After limiting `find_package()`/`find_dependency()` calls to libssh2
local Find modules via the `MODULES` keyword, it became possible to
detect dependencies via CMake Configs from within those local Find
modules, by calling `find_package()` again with the `CONFIG` keyword.
This patch implements this. Then maps detection results to the result
variables and libssh2-specific imported targets the rest of the build
expects.
This adds CMake Configs as an alternative to the existing `pkg-config`
and `find_path()`/`find_library()` auto-detection methods.
Enabled by default for MSVC, outside vcpkg and when not cross-building.
To enable for other cases, or override the default, you can use
`-DLIBSSH2_USE_CMAKECONFIG=ON` or `OFF`.
When enabled, Config detection happens after `pkg-config` and before
`find_path()`/`find_library()`. Using CMake's built-in options, you may
also manually point to the absolute directory holding Config files:
`MbedTLS_DIR`, `wolfssl_DIR`
E.g. `-DMbedTLS_DIR=/path/to/mbedtls/lib/cmake/MbedTLS`
mbedTLS needs to be built with CMake for this to work. wolfSSL 5.9.0+
also supports it when it was built with autotools.
Experimental.
Refs:
8fce3e17e6https://github.com/curl/curl/pull/20814a56ab9dbc8https://github.com/curl/curl/pull/21098
Follow-up to dd5f3fff39#2262Closes#2264
When enabled, make a "best effort" finding static lib first and set
the "build static" macro (on Windows) as required by the dependency.
When doing `pkg-config`-based detections, make the build select the
static configuration, which shall set the "build static" macro also.
This option resemble CMake's `OPENSSL_USE_STATIC_LIBS` and
`ZLIB_USE_STATIC_LIBS` (the latter does not support `pkg-config` as of
CMake v4.2.2).
Shared/static library selection based on loose filename conventions is
fragile and prone to break if the non-static-suffixed library is found
and happens to be a shared library, or, if the linker decides to pick up
a shared copy (e.g. `.a.dll`) that shadows the static one. It may help
to provide either static or shared, but not both, on the disk, and match
that with this setting.
Experimental.
Refs:
26c39d8df1https://github.com/curl/curl/pull/20015Closes#2263
By forcing local Find module invocations into `MODULE` mode. To avoid
accidentally picking up such a dependency via CMake Config-based
detection, which does not provide the expected imported target and make
the build fail.
It also prepares the scripts to alllow CMake Config support in local
Find modules.
Also:
- add reproducer in CI.
- allow custom options in CMake integration test script.
Refs:
91e06fde1bhttps://github.com/curl/curl/pull/20784https://github.com/curl/curl/issues/20729Closes#2262
Also:
- sync with canonical `BSD-3-Clause.txt`:
- number the clauses.
- wording in the 3rd clause.
- add 'All rights reserved.' where missing.
- agent: sync with rest of files.
- agent: merge two, identical, embedded headers.
- fix comments nits found nearby.
Closes#2247
This feature has been permanently enabled since the initial commit
adding CMake builds to libssh2. Limited to libssh2's own DLL (if built
that way), and OpenSSL's crypto DLL. While limited to these two DLLs
(and not supporting other dependencies), history shows this feature was
prone to break, and recently started breaking parallel builds, due to
MSBuild failing while copying the DLLs to the same location in
concurrent threads. This recently made MSVC GHA jobs flaky.
It's also a potential performance and disk trashing issue when copying
large DLLs (OpenSSL `libcrypto-*.dll`) on each build, for each of the 52
(at the time of this commit) targets. That's potentially 104 copy
operations. Perhaps this could be limited to once per each target
directory, but that's adding even more complexity and development time.
There is also no generalized/trivial way to pick up the complete set of
DLL dependencies; e.g. libcrypto.dll may need other DLLs. Another
disadvantage is copying around DLLs eventually ends up contributing to
DLL-hell, copies may go stale, picked up when undesired, or due the
heuristic detection, they may not match the dependency version/instance
actually linked. The copying was done on all platforms, while typically
the issue is exclusive to Windows MSVC (and it's also where it breaks.)
