[Bug c/80116] New: Warn about macros expanding to multiple statements

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80116

            Bug ID: 80116
           Summary: Warn about macros expanding to multiple statements
           Product: gcc
           Version: 7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mpolacek at gcc dot gnu.org
  Target Milestone: ---

See PR80063:

  #define DEF_SANITIZER_BUILTIN(ENUM, NAME, TYPE, ATTRS) \
  decl = add_builtin_function ("__builtin_" NAME, TYPE, ENUM,           \
                               BUILT_IN_NORMAL, NAME, NULL_TREE);       \
  set_call_expr_flags (decl, ATTRS);                                    \
  set_builtin_decl (ENUM, decl, true);

  #include "sanitizer.def"

  /* -fsanitize=object-size uses __builtin_object_size, but that might
     not be available for e.g. Fortran at this point.  We use
     DEF_SANITIZER_BUILTIN here only as a convenience macro.  */
  if ((flag_sanitize & SANITIZE_OBJECT_SIZE)
      && !builtin_decl_implicit_p (BUILT_IN_OBJECT_SIZE))
    DEF_SANITIZER_BUILTIN (BUILT_IN_OBJECT_SIZE, "object_size",         // <=
                           BT_FN_SIZE_CONST_PTR_INT,
                           ATTR_PURE_NOTHROW_LEAF_LIST)