test using multiple c-variadic ABIs in the same program #144379

folkertdev · 2025-07-23T22:16:37Z

tracking issue: #100189

Check that multiple c-variadic calling conventions can be used in the same program.

Clang and gcc reject defining functions with a non-default calling convention and a variable
argument list, so C programs that use multiple c-variadic calling conventions are unlikely
to come up. Here we validate that our codegen backends do in fact generate correct code.

(CI will not run this test because it runs on aarch64, I would like to at least test that this runs on windows)

try-job: x86_64-gnu
try-job: x86_64-msvc-*
try-job: x86_64-apple-2

rustbot · 2025-07-23T22:16:41Z

r? @oli-obk

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folkertdev · 2025-07-23T22:16:51Z

@bors2 try

…bis, r=<try> test using multiple c-variadic ABIs in the same program try-job: `x86_64-*`

rust-bors · 2025-07-23T22:16:55Z

⌛ Trying commit 596d8e8 with merge 94c4410…

To cancel the try build, run the command @bors try cancel.

rust-bors · 2025-07-23T22:17:43Z

💔 Test failed (CI). Failed job:

Calculate job matrix (web logs, extended logs)

folkertdev · 2025-07-23T22:23:03Z

@bors2 try

rust-bors · 2025-07-23T22:23:07Z

⌛ Trying commit 596d8e8 with merge 27b661f…

To cancel the try build, run the command @bors try cancel.

…bis, r=<try> test using multiple c-variadic ABIs in the same program try-job: `x86_64-gnu` try-job: `x86_64-msvc-*`

rust-bors · 2025-07-24T00:47:06Z

☀️ Try build successful (CI)
Build commit: 27b661f (27b661fc99a51243cb90353daf6f7f111102b969, parent: 29a58723b05d004c2e19ddcf2be80d514401f22e)

RalfJung · 2025-07-24T07:12:08Z

Ah, that's a fun way of testing this.

Could you add the C source code for that assembly in the test file, so we have it checked in to git?

tests/ui/c-variadic/same-program-multiple-abis.rs

oli-obk · 2025-07-24T09:50:19Z

I know nothing about these ABIs or issues with it, @workingjubilee do you want to take this one?

RalfJung · 2025-07-24T10:07:13Z

I was about to approve -- I don't know how the ABIs are implemented, but the way this is being tested looks sound to me.

oli-obk · 2025-07-24T10:09:28Z

Ah cool, that wfm

RalfJung · 2025-07-24T10:10:57Z

Let's land this then, we can always adjust later if @workingjubilee has more comments. It's just a test after all.

@bors r+ rollup

bors · 2025-07-24T10:11:00Z

📌 Commit 963cd8a has been approved by RalfJung

It is now in the queue for this repository.

…-multiple-abis, r=RalfJung test using multiple c-variadic ABIs in the same program tracking issue: rust-lang#100189 Check that multiple c-variadic calling conventions can be used in the same program. Clang and gcc reject defining functions with a non-default calling convention and a variable argument list, so C programs that use multiple c-variadic calling conventions are unlikely to come up. Here we validate that our codegen backends do in fact generate correct code. (CI will not run this test because it runs on aarch64, I would like to at least test that this runs on windows) try-job: `x86_64-gnu` try-job: `x86_64-msvc-*`

Rollup of 13 pull requests Successful merges: - #144356 (Add `ignore-backends` annotations in failing GCC backend ui tests) - #144359 (add codegen test for variadics) - #144376 (Suggest unwrapping when private method name is available in inner type) - #144379 (test using multiple c-variadic ABIs in the same program) - #144383 (disable cfg.has_reliable_f128 on amdgcn) - #144409 (Stop compilation early if macro expansion failed) - #144412 (Small cleanup: Use LocalKey<Cell> methods more) - #144421 (Call `is_parsed_attribute` rather than keeping track of a list of parsed attributes manually) - #144422 (library/windows_targets: Fix macro expansion error in 'link' macro) - #144424 (Allow setting `release-blog-post` label with rustbot) - #144430 (tests: aarch64-outline-atomics: Remove hardcoded target) - #144435 (rustc-dev-guide subtree update) - #144445 (Fix `./x check bootstrap` (again)) r? `@ghost` `@rustbot` modify labels: rollup

…-multiple-abis, r=RalfJung test using multiple c-variadic ABIs in the same program tracking issue: rust-lang#100189 Check that multiple c-variadic calling conventions can be used in the same program. Clang and gcc reject defining functions with a non-default calling convention and a variable argument list, so C programs that use multiple c-variadic calling conventions are unlikely to come up. Here we validate that our codegen backends do in fact generate correct code. (CI will not run this test because it runs on aarch64, I would like to at least test that this runs on windows) try-job: `x86_64-gnu` try-job: `x86_64-msvc-*`

