cmake: separate target for examples, optimize CI, fix fallouts

- Move `docs/examples` builds under a separate target.

- Make `BUILD_EXAMPLES` default to `ON`. It means to generate t

cmake: separate target for examples, optimize CI, fix fallouts

- Move `docs/examples` builds under a separate target.

- Make `BUILD_EXAMPLES` default to `ON`. It means to generate the rules
for `docs/examples` by default, but not build them. To build them,
an explicit `make curl-examples` (or ninja, etc) command is necessary.
This syncs behaviour with autotools, and also how both cmake and
autotools are building tests.

- GHA: update cmake jobs to use the new way of building examples.

- GHA: move examples build step at the end of the job, after building
and running tests. This allows to have build and test run results
faster, and leave the seldom-changing examples build to the end.
Building examples is the slowest build step with no practical way to
make them fast.

- appveyor: enable building examples in two old-MSVC jobs.

- examples: fix examples to build cleanly with old MSVC versions.

- GHA/non-native: move example build log under a GHA foldable section.

- GHA/windows: move building examples into separate step for Linux cross
jobs.

Follow-up to dfdd978f7c60224dffe2aac25b436dc0a5cd0186 #13491
Closes #14906

show more ...

printf: fix mingw-w64 format checks

Change mingw-w64 printf format checks in public curl headers to use
`__MINGW_PRINTF_FORMAT` instead of `gnu_printf`. This syncs the format
checker

printf: fix mingw-w64 format checks

Change mingw-w64 printf format checks in public curl headers to use
`__MINGW_PRINTF_FORMAT` instead of `gnu_printf`. This syncs the format
checker with format string macros published via `curl/system.h`. (Also
disable format checks for mingw-w64 older than 3.0.0 (2013-09-20) and
classic-mingw, which do not support this macro.)

This fixes bogus format checker `-Wformat` warnings in 3rd party code
using curl format strings with the curl printf functions, when using
mingw-w64 7.0.0 (2019-11-10) and older (with GCC, MSVCRT).

It also allows to delete two workaounds for this within curl itself:
- setting `-D__USE_MINGW_ANSI_STDIO=1` for mingw-w64 via cmake and
configure for `docs/examples` and `tests/http/clients`.
Ref: c730c8549b5b67e7668ca5d2cd82c3cc183e125d #14640

The format check macro is incompatible (depending on mingw-w64 version
and configuration) with the C99 `%z` (`size_t`) format string used
internally by curl.

To work around this problem, override the format check style in curl
public headers to use `gnu_printf`. This is compatible with `%z` in all
mingw-w64 versions and allows keeping the C99 format strings internally.

Also:
- lib/ws.c: add missing space to an error message.
- docs/examples/ftpgetinfo.c: fix to use standard printf.

Ref: #14643 (take 1)
Follow-up to 3829759bd042c03225ae862062560f568ba1a231 #12489

Closes #14703

show more ...

cmake: sync code between test/example targets

- reuse local variable names.
- sync `PROJECT_LABEL`, add where missing.
- namespace all target names.
- bind header directories to

cmake: sync code between test/example targets

- reuse local variable names.
- sync `PROJECT_LABEL`, add where missing.
- namespace all target names.
- bind header directories to each target.
- tests/server: limit `CURL_STATICLIB` to Windows (as in autotools.)
- drop functions with a single caller.

Closes #14660

show more ...

build: make `CURL_FORMAT_CURL_OFF_T[U]` work with mingw-w64 <=7.0.0

Add tweak for mingw-w64 when building tests/http/client programs to
avoid a bogus `-Wformat` warning when using mingw-

build: make `CURL_FORMAT_CURL_OFF_T[U]` work with mingw-w64 <=7.0.0

Add tweak for mingw-w64 when building tests/http/client programs to
avoid a bogus `-Wformat` warning when using mingw-w64 v7.0.0 or older.
The warning is bogus because these programs use curl's `printf()`
implementation that is guaranteed to support that format spec.

Add this for both CMake and autotools. (But only CMake is CI tested with
an old toolchain.)

Apply the workaround to `docs/examples`, and fix an example to use
curl's `printf()` with `CURL_FORMAT_CURL_OFF_T`.

Reintroduce curl `printf()` calls into `tests/http/client`, via #14625.
Also restore large number masks to a printf, changed earlier in #14382.

Follow-up to 232302f88a152a1d1722da9f69c383a766528918 #14382
Ref: https://github.com/curl/curl/pull/14625#issuecomment-2302361737

Closes #14640

show more ...

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: cleanup header paths

- sync build-dir/source-dir header path order with autotools, by
including build-dir first, then source-dir.
This prevents out-of-tree builds breaking

cmake: cleanup header paths

- sync build-dir/source-dir header path order with autotools, by
including build-dir first, then source-dir.
This prevents out-of-tree builds breaking due to leftover generated
headers in the source tree.

- tests/unit: move `src` ahead of `libtest` in header path, syncing with
autotools.

- stop adding non-existing generated `include` dir to header path.
There are no generated `include` headers and this directory is either
missing in out-of-tree builds or the same as the one already added
globally via the root `CMakeLists.txt`.

- lib: stop adding a duplicate source include directory to the header
path.
It's already added globally via the root `CMakeLists.txt`.

- lib: stop adding the project root to the header path.

- docs/examples: drop internal header paths.
Examples do not and should not use internal headers.

- replace `curl_setup_once.h` in comments with `curl_setup.h`,
the header actually used, and also referred to in autotools comments.

- add comment why we need `src` in include path for `tests/server`.

- add quotes around header directories.

Closes #14416

show more ...

cmake: tidy-ups

- tidy-up comments.
- use lowercase, underscore prefixed names for internal variables.
- use `IN LISTS` and `IN ITEMS` in `foreach()` loops.
- rename variable nam

cmake: tidy-ups

- tidy-up comments.
- use lowercase, underscore prefixed names for internal variables.
- use `IN LISTS` and `IN ITEMS` in `foreach()` loops.
- rename variable name `OUTPUT` to a more distinctive one.
- tidy-up `STREQUAL` syntax.
- delete commented code.
- indent/whitespace.

Closes #14197

show more ...

cmake: add `BUILD_EXAMPLES` option to build examples

You can enable it with `-DBUILD_EXAMPLES=ON`.

To match autotools' `make examples` feature.
Windows (static) builds not teste

cmake: add `BUILD_EXAMPLES` option to build examples

You can enable it with `-DBUILD_EXAMPLES=ON`.

To match autotools' `make examples` feature.
Windows (static) builds not tested.

Also enable examples in a pair of CI jobs.

Apply related updates to the macOS CI workflow:
- drop unused `CXX` envs.
- drop no longer needed `-Wno-error=undef -Wno-error=conversion` flags.
- pass `-Wno-deprecated-declarations` to GCC too (for `BUILD_EXAMPLES`).
- document why `-Wno-deprecated-declarations` is necessary.

Closes #13491

show more ...