digitalmars.D.bugs - [Issue 6230] New: Member functions can no longer be weakly pure
- d-bugmail puremagic.com (68/68) Jun 30 2011 http://d.puremagic.com/issues/show_bug.cgi?id=6230
- d-bugmail puremagic.com (72/72) Jun 30 2011 http://d.puremagic.com/issues/show_bug.cgi?id=6230
- d-bugmail puremagic.com (11/11) Jul 04 2011 http://d.puremagic.com/issues/show_bug.cgi?id=6230
- d-bugmail puremagic.com (12/12) Jul 06 2011 http://d.puremagic.com/issues/show_bug.cgi?id=6230
- d-bugmail puremagic.com (6/6) Aug 01 2011 http://d.puremagic.com/issues/show_bug.cgi?id=6230
http://d.puremagic.com/issues/show_bug.cgi?id=6230
Summary: Member functions can no longer be weakly pure
Product: D
Version: D2
Platform: All
OS/Version: All
Status: NEW
Keywords: rejects-valid
Severity: blocker
Priority: P2
Component: DMD
AssignedTo: nobody puremagic.com
ReportedBy: kennytm gmail.com
(See http://lists.puremagic.com/pipermail/phobos/2011-June/005487.html and
comments in Phobos commit 4f28d** for existing discussion.)
After DMD commit 84b4f* a member function can no longer be pure, claiming
itself as a nested function. I believe this is a bug because the relevant DMD
code
Dsymbol *vparent = v->toParent2();
for (Dsymbol *s = sc->func; s; s = s->toParent2())
{
if (s == vparent)
break;
FuncDeclaration *ff = s->isFuncDeclaration();
if (!ff)
break;
if (ff->setImpure())
{ error("pure nested function '%s' cannot access mutable data
'%s'",
ff->toChars(), v->toChars());
break;
}
}
cannot check the case when 'vparent' is an aggregrate. Nevertheless, this leads
to commits d014a and 40def in druntime, and 4f28d in Phobos**, which probably
means this bug is INVALID.
Test case:
-----------------------
struct S {
int p;
int q() const pure { // <-- Error
return p;
}
}
class C {
int p;
int q() const pure { // <-- Error
return p;
}
}
int q2(ref const S s) pure { // <-- Currently OK
return s.p;
}
int q3(ref const C c) pure { // <-- Currently OK
return c.p;
}
-----------------------
y.d(4): Error: pure nested function 'q' cannot access mutable data 'p'
y.d(11): Error: pure nested function 'q' cannot access mutable data 'p'
-----------------------
* https://github.com/D-Programming-Language/dmd/commit/84b4f
** https://github.com/D-Programming-Language/druntime/commit/d014a
https://github.com/D-Programming-Language/druntime/commit/40def
https://github.com/D-Programming-Language/phobos/commit/4f28d
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One possible patch:
diff --git a/src/expression.c b/src/expression.c
index 57cdd61..71f6239 100644
--- a/src/expression.c
+++ b/src/expression.c
-1366,17 +1366,23 void Expression::checkPurity(Scope *sc, VarDeclaration
*v, Expression *ethis)
* requiring each function in between to be impure.
*/
Dsymbol *vparent = v->toParent2();
- for (Dsymbol *s = sc->func; s; s = s->toParent2())
+ Dsymbol *s = sc->func, *snext = s->toParent2();
+ // Make sure we're really finding parent *functions*, not parent
+ // class.
+ if (vparent->isFuncDeclaration() || snext != vparent)
{
- if (s == vparent)
- break;
- FuncDeclaration *ff = s->isFuncDeclaration();
- if (!ff)
- break;
- if (ff->setImpure())
- { error("pure nested function '%s' cannot access mutable
data '%s'",
- ff->toChars(), v->toChars());
- break;
+ for (; s; s = s->toParent2())
+ {
+ if (s == vparent)
+ break;
+ FuncDeclaration *ff = s->isFuncDeclaration();
+ if (!ff)
+ break;
+ if (ff->setImpure())
+ { error("pure nested function '%s' cannot access mutable
data '%s'",
+ ff->toChars(), v->toChars());
+ break;
+ }
}
}
}
diff --git a/src/func.c b/src/func.c
index 9957d7f..1cccbed 100644
--- a/src/func.c
+++ b/src/func.c
-2664,9 +2664,9 enum PURE FuncDeclaration::isPure()
TypeFunction *tf = (TypeFunction *)type;
if (flags & FUNCFLAGpurityInprocess)
setImpure();
- enum PURE purity = tf->purity;
- if (purity == PUREfwdref)
+ if (tf->purity == PUREfwdref)
tf->purityLevel();
+ enum PURE purity = tf->purity;
if (purity > PUREweak && needThis())
{ // The attribute of the 'this' reference affects purity strength
if (type->mod & (MODimmutable | MODwild))
-2676,6 +2676,9 enum PURE FuncDeclaration::isPure()
else
purity = PUREweak;
}
+ tf->purity = purity;
+ // ^ This rely on the current situation that every FuncDeclaration has a
+ // unique TypeFunction.
return purity;
}
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kennytm gmail.com changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |patch
https://github.com/D-Programming-Language/dmd/pull/210
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Jul 04 2011
http://d.puremagic.com/issues/show_bug.cgi?id=6230
Walter Bright <bugzilla digitalmars.com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
CC| |bugzilla digitalmars.com
Resolution| |FIXED
20:34:27 PDT ---
https://github.com/D-Programming-Language/dmd/commit/47efdef731e2ed1333aeedc053d37adff4356585
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Jul 06 2011
http://d.puremagic.com/issues/show_bug.cgi?id=6230 21:44:14 PDT --- https://github.com/D-Programming-Language/dmd/commit/1dac08b77af2826996567f629acf7f43d724cd48 -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Aug 01 2011