As a replacement, I propose to add any necessary DLL location to `PATH`
before running examples or tests. It works well in CI. Also in curl.
Fixing:
```
Version: 20260616.203.1
[...]
MSBuild version 17.14.40+3e7442088 for .NET Framework
[...]
D:/a/libssh2/libssh2/bld/tests/Release\libssh2.dll: message: deploying dependencies
D:/a/libssh2/libssh2/bld/tests/Release\libcrypto-3-x64.dll: message: deploying dependencies
The process cannot access the file because it is being used by another process.
[...]
C:\Program Files\Microsoft Visual Studio\2022\Enterprise\MSBuild\Microsoft\VC\v170\Microsoft.CppCommon.targets(166,5): error MSB3073: :cmDone [D:\a\libssh2\libssh2\bld\tests\test_auth_pubkey_ok_rsa_sha2_256_signed.vcxproj]
C:\Program Files\Microsoft Visual Studio\2022\Enterprise\MSBuild\Microsoft\VC\v170\Microsoft.CppCommon.targets(166,5): error MSB3073: if %errorlevel% neq 0 goto :VCEnd [D:\a\libssh2\libssh2\bld\tests\test_auth_pubkey_ok_rsa_sha2_256_signed.vcxproj]
C:\Program Files\Microsoft Visual Studio\2022\Enterprise\MSBuild\Microsoft\VC\v170\Microsoft.CppCommon.targets(166,5): error MSB3073: :VCEnd" exited with code 32. [D:\a\libssh2\libssh2\bld\tests\test_auth_pubkey_ok_rsa_sha2_256_signed.vcxproj]
D:/a/libssh2/libssh2/bld/tests/Release/test_auth_keyboard_info_request.exe: message: deploying dependencies
D:/a/libssh2/libssh2/bld/tests/Release\libcrypto-3-x64.dll: message: deploying dependencies
test_auth_pubkey_ok_rsa_openssh.vcxproj -> D:\a\libssh2\libssh2\bld\tests\Release\test_auth_pubkey_ok_rsa_openssh.exe
```
Refs (MSVC):
https://github.com/libssh2/libssh2/actions/runs/27838566519/job/82392203784 OpenSSL
https://github.com/libssh2/libssh2/actions/runs/27838566519/job/82392203753 WinCNG
https://github.com/libssh2/libssh2/actions/runs/27823077802/job/82340632890 WinCNG UWP
Examples, with shared libssh2:
combined with WINCNG:
Before: https://github.com/libssh2/libssh2/actions/runs/27891639324/job/82535960547 (277 steps)
After: https://github.com/libssh2/libssh2/actions/runs/27901568257/job/82562736781 (229 steps)
combined with OpenSSL:
Before: https://github.com/libssh2/libssh2/actions/runs/27902131772/job/82564199274 (326 steps)
After: https://github.com/libssh2/libssh2/actions/runs/27902733625/job/82565870012 (229 steps)
Observe these steps no longer performed:
```
D:/a/libssh2/libssh2/bld/example/Release\libcrypto-3-x64.dll: message: deploying dependencies
D:/a/libssh2/libssh2/bld/example/Release\libssh2.dll: message: deploying dependencies
```
Ref: #2078
Ref: 1e5e2923f7
Follow-up to a95a02c8fb#2093
Follow-up to 97d8e8d49a#2091
Follow-up to d652ba0205#2090
Follow-up to dd50a41152#1638
Follow-up to 694b9d964b#1610
Follow-up to 97417ad37f#899
Follow-up to 19884e5055#818
Follow-up to 6bf8983368Closes#2101
- sync picky compiler warning options with curl:
- update version mappings for latest Apple clang.
- replace `-pedantic` with `-Wpedantic` on newer toolchains.
- adjust warning cutoff versions.
- enable new picky warnings.
- unlock picky warnings for most recent MSVC.
- GHA: bump some MSVC jobs to to VS2026.
Fix fallouts:
- configure: replace `-I` with `-isystem` for dependency headers.
