Commit graph

69 commits

Author SHA1 Message Date
Viktor Szakats
62d77b12fc
spacecheck: check long lines and repeat spaces, fix fallouts
Verify if lines are not longer than 192 characters. Also verify if lines
have less than 79 repeat spaces (and fix one fallout).

To improve readability by avoiding long lines and to prevent adding
overly long lines with text that may go unnoticed in an editor or diff
viewer.

In addition to pre-existing line length limits: 79 for C, 132 for CMake
sources.

Also:
- spacecheck: fix/harden allowlist regexes.
- spacecheck: tidy-up quotes and simplify escaping.
- spacecheck: allow folding strings with repeat spaces.
- GHA: fix a suppressed shellcheck warning.
- GHA/macos: simplify by dropping brew bundle.
- test1119.pl: precompile a regex.
- FAQ.md: delete very long link to a Windows 7/2008 support article
  that's lost it relevance.

Closes #21087
2026-03-25 11:02:08 +01:00
Viktor Szakats
f45bf74b5a
curl/curl.h: replace recursive macros with C++-friendly method to enforce 3 args
Certain uses may still trigger a C compiler warning
`-Wdisabled-macro-expansion` after this, e.g. when the call is wrapped
in the `CURL_IGNORE_DEPRECATION()` macro as seen in docs/examples.

Suggested-by: Kai Pastor
Ref: https://github.com/curl/curl/issues/20682#issuecomment-3949788664

Follow-up to ee9b000438 #20686
Follow-up to daa6b27b4d #20597

Closes #20709
2026-03-21 13:21:06 +01:00
Viktor Szakats
43397b0283
cmake: extend C89-specific warning suppressions to all llvm/clang
From Apple clang-only prior to this patch.

Silencing (seen after macos-15 runner accidentally switched to
llvm/clang by default):
```
/Users/runner/work/curl/curl/lib/curlx/warnless.h:64:1: error: '_Bool' is a C99 extension [-Werror,-Wc99-extensions]
   64 | bool curlx_sztouz(ssize_t sznum, size_t *puznum);
      | ^
/opt/homebrew/Cellar/llvm@18/18.1.8/lib/clang/18/include/stdbool.h:20:14: note: expanded from macro 'bool'
   20 | #define bool _Bool
      |              ^
[...]
```
Ref: https://github.com/curl/curl/actions/runs/23304345180/job/67774031335?pr=21014#step:11:39

Follow-up to 09c9afdd71 #20363
Ref: https://github.com/actions/runner-images/issues/13827

Closes #21015
2026-03-19 17:54:10 +01:00
Viktor Szakats
59405ffb7d
build: enable -Wimplicit-int-enum-cast compiler warning, fix issues
Offered by clang 21+.

Closes #20990
2026-03-19 11:17:17 +01:00
Viktor Szakats
578ee6b79b
gcc: guard #pragma diagnostic in core code for <4.6, disable picky warnings
Extend `#pragma diagnostic push`/`pop` guards to the whole codebase
(from tests and examples only) to disable it for GCC <4.6. Rename guard
to `CURL_HAVE_DIAG` and make it include llvm/clang to be interchangeable
with `__GNUC__ || __clang__` in this context.

The above means no longer disabling certain warnings locally, so pair
this with disabling all picky warnings for GCC <4.6.

Also:
- drop global workarounds for misbehaving GCC <4.6 compiler warnings.
  Not needed with picky warnings disabled.

Reported-by: fds242 on github
Reported-by: Sergey Fedorov
Thanks-to: Orgad Shaneh
Follow-up to f07a98ae11 #20366
Fixes #20892
Fixes #20924
Closes #20902
Closes #20907
2026-03-18 11:33:37 +01:00
Viktor Szakats
86a2a6b547
cmake: stop disabling C4774 after replacing snprintf(), update comment (MSVC)
- update comment for `-wd4710` option.
  Ref: https://ci.appveyor.com/project/curlorg/curl/builds/53627545
- stop suppressing C4774. Not triggered by the replacement call
  `vsnprintf()`, as also confirmed by local tests.
  Follow-up to 192b9214a7
  Ref: https://devblogs.microsoft.com/cppblog/format-specifiers-checking/
  Ref: https://learn.microsoft.com/cpp/error-messages/compiler-warnings/compiler-warnings-c4600-through-c4799

Follow-up to 64f28b8f88 #20765

Closes #20792
2026-03-03 00:46:41 +01:00
Viktor Szakats
92eddc1fae
build: map Apple clang 26.4+ to llvm/clang 21.1
Ref: https://en.wikipedia.org/wiki/Xcode#Xcode_26.0_(since_version_number_change)_2

Closes #20717
2026-02-25 13:16:07 +01:00
Viktor Szakats
baf32a5cf4
build: enable -Wjump-misses-init for clang 21+
Refs:
543f112e14
43c05d9738

Follow-up to db4d617c1c #16252

Closes #20716
2026-02-25 12:28:58 +01:00
Viktor Szakats
ee9b000438
curl/curl.h: revert to recursive macros to keep supporting C++ use-case
To avoid breaking 3rd-party code reusing these symbols as C++ methods,
e.g. in CMake sources:
```
cmake/src/v4.0.0-b30653ae0c.clean/Source/cmCurl.cxx:119:24: error: expected unqualified-id
  119 |     ::CURLcode res = ::curl_easy_setopt(curl, CURLOPT_CAINFO, cafile.c_str());
      |                        ^
```

Also expand comment to highlight the case.

