compiler warning "sqrtpi defined but not used"

[zhangyangyu]

BPO	29946
Nosy	@rhettinger, @mdickinson, @serhiy-storchaka, @zhangyangyu, @mlouielu
PRs	bpo-29946: Fix "sqrtpi defined but not used" #908

^{Note: these values reflect the state of the issue at the time it was migrated and might not reflect the current state.}

Show more details

GitHub fields:

assignee = None
closed_at = <Date 2017-03-31.03:22:25.253>
created_at = <Date 2017-03-30.08:28:04.786>
labels = ['build', '3.7']
title = 'compiler warning "sqrtpi defined but not used"'
updated_at = <Date 2017-03-31.03:22:25.252>
user = 'https://github.com/zhangyangyu'

bugs.python.org fields:

activity = <Date 2017-03-31.03:22:25.252>
actor = 'xiang.zhang'
assignee = 'none'
closed = True
closed_date = <Date 2017-03-31.03:22:25.253>
closer = 'xiang.zhang'
components = ['Build']
creation = <Date 2017-03-30.08:28:04.786>
creator = 'xiang.zhang'
dependencies = []
files = []
hgrepos = []
issue_num = 29946
keywords = []
message_count = 4.0
messages = ['290836', '290837', '290854', '290862']
nosy_count = 6.0
nosy_names = ['rhettinger', 'mark.dickinson', 'stutzbach', 'serhiy.storchaka', 'xiang.zhang', 'louielu']
pr_nums = ['908']
priority = 'normal'
resolution = 'fixed'
stage = 'resolved'
status = 'closed'
superseder = None
type = None
url = 'https://bugs.python.org/issue29946'
versions = ['Python 3.7']

[zhangyangyu]

Ubuntu 16.10, GCC 6.2.0

/home/angwer/repos/cpython/Modules/mathmodule.c:74:21: warning: ‘sqrtpi’ defined but not used [-Wunused-const-variable=]
 static const double sqrtpi = 1.772453850905516027298167483341145182798;

[mlouielu]

I can reproduce on ArchLinux 4.10.1-1, GCC 6.3.1:

/home/louielu/Python/cpython/Modules/mathmodule.c:74:21: warning: ‘sqrtpi’ defined but not used [-Wunused-const-variable=]
 static const double sqrtpi = 1.772453850905516027298167483341145182798;

---

Is used by m_erfc_contfrac and m_erf_series, and inside the block of "#if !defined(HAVE_ERF) || !defined(HAVE_ERFC)", maybe sqrtpi should do the same condition?

[mdickinson]

This is almost certainly the result of bpo-26121.

+1 to moving the sqrtpi definition inside the relevant #if blocks.

[serhiy-storchaka]

New changeset 7a26464 by Serhiy Storchaka (Louie Lu) in branch 'master':
bpo-29946: Fix "sqrtpi defined but not used" (#908)
7a26464