Notably it silences picky warnings otherwise found in 3rd-party
headers, e.g. `-Wreserved-identifier` in `gpg-error.h`,
`openssl/lhash.h`, `wolfssl/wolfcrypt/hmac.h`, or
`-Wcast-function-type-strict` in `openssl/rsa.h`.
It also aligns autotools builds with CMake (and curl builds).
Logic copied from curl.
- example/x11: fix to not use reserved symbols.
- include, src/libssh2_priv.h: silence `-Wreserved-identifier` locally.
May be fixed for real in a future patch.
- avoid using reserved C++ keyword `public`.
- openssl: silence `-Wcast-function-type-strict` locally for
non-OpenSSL3 builds.
- mbedtls, openssl: fix potentially uninitialized variable warnings.
(extend to all compilers from MSVC in openssl)
- fix `LIBSSH2_SOCKET_MASK` signedness on Windows.
- wincng: apply casts from `int` to `enum` to silence
`-Wimplicit-int-enum-cast`.
- configure: disable `-Wleading-whitespace=spaces` to due
incompatibility with `AC_FUNC_ALLOCA`.
- packet: fix to pass `int` as mask length.
- fix `-Wformat-signedness`.
- src/libssh2_priv.h: silence `-Wreserved-macro-identifier` locally for
mingw-w64 builds.
- GHA: add workaround for missing NSIS on windows-2025 runner images.
Closes#1972
Checker script and wordlist comes from curl.
Also:
- checksrc.pl: sync up with curl.
- unfold an IETF URL.
- update all IETF URLs where missing.
Closes#1959
Require CMake 3.18 (2020-07-15) or newer, up from 3.7 (2016-11-11) prior
to this patch.
This requirement also applies to the distributed `libssh2-config.cmake`.
To allow dropping compatibility code maintained for old versions, and to
use features which were unpractical in separate code paths. Also to make
testing, documentation and development easier, and builds faster due
CMake performance improvements over time.
CMake offers pre-built binaries for major platforms. They work without
an install step, just by unpacking and pointing the cmake command to
them. Making upgrades easy in many cases:
https://cmake.org/download/https://cmake.org/files/https://github.com/Kitware/CMake/releases
CMake 3.18 brings these feature as generally available when building or
consuming curl/libcurl:
LTO support, improved performance, `pkg-config` and interface target
support, `OBJECT` target (for faster libcurl builds), modern invocation
with `-S`/`-B` options, better support for custom linker options,
FetchContent, `--verbose` and `--install` options, `CMAKE_GENERATOR`
env, last but not least unity mode and Ninja generator.
Ref: https://github.com/curl/curl/discussions/18704Closes#1839
The mbedTLS API is not one API but distinctly incompatible APIs
depending on its version. 2.x is largely incompatible with 3.x, and 4.x
is largely incompatible with 3.x, also dropping certain legacy crypto
primitives.
Following the release of 3.x in 2021, libssh2 added support for 3.x in
2022. 4.x was released in October 2025, and it makes using the PSA
Crypto API mandatory, after adding it in 3.x.
Supporting 2.x while also supporting the PSA Crypto API would mean
supporting 3 different crypto backends meshed together in a single
source file, with various overlapping and per-version parts, with
different features and separate needs to test.
2.x is also no longer maintained, supported, or security patched, as
written in its latest, and final, release notes on 2025-03-24:
https://github.com/Mbed-TLS/mbedtls/releases/tag/mbedtls-2.28.10
The mbedTLS project recommends upgrading to an upper major version.
To allow adding support for the PSA Crypto API and the 4.x series, and
to avoid an unmaintained 2.x major version, this patch drops support for
mbedTLS 2.x.
Also:
- GHA: update CI jobs to either use Linuxbrew mbedtls 3.x, or build from
source and cache it.
- Require 3.1.0 minimum (instead of 3.0.0), because libssh2 never built
with 3.0.0 due the use of API `mbedtls_cipher_info_get_key_bitlen()`.
Nobody complained since the initial commit introducing it.