Reported-by: Kai Pastor
Bug: daa6b27b4d (r177869049)
Reported-by: Marcel Raad
Bug: https://curl.se/mail/lib-2026-02/0020.html
Fixes #20682
Follow-up to daa6b27b4d #20597

Closes #20686
2026-02-23 13:56:59 +01:00
Viktor Szakats
25512ab34e
build: adjust minimum version for some clang picky warnings
Enable 3 warnings earlier with autotools, update comments for the rest.

Ref: https://godbolt.org/

Closes #20665
2026-02-22 00:58:04 +01:00
Viktor Szakats
daa6b27b4d
include: avoid recursive macros
To fix potential `-Wdisabled-macro-expansion` warnings when using these
macros within other macros. Fixing for example:
```
lib/doh.c:328:3: error: disabled expansion of recursive macro [clang-diagnostic-disabled-macro-expansion,-warnings-as-errors]
  328 |   ERROR_CHECK_SETOPT(CURLOPT_URL, url);
      |   ^
lib/doh.c:271:14: note: expanded from macro 'ERROR_CHECK_SETOPT'
  271 |     result = curl_easy_setopt((CURL *)doh, x, y);       \
      |              ^
include/curl/curl.h:3332:44: note: expanded from macro 'curl_easy_setopt'
 3332 | #define curl_easy_setopt(handle,opt,param) curl_easy_setopt(handle,opt,param)
      |                                            ^
[...]
```

Also update comments on why curl continues to disable
`-Wdisabled-macro-expansion` and `-Wused-but-marked-unused` warnings.

Follow-up to 92f215fea1 #18477

Closes #20597
2026-02-15 22:54:32 +01:00
Viktor Szakats
3ce596a956
msvc: VS2026: unlock picky warning in cmake, test in CI
Upgrade a GHA/windows job to VS2026 (from VS2022), using a runner image
released a week ago. It also comes with the same Windows SDK as VS2022:
v10.0.26100.0.

The runner image uses Windows 2025 unfortunately, which makes the job
run significantly slower than before this patch:
- configure: 49s -> 1m10s
- build: 3s -> 5s
- install test prereqs: 23s -> 27s
- run tests: 3m18s -> 4m11s
- build examples: 15s -> 25s

It's a shame.

Also:
- cmake: enable picky warnings for VS2026 internal version 19.50.
  Build is clean with existing options.
- GHA/windows: make the built-in OpenSSH intall path recognize
  the windows-2025-vs2026 image as windows-2025.
- windows-2025-vs2026 is able to load the cached stunnel made on
  the windows-2022 runner.
- disk use of the build is almost identical to VS2022.

Before: https://github.com/curl/curl/actions/runs/21955482367/job/63418133880
After: https://github.com/curl/curl/actions/runs/21957589847/job/63426546943

Ref: 71f0157880/images/windows/Windows2025-VS2026-Readme.md
Ref: #20575

Closes #20577
2026-02-12 19:04:51 +01:00
Viktor Szakats
09c9afdd71
cmake: silence silly Apple clang warnings in C89 mode, test in CI
- `stdbool.h` is also included via system headers. Disabling it from curl
  does not fix it. Silencing lots of these:
  ```
  curl/lib/curlx/warnless.h:64:1: warning: '_Bool' is a C99 extension [-Wc99-extensions]
   64 | bool curlx_sztouz(ssize_t sznum, size_t *puznum);
      | ^
  /Library/Developer/CommandLineTools/usr/lib/clang/17/include/stdbool.h:24:14: note: expanded from macro 'bool'
   24 | #define bool _Bool
      |              ^
  ```

- silence `-Wcomma` warnings.
  in favor of the global silencing approach, since a couple of more of
  these were hit (in vquic, tool1622, unit1309, unit1636), and it seems
  silly to update them all.
  Revert e8189c4420 #20362

Also:
- cmake: include C standard in 'platform flags' log line.
- GHA/macos: switch a job to C89 to verify.
- GHA/linux: show 'C89' in job names.

Ref: https://cmake.org/cmake/help/v3.7/variable/CMAKE_C_STANDARD.html

Closes #20363
2026-01-20 13:05:01 +01:00
Viktor Szakats
f07a98ae11
build: drop global suppression of -Wformat-nonliteral, fix fallouts
Extend two existing local suppressions to GCC, and add another
GCC-specific one as a replacement.

Before this patch suppressing this warning was odd with clang, because
after this option, `-Wformat=2` is used, which re-enables it.

Also:
- mprintf: minimize scope of a warning suppression.
- tests/server: suppress this warning for a system `vsnprintf()` call
  where it could trigger in C89 builds or with
  `CFLAGS=-DCURL_NO_FMT_CHECKS` set. Seen with Apple clang 17:
  ```
  curl/tests/server/util.c:114:37: warning: format string is not a string literal [-Wformat-nonliteral]
    114 |   vsnprintf(buffer, sizeof(buffer), msg, ap);
        |                                     ^~~
  /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/secure/_stdio.h:124:69: note: expanded from macro 'vsnprintf'
    124 | #define vsnprintf(str, len, ...) __vsnprintf_chk_func (str, len, 0, __VA_ARGS__)
        |                                                                     ^~~~~~~~~~~
  /Library/Developer/CommandLineTools/SDKs/MacOSX.sdk/usr/include/secure/_stdio.h:81:65: note: expanded from macro '__vsnprintf_chk_func'
     81 |         __builtin___vsnprintf_chk (str, len, flag, __darwin_obsz(str), format, ap)
        |                                                                        ^~~~~~
  ```

Ref: #20363

Closes #20366
2026-01-20 12:38:02 +01:00
Viktor Szakats
0431cbe71a
build: globally suppress DJGPP warnings in FD_SET()
Replacing the many local `#pragma` used before this patch,
reducing the number of `__DJGPP__` guards from 58 to 13.

