Add SECP256K1_WARN_UNUSED_RESULT to all relevant static int functions #1876

pull shivv23 wants to merge 3 commits into bitcoin-core:master from shivv23:add-warn-unused-result changing 38 files +197 −193

shivv23 commented at 7:29 PM on June 18, 2026: none
Annotate all static int functions in the library (non-test code) with SECP256K1_WARN_UNUSED_RESULT so that compilers can warn when return values are accidentally discarded. This covers ~140 functions across all modules.

Changes:
- Add SECP256K1_WARN_UNUSED_RESULT to field, scalar, group, eckey, ecmult, ecdsa, int128 utility functions and all module header/impl files
- Fix call sites where return values were being discarded:
  
  secp256k1_ec_pubkey_combine: check pubkey_load return
  
  secp256k1_ecdh: check pubkey_load return
  
  secp256k1_ellswift_swiftec_var, ellswift_xdh: use assignment pattern
  
  bench_internal.c, bench_ecmult.c, test files: wrap in CHECK()
- Exclude scalar_add and scalar_cond_negate whose returns are intentionally informational/redundant at all existing call sites
See #1610 for prior discussion.

Add SECP256K1_WARN_UNUSED_RESULT to all relevant static int functions

Annotate all static int functions in the library (non-test code) with
SECP256K1_WARN_UNUSED_RESULT to catch bugs where return values are
accidentally discarded. This covers ~140 functions across all modules.

Key changes:
- Add WARN_UNUSED_RESULT to field, scalar, group, eckey, ecmult,
  ecdsa, int128 utility functions and all module functions
- Fix 4 call sites where return values were being ignored:
  - secp256k1_ec_pubkey_combine: check pubkey_load return
  - secp256k1_ecdh: check pubkey_load return
  - secp256k1_ellswift_swiftec_var: VERIFY_CHECK ge_set_xo_var
  - ellswift_xdh: (void) cast for ecmult_const_xonly with known_on_curve=1
- Do not annotate scalar_add or scalar_cond_negate whose returns are
  intentionally informational/redundant at all call sites

b03ce92afa

Fix ignored return values that caused CI failures 6344822ac3
gatleas17 commented at 12:23 AM on June 19, 2026: none

Ñla
Fix ignored return values in test/bench files 2c77462563
shivv23 closed this on Jun 19, 2026
real-or-random added the label assurance on Jun 19, 2026
real-or-random added the label tweak/refactor on Jun 19, 2026
real-or-random added the label meta/development on Jun 19, 2026

Contributors

shivv23

gatleas17

Labels

assurance tweak/refactor meta/development

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#1610 Add extra API for offline/online phases in ECDSA signing