Refs:
https://github.com/Mbed-TLS/TF-PSA-Crypto/blob/tf-psa-crypto-1.0.0/docs/1.0-migration-guide.mdhttps://github.com/Mbed-TLS/TF-PSA-Crypto/blob/tf-psa-crypto-1.0.0/docs/psa-transition.md#asymmetric-cryptographyCloses#1727
Note: On Linux with glibc, ISO mode also requires setting
the `_DEFAULT_SOURCE` macro to enable necessary POSIX features when
building tests (for `popen()`, `pclose()` and examples (for `fileno()`,
`tcsetattr()`). On other platforms and environments it may require
something else.
- replace `strdup()` with local implementation.
- replace `getline()` with C89 `fgets()`.
- replace `u_char`, `u_int` with C89 types.
- fix type mismatches in chacha-poly1305 code.
- silence `-Wno-format-nonliteral` locally. The global method was not
effective (like because it was overridden by `-Wformat=2`) and caused
these warnings when building in C89 mode.
- GHA: test ISO C89 in zlib-enabled Linux jobs with all crypto backends.
- fix formatting nits along the way.
- configure, cmake: silence silly `-Wno-comma` warnings with clang in
C89 mode.
- examples: include `select.h` again, where `select()` is used. As its
canonical header. Seen required on Linux glibc non-GNU/ISO builds.
Follow-up to a683133dfe#999
Assisted-by: Raul Tambre
Ref: #1674Closes#1688
This also means that we no longer pass any picky warning option to
ossfuzz. It's probably not worth maintaining picky C++ options for this
single, small target.
Silencing:
```
cc1plus: warning: command-line option '-Wbad-function-cast' is valid for C/ObjC but not for C++
cc1plus: warning: command-line option '-Wdeclaration-after-statement' is valid for C/ObjC but not for C++
cc1plus: warning: command-line option '-Wenum-int-mismatch' is valid for C/ObjC but not for C++
cc1plus: warning: command-line option '-Wjump-misses-init' is valid for C/ObjC but not for C++
cc1plus: warning: command-line option '-Wmissing-parameter-type' is valid for C/ObjC but not for C++
cc1plus: warning: command-line option '-Wmissing-prototypes' is valid for C/ObjC but not for C++
cc1plus: warning: command-line option '-Wnested-externs' is valid for C/ObjC but not for C++
cc1plus: warning: command-line option '-Wold-style-declaration' is valid for C/ObjC but not for C++
cc1plus: warning: command-line option '-Wold-style-definition' is valid for C/ObjC but not for C++
cc1plus: warning: command-line option '-Wstrict-prototypes' is valid for C/ObjC but not for C++
```
Ref: https://github.com/libssh2/libssh2/actions/runs/18063134305/job/51402236388#step:7:15Closes#1686
- cmake: sync `-ftree-vrp` behavior with autotools.
- build: enable `-Wjump-misses-init` for GCC 4.5+.
Credits-to: Marcel Raad
- packet: fix `-Wjump-misses-init` warnings.
```
src/packet.c: In function ‘_libssh2_packet_add’:
src/packet.c:671:9: error: jump skips variable initialization [-Werror=jump-misses-init]
src/packet.c:920:31: note: ‘want_reply’ declared here
src/packet.c:671:9: error: jump skips variable initialization [-Werror=jump-misses-init]
src/packet.c:919:26: note: ‘len’ declared here
src/packet.c:669:9: error: jump skips variable initialization [-Werror=jump-misses-init]
src/packet.c:1121:31: note: ‘want_reply’ declared here
src/packet.c:669:9: error: jump skips variable initialization [-Werror=jump-misses-init]
src/packet.c:1120:26: note: ‘len’ declared here
src/packet.c:669:9: error: jump skips variable initialization [-Werror=jump-misses-init]
src/packet.c:1119:26: note: ‘channel’ declared here
```
- build: enable gcc-12/13+, clang-10+ picky warnings
- acinclude.m4: sync formatting/comments with curl.
- autotools: fix `-Wtrampolines` picky warning for gcc 4.x versions.
Follow-up to 854cfa8292#1524
- cmake: enable `-Wall` for MSVC when `PICKY_COMPILER=ON`.
- MSVC: fix `-Wall` warnings.
