg-config` detection for mbedTLS, MSH3, Quiche, Rustls, wolfSSL

Also:
- detect and add required system libraries for Rustls on macOS and
non-Windows.
- add

cmake: add native `pkg-config` detection for mbedTLS, MSH3, Quiche, Rustls, wolfSSL

Also:
- detect and add required system libraries for Rustls on macOS and
non-Windows.
- add Linux CMake jobs for the touched dependencies.
Caveats:
- MSH3 generates a broken `libmsh3.pc`, so needs manual config.
Upstream PR: https://github.com/nibanks/msh3/pull/225
- Rustls `.pc` file missing, so needs manual config.

An internal change worthy of mention is that we are using the lib path
and name information returned by `pkg-config` as-is. Meaning the libname
doesn't include the full path, like it's usual with native cmake
detection. The path comes separately and needs to be rolled separately.
For this we add it to targets via `link_directories()`. We also keep tab
of them in `CURL_LIBDIRS` and use that in `libcurl.pc`. Feature checks
also need to receive these paths. CMake doesn't offer
a `CMAKE_REQUIRED_*` variable for this purpose, only
a `CMAKE_REQUIRED_LINK_OPTIONS` accepting raw linker flags. Add a macro
to convert a list of paths to linker options to solve it. wolfSSL
requires this for now.

Closes #15193

show more ...

cmake: tidy up more in Find modules

- add `NAMES` where missing.
- document input variables (including deprecated ones.)
- comment cleanups.
- FindWolfSSL: drop stray `QUIET` fro

cmake: tidy up more in Find modules

- add `NAMES` where missing.
- document input variables (including deprecated ones.)
- comment cleanups.
- FindWolfSSL: drop stray `QUIET` from `pkg_check_modules()`.
(`QUIET` may be re-added for all modules in the future.)

Closes #14579

show more ...

cmake: rename wolfSSL and zstd config variables to uppercase

To match with other config variables and other projects.

Rename these CMake configuration variables:
- `WolfSSL_INCL

cmake: rename wolfSSL and zstd config variables to uppercase

To match with other config variables and other projects.

Rename these CMake configuration variables:
- `WolfSSL_INCLUDE_DIR` -> `WOLFSSL_INCLUDE_DIR`
- `WolfSSL_LIBRARY` -> `WOLFSSL_LIBRARY`
- `Zstd_INCLUDE_DIR` -> `ZSTD_INCLUDE_DIR`
- `Zstd_LIBRARY` -> `ZSTD_LIBRARY`

The old values continue to work, with a warning suggesting the new name.

Also:
- add similar warnings for earlier renames for mbedTLS and BearSSL.
- rename internal variables `PC_Zstd_*` to uppercase.

Follow-up to db39c668a8e33e064b9eb20892cd027f46302f77 #14542

Closes #14574

show more ...

cmake: revert to `pkg_check_modules()`

Prefer `pkg_check_modules()` over `pkg_search_module()`.

`pkg_check_modules()` logs a line when there is a hit, and also warnings
if a sub

cmake: revert to `pkg_check_modules()`

Prefer `pkg_check_modules()` over `pkg_search_module()`.

`pkg_check_modules()` logs a line when there is a hit, and also warnings
if a sub-dependency is missing. In `QUIET` mode, both are silent.

The extra info is useful to see if a detection happened via
`pkg-config`.

Keep `pkg_search_module()` in `FindGSS`. We pass two dependencies
there and we want to keep stopping on the first one.

Partially reverts c2889a7b4180fc963ae30811f59ab547b6eb03cd #14388

Closes #14573

show more ...

cmake: add missing version detection to Find modules

- use `pkg-config` version when available and where it wasn't yet used.

- add manual version detection for dependencies where th

cmake: add missing version detection to Find modules

- use `pkg-config` version when available and where it wasn't yet used.

- add manual version detection for dependencies where this is possible
(via a public header) and where it wasn't done yet.

Closes #14548

show more ...

cmake: add missing `pkg-config` hints to Find modules

- brotli, c-ares, libpsl, libssh2, mbedtls, rustls:
Use `pkg-config` for path hints and version info. Syncing them up with
t

cmake: add missing `pkg-config` hints to Find modules

- brotli, c-ares, libpsl, libssh2, mbedtls, rustls:
Use `pkg-config` for path hints and version info. Syncing them up with
the rest of Find modules.

- GHA/macos: force-disable libssh2 with cmake to sync with autotools.
After this patch, cmake auto-detects libssh2 in this job.

Closes #14545

show more ...

cmake: sync up result variable names in Find modules

- bearssl, c-ares, gss, libpsl, libssh2, mbedtls:
Before this patch these Find modules returned results via
`<NAME>_INCLUDE_D

cmake: sync up result variable names in Find modules

- bearssl, c-ares, gss, libpsl, libssh2, mbedtls:
Before this patch these Find modules returned results via
`<NAME>_INCLUDE_DIR` and `<NAME>_LIBRARY`.

This patch makes them return `<NAME>_INCLUDE_DIRS` (note the `S`)
and `<NAME>_LIBRARIES` like other modules already did.

