https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66943
Bug ID: 66943
Summary: GCC warns of Unknown Pragma for OpenMP, even though it
support it.
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: noloader at gmail dot com
Target Milestone: ---
The following source code results in a slew of Unknown Pragma messages. The
problem is, GCC supports OpenMP. GCC responds properly to -fopenmp, and even
defines _OPENMP when it encounters -fopenmp.
This is related to https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53431, and
managing warnings with pragmas when using -Wall. The relation to 53431 is: I
can't seem to get "pragma GCC diagnostic" to work to ignore the warnings when
-Wall is in effect.
// Defines GCC_DIAGNOSTIC_AWARE if GCC 4.7 or above.
#define GCC_DIAGNOSTIC_AWARE 1
#if GCC_DIAGNOSTIC_AWARE
# pragma GCC diagnostic ignored "-Wunknown-pragmas"
#endif
...
Integer ModularRoot(const Integer &a, const Integer &dp, const Integer &dq,
const Integer &p, const Integer &q, const Integer &u)
{
Integer p2, q2;
#pragma omp parallel
#pragma omp sections
{
#pragma omp section
p2 = ModularExponentiation((a % p), dp, p);
#pragma omp section
q2 = ModularExponentiation((a % q), dq, q);
}
return CRT(p2, p, q2, q, u);
}
...
**********
To duplicate:
git clone https://github.com/weidai11/cryptopp.git cryptopp-warn
cd cryptopp-warn
export CXXFLAGS="-g2 -O3 -DNDEBUG -Wall"
make