Rollup of 14 pull requests Successful merges: - #144316 (bootstrap: Move musl-root fallback out of sanity check) - #144352 (RustWrapper: Suppress getNextNonDebugInfoInstruction) - #144356 (Add `ignore-backends` annotations in failing GCC backend ui tests) - #144359 (add codegen test for variadics) - #144376 (Suggest unwrapping when private method name is available in inner type) - #144379 (test using multiple c-variadic ABIs in the same program) - #144383 (disable cfg.has_reliable_f128 on amdgcn) - #144412 (Small cleanup: Use LocalKey<Cell> methods more) - #144421 (Call `is_parsed_attribute` rather than keeping track of a list of parsed attributes manually) - #144422 (library/windows_targets: Fix macro expansion error in 'link' macro) - #144424 (Allow setting `release-blog-post` label with rustbot) - #144430 (tests: aarch64-outline-atomics: Remove hardcoded target) - #144435 (rustc-dev-guide subtree update) - #144445 (Fix `./x check bootstrap` (again)) r? `@ghost` `@rustbot` modify labels: rollup

jieyouxu · 2025-07-26T08:45:11Z

Failed in rollup: #144466 (comment)

---- [ui] tests/ui/c-variadic/same-program-multiple-abis.rs stdout ----

error: test compilation failed although it shouldn't!
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/Users/runner/work/rust/rust/build/x86_64-apple-darwin/stage2/bin/rustc" "/Users/runner/work/rust/rust/tests/ui/c-variadic/same-program-multiple-abis.rs" "-Zthreads=1" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/Users/runner/.cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/Users/runner/work/rust/rust/vendor" "--sysroot" "/Users/runner/work/rust/rust/build/x86_64-apple-darwin/stage2" "--target=x86_64-apple-darwin" "--check-cfg" "cfg(test,FALSE)" "-O" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "-C" "prefer-dynamic" "-o" "/Users/runner/work/rust/rust/build/x86_64-apple-darwin/test/ui/c-variadic/same-program-multiple-abis/a" "-A" "internal_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/Users/runner/work/rust/rust/build/x86_64-apple-darwin/native/rust-test-helpers"
stdout: none
--- stderr -------------------------------
error: linking with `cc` failed: exit status: 1
   |
   = note:  "cc" "/var/folders/vk/nx37ffx50hv5djclhltc26vw0000gn/T/rustcOb3uu5/symbols.o" "<1 object files omitted>" "<sysroot>/lib/rustlib/x86_64-apple-darwin/lib/libstd-9498668422812724.dylib" "<sysroot>/lib/rustlib/x86_64-apple-darwin/lib/libcompiler_builtins-*.rlib" "-lSystem" "-lc" "-lm" "-arch" "x86_64" "-mmacosx-version-min=10.12.0" "-L" "/Users/runner/work/rust/rust/build/x86_64-apple-darwin/native/rust-test-helpers" "-o" "/Users/runner/work/rust/rust/build/x86_64-apple-darwin/test/ui/c-variadic/same-program-multiple-abis/a" "-Wl,-dead_strip" "-nodefaultlibs" "-Wl,-rpath,@loader_path/../../../../stage2/lib/rustlib/x86_64-apple-darwin/lib"
   = note: some arguments are omitted. use `--verbose` to show all linker arguments
   = note: ld: Undefined symbols:
             _variadic_sysv64, referenced from:
                 same_program_multiple_abis::main::h19382578e34d292b in a.same_program_multiple_abis.180f9a3e337e18ef-cgu.0.rcgu.o
             _variadic_win64, referenced from:
                 same_program_multiple_abis::main::h19382578e34d292b in a.same_program_multiple_abis.180f9a3e337e18ef-cgu.0.rcgu.o
           clang: error: linker command failed with exit code 1 (use -v to see **invocation)**

@bors r-

folkertdev · 2025-07-26T10:30:53Z

Of course it's macos symbol mangling

Usually the way to resolve this sort of problem is to use a naked function, but those can't yet use ... with non-default ABIs. Casting function pointers is also just kind of fraught, so instead we're using a cool trick where the extern block defines the symbol, and the assembly uses that via a sym operand.

@bors2 try

…bis, r=<try> test using multiple c-variadic ABIs in the same program try-job: `x86_64-gnu` try-job: `x86_64-msvc-*` try-job: `x86_64-apple-2`

rust-bors · 2025-07-26T10:30:57Z

⌛ Trying commit 69ebf70 with merge a6a0deb…

To cancel the try build, run the command @bors try cancel.

rust-bors · 2025-07-26T12:53:21Z

☀️ Try build successful (CI)
Build commit: a6a0deb (a6a0deb8c7c83d00e666502bb897f5b3fdb65b4b, parent: 051d0e8a957c98f87ddaf6295c3a3ecd88742ff9)

folkertdev · 2025-07-26T12:56:29Z

@bors r=RalfJung

bors · 2025-07-26T12:56:32Z

📌 Commit 69ebf70 has been approved by RalfJung

It is now in the queue for this repository.