- bearssl, mbedtls:
Before this patch these Find modules allowed custom configuration
via `<NAME>_INCLUDE_DIRS` (note the `S`).

This patch makes them accept `<NAME>_INCLUDE_DIR`, like the rest of
the modules did.

Deprecate the old variables, but keep accepting them for
compatibility.

- bearssl: add missing `mark_as_advanced()` call.

Closes #14542

show more ...

cmake: tidy up Find modules

Smoothen out minor differences between Find modules.

- brotli, nghttp2: drop redundant `FOUND_VAR` specifiers from
`find_package_handle_standard_ar

cmake: tidy up Find modules

Smoothen out minor differences between Find modules.

- brotli, nghttp2: drop redundant `FOUND_VAR` specifiers from
`find_package_handle_standard_args()` calls.
This function sets both `<NAME_UPPER>_FOUND` and `<NAME>_FOUND`
by default.

- brotli: set result vars only when found.

- brotli: add missing `mark_as_advanced()` call.

- brotli: delete custom fail message.

- mbedtls, bearssl: use `REQUIRED_VARS` instead of `DEFAULT_MSG`.

- msh3, quiche: set `<NAME>_VERSION` (via pkg-config).

- wolfssl: also use `PC_WOLFSSL_INCLUDEDIR`, `PC_WOLFSSL_LIBDIR`
as hints.

- libpsl, libssh2, zstd: clear temporary variables used for version
detection.

- gss, msh3, nghttp2, nghttp3, ngtcp2, quiche, zstd: fix to apply
`mark_as_advanced()` to internal variables only.

Closes #14538

show more ...

cmake: sync up formatting in Find modules

- lowercase internal variable names (FindGSS)
- comments
- whitespace

Closes #14527

cmake: more syntax tidy-up

- quote string literals.
In the hope it improves syntax-highlighting and readability.

- use lowercase, underscore-prefixed local var names.
As

cmake: more syntax tidy-up

- quote string literals.
In the hope it improves syntax-highlighting and readability.

- use lowercase, underscore-prefixed local var names.
As a hint for scope, to help readability.

- prefer `pkg_search_module` (over `pkg_check_modules`).
They are the same, but `pkg_search_module` stops searching
at the first hit.

- more `IN LISTS` in `foreach()`.

- OtherTests.cmake: clear `CMAKE_EXTRA_INCLUDE_FILES` after use.

- add `PROJECT_LABEL` for http/client and unit test targets.

- sync `Find*` module comments and formatting.

- drop a few local variables.

- drop bogus `CARES_LIBRARIES` from comment.

- unquote numeric literal.

Follow-up to acbc6b703f6b0ee568d053f6f2565fbc107b5fd3 #14197
Closes #14388

show more ...

cmake: whitespace, formatting/tidy-up in comments

Also correct casing in a few option descriptions.

Closes #13711

copyright: update all copyright lines and remove year ranges

- they are mostly pointless in all major jurisdictions
- many big corporations and projects already don't use them
- save

copyright: update all copyright lines and remove year ranges

- they are mostly pointless in all major jurisdictions
- many big corporations and projects already don't use them
- saves us from pointless churn
- git keeps history for us
- the year range is kept in COPYING

checksrc is updated to allow non-year using copyright statements

Closes #10205

show more ...

copyright: make repository REUSE compliant

Add licensing and copyright information for all files in this repository. This
either happens in the file itself as a comment header or in the

copyright: make repository REUSE compliant

Add licensing and copyright information for all files in this repository. This
either happens in the file itself as a comment header or in the file
`.reuse/dep5`.

This commit also adds a Github workflow to check pull requests and adapts
copyright.pl to the changes.

Closes #8869

show more ...

cmake: prevent dev warning due to mismatched arg

-- curl version=[7.81.0-DEV]
CMake Warning (dev) at /usr/share/cmake-3.22.1/Modules/FindPackageHandleStandardArgs.cmake:438 (message):

cmake: prevent dev warning due to mismatched arg

-- curl version=[7.81.0-DEV]
CMake Warning (dev) at /usr/share/cmake-3.22.1/Modules/FindPackageHandleStandardArgs.cmake:438 (message):
The package name passed to `find_package_handle_standard_args` (MBEDTLS)
does not match the name of the calling package (MbedTLS). This can lead to
problems in calling code that expects `find_package` result variables
(e.g., `_FOUND`) to follow a certain pattern.
Call Stack (most recent call first):
deps/curl/CMake/FindMbedTLS.cmake:31 (find_package_handle_standard_args)
deps/curl/CMakeLists.txt:473 (find_package)
This warning is for project developers. Use -Wno-dev to suppress it.

Closes #8207

show more ...

curl.se: new home

Closes #6172

copyright: fix out-of-date copyright ranges and missing headers

Reported by the new script 'scripts/copyright.pl'. The script has a
regex whitelist for the files that don't need copyrigh

copyright: fix out-of-date copyright ranges and missing headers

Reported by the new script 'scripts/copyright.pl'. The script has a
regex whitelist for the files that don't need copyright headers.

Removed three (mostly usesless) README files from docs/

Closes #5141

show more ...

CMake: Add mbedTLS support

Ref: https://github.com/curl/curl/pull/1228