Seen on VS2015. Not seen on VS2022. Unknown for other versions.
```
tests\test_simple.c(60): warning C4777: 'fprintf' : format string '%d' requires an argument of type 'int', but variadic argument 1 has type 'std::size_t'
tests\test_simple.c(60): warning C4777: 'fprintf' : format string '%.*s' requires an argument of type 'int', but variadic argument 2 has type 'std::size_t'
```
- mbedtls: stop silencing warnings in 3rd-party header.
Follow-up to a3aa6b4ca8#1525
- cmake: stop deleting `-W<n>` from `CMAKE_C_FLAGS` (MSVC)
1. `CMAKE_C_FLAGS` may apply to other projects, and deleting/altering it
may be unexpected.
2. We pass `-W4`/`-Wall` internally now, which do override custom
`-W<n>` options as tested with VS2008 and newer VS generators.
Closes#1588
Also to sync up with similar `./configure` feature via
`CURL_ADD_COMPILER_WARNINGS()`.
Example: `-DCMAKE_C_FLAGS=-Wno-xor-used-as-pow`
It may be useful as a workaround if a specific build combination hits
a picky warning within libssh2's source code. If such happens, we do
appreciate a report to fix it in libssh2 itself.
Closes#1590
- fix `add_subdirectory` builds for old CMake versions.
- libssh2-config.cmake: fix to set CMP0099 for CMake 3.17+ only.
- libssh2-config.cmake: generalize code to support any number of deps.
(mainly to sync with curl.)
- libssh2-config.cmake: bind dependencies to the static libssh2 only.
Follow-up to a0d8529b08#1571
Follow-up to df0563a857#1535Closes#1581
Fixes:
```
CMake Error at bld-libssh2/_pkg/lib/cmake/libssh2/libssh2-config.cmake:35 (add_library):
add_library cannot create ALIAS target "libssh2::libssh2" because target
"libssh2::libssh2_shared" is imported but not globally visible.
Call Stack (most recent call first):
CMakeLists.txt:27 (find_package)
CMake Error at bld-libssh2/_pkg/lib/cmake/libssh2/libssh2-config.cmake:40 (add_library):
add_library cannot create ALIAS target "Libssh2::libssh2" because target
"libssh2::libssh2_shared" is imported but not globally visible.
Call Stack (most recent call first):
CMakeLists.txt:27 (find_package)
```
tests/cmake reproducer (requires #1581):
```shell
export CMAKE_CONSUMER=/path/to/CMake-3.12.0/bin/cmake
./test.sh find_package
```
I don't understand what this error says, why it happens in certain CMake
versions, and why a workaround is necessary for what seems like
a standard export/consume configuration. This patch is based on internet
suggestions and other projects ending up with this workaround.
Ref: https://github.com/curl/curl/pull/16973
Ref: https://github.com/curl/curl/pull/17140
Cherry-picked from #1581Closes#1587
Tidy up the way we handle options not to be passed to feature checks,
and make sure to show them in the configure log.
Also:
- drop redundant and obsolete compiler check.
- drop redundant parenthesis.
Closes#1576
- replace `CMAKE_C_FLAGS*` and `CMAKE_CXX_FLAGS` with `COMPILE_OPTIONS`.
- replace `CMAKE_SHARED_LINKER_FLAGS_DEBUG` with
`LINK_OPTIONS`/`LINK_FLAGS`.
- make it explicit to pass these C flags to feature checks.
- enable `-pedantic-errors` picky option for GCC with CMake <3.23.
- drop redundant condition when stripping existing MSVC `/Wn` options.
CMake passes `CMAKE_C_FLAGS` to targets, feature checks and raw
`try_compile()` calls. With `COMPILE_OPTIONS`, this is limited to
targets, and we must explicitly pass them to feature checks. This
makes the build logic clearer, and offers more control. It also
reduces log noise by omitting these options from linker commands,
and from `CMAKE_C_FLAGS` dumps in feature checks.
Closes#1575
- drop `VERSION` target property for cmake <3.19 compatibility
```
CMake Error at CMake/Find*.cmake:90 (set_target_properties):
INTERFACE_LIBRARY targets may only have whitelisted properties.
