https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104092
--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Richard Biener <rgue...@gcc.gnu.org>: https://gcc.gnu.org/g:551aa75778a4c5165d9533cd447c8fc822f583e1 commit r12-7044-g551aa75778a4c5165d9533cd447c8fc822f583e1 Author: Richard Biener <rguent...@suse.de> Date: Wed Feb 2 14:24:39 2022 +0100 Add CLOBBER_EOL to mark storage end-of-life clobbers This adds a flag to CONSTRUCTOR nodes indicating that for clobbers this marks the end-of-life of storage as opposed to just ending the lifetime of the object that occupied it. The dangling pointer diagnostics uses CLOBBERs but is confused by those emitted by the C++ frontend for example which emits them for the second purpose at the start of CTORs. The issue is also appearant for aarch64 in PR104092. Distinguishing the two cases is also necessary for the PR90348 fix. Since I'm going to add another flag I added an enum clobber_flags and a defaulted argument to build_clobber plus a convenient way to query the enum from the CTOR tree and specify it for gimple_clobber_p. Since 'CLOBBER' is already taken and I needed a name for the unspecified clobber we have now I used 'CLOBBER_UNDEF'. 2022-02-03 Richard Biener <rguent...@suse.de> PR middle-end/90348 PR middle-end/104092 gcc/ * tree-core.h (clobber_kind): New enum. (tree_base::u::bits::address_space): Document use in CONSTRUCTORs. * tree.h (CLOBBER_KIND): Add. (build_clobber): Add clobber kind argument, defaulted to CLOBBER_UNDEF. * tree.cc (build_clobber): Likewise. * gimple.h (gimple_clobber_p): New overload with specified kind. * tree-streamer-in.cc (streamer_read_tree_bitfields): Stream CLOBBER_KIND. * tree-streamer-out.cc (streamer_write_tree_bitfields): Likewise. * tree-pretty-print.cc (dump_generic_node): Mark EOL CLOBBERs. * gimplify.cc (gimplify_bind_expr): Build storage end-of-life clobbers with CLOBBER_EOL. (gimplify_target_expr): Likewise. * tree-inline.cc (expand_call_inline): Likewise. * tree-ssa-ccp.cc (insert_clobber_before_stack_restore): Likewise. * gimple-ssa-warn-access.cc (pass_waccess::check_stmt): Only treat CLOBBER_EOL clobbers as ending lifetime of storage. gcc/lto/ * lto-common.cc (compare_tree_sccs_1): Compare CLOBBER_KIND. gcc/testsuite/ * gcc.dg/pr87052.c: Adjust.
