various: Fix gcc -fsanitize=undefined errors #7237

[messages truncated to pass ci_commit_formatting_run] [the line numbers match 0e87459] ``` binary.c:210:13: runtime error: left shift of negative val... crypto-algorithms/sha256.c:49:19: runtime error: left shif... moduasyncio.c:106:35: runtime error: member access within ... mpz.c:711:5: runtime error: null pointer passed as argumen... mpz.c:744:16: runtime error: negation of -9223372036854775... objarray.c:130:9: runtime error: null pointer passed as ar... objarray.c:377:5: runtime error: null pointer passed as ar... objarray.c:457:21: runtime error: null pointer passed as a... objarray.c:457:21: runtime error: null pointer passed as a... objarray.c:461:21: runtime error: null pointer passed as a... objdict.c:250:5: runtime error: null pointer passed as arg... objdict.c:250:5: runtime error: null pointer passed as arg... objint.c:109:22: runtime error: left shift of # by 31 plac... objint_mpz.c:374:9: runtime error: left shift of # by 1 pl... objint_mpz.c:374:9: runtime error: left shift of negative ... objset.c:181:5: runtime error: null pointer passed as argu... objset.c:181:5: runtime error: null pointer passed as argu... parsenum.c:106:14: runtime error: left shift of # by 1 pla... qstr.c:181:78: runtime error: null pointer passed as argum... runtime.c:395:33: runtime error: left shift of negative va... runtime.c:534:17: runtime error: left shift of negative va... sequence.c:108:15: runtime error: null pointer passed as a... sequence.c:108:15: runtime error: null pointer passed as a... showbc.c:177:28: runtime error: left shift of negative val... vm.c:321:36: runtime error: left shift of negative value -... ``` With these cumulative changes, `make VARIANT=coverage test_full` with -fsanitize=undefined passes, except for some problems in axtls. My testing was done on an amd64 debian buster system using gcc-8.3 and these settings: ``` CFLAGS += -g3 -Og -fsanitize=undefined LDFLAGS += -fsanitize=undefined ``` The changes are intended/expected to produce no runtime overhead, as the behavior of the mem* functions is only actually modified for the unix coverage run (MICROPY_NONNULL_COMPLIANT). The introduced PAIRHEAP macro's conditional (x ? &x->i : NULL) assembles (under amd64 gcc 8.3 -Os) to the same as &x->i, since i is the initial field of the struct. However, for the purposes of undefined behavior analysis the conditional is needed. Signed-off-by: Jeff Epler <jepler@gmail.com>

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

various: Fix gcc -fsanitize=undefined errors #7237

various: Fix gcc -fsanitize=undefined errors #7237

Commits on May 10, 2021