digitalmars.D.bugs - [Issue 2383] New: default arguments can implicitly access private global variables that are not visible at call site
- d-bugmail puremagic.com (41/41) Oct 01 2008 http://d.puremagic.com/issues/show_bug.cgi?id=2383
- d-bugmail puremagic.com (6/6) Oct 02 2008 http://d.puremagic.com/issues/show_bug.cgi?id=2383
- d-bugmail puremagic.com (5/5) Oct 02 2008 http://d.puremagic.com/issues/show_bug.cgi?id=2383
- d-bugmail puremagic.com (5/5) Oct 02 2008 http://d.puremagic.com/issues/show_bug.cgi?id=2383
- d-bugmail puremagic.com (4/4) Oct 02 2008 http://d.puremagic.com/issues/show_bug.cgi?id=2383
- d-bugmail puremagic.com (9/9) Oct 02 2008 http://d.puremagic.com/issues/show_bug.cgi?id=2383
- d-bugmail puremagic.com (7/7) Oct 02 2008 http://d.puremagic.com/issues/show_bug.cgi?id=2383
- d-bugmail puremagic.com (5/7) Oct 02 2008 http://d.puremagic.com/issues/show_bug.cgi?id=2383
- d-bugmail puremagic.com (7/7) Oct 16 2008 http://d.puremagic.com/issues/show_bug.cgi?id=2383
- d-bugmail puremagic.com (9/9) Oct 20 2008 http://d.puremagic.com/issues/show_bug.cgi?id=2383
http://d.puremagic.com/issues/show_bug.cgi?id=2383 Summary: default arguments can implicitly access private global variables that are not visible at call site Product: D Version: unspecified Platform: PC OS/Version: Linux Status: NEW Keywords: accepts-invalid, spec Severity: normal Priority: P2 Component: DMD AssignedTo: bugzilla digitalmars.com ReportedBy: tomas famolsen.dk Consider the following testcase: ------------------------ 1st module: module privateconst1; extern(C) int rand(); private const int abc; static this() { abc = rand(); } void foo(int i = abc) {} ------------------------ 2nd module: module privateconst2; import privateconst1; void main() { foo(); } ------ this is accepted by dmd and works. however this makes it impossible for another compiler to mark 'abc' as internal (or in C terms, static) disabling a lot of valuable optimizations. in the 2nd module the call to 'foo' has to load the value of 'abc' which is private and should not be accessible. I can't find anywhere in the spec where it says this is allowed, hence marking both 'spec' and 'accepts-invalid' --
Oct 01 2008
http://d.puremagic.com/issues/show_bug.cgi?id=2383 It's legal because the default parameter value is evaluated in the context where it appears, and so has access to private values where it appears. I'll clarify the documentation. --
Oct 02 2008
http://d.puremagic.com/issues/show_bug.cgi?id=2383 ------- "The default parameter value is evaluated in the context where it appears" - should I reopen Issue 191, then? --
Oct 02 2008
http://d.puremagic.com/issues/show_bug.cgi?id=2383 how can I detect this and still make private globals internal to the module in the normal case ? --
Oct 02 2008
http://d.puremagic.com/issues/show_bug.cgi?id=2383 I mean in terms of DMD... --
Oct 02 2008
http://d.puremagic.com/issues/show_bug.cgi?id=2383 ------- Isn't the case just the same as the following? (I wish default args were always semantically equivalent to this, but oh well...) private const int abc; void foo() { foo(abc); } void foo(int i) {} That shouldn't require making abc non-private, or? --
Oct 02 2008
http://d.puremagic.com/issues/show_bug.cgi?id=2383 reason I'm asking this is that DMD puts a the private global value in the AST at the call site. thus I can't make this specific global internal and I can't find any information to tell me that this specific global does not follow usual symbol visibility rules. --
Oct 02 2008
http://d.puremagic.com/issues/show_bug.cgi?id=2383"The default parameter value is evaluated in the context where it appears" - should I reopen Issue 191, then?No, because a 'this' pointer would still be needed. --
Oct 02 2008
http://d.puremagic.com/issues/show_bug.cgi?id=2383 *bump* I could really use some hints on how to fix this in LDC .. Walter? How do you do it in DMD? As I've already said, the callsite references the global variable, so I need some way to figure out that this in fact is not a real private. --
Oct 16 2008
http://d.puremagic.com/issues/show_bug.cgi?id=2383 bugzilla digitalmars.com changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution| |FIXED Fixed dmd 1.036 and 2.020 --
Oct 20 2008