public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
From: "Artem dot Andreev at oktetlabs dot ru" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug ada/38975] New: deferred constants of not null access types are not possible Date: Mon, 26 Jan 2009 12:28:00 -0000 [thread overview] Message-ID: <bug-38975-17228@http.gcc.gnu.org/bugzilla/> (raw) The following does not compile: package Test is type X is new Positive; type X_Access is not null access constant X; Y : constant X_Access; private Y_Val : aliased constant X := 1; Y : constant X_Access := Y_Val'Access; end Test; with the following diagnostics: test.ads:6:09: warning: (Ada 2005) null-excluding objects must be initialized test.ads:6:09: warning: "Constraint_Error" will be raised at run time test.ads:11:09: "Y" conflicts with declaration at line 6 If "not null" modifier is removed, everything is fine. As I can see from the following code, the semantic analyzer sees a deferred constant and (erroneously) assumes that it's an uninitialized object. It then inserts an implicit null initialization. And when it comes to a full definition of the constant, the compiler thinks it has been already defined: (gcc/ada/checks.adb, procedure Null_Exclusion_Static_Checks, line 2728): if K = N_Object_Declaration and then No (Expression (N)) and then not No_Initialization (N) then -- Add an expression that assigns null. This node is needed by -- Apply_Compile_Time_Constraint_Error, which will replace this with -- a Constraint_Error node. Set_Expression (N, Make_Null (Sloc (N))); Set_Etype (Expression (N), Etype (Defining_Identifier (N))); Apply_Compile_Time_Constraint_Error (N => Expression (N), Msg => "(Ada 2005) null-excluding objects must be initialized?", Reason => CE_Null_Not_Allowed); end if; The code can be traced back to at least gcc 4.1.2 -- Summary: deferred constants of not null access types are not possible Product: gcc Version: 4.3.2 Status: UNCONFIRMED Severity: normal Priority: P3 Component: ada AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: Artem dot Andreev at oktetlabs dot ru http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38975
next reply other threads:[~2009-01-26 12:28 UTC|newest] Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top 2009-01-26 12:28 Artem dot Andreev at oktetlabs dot ru [this message] 2009-10-03 10:11 ` [Bug ada/38975] " sam at gcc dot gnu dot org 2009-10-03 10:32 ` ebotcazou at gcc dot gnu dot org
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=bug-38975-17228@http.gcc.gnu.org/bugzilla/ \ --to=gcc-bugzilla@gcc.gnu.org \ --cc=gcc-bugs@gcc.gnu.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).