[Issue 17819] static foreach segfaults on __traits(allMembers)

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https://issues.dlang.org/show_bug.cgi?id=17819

--- Comment #9 from github-bugzi...@puremagic.com ---
Commits pushed to master at https://github.com/dlang/dmd

https://github.com/dlang/dmd/commit/ebbd8e92b61bcf05df443b62deeff0786581067c
fix Issue 17819 - static foreach segfaults on __traits(allMembers)

https://github.com/dlang/dmd/commit/b625e01f4464768d0e7b1b8119d8f6ca3543efa1
Merge pull request #8213 from tgehr/fix17819

fix Issue 17819 - static foreach segfaults on __traits(allMembers)
merged-on-behalf-of: Razvan Nitu 

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[Issue 17819] static foreach segfaults on __traits(allMembers)

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https://issues.dlang.org/show_bug.cgi?id=17819

github-bugzi...@puremagic.com changed:

   What|Removed |Added

 Status|NEW |RESOLVED
 Resolution|--- |FIXED

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[Issue 17819] static foreach segfaults on __traits(allMembers)

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https://issues.dlang.org/show_bug.cgi?id=17819

--- Comment #8 from timon.g...@gmx.ch ---
https://github.com/dlang/dmd/pull/8213

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[Issue 17819] static foreach segfaults on __traits(allMembers)

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https://issues.dlang.org/show_bug.cgi?id=17819

--- Comment #7 from timon.g...@gmx.ch ---
*** Issue 18718 has been marked as a duplicate of this issue. ***

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[Issue 17819] static foreach segfaults on __traits(allMembers)

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https://issues.dlang.org/show_bug.cgi?id=17819

timon.g...@gmx.ch changed:

   What|Removed |Added

 CC||timon.g...@gmx.ch

--- Comment #6 from timon.g...@gmx.ch ---
This is not really a `static foreach` issue, but rather a general issue with
how DMD handles (or rather, does not handle) circular dependencies.

The following code runs into the same problem:

---
module c;
static if(__traits(allMembers,__traits(parent,{}))[0]=="c"){}
---

Here, DMD explicitly catches the infinite recursion and prints:
c.d(3): Error: error evaluating `static if` expression

(The code that does this has a bug in it, therefore the error message is not
useful:

if (exp.op == TOK.error || nest > 100)
{
error(loc, (nest > 1000) ? "unresolvable circular `static if`
expression" : "error evaluating `static if` expression");
return errorReturn();
}
)

It is trivial to apply a similar "fix" for `static foreach`, but I doubt this
is what Jean-Louis had in mind.


Interestingly enough, this "works" with string mixins:

module c;
mixin("enum "~__traits(allMembers,c)[1]~"2 = 2;");
int x;
pragma(msg, x2);
pragma(msg, __traits(allMembers,c)[1]);

(Clearly, the code actually has no reasonable interpretation, but DMD still
successfully compiles it.)

This is because `CompileDeclaration.include` just returns null. I can "fix" the
`static foreach` case by returning "null" in case a call to "include" is
already on the stack. In fact, I could do the same to the `static if` case to
make that "work" too.

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[Issue 17819] static foreach segfaults on __traits(allMembers)

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https://issues.dlang.org/show_bug.cgi?id=17819

--- Comment #5 from Seb  ---
https://issues.dlang.org/show_bug.cgi?id=18718 is very related.

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[Issue 17819] static foreach segfaults on __traits(allMembers)

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https://issues.dlang.org/show_bug.cgi?id=17819

Seb  changed:

   What|Removed |Added

 CC||greensunn...@gmail.com
   See Also||https://issues.dlang.org/sh
   ||ow_bug.cgi?id=18718

--- Comment #4 from Seb  ---
Not really a fix, but a start https://github.com/dlang/dmd/pull/8125

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[Issue 17819] static foreach segfaults on __traits(allMembers)

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https://issues.dlang.org/show_bug.cgi?id=17819

bitter.ta...@gmx.com changed:

   What|Removed |Added

 CC||bitter.ta...@gmx.com

--- Comment #3 from bitter.ta...@gmx.com ---
There's a stack overflow in Dsymbol's _foreach, every time it recurses into a
AttribDeclaration (such as the `static foreach') the stack gets deeper until it
explodes.

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[Issue 17819] static foreach segfaults on __traits(allMembers)

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https://issues.dlang.org/show_bug.cgi?id=17819

--- Comment #2 from Jean-Louis Leroy  ---
Still present in v2.078.3 - it seems that no one is looking into this.

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[Issue 17819] static foreach segfaults on __traits(allMembers)

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https://issues.dlang.org/show_bug.cgi?id=17819

Jean-Louis Leroy  changed:

   What|Removed |Added

 CC||j...@leroy.nyc

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[Issue 17819] static foreach segfaults on __traits(allMembers)

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https://issues.dlang.org/show_bug.cgi?id=17819

--- Comment #1 from Jean-Louis Leroy  ---
The bug is still present in 2.078.

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