[AIX] Replace sa_sigaction with sa_union.__su_sigaction for AIX

[xingxue-ibm]

On AIX, the sa_sigaction member of struct sigaction is accessed as the union member sa_union.__su_sigaction.

[rustbot]

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[nnethercote]

What is the exact effect of this change? Does it make these tests pass on AIX where they previously didn't?

Grepping through the codebase I see some other lines setting this field:

compiler/rustc_driver_impl/src/signal_handler.rs:        sa.sa_sigaction = print_stack_trace as libc::sighandler_t;
library/std/src/sys/pal/unix/process/process_unix.rs:                    action.sa_sigaction = libc::SIG_DFL;
library/std/src/sys/pal/unix/stack_overflow.rs:            action.sa_sigaction = SIG_DFL;
library/std/src/sys/pal/unix/stack_overflow.rs:            if action.sa_sigaction == SIG_DFL {
library/std/src/sys/pal/unix/stack_overflow.rs:                action.sa_sigaction = signal_handler as sighandler_t;

Do these need to be changed as well?

[xingxue-ibm]

What is the exact effect of this change? Does it make these tests pass on AIX where they previously didn't?

This change allows two out of the three test cases to pass on AIX. The exception is tests/ui/runtime/signal-alternate-stack-cleanup.rs, which fails due to a different issue.

Grepping through the codebase I see some other lines setting this field:

compiler/rustc_driver_impl/src/signal_handler.rs:        sa.sa_sigaction = print_stack_trace as libc::sighandler_t;
library/std/src/sys/pal/unix/process/process_unix.rs:                    action.sa_sigaction = libc::SIG_DFL;
library/std/src/sys/pal/unix/stack_overflow.rs:            action.sa_sigaction = SIG_DFL;
library/std/src/sys/pal/unix/stack_overflow.rs:            if action.sa_sigaction == SIG_DFL {
library/std/src/sys/pal/unix/stack_overflow.rs:                action.sa_sigaction = signal_handler as sighandler_t;

Do these need to be changed as well?

Yeah, I saw these lines as well. The AIX path does not pass through them, so it does not encounter any issues.

[nnethercote]

@bors r+

[bors]

📌 Commit 3109f07 has been approved by nnethercote

It is now in the queue for this repository.

[nnethercote]

@bors rollup