https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105273
--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by David Malcolm <dmalc...@gcc.gnu.org>: https://gcc.gnu.org/g:ccd4df81aa6537c3c935b026905f6e2fd839654e commit r13-5159-gccd4df81aa6537c3c935b026905f6e2fd839654e Author: David Malcolm <dmalc...@redhat.com> Date: Fri Jan 13 17:51:26 2023 -0500 analyzer: add heuristics for switch on enum type [PR105273] Assume that switch on an enum doesn't follow an implicit default skipping all cases when all enum values are covered by cases. Fixes various false positives from -Wanalyzer-use-of-uninitialized-value such as this one seen in Doom: p_maputl.c: In function 'P_BoxOnLineSide': p_maputl.c:151:8: warning: use of uninitialized value 'p1' [CWE-457] [-Wanalyzer-use-of-uninitialized-value] 151 | if (p1 == p2) | ^ 'P_BoxOnLineSide': events 1-5 | | 115 | int p1; | | ^~ | | | | | (1) region created on stack here | | (2) capacity: 4 bytes |...... | 118 | switch (ld->slopetype) | | ~~~~~~ | | | | | (3) following 'default:' branch... |...... | 151 | if (p1 == p2) | | ~ | | | | | (4) ...to here | | (5) use of uninitialized value 'p1' here | where "ld->slopetype" is a "slopetype_t" enum, and for every value of that enum the switch has a case that initializes "p1". gcc/analyzer/ChangeLog: PR analyzer/105273 * region-model.cc (has_nondefault_case_for_value_p): New. (has_nondefault_cases_for_all_enum_values_p): New. (region_model::apply_constraints_for_gswitch): Skip implicitly-created "default" when switching on an enum and all enum values have non-default cases. (rejected_default_case::dump_to_pp): New. * region-model.h (region_model_context::possibly_tainted_p): New decl. (class rejected_default_case): New. * sm-taint.cc (region_model_context::possibly_tainted_p): New. * supergraph.cc (switch_cfg_superedge::dump_label_to_pp): Dump when implicitly_created_default_p. (switch_cfg_superedge::implicitly_created_default_p): New. * supergraph.h (switch_cfg_superedge::implicitly_created_default_p): New decl. gcc/testsuite/ChangeLog: PR analyzer/105273 * gcc.dg/analyzer/switch-enum-1.c: New test. * gcc.dg/analyzer/switch-enum-2.c: New test. * gcc.dg/analyzer/switch-enum-pr105273-git-vreportf-2.c: New test. * gcc.dg/analyzer/switch-enum-taint-1.c: New test. * gcc.dg/analyzer/switch-wrong-enum.c: New test. * gcc.dg/analyzer/torture/switch-enum-pr105273-doom-p_floor.c: New test. * gcc.dg/analyzer/torture/switch-enum-pr105273-doom-p_maputl.c: New test. * gcc.dg/analyzer/torture/switch-enum-pr105273-git-vreportf-1.c: New test. Signed-off-by: David Malcolm <dmalc...@redhat.com>