Closes #20299
2026-01-13 23:17:10 +01:00
Viktor Szakats
91c24d3e10
cmake: silence useless compiler warnings triggered by the FASTBuild generator
Silencing all of these:
```
11>/tmp/_fbuild.tmp/0x0752c383/core_2/70816E19/krb5_sspi.c:1:5: error: this style of line directive is a GNU extension [-Werror,-Wgnu-line-marker]
    1 | # 1 "<built-in>"
      |     ^
/path/to/curl/lib/vauth/krb5_sspi.c:29:6: error: this style of line directive is a GNU extension [-Werror,-Wgnu-line-marker]
   29 | # 26 "/path/to/curl/lib/vauth/krb5_sspi.c"
      |      ^
[...]
```

FASTBuild is slightly faster than Ninja in basic (single-machine, build
from scratch) cases (and can be more faster in other build cases). It
doesn't support unity builds. Maybe it can bring slightly better
performance to non-unity cmake CI jobs, in jobs having an 'install
prereq' phase already, and installing the fastbuild package being faster
than this gain. It overall seems marginal if any in curl CI. At least
for now. But it doesn't hurt if it works, and may be useful for some.

Requires CMake 4.2+.

That said this workaround may have a better place within CMake.

Refs:
https://www.kitware.com/cmake-fastbuild-distributed-cached-and-fast/
https://cmake.org/cmake/help/latest/generator/FASTBuild.html
https://github.com/fastbuild/fastbuild
https://fastbuild.org/docs/home.html

Closes #20230
2026-01-09 17:05:16 +01:00
Viktor Szakats
7e2b15ee56
build: replace -pedantic with -Wpedantic when supported
To use the modern form when possible. The modern option also allows
using the `no-` prefix to disable.

Supported by: gcc 4.8+, clang 3.2+ (= appleclang 4.2+)

This also automatically changes `-clang:-pedantic` to `-Wpedantic` in
clang-cl builds.

Refs:
9877f689f2
https://gcc.gnu.org/onlinedocs/gcc-4.8.5/gcc/Warning-Options.html

Closes #20010
2025-12-18 01:35:59 +01:00
Viktor Szakats
bd19433b0e
build: set -Wno-format-signedness
Explicitly disable these warnings to allow using `-Weverything`.

There are around 600 of them across the codebase.

Silencing them has some drawbacks:
- enums (`CURLcode` mostly) would have to be cast to int to avoid
  different signedness depending on C compiler.
  (llvm/gcc: unsigned, MSVC/clang-cl: signed by default)
- hex masks need casts to unsigned to avoid the warning.
- fixing remaining warnings is annoying without fixing the above.
- without fixing all warnings the option cannot be enabled, to keep
  the codebase warning free.

Ref: #18343 (silenced all warnings, but without the enum cast)
Follow-up to 92f215fea1 #18477
Closes #19907
2025-12-09 23:54:55 +01:00
Marcel Raad
e9a973c513
build: exclude clang prereleases from compiler warning options
Starting with clang 18, stable clang releases start with minor version 1.
Exclude pre-releases with minor version 0 from the compiler warning
options for that major version.

This fixes the build with Android NDK r29, which uses a prerelease
version of clang 21 that doesn't know the new options yet.

Closes #19566
2025-11-17 13:43:50 +01:00
Viktor Szakats
921ff01263
cmake: two minor tidy-ups
- flatten an if tree.
- fix a typo in comment.

Closes #19171
2025-10-21 01:08:04 +02:00
Viktor Szakats
92f215fea1
build: address some -Weverything warnings, update picky warnings
`-Weverything` is not enabled by curl, and not recommended by LLVM,
because it may enable experimental options, and will result in new
fallouts after toolchain upgrades. This patch aims to fix/silence as much
as possible as found with llvm/clang 21.1.0. It also permanently enables
warnings that were fixed in source and deemed manageable in the future.
`-Wformat` warnings are addressed separately via #18343.

Fix/silence warnings in the source:
- typecheck-gcc.h: fix `-Wreserved-identifier`.
- lib: silence `-Wcast-function-type-strict`.
  For llvm 16+ or Apple clang 16+.
- asyn-ares: limit `HAPPY_EYEBALLS_DNS_TIMEOUT` to old c-ares versions.
- curl_trc: fix `-Wc++-hidden-decl`.
- doh: fix `-Wc++-keyword`.
- ftp: fix `-Wreserved-identifier`.
- ldap: fix `-Wreserved-identifier`.
- mqtt: comment unused macro to avoid warning.
- multi_ev: drop unused macros to avoid warnings.
- setopt: fix useless `break;` after `return;`.
- gtls, mbedtls, rustls: silence `-Wconditional-uninitialized`.
- socks_sspi, schannel, x509asn1: fix `-Wimplicit-int-enum-cast`.
- x509asn1: fix `-Wc++-keyword`.
- openssl: scope `OSSL_UI_METHOD_CAST` to avoid unused macro warning.
- libssh2, wolfssl: drop unused macros.
- curl_ngtcp2, curl_quiche, httpsrr, urlapi: drop/limit unused macros.
- tool_getparam: fix useless `break;` after `return;` or `break;`.
  Not normally enabled because it doesn't work with unity.
  https://github.com/llvm/llvm-project/issues/71046
- tool_operate: fix `-Wc++-keyword`.
- curlinfo: fix a `-Wunsafe-buffer-usage`.
- tests: silence `-Wformat-non-iso`.
- lib557: fix `-Wreserved-identifier`.
- lib1565: silence `-Wconditional-uninitialized`.

