refactor: Use && in boolean context to avoid compiler warning #1006

pull maflcko wants to merge 1 commits into bitcoin-core:master from maflcko:2111-amp changing 1 files +1 −1

maflcko commented at 3:10 PM on November 8, 2021: contributor

This fixes a compiler warning:

./src/ecdsa_impl.h:312:12: warning: use of bitwise '&' with boolean operands [-Wbitwise-instead-of-logical]
    return !secp256k1_scalar_is_zero(sigr) & !secp256k1_scalar_is_zero(sigs);
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                                           &&

refactor: Use && in boolean context to avoid compiler warning

This fixes a compiler warning:

./src/ecdsa_impl.h:312:12: warning: use of bitwise '&' with boolean operands [-Wbitwise-instead-of-logical]
    return !secp256k1_scalar_is_zero(sigr) & !secp256k1_scalar_is_zero(sigs);
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                                           &&

e24b9ac353

maflcko commented at 3:12 PM on November 8, 2021: contributor

I didn't try to reproduce this, but I randomly saw it in logs on a 32-bit compilation with clang-14 (trunk) and some odd compiler flags like -O0.
maflcko commented at 3:23 PM on November 8, 2021: contributor

Ah, I see.

Good thing there are tests.
maflcko closed this on Nov 8, 2021
maflcko deleted the branch on Nov 8, 2021
sipa commented at 3:24 PM on November 8, 2021: contributor

:)
maflcko commented at 4:42 PM on November 8, 2021: contributor

This is in clang-14 (for now): https://github.com/llvm/llvm-project/commit/f62d18ff140f67a8776a7a3c62a75645d8d540b5
sipa commented at 5:26 PM on November 8, 2021: contributor

If there is a need to silence anything, I think the correct approach is suggested there: cast one of the inputs to & to int.
real-or-random referenced this in commit 74c34e727b on Nov 9, 2021

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maflcko

sipa

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#1009 refactor: Use (int)&(int) in boolean context to avoid compiler warning