kmarshall added a comment.
That makes sense. In the cases that I'm finding, the original call site is in
application source code, but the warning is generated from inside a system
header. So, I suppose the suppressions are working as intended, and we just
need to add one-off suppressions for the known noisy sources? Where is the
suppression database located? FWIW, there aren't many unique error sources - I
only counted 9 after running the warnings through "uniq | sort".
Re: specifics, here the most common one that I'm seeing. It seems like a bogus
buffer overrun warning?
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:1258:9:
note: Assigned value is garbage or undefined
*__s++ = *__first++;
^ ~~~~~~~~~~
The error is generated from this trivial logging line
<https://cs.chromium.org/chromium/src/dbus/message.cc?rcl=255d25e6d389106b75c90110b4e00b022e472cc5&l=233>:
LOG(FATAL) << "Unknown type: " << type; // |type| is an enum
The offending C++ library code snippet is here (note the line w/comment
"GENERATES WARNING")
template<typename _CharT>
_CharT*
__add_grouping(_CharT* __s, _CharT __sep,
const char* __gbeg, size_t __gsize,
const _CharT* __first, const _CharT* __last)
{
size_t __idx = 0;
size_t __ctr = 0;
while (__last - __first > __gbeg[__idx]
&& static_cast<signed char>(__gbeg[__idx]) > 0
&& __gbeg[__idx] != __gnu_cxx::__numeric_traits<char>::__max)
{
__last -= __gbeg[__idx];
__idx < __gsize - 1 ? ++__idx : ++__ctr;
}
while (__first != __last)
*__s++ = *__first++; // <------ GENERATES WARNING
while (__ctr--)
{
*__s++ = __sep;
for (char __i = __gbeg[__idx]; __i > 0; --__i)
*__s++ = *__first++;
}
while (__idx--)
{
*__s++ = __sep;
for (char __i = __gbeg[__idx]; __i > 0; --__i)
*__s++ = *__first++;
}
return __s;
}
Here's a full snippet of the analysis trace:
../../dbus/message.cc:233:9: note: Calling 'basic_ostream::operator<<'
LOG(FATAL) << "Unknown type: " << type;
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../base/logging.h:414:23: note: expanded from macro 'LOG'
#define LOG(severity) LAZY_STREAM(LOG_STREAM(severity), LOG_IS_ON(severity))
^
../../base/logging.h:402:62: note: expanded from macro 'LAZY_STREAM'
!(condition) ? (void) 0 : ::logging::LogMessageVoidify() & (stream)
^
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/ostream.tcc:113:11:
note: Assuming '__fmt' is not equal to 'oct'
if (__fmt == ios_base::oct || __fmt == ios_base::hex)
^~~~~~~~~~~~~~~~~~~~~~
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/ostream.tcc:113:11:
note: Left side of '||' is false
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/ostream.tcc:113:37:
note: Assuming '__fmt' is not equal to 'hex'
if (__fmt == ios_base::oct || __fmt == ios_base::hex)
^~~~~~~~~~~~~~~~~~~~~~
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/ostream.tcc:113:7:
note: Taking false branch
if (__fmt == ios_base::oct || __fmt == ios_base::hex)
^
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/ostream.tcc:116:9:
note: Calling 'basic_ostream::_M_insert'
return _M_insert(static_cast<long>(__n));
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/ostream.tcc:69:2:
note: Taking true branch
if (__cerb)
^
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/ostream.tcc:75:7:
note: Calling 'num_put::put'
if (__np.put(*this, *this, this->fill(), __v).failed())
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.h:2336:16:
note: Calling 'num_put::do_put'
{ return this->do_put(__s, __f, __fill, __v); }
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.h:2475:16:
note: Calling 'num_put::_M_insert_int'
{ return _M_insert_int(__s, __io, __fill, __v); }
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:868:22:
note: Assuming '__basefield' is equal to 'oct'
const bool __dec = (__basefield != ios_base::oct
^~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:869:8:
note: Left side of '&&' is false
&& __basefield != ios_base::hex);
^
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:870:32:
note: Assuming '__v' is <= 0
const __unsigned_type __u = ((__v > 0 || !__dec)
^~~~~~~
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:870:32:
note: Left side of '||' is false
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:870:31:
note: '?' condition is true
const __unsigned_type __u = ((__v > 0 || !__dec)
^
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:877:6:
note: Assuming the condition is true
if (__lc->_M_use_grouping)
^~~~~~~~~~~~~~~~~~~~~
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:877:2:
note: Taking true branch
if (__lc->_M_use_grouping)
^
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:884:6:
note: Calling 'num_put::_M_group_int'
_M_group_int(__lc->_M_grouping, __lc->_M_grouping_size,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:839:21:
note: Calling '__add_grouping'
_CharT* __p = std::__add_grouping(__new, __sep, __grouping,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:1249:14:
note: Assuming the condition is true
while (__last - __first > __gbeg[__idx]
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:1249:14:
note: Left side of '&&' is true
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:1250:10:
note: Assuming the condition is true
&& static_cast<signed char>(__gbeg[__idx]) > 0
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:1249:14:
note: Left side of '&&' is true
while (__last - __first > __gbeg[__idx]
^
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:1249:7:
note: Loop condition is true. Entering loop body
while (__last - __first > __gbeg[__idx]
^
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:1254:4:
note: Assuming the condition is false
__idx < __gsize - 1 ? ++__idx : ++__ctr;
^~~~~~~~~~~~~~~~~~~
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:1254:4:
note: '?' condition is false
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:1250:7:
note: Left side of '&&' is false
&& static_cast<signed char>(__gbeg[__idx]) > 0
^
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:1257:7:
note: Loop condition is true. Entering loop body
while (__first != __last)
^
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:1257:7:
note: Loop condition is true. Entering loop body
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:1257:7:
note: Loop condition is true. Entering loop body
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:1257:7:
note: Loop condition is true. Entering loop body
../../build/linux/debian_wheezy_amd64-sysroot/usr/lib/gcc/x86_64-linux-gnu/4.6/../../../../include/c++/4.6/bits/locale_facets.tcc:1258:9:
note: Assigned value is garbage or undefined
*__s++ = *__first++;
^ ~~~~~~~~~~
Repository:
rL LLVM
https://reviews.llvm.org/D30593
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