The property "VERSION" is not allowed.
```
- move custom target property to the `INTERFACE_` namespace
for cmake <3.19 compatibility. (To avoid same error as above)
- fix forwarding multiple `CFLAGS`, when detected via `pkg-config`.
- restore support for `-framework` and raw libs when processing
the internal lib list for generating `libssh2.pc`. For good measure,
at the moment libssh2 doesn't depend on a Framework.
- limit `libssh2_dumptargetprops()` to cmake 3.19+. It doesn't work with
older versions.
Issues found while applying this change to curl. They did not surface in
libssh2 CI.
Follow-up to df0563a857#1535Closes#1571
- move dependency properties (libs, libdirs, C flags, header dirs,
pkg-config module names) from global lists to imported target
`INTERFACE` properties. Rework FInd modules to return their results
like this and update the libssh2 build process to use it. It makes
Find modules re-usable from the cmake-config script by libssh2
consumers, to integrate with libssh2 dependencies.
- define libssh2 dependencies as "imported targets" by the name:
`libssh2::<depname>`, e.g. `libssh2::libgcrypt`.
- cmake-config: add fall-back logic for CMake without
CMP0099 (v3.17 2020-03-20) to set lib directories.
- generate `libssh2.pc` based on imported target properties (instead of
global lists).
- add target property dump debug function.
- ci/GHA: also test cmake integration on macOS.
Follow-up to 96d7f404e7#1534Closes#1535
CMake:
- Find*: set `<modulename>_FOUND` for compatibility when found via
`pkg-config`. E.g. `MbedTLS_FOUND`.
`find_package_handle_standard_args()` sets both `<MODULENAME>_FOUND`
and `<Modulename>_FOUND` when detecting the dependency. Some CMake
code relies on this and 3rd-party code may rely on it too. Make sure
to set the latter variant when detecting the dependency via
`pkg-config`, where we don't call
`find_package_handle_standard_args()`.
CMake sets these variable to `TRUE` (not `ON` or `1`). Replicate this
for compatibility.
- libssh2-config.cmake: inherit default `LIBSSH2_USE_PKGCONFIG`.
Follow-up to a3aa6b4ca8#1525
- document variables consumed by `libssh2-config.cmake.in`.
- `libssh2-config.cmake`: fix to link to non-OpenSSL crypto backends.
This is most likely not how this is supposed to be done, but better
than failing.
What's the canonical way to do this, and how OpenSSL and zlib does it
is yet to be figured out.
- use `ZLIB::ZLIB` to reference zlib.
- use `IN ITEMS` where missed.
- harmonize variable dump output formats.
CMake `find_package` integration tests:
- extend to all crypto backends (was: OpenSSL).
- show libssh2 variables set by `find_package()`.
- stop building examples and tests for the consumed package.
For performance.
- enable zlib, for coverage.
- be verbose when building the test targets.
ci/GHA:
- add packaged mbedTLS (2.x) build to Linux matrix.
- alphasort some tests.
Follow-up to d9c2e550ca#1460
Follow-up to 82b09f9b3a#1322Closes#1534
- enable compiler warning `-Wcast-qual`.
- add `LIBSSH2_UNCONST()` macro to strip const where absolutely
necessary to avoid compiler warnings.
- fix const stripping by constifying where necessary.
- fix const stripping by using `LIBSSH2_UNCONST()`.
- libgcrypt.h: drop unnecessary casts.
- openssl: fix to use new `BIO_new_mem_buf()` parameter types
with wolfSSL.
Cherry-picked from #1484Closes#1527
- show platform flags (via curl).
- add `LIBSSH2_USE_PKGCONFIG` option to control whether to use
`pkg-config` to find dependencies.
- set `.pc` names withing the Find modules.
- add `mbedcrypto` to `libssh2.pc` only when detected via `pkg-config`.
Workaround for older mbedtls versions and non-CMake mbedTLS builds
(as of mbedTLS 3.6.2) that don't emit an `mbedcrypto.pc` file.
