msun: provide external linkage for all fenv.h functions

[kib]

Summary

msun/x86: convert rest of the extern inline fenv functions to proper linkage

namely
        fegetexceptflag(3)
        fetestexcept(3)
        fesetround(3)
        fegetround(3)
        fesetenv(3)
Same as it was done in f39754d51b7dc65c4cf9f for feclearexcept(3).

PR:     277958


msun/aarch64: convert fenv functions to proper linkage

namely
        fegetexceptflag(3)
        fesetexceptflag(3)
        feraiseexcept(3)
        fetestexcept(3)
        fegetround(3)
        fesetround(3)
        fegetenv(3)
        feholdexcept(3)
        fesetenv(3)
        feupdateenv(3)
        feenableexcept(3)
        fedisableexcept(3)
        fegetexcept(3)

PR:     277958


msun/riscv: convert fenv functions to proper linkage

namely
        fegetexceptflag(3)
        fesetexceptflag(3)
        feraiseexcept(3)
        fetestexcept(3)
        fegetround(3)
        fesetround(3)
        fegetenv(3)
        feholdexcept(3)
        fesetenv(3)
        feupdateenv(3)
        feenableexcept(3)
        fedisableexcept(3)
        fegetexcept(3)

PR:     277958


msun/powerpc: convert fenv functions to proper linkage

namely
        fegetexceptflag(3)
        fesetexceptflag(3)
        feraiseexcept(3)
        fetestexcept(3)
        fegetround(3)
        fesetround(3)
        fegetenv(3)
        feholdexcept(3)
        fesetenv(3)
        feupdateenv(3)
        feenableexcept(3)
        fedisableexcept(3)
        fegetexcept(3)

PR:     277958


msun/arm: convert fenv functions to proper linkage

namely
        fegetexceptflag(3)
        fesetexceptflag(3)
        feraiseexcept(3)
        fetestexcept(3)
        fegetround(3)
        fesetround(3)
        fegetenv(3)
        feholdexcept(3)
        fesetenv(3)
        feupdateenv(3)
        feenableexcept(3)
        fedisableexcept(3)
        fegetexcept(3)

PR:     277958


msun: remove requirement to have C99 inline semantic

The 'extern inline' usage is removed.

PR:     277958

[markmi_dsl-only.net]

The status of fegetexcept, feenableexcept, and fedisableexcept and their relationship to __BSD_VISIBLE seems to be rather variable. Some of that variability may be incorrect and other parts expected. I just note the variability itself. A quick look seemed to show:

aarch64/fenv.c does not provide any external/exportable definitions for those.
aarch64/fenv.h has just __BSD_VISIBLE conditional __fenv_static based definitions, nothing for external/exportable support.

arm/fenv.c has definitions not conditional on __BSD_VISIBLE. fegetexcept is exported, unlike for the others. There is no use of weak references.
arm/fenv.h has __BSD_VISIBLE conditional external/exportable-supported based code, including for fegetexcept.
arm/fenv.h has fegetexcept for __ARM_PCS_VFP both inside and outside __BSD_VISIBLE.

powerpc/fenv.h has feenableexcept and fedisableexcept set up for exportable and conditional on __BSD_VISIBLE but fegetexcept is just for the __fenv_static definition.
powerpc/fenv.c has unconditional feenableexcept and fedisableexcept and no fegetexcept. Thre is no use of weak references.

riscv is like powerpc.

x86/fenv.h has the __BSD_VISIBLE conditionality but does not have static implementations of feenableexcept and fedisableexcept.
i387/fenv.c has unconditional feenableexcept and fedisableexcept with weak reference indicated and does not have fegetexcept.
amd64/fenv.c does that as well.

[dim]

LGTM.

[kib]

In D56139#1284163, @markmi_dsl-only.net wrote:

The status of fegetexcept, feenableexcept, and fedisableexcept and their relationship to __BSD_VISIBLE seems to be rather variable. Some of that variability may be incorrect and other parts expected. I just note the variability itself. A quick look seemed to show:

aarch64/fenv.c does not provide any external/exportable definitions for those.
aarch64/fenv.h has just __BSD_VISIBLE conditional __fenv_static based definitions, nothing for external/exportable support.

arm/fenv.c has definitions not conditional on __BSD_VISIBLE. fegetexcept is exported, unlike for the others. There is no use of weak references.
arm/fenv.h has __BSD_VISIBLE conditional external/exportable-supported based code, including for fegetexcept.
arm/fenv.h has fegetexcept for __ARM_PCS_VFP both inside and outside __BSD_VISIBLE.

powerpc/fenv.h has feenableexcept and fedisableexcept set up for exportable and conditional on __BSD_VISIBLE but fegetexcept is just for the __fenv_static definition.
powerpc/fenv.c has unconditional feenableexcept and fedisableexcept and no fegetexcept. Thre is no use of weak references.

riscv is like powerpc.

x86/fenv.h has the __BSD_VISIBLE conditionality but does not have static implementations of feenableexcept and fedisableexcept.
i387/fenv.c has unconditional feenableexcept and fedisableexcept with weak reference indicated and does not have fegetexcept.
amd64/fenv.c does that as well.

I have no idea why it grown this way, and what was the rationale of the arch maintainers when it did.
I am only interested in re-checking that my patch does not change the current state there. If somebody do it, I would appreciate.

[markmi_dsl-only.net]

In D56139#1284436, @kib wrote:

In D56139#1284163, @markmi_dsl-only.net wrote:

. . .

I have no idea why it grown this way, and what was the rationale of the arch maintainers when it did.
I am only interested in re-checking that my patch does not change the current state there. If somebody do it, I would appreciate.

I have submitted https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=294143 "Variability in defining fegetexcept, feenableexcept, and fedisableexcept across platforms" via mostly quoting your comment that contained my comment as well.