Enable the above clang warnings permanently in picky mode:
- `-Wc++-hidden-decl`
- `-Wc++-keyword` (except for Windows, where it collides with `wchar_t`)
- `-Wcast-function-type-strict`
- `-Wcast-function-type`
- `-Wconditional-uninitialized`
- `-Wformat-non-iso` (except for clang-cl)
- `-Wreserved-identifier`
- `-Wtentative-definition-compat`

Silence problematic `-Weverything` warnings globally (in picky mode):
- `-Wused-but-marked-unused` (88000+ hits) and
  `-Wdisabled-macro-expansion` (2600+ hits).
  Triggered by `typecheck-gcc.h` when building with clang 14+.
  Maybe there exists a way to fix within that header?
  Ref: https://discourse.llvm.org/t/removing-wused-but-marked-unused/55310
- `-Wunsafe-buffer-usage`. clang 16+. 7000+ hits.
  May be useful in theory, but such high volume of hits makes it
  impractical to review and possibly address. Meant for C++.
  Ref: https://clang.llvm.org/docs/SafeBuffers.html
  Ref: https://stackoverflow.com/questions/77017567/how-to-fix-code-to-avoid-warning-wunsafe-buffer-usage
  Ref: https://discourse.llvm.org/t/rfc-c-buffer-hardening/65734
  Ref: https://github.com/llvm/llvm-project/pull/111624
- `-Wimplicit-void-ptr-cast`. clang 21+. 1700+ hits.
  C++ warning, deemed pure noise.
  Ref: https://github.com/curl/curl/issues/18470#issuecomment-3253506266
- `-Wswitch-default` (180+ hits), `-Wswitch-enum` (190+ hits),
  `-Wcovered-switch-default` (20+ hits).
  Next to impossible to fix cleanly, esp. when the covered `case`
  branches depend on compile-time options.
- `-Wdocumentation-unknown-command` (8+ hits).
  Triggered in a few sources. Seems arbitrary and bogus.
- `-Wpadded` (550+ hits).
- `-Wc++-keyword` on Windows, where it collides with `wchar_t`.
  (100+ hits)
  Ref: https://github.com/llvm/llvm-project/issues/155988
- `-Wreserved-macro-identifier`. clang 13+. 5+ hits.
  Sometimes it's necessary to set external macros that use
  the reserved namespace. E.g. `_CRT_NONSTDC_NO_DEPRECATE`,
  `__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__`, `__NO_NET_API`,
  possibly `_REENTRANT`, and more.
  It's not worth trying to silence them individually.
- `-Wnonportable-system-include-path` with `clang-cl`.
  It'd be broken by doing what the warning suggests.
- `-Wformat-non-iso` for clang-cl.

CMake `PICKY_COMPILER=ON` (the default) or `./configure`
`--enable-warnings` (not the default) is required to enable these
silencing rules.

Also:
- autotools, cmake: fix Apple clang and mainline llvm version translations.
  Ref: https://en.wikipedia.org/wiki/Xcode#Toolchain_versions
- autotools, cmake: enable `-Warray-compare` for clang 20+.
  Follow-up to 4b7accda5a #17196
- cmake: fix to enable `-Wmissing-variable-declarations` at an earlier
  clang version.
- cmake: update internal logic to handle warning options with `+` in
  them.
- cmake: fix internal logic to match the whole option when looking
  into `CMAKE_C_FLAGS` for custom-disabled warnings.

Follow-up to b85cb8cb4e #18485

Closes #18477
2025-09-20 10:16:15 +02:00
Viktor Szakats
ffafec8ffa
cmake: enable -Wall for MSVC 1944
MSVC=1944 is now tested in CI. It did not trigger new `-Wall` compiler
warnings, thus safe to enable `-Wall` for.

Closes #18165
2025-08-04 19:08:27 +02:00
Viktor Szakats
b761eb5add
cmake: replace cmakelint with cmake-lint from cmakelang, fix issues
This linter detects formatting and naming issues with minimal amount of
noise. It seems to be an improvement over the existing linter which was
only detecting line width overruns.

Also: fix to exclude `CurlTests.c` from linter.

Ref: https://cmake-format.readthedocs.io/en/latest/cmake-lint.html
Ref: https://github.com/cheshirekow/cmake_format

Closes #17576
2025-06-11 07:07:49 +02:00
Viktor Szakats
9daca35b13
build: enable gcc-15 picky warnings
Closes #17199
2025-04-29 19:35:55 +02:00
Viktor Szakats
978ef7074a
cmake: honor individual picky option overrides found in CMAKE_C_FLAGS
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 curl's source code. If such happens, we do
appreciate a report to fix it in curl itself.

Closes #17197
2025-04-26 12:59:54 +02:00
Viktor Szakats
4b7accda5a
build: enable gcc-12/13+, clang-10+ picky warnings
Cherry-picked from #17190
Closes #17196
2025-04-26 12:59:54 +02:00
Viktor Szakats
c3aa22272d
cmake: use CMAKE_COMPILE_WARNING_AS_ERROR if available
It's available in CMake >= 3.24.

Ref: https://cmake.org/cmake/help/latest/variable/CMAKE_COMPILE_WARNING_AS_ERROR.html

Closes #17183
2025-04-25 11:42:24 +02:00
Viktor Szakats
1e9b48c010
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 in all supported MSVC versions.
   (as tested with Visual Studio generators)
   Ref: https://ci.appveyor.com/project/curlorg/curl/builds/51945416

Follow-up to e86542038d #17047
Ref: 866e02935d #1711

Closes #17179
2025-04-25 11:42:24 +02:00
Viktor Szakats
8478365e29
cmake: enable -Wall for MSVC when PICKY_COMPILER=ON
Enable it for `_MSC_VER <= 1943`.

