[Bug c++/51264] O0 Bootstrap failure: control reaches end of non-void function

[vries at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51264

vries at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |matz at suse dot de

--- Comment #3 from vries at gcc dot gnu.org 2011-11-22 02:38:30 UTC ---
Triggered/caused by r181172:
...
r181172 | matz | 2011-11-08 17:47:16 +0100 (Tue, 08 Nov 2011) | 44 lines

    * gengtype.c (write_field_root): Avoid out-of-scope access of newv.

    * tree-stdarg.c (execute_optimize_stdarg): Accept clobbers.

    * tree.h (TREE_CLOBBER_P): New macro.
    * gimple.h (gimple_clobber_p): New inline function.
    * gimplify.c (gimplify_bind_expr): Add clobbers for all variables
    that go out of scope and live in memory.
    * tree-ssa-operands.c (get_expr_operands): Transfer volatility also
    for constructors.
    * cfgexpand.c (decl_to_stack_part): New static variable.
    (add_stack_var): Allocate it, and remember mapping.
    (fini_vars_expansion): Deallocate it.
    (stack_var_conflict_p): Add early outs.
    (visit_op, visit_conflict, add_scope_conflicts_1,
    add_scope_conflicts): New static functions.
    (expand_used_vars_for_block): Don't call add_stack_var_conflict, tidy.
    (expand_used_vars): Add scope conflicts.
    (expand_gimple_stmt_1): Expand clobbers to nothing.
    (expand_debug_expr): Ditto.

    * tree-pretty-print.c (dump_generic_node): Dump clobbers nicely.
    * tree-ssa-live.c (remove_unused_locals): Remove clobbers that
    refer to otherwise unused locals.
    * tree-sra.c (build_accesses_from_assign): Ignore clobbers.
    * tree-ssa-dce.c (mark_stmt_if_obviously_necessary): Clobbers of
    SSA names aren't necessary.
    (propagate_necessity): Accept and ignore constructors on the rhs,
    tidy.
    * gimple.c (walk_gimple_op): Accept constructors like mem_rhs.
    * tree-ssa-structalias.c (find_func_aliases): Clobbers don't store
    any known value.
    * tree-ssa-sccvn.c (vn_reference_lookup_3): Ditto, in particular they
    don't zero-initialize something.
    * tree-ssa-phiopt.c (cond_if_else_store_replacement_1): Ignore
    clobber RHS, we don't want PHI nodes with those.
...