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| author | TAKAI Kousuke <62541129+t-a-k@users.noreply.github.com> | 2022-06-15 01:55:36 +0900 |
|---|---|---|
| committer | Tony Cook <tony@develop-help.com> | 2022-07-01 08:26:55 +1000 |
| commit | b52cb8576e7432bf7e962089e9e54451381968c8 (patch) | |
| tree | 5bb0ac3ae070d861f51935ccb32ca5c06dc05afa | |
| parent | 878d0f6b930a6f3a1e01768796d2f7a1b71f9da0 (diff) | |
| download | perl-b52cb8576e7432bf7e962089e9e54451381968c8.tar.gz | |
sv.c: Replace a runtime check with compile-time static assertion
The original code used to check U_V(Perl_fabs(SvNVX(sv))) < (UV)IV_MAX
in runtime, but possibility of failing this check will imply that
such perl configuration is unusable anyway. To make this check never fail,
the first non-preserved integer, which is (1 << NV_PRESERVES_UV_BITS),
is required to be less than (or equal to) IV_MAX, which can be checked
at compile time without runtime overhead.
| -rw-r--r-- | sv.c | 11 | ||||
| -rw-r--r-- | t/porting/diag.t | 1 |
2 files changed, 6 insertions, 6 deletions
@@ -2187,11 +2187,12 @@ S_sv_2iuv_common(pTHX_ SV *const sv) SvIV_set(sv, I_V(SvNVX(sv))); if ((NV)(SvIVX(sv)) == SvNVX(sv)) SvIOK_on(sv); - /* Assumption: first non-preserved integer is < IV_MAX, - this NV is in the preserved range, therefore: */ - if (!(U_V(Perl_fabs(SvNVX(sv))) < (UV)IV_MAX)) { - Perl_croak(aTHX_ "sv_2iv assumed (U_V(Perl_fabs(SvNVX(sv))) < (UV)IV_MAX) but SvNVX(sv)=%" NVgf " U_V is 0x%" UVxf ", IV_MAX is 0x%" UVxf "\n", SvNVX(sv), U_V(Perl_fabs(SvNVX(sv))), (UV)IV_MAX); - } + /* There had been runtime checking for + "U_V(Perl_fabs(SvNVX(sv))) < (UV)IV_MAX" here to ensure + that this NV is in the preserved range, but this should + be always true if the following assertion is true: */ + STATIC_ASSERT_STMT(((UV)1 << NV_PRESERVES_UV_BITS) <= + (UV)IV_MAX); } else { /* IN_UV NOT_INT 0 0 already failed to read UV. diff --git a/t/porting/diag.t b/t/porting/diag.t index 80f7458562..7645a0f0cb 100644 --- a/t/porting/diag.t +++ b/t/porting/diag.t @@ -670,7 +670,6 @@ socketpair not implemented! %s: %s Starting Full Screen process with flag=%d, mytype=%d Starting PM process with flag=%d, mytype=%d -sv_2iv assumed (U_V(Perl_fabs(SvNVX(sv))) < (UV)IV_MAX) but SvNVX(sv)=%f U_V is 0x%x, IV_MAX is 0x%x switching effective gid is not implemented switching effective uid is not implemented System V IPC is not implemented on this machine |