Omit it for not yet CI-tested MSVC versions, to avoid hitting unfixed
warnings emitted by future toolchain releases. It means we need
to explicitly opt-in to newer MSVC versions while fixing any new issues.

The newly enabled warnings did not reveal new issues. It hints that we
catch those with clang/gcc. Yet, these warnings may be useful for local
development done with MSVC.

Also:
- disable and document warnings that don't seem useful, unactionable,
  or unfixable.
- disable and document warnings found in Windows SDK headers.
- tidy up a few comments, also to avoid
  `-Wdocumentation-unknown-command`, part of llvm/clang `-Wall`.
  ```
  lib\dynhds.h(159,29): error : unknown command tag name [-Werror,-Wdocumentation-unknown-command]
  lib\ftp.c(337,15): error : unknown command tag name [-Werror,-Wdocumentation-unknown-command]
  ```
  (This patch did not end up enabling `-Wall` for clang-cl.)

Closes #17050
2025-04-16 14:34:12 +02:00
Viktor Szakats
01c429c4a8
cmake: merge CURL_WERROR logic into PickyWarnings.cmake
Safe to do this now, as the code no longer relies on setting these
options after feature detection.

Also: Tidy up the way we handle options not to be passed to feature
checks, and make sure to show them in the configure log.

Follow-up to e86542038d #17047
Closes #17062
2025-04-15 14:48:48 +02:00
Viktor Szakats
111b58fbb6
cmake: append picky warnings to CMAKE_REQUIRED_FLAGS as string
Also:
- drop unnecessary type conversion. `CMAKE_REQUIRED_FLAGS` is already
  space-separated.
  https://cmake.org/cmake/help/latest/module/CheckCSourceCompiles.html

Follow-up to e86542038d #17047
Closes #17055
2025-04-15 01:49:56 +02:00
Viktor Szakats
e86542038d
cmake: prefer COMPILE_OPTIONS over CMAKE_C_FLAGS for custom C options
Also:
- pass `-D_GNU_SOURCE` via `COMPILE_DEFINITIONS`.
- make it explicit to pass these C flags to feature checks.
- update `_GNU_SOURCE` comment with `pipe2()`.
- 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 #17047
2025-04-14 21:31:39 +02:00
Viktor Szakats
6af7ab3b39
cmake: quotes, whitespace, use VERSION_GREATER_EQUAL
- `NOT` + `VERSION_LESS` -> `VERSION_GREATER_EQUAL`
  Available since 3.7, which is the minimum required for curl:
  https://cmake.org/cmake/help/latest/command/if.html#version-greater-equal
- make `CMAKE_REQUIRED_*` argument quotes consistent.
- make `CMAKE_REQUIRED_*` space alignment consistent.
- drop quote from version value for consistency with other cases.
- formatting

Closes #17002
2025-04-10 01:42:59 +02:00
Peter Kokot
dd0c9feb54
cmake: replace CMAKE_COMPILER_IS_GNUCC with CMAKE_C_COMPILER_ID
Variable `CMAKE_COMPILER_IS_GNUCC` is deprecated and
`CMAKE_C_COMPILER_ID` should be used instead.

Closes #16797
2025-03-23 00:06:25 +01:00
Viktor Szakats
f4e23950c7
build: enable -Wcast-qual, fix or silence compiler warnings
The issues found fell into these categories, with the applied fixes:

- const was accidentally stripped.
  Adjust code to not cast or cast with const.

- const/volatile missing from arguments, local variables.
  Constify arguments or variables, adjust/delete casts. Small code
  changes in a few places.

- const must be stripped because an API dependency requires it.
  Strip `const` with `CURL_UNCONST()` macro to silence the warning out
  of our control. These happen at API boundaries. Sometimes they depend
  on dependency version, which this patch handles as necessary. Also
  enable const support for the zlib API, using `ZLIB_CONST`. Supported
  by zlib 1.2.5.2 and newer.

- const must be stripped because a curl API requires it.
  Strip `const` with `CURL_UNCONST()` macro to silence the warning out
  of our immediate control. For example we promise to send a non-const
  argument to a callback, though the data is const internally.

- other cases where we may avoid const stripping by code changes.
  Also silenced with `CURL_UNCONST()`.

- there are 3 places where `CURL_UNCONST()` is cast again to const.
  To silence this type of warning:
  ```
  lib/vquic/curl_osslq.c:1015:29: error: to be safe all intermediate
    pointers in cast from 'unsigned char **' to 'const unsigned char **'
    must be 'const' qualified [-Werror=cast-qual]
  lib/cf-socket.c:734:32: error: to be safe all intermediate pointers in
    cast from 'char **' to 'const char **' must be 'const' qualified
    [-Werror=cast-qual]
  ```
  There may be a better solution, but I couldn't find it.

These cases are handled in separate subcommits, but without further
markup.

If you see a `-Wcast-qual` warning in curl, we appreciate your report
about it.

Closes #16142
2025-03-10 22:30:15 +01:00
Viktor Szakats
baa9c647d3
cmake: sync cutoff version with autotools for picky option -ftree-vrp
Sync cutoff version for `-ftree-vrp` with autotools, which enables it
for gcc 4.3+ (cmake builds enabled it for 5.0+, before this patch).