…-multiple-abis, r=RalfJung test using multiple c-variadic ABIs in the same program tracking issue: rust-lang#100189 Check that multiple c-variadic calling conventions can be used in the same program. Clang and gcc reject defining functions with a non-default calling convention and a variable argument list, so C programs that use multiple c-variadic calling conventions are unlikely to come up. Here we validate that our codegen backends do in fact generate correct code. (CI will not run this test because it runs on aarch64, I would like to at least test that this runs on windows) try-job: `x86_64-gnu` try-job: `x86_64-msvc-*` try-job: `x86_64-apple-2`

Rollup of 13 pull requests Successful merges: - #144359 (add codegen test for variadics) - #144379 (test using multiple c-variadic ABIs in the same program) - #144383 (disable cfg.has_reliable_f128 on amdgcn) - #144409 (Stop compilation early if macro expansion failed) - #144422 (library/windows_targets: Fix macro expansion error in 'link' macro) - #144429 (Enable outline-atomics for aarch64-unknown-linux-musl) - #144430 (tests: aarch64-outline-atomics: Remove hardcoded target) - #144445 (Fix `./x check bootstrap` (again)) - #144453 (canonicalize build root in `tests/run-make/linker-warning`) - #144464 (Only run bootstrap tests in `x test` on CI) - #144470 (clif: Don't set the `compiler-builtins-no-f16-f128` feature) - #144480 (Revert "coverage: Enlarge empty spans during MIR instrumentation, not codegen") - #144495 (bump cargo_metadata) r? `@ghost` `@rustbot` modify labels: rollup

Rollup of 13 pull requests Successful merges: - #141840 (If `HOME` is empty, use the fallback instead) - #144359 (add codegen test for variadics) - #144379 (test using multiple c-variadic ABIs in the same program) - #144383 (disable cfg.has_reliable_f128 on amdgcn) - #144409 (Stop compilation early if macro expansion failed) - #144422 (library/windows_targets: Fix macro expansion error in 'link' macro) - #144429 (Enable outline-atomics for aarch64-unknown-linux-musl) - #144430 (tests: aarch64-outline-atomics: Remove hardcoded target) - #144445 (Fix `./x check bootstrap` (again)) - #144453 (canonicalize build root in `tests/run-make/linker-warning`) - #144464 (Only run bootstrap tests in `x test` on CI) - #144470 (clif: Don't set the `compiler-builtins-no-f16-f128` feature) - #144480 (Revert "coverage: Enlarge empty spans during MIR instrumentation, not codegen") r? `@ghost` `@rustbot` modify labels: rollup

Rollup merge of #144379 - folkertdev:c-variadic-same-program-multiple-abis, r=RalfJung test using multiple c-variadic ABIs in the same program tracking issue: #100189 Check that multiple c-variadic calling conventions can be used in the same program. Clang and gcc reject defining functions with a non-default calling convention and a variable argument list, so C programs that use multiple c-variadic calling conventions are unlikely to come up. Here we validate that our codegen backends do in fact generate correct code. (CI will not run this test because it runs on aarch64, I would like to at least test that this runs on windows) try-job: `x86_64-gnu` try-job: `x86_64-msvc-*` try-job: `x86_64-apple-2`

rustbot assigned oli-obk Jul 23, 2025

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Jul 23, 2025

rust-bors bot added a commit that referenced this pull request Jul 23, 2025

Auto merge of #144379 - folkertdev:c-variadic-same-program-multiple-a…

94c4410

…bis, r=<try> test using multiple c-variadic ABIs in the same program try-job: `x86_64-*`

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folkertdev mentioned this pull request Jul 23, 2025

stabilize c-style varargs for system, sysv64, win64, efiapi, aapcs #144066

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rust-bors bot added a commit that referenced this pull request Jul 23, 2025

Auto merge of #144379 - folkertdev:c-variadic-same-program-multiple-a…

27b661f

…bis, r=<try> test using multiple c-variadic ABIs in the same program try-job: `x86_64-gnu` try-job: `x86_64-msvc-*`

folkertdev force-pushed the c-variadic-same-program-multiple-abis branch from 596d8e8 to aea74c4 Compare July 24, 2025 09:37

RalfJung reviewed Jul 24, 2025

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folkertdev force-pushed the c-variadic-same-program-multiple-abis branch from aea74c4 to 963cd8a Compare July 24, 2025 09:47

oli-obk assigned RalfJung and unassigned oli-obk Jul 24, 2025

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Jul 24, 2025

GuillaumeGomez mentioned this pull request Jul 25, 2025

Rollup of 13 pull requests #144450

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GuillaumeGomez mentioned this pull request Jul 25, 2025

Rollup of 14 pull requests #144466

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bors added S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. and removed S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. labels Jul 26, 2025

test using multiple c-variadic ABIs in the same program

69ebf70

folkertdev force-pushed the c-variadic-same-program-multiple-abis branch from 963cd8a to 69ebf70 Compare July 26, 2025 10:30

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-author Status: This is awaiting some action (such as code changes or more information) from the author. labels Jul 26, 2025

jhpratt mentioned this pull request Jul 26, 2025

Rollup of 13 pull requests #144520

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jhpratt mentioned this pull request Jul 27, 2025

Rollup of 13 pull requests #144526

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bors merged commit c96c802 into rust-lang:master Jul 27, 2025
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folkertdev mentioned this pull request Jul 27, 2025

c-variadic: multiple ABIs in the same program for arm #144541

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test using multiple c-variadic ABIs in the same program #144379

test using multiple c-variadic ABIs in the same program #144379

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