- set header paths relative to the project root (tidy-up).
- use `-isystem` for crypto backend and zlib header paths.
To match autotools.
- sync header path order with autotools.
- rename local variables to underscore-lowercase.
- minor tidy-ups.
Cherry-picked from #1484Closes#1525
- cmake: add support to build ossfuzz.
Enable with `-DBUILD_OSSFUZZ=ON`.
Also supports `-DLIB_FUZZING_ENGINE=` like autotools does.
- check for `__clang__` when suppressing warnings in source. Necessary
for clang-cl, which set `__clang__`, but doesn't set `__GNU__`.
- cmake: optimize out 4 picky warning option detections with gcc.
- cmake: bring `-pedantic-error`, `-Wall` use closer to curl's.
- cmake: set `-Wno-language-extension-token` for clang-cl.
- cmake: escape only the necessary `-W` options for clang-cl.
- cmake: apply picky warnings to C++.
- cmake: replace `unset(VAR)` with `set(VAR "")` for init.
- cmake: prefer dash-style MSVC options.
- cmake: simplify `MATCHES` expression.
- cmake: formatting/whitespace.
- ci/GHA: bump `actions/upload-artifact` to v4
Closes#1524
```
CMake Warning (dev) at cmake/CopyRuntimeDependencies.cmake:59 (add_custom_command):
The following keywords are not supported when using
add_custom_command(TARGET): DEPENDS.
Policy CMP0175 is not set: add_custom_command() rejects invalid arguments.
Run "cmake --help-policy CMP0175" for policy details. Use the cmake_policy
command to set the policy and suppress this warning.
Call Stack (most recent call first):
example/CMakeLists.txt:58 (add_target_to_copy_dependencies)
```
```
CMake Warning (dev) at cmake/CopyRuntimeDependencies.cmake:59 (add_custom_command):
Exactly one of PRE_BUILD, PRE_LINK, or POST_BUILD must be given. Assuming
POST_BUILD to preserve backward compatibility.
Policy CMP0175 is not set: add_custom_command() rejects invalid arguments.
Run "cmake --help-policy CMP0175" for policy details. Use the cmake_policy
command to set the policy and suppress this warning.
Call Stack (most recent call first):
example/CMakeLists.txt:58 (add_target_to_copy_dependencies)
```
Ref: https://github.com/libssh2/libssh2/actions/runs/12614228505/job/35152908184?pr=1510#step:15:77
This warning remains silent in unity builds. Since we're using unity
in CI for most jobs, warnings remain undetected there.
Disable them for all builds to avoid a surprise warning outside our CI.
It also doesn't work in any #included `.c` sources, like the crypto
backend sources.
The issue caught by the warning is useful for a tidy codebase, but
doesn't affect executed code. It was enabled in
84338c4de2d7c798e3c270c9610d51a4ad18a90b #12331 (2023-11-15).
llvm source: fee2953f23/clang/lib/Sema/AnalysisBasedWarnings.cpp (L125-L134)
llvm issue: https://github.com/llvm/llvm-project/issues/71046
Follow-up to 7ecc309cd1#1224Closes#1481
`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 Libgcrypt (missing: LIBGCRYPT_INCLUDE_DIR LIBGCRYPT_LIBRARY)
(found version "")
```
Clear the version number to avoid the confusion:
```
Could NOT find Libgcrypt (missing: LIBGCRYPT_INCLUDE_DIR LIBGCRYPT_LIBRARY)
```
Seen with CMake v3.30.3 and 3.30.5.
Closes#1479
- sync code between Find modules.
- wolfssl: replace `pkg-config` hints with native detection.
- libgcrypt, mbedtls: add `pkg-config`-based native detection.
- libgcrypt: add version detection.
- limit `pkg-config` use for `UNIX`, vcpkg, and non-cross MinGW builds,
and builds with no manual customization via `*_INCLUDE_DIR` or
`*_LIBRARY`.
- replace and sync Find module header comments.
- ci: delete manual mbedTLS config that's now redundant.
Based on similar work done in curl.
Second attempt at #1420Closes#1445