Cherry-picked from #16476
Closes #16478
2025-02-25 16:57:45 +01:00
Viktor Szakats
ee3f657607
build: silence bogus -Wconversion warnings with gcc 5.1-5.4
It's fixed in gcc 5.5.0.

Example: https://godbolt.org/z/x6Th8q844

Seen in gcc 5.1.0, 5.4.0 (both 32/64-bit) with dl-mingw:
```
lib/rtsp.c: In function 'rtsp_parse_transport':
lib/rtsp.c:1025:36: error: conversion to 'unsigned char' from 'int' may alter its value [-Werror=conversion]
           rtp_channel_mask[idx] |= (unsigned char)(1 << off);
                                    ^
lib/mprintf.c: In function 'parsefmt':
lib/mprintf.c:526:31: error: conversion to 'unsigned char' from 'int' may alter its value [-Werror=conversion]
         usedinput[width/8] |= (unsigned char)(1 << (width&7));
                               ^
lib/mprintf.c:544:35: error: conversion to 'unsigned char' from 'int' may alter its value [-Werror=conversion]
         usedinput[precision/8] |= (unsigned char)(1 << (precision&7));
                                   ^
lib/mprintf.c:559:29: error: conversion to 'unsigned char' from 'int' may alter its value [-Werror=conversion]
       usedinput[param/8] |= (unsigned char)(1 << (param&7));
                             ^
lib/cfilters.c: In function 'Curl_pollset_change':
lib/cfilters.c:935:25: error: conversion to 'unsigned char' from 'int' may alter its value [-Werror=conversion]
       ps->actions[i] |= (unsigned char)add_flags;
                         ^
```
gcc 5.1.0: https://github.com/curl/curl/actions/runs/13413103492/job/37467698381#step:9:21
gcc 5.4.0: https://github.com/curl/curl/actions/runs/13413103492/job/37467694479#step:9:19

Closes #16398
2025-02-19 18:03:23 +01:00
Marcel Raad
db4d617c1c
build: enable -Wjump-misses-init for GCC 4.5+
This should have caught https://github.com/curl/curl/issues/16246.

Closes https://github.com/curl/curl/pull/16252
2025-02-17 08:48:36 +01:00
Viktor Szakats
ca2f49ded0
build: fix compiler warnings in feature detections
Fix or silence compiler warnings happening in feature detections
to reduce log noise. Warnings may also get promoted to errors in certain
cases, causing missed detections.

It reduces the number of warnings by 4500+ across the linux, linux-old,
macos, non-native and windows GHA workflows (~142 jobs).

Also move picky warning logic for MSVC/Borland to
`CMake/PickyWarnings.cmake. To make them listed in the picky-warnings
log output, and to also apply to feature detections to make them compile
under the same conditions as source code. The hope is to help catching
issues faster. It also improves code quality of feature tests.

Fixed/silenced:
```
warning #177: variable "dummy" was declared but never referenced
warning #177: variable "flag" was declared but never referenced
warning #177: variable "res" was declared but never referenced
warning #592: variable "s" is used before its value is set
warning #1011: missing return statement at end of non-void function "main"
warning #1786: function "SSL_CTX_set_srp_password" (declared at line 1888 of "/usr/include/openssl/ssl.h") was declared deprecated ("Since OpenSSL 3.0")
warning #1786: function "SSL_CTX_set_srp_username" (declared at line 1887 of "/usr/include/openssl/ssl.h") was declared deprecated ("Since OpenSSL 3.0")
warning #2332: a value of type "const char *" cannot be assigned to an entity of type "char *" (dropping qualifiers)
warning: 'SSL_CTX_set_srp_password' is deprecated [-Wdeprecated-declarations]
warning: 'SSL_CTX_set_srp_password' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
warning: 'SSL_CTX_set_srp_username' is deprecated [-Wdeprecated-declarations]
warning: 'SSL_CTX_set_srp_username' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
warning: 'b' is used uninitialized [-Wuninitialized]
warning: 'gethostname' redeclared without dllimport attribute: previous dllimport ignored [-Wattributes]
warning: Undefined or garbage value returned to caller [core.uninitialized.UndefReturn]
warning: Value stored to 'i' is never read [deadcode.DeadStores]
warning: assigning to 'char *' from 'const char *' discards qualifiers [-Wincompatible-pointer-types-discards-qualifiers]
warning: assignment discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
warning: control reaches end of non-void function [-Wreturn-type]
warning: empty expression statement has no effect; remove unnecessary ';' to silence this warning [-Wextra-semi-stmt]
warning: excess elements in struct initializer
warning: initialization discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
warning: macro "_FILE_OFFSET_BITS" is not used [-Wunused-macros]
warning: macro "_REENTRANT" is not used [-Wunused-macros]
warning: missing braces around initializer [-Wmissing-braces]
warning: no previous extern declaration for non-static variable 'off_t_is_large' [-Wmissing-variable-declarations]
warning: no previous prototype for 'check' [-Wmissing-prototypes]
warning: no previous prototype for function 'check' [-Wmissing-prototypes]
warning: null argument where non-null required (argument 2) [-Wnonnull]
warning: passing 'const char[1]' to parameter of type 'char *' discards qualifiers [-Wincompatible-pointer-types-discards-qualifiers]
warning: passing argument 2 of 'SSL_CTX_set_srp_password' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
warning: passing argument 2 of 'SSL_CTX_set_srp_username' discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
warning: unused parameter 'c' [-Wunused-parameter]
warning: unused parameter 'f' [-Wunused-parameter]
warning: unused variable 'data' [-Wunused-variable]
warning: unused variable 'dummy' [-Wunused-variable]
warning: unused variable 'flag' [-Wunused-variable]
warning: unused variable 'res' [-Wunused-variable]
warning: unused variable 's' [-Wunused-variable]
warning: variable 's' set but not used [-Wunused-but-set-variable]
warning: variable 'ts' set but not used [-Wunused-but-set-variable]
```

Closes #16287
2025-02-16 02:39:35 +01:00
Viktor Szakats
784a8ec2c1
tidy-up: delete, comment or scope C macros reported unused
To reduce the number `-Wunused-macro` compiler warnings:
- delete unused macros.
- comment out unused macro that are part of a set.
- move macros into the scope they are used.

This may be useful to enable by default, but there are tricky cases that
I didn't manage to fix and paused the effort. E.g. internal features
checks in `openssl.c`. There is more, once those are fixed.

Closes #16279
2025-02-14 10:37:14 +01:00
Viktor Szakats
3c128966ed
cmake: tidy up string append and list prepend syntax
- `set(VAR "${VAR}<value>")` ->
  `string(APPEND VAR "<value>")`
  Available since CMake 3.4:
  https://cmake.org/cmake/help/latest/command/string.html#append

- `set(VAR "${VAR2}-or-<value>;${VAR}")` ->
  `set(VAR "${VAR2}-or-<value>" ${VAR})`

Closes #16144
2025-02-06 23:25:40 +01:00
Viktor Szakats
2ed232a4e6
build: drop macro used to enable -Wsign-conversion warnings in CI
We don't pursue this, and the necessary `#pragma` got in the way of
compiling curl with gcc 4.2 and older. Drop the logic completely.

Follow-up to 8a266ac488 #15939

Reported-by: prpr19xx on Github
Fixes #16152
Closes #16157
2025-02-03 22:28:08 +01:00
Viktor Szakats
7e814c8717
build: fix compiling with GCC 4.x versions
- silence false positive picky warnings.
- avoid "possible noreturn" warnings for standalone tests and examples.
- fix to compile without `#pragma GCC diagnostic push` support.
- fix "#pragma GCC diagnostic not allowed inside functions".

Prerequisite for #15975 that needs GCC 4.4 for the latest pre-built
CeGCC/mingw32ce toolchain for Windows CE.

Cherry-picked from #15975
Closes #16062
2025-01-22 11:26:15 +01:00
Viktor Szakats
8dfd271c35
cmake: prefer dash-style MSVC options
They play better with Unixy shells. The compiler has been supporting
dash options since its early versions.

Also fix to detect warnings options passed in dash-style.

Closes #16063
2025-01-22 11:21:42 +01:00
Viktor Szakats
95658f9ca3
build: fix -Wtrampolines picky warning for gcc 4.x versions
Caused an error when using cmake with gcc 4.4 and 4.5.
Also 4.3 when using autotools.

Seen with GNU 4.4.0 in CeGCC 0.59.1:
```
cc1: error: unrecognized command line option "-Wtrampolines"
```

`-Wtrampolines` requires gcc 4.6 or upper.

Ref: https://gcc.gnu.org/onlinedocs/gcc-4.6.0/gcc/Warning-Options.html
Ref: https://master.dl.sourceforge.net/project/cegcc/cegcc/0.59.1/cegcc_mingw32ce_snowleopard_r1397.tar.bz2

Closes #15962
2025-01-10 18:21:10 +01:00
Viktor Szakats
8a266ac488
build: delete -Wsign-conversion related FIXMEs
We decided last year not to pursue avoiding this warning, because it
adds noise and friction, while in most cases not revealing actual code
issues. We fixed the interesting portion of them throughout mid-2024.

Conclude this effort by deleting related FIXMEs and temporary comments.

Follow-up to 3829759bd0 #12489
Closes #15939
2025-01-09 02:12:52 +01:00
Viktor Szakats
abb4fa5b62
cmake: optimize out 4 picky warning option detections with gcc
Follow-up to 9c543de0ec #10973
Closes #15850
2024-12-29 01:13:31 +01:00
Viktor Szakats
c80c399c45
build: drop -Winline picky warning
To avoid this in certain debug build cases:
```
./lib/easy_lock.h:72:20: error: inlining failed in call to 'curl_simple_lock_lock': function not considered for inlining [-Werror=inline]
```

Ref: #13596
Reported-by: Rudi Heitbaum
Fixes #15815
Closes #15819
2024-12-23 22:13:23 +01:00
Viktor Szakats
a3585c9576
Makefile.mk: drop in favour of autotools and cmake (MS-DOS, AmigaOS3)
`Makefile.mk` supported MS-DOS and Amiga, but `./configure` also
supported them in a better tested and more flexible way.

This patch also adds CMake support for MS-DOS/DJGPP and Amiga OS 3.

`Makefile.mk` was not maintained. Delete it in favour of first-tier
build methods.

Also include some non-MS-DOS/AmigaOS-specific tidy-up, see details at
the end of this message.

Details:

- fix/silence all MS-DOS/DJGPP build warnings and issues.
- add MS-DOS support to cmake.
  - default to `ENABLE_THREADED_RESOLVER=OFF` for MS-DOS.
  - add support for `WATT_ROOT`.
  - use static libcurl with MS-DOS.
  - fixup default CMake suffixes/prefixes for DJGPP.
  - disable hidden symbols for MS-DOS. Not supported on MS-DOS.
  - opt-in MS-DOS into `USE_UNIX_SOCKETS`.
- improve MS-DOS support in autotools.
  - default to `--disable-threaded-resolver` for MS-DOS.
- make sure to use `close_s()` (from Watt-32) with autotools and cmake.
  `Makefile.mk` used it before this patch.
- GHA: add DJGPP cmake (~30s) and autotools (~60s) build jobs.
  Also build tests and examples with cmake.
- improve AmigaOS support in autotools:
  - configure: detect `CloseSocket()` when it's a macro.
  - configure: fix `IoctlSocket` detection on AmigaOS.
  - curl-amissl.m4: pass AmiSSL libs to tests/servers.
- add AmigaOS3 support to cmake:
  - cmake: fix `HAVE_IOCTLSOCKET_CAMEL` and
    `HAVE_IOCTLSOCKET_CAMEL_FIONBIO` detections.
  - set necessary system libs.
  - add AmiSSL support.
  - inet_ntop, inet_pton: fix using it for AmigaOS. cmake detects them,
    and they did not compile with AmigaOS.
  - cmake: better sync `gethostname` detection with autotools.
    Fixes detection for AmigaOS, where `gethostname` is a macro.
  - cmake: fix `sys/utime.h` detection on AmigaOS.
  - cmake: force-disable `getaddrinfo` for AmigaOS.
  - cmake: tweak threading and static/shared default for AmigaOS.
  - cmake: rely on manual variable `AMIGA` to enable the platform.
- GHA: add AmigaOS cmake and autotools (~45s) jobs.
  Also build tests and examples with cmake.
- INSTALL: update MS-DOS and AmigaOS build instructions.
- amigaos: fix `-Wpointer-sign` and
  `zero or negative size array '_args'` in `Printf()`.
- amigaos: fix `-Wpointer-sign`
- amigaos: fix `-Wredundant-decls` `errno` and `h_errno`.
- amigaos: brute-force silence `lseek()` size warnings.
- amigaos: server/resolve: silence `-Wdiscarded-qualifiers`.
- amigaos: server/resolve: fix `-Wpointer-sign`.
- amigaos: fix `CURL_SA_FAMILY_T` type.
- nonblock: prefer `HAVE_IOCTLSOCKET_CAMEL_FIONBIO` for AmigaOS.
  `ioctl` is also detected, but fails when used. Make the above override
  it for a successful build.
  Authored-by: Darren Banfi
  Fixes #15537
  Closes #15603
- tftpd: prefer `HAVE_IOCTLSOCKET_CAMEL_FIONBIO` for AmigaOS.
- tftpd: tidy-up conditional code.
- curl: set stack size to 16384 for AmigaOS3/4
  Overriding the default 4096.
  Suggested-by: Darren Banfi
  Ref: https://github.com/curl/curl/pull/15543#issuecomment-2498783123
  Ref: https://wiki.amigaos.net/wiki/Controlling_Application_Stack
- functypes.h: fix `SEND_QUAL_ARG2` for AmigaOS.
- tftp: add missing cast in sendto() call for AmigaOS.
- getinfo: fix warning with AmigaOS.
- tool_operate: silence warning with AmigaOS
- amigaos: fix building libtests due to missing `RLIMIT_NOFILE`.
- curl_gethostname: silence warning for AmigaOS.
- ftp: silence `-Wtype-limits` for AmigaOS.
- libtest: fix timeval initialization for AmigaOS.
- examples: fix `timeval` initialization for AmigaOS.
- examples: silence warning for AmigaOS.
- configure: fix IPv6 detection for cross-builds.
- netrc: fix to build with AmigaOS cleanly.
- buildinfo: detect and add `DOS` tag for MS-DOS builds.
- buildinfo: add `AMIGA` to buildinfo.txt in auttools.
- build: move `USE_WATT32` macro definition to cmake/configure.

Non-MS-DOS/AmigeOS-specific tidy-ups:

- configure: sync `sa_family_t` detection with cmake.
- configure: sync `ADDRESS_FAMILY` detection signals with cmake.
- doh: use `CURL_SA_FAMILY_T`.
- lib: drop mingw-specific `CURL_SA_FAMILY_T` workaround.
- cmake: extend instead of override check-specific
  configurations/requirements.
  This allows to honor global requirements added earlier.
  Necessary for AmigaOS for example.
- cmake: omit warning on disabled IPv6 for MS-DOS and AmigaOS.
  No IPv6 support on these platforms. Also sync with autotools.
- lib1960: use libcurl `inet_pton()` wrapper.
- cmake: detect LibreSSL (to match autotools).
- cmake: say the specific OpenSSL flavour detected.
- hostip: add missing `HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID` guard.
- lib: simplify classic mac feature guards.

Follow-up to a8861b6ccd #9764

Closes #15543
2024-12-16 23:20:55 +01:00
Viktor Szakats
fa676a6985
cmake: clang-cl improvements
- drop `/clang:` prefix for `-W` options for clang-cl.
  Except for `-Wall` which gets interpreted as MSVC `/Wall`
  and translated to `-Weverything`, which is undesired.
  Related: https://github.com/llvm/llvm-project/issues/102982

- include `MSVC_VERSION` in target flags.
  Useful for clang-cl builds where this information doesn't appear
  elsewhere in the cmake configure log.

- suppress `-Wlanguage-extension-token` more for clang-cl.
  This fixes clang-cl builds with default `CURL_WERROR=OFF` and
  `PICKY_COMPILER=ON`.
  This warning is enabled by `-pedantic` as a warning and by
  `-pedantic-errors` as an error. Verifiable using llvm's
  `diagtool show-enabled -pedantic test.c`.
  Follow-up to fb711b5098 #15449

Closes #15478
2024-12-16 21:45:07 +01:00