https://issues.dlang.org/show_bug.cgi?id=17836

b2.temp@gmx.com changed:

           What    |Removed                     |Added
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           Keywords|                            |ice, ice-on-invalid-code
                 CC|                            |b2.temp@gmx.com

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https://issues.dlang.org/show_bug.cgi?id=17836

--- Comment #1 from elronnd@protonmail.ch ---
Potentially relevant: dmd just segfaults, but gdc actually prints a message:

test.d: In function ‘mmap’:
test.d:7:8: internal compiler error: in get_frame_for_symbol, at
d/d-codegen.cc:2208
     fun(item);
        ^

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https://issues.dlang.org/show_bug.cgi?id=17836

Iain Buclaw <ibuclaw@gdcproject.org> changed:

           What    |Removed                     |Added
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                 CC|                            |ibuclaw@gdcproject.org

--- Comment #2 from Iain Buclaw <ibuclaw@gdcproject.org> ---
The compiler is checking if the nested function 'printer' is reachable from the function 'mmap'.

It's not, because 'printer' is nested inside 'printstuffs', as so is not reachable.

This would fall under a category of functions that are called by alias ('fun' is an alias to the function to call, of which the actual function is unreachable from the scope of 'mmap').

The front-end should ideally have a way to notify the code generator of this somehow, to notify us that there's no need to check whether the call is legal.

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https://issues.dlang.org/show_bug.cgi?id=17836

--- Comment #3 from Iain Buclaw <ibuclaw@gdcproject.org> ---
(In reply to Iain Buclaw from comment #2)
> 
> The front-end should ideally have a way to notify the code generator of this somehow, to notify us that there's no need to check whether the call is legal.

You would, however, run into other problems if 'printer' actually modifies anything in the parent frame.

        void printstuffs(T...)(T args) {
                int count = 0;
                void printer(G)(G arg) {
                        writeln(arg);
                        count++;
                }

                mmap!printer(args);
        }


In the above case, runtime would segfault.  As we have no way of determining the context pointer IIUC.

The current AST handed from the front-end may be broken in this regard.

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https://issues.dlang.org/show_bug.cgi?id=17836

--- Comment #4 from Iain Buclaw <ibuclaw@gdcproject.org> ---
Note to anyone looking.

For function call to mmap(...).


Given that:

FuncDeclaration fd = void mmap(T...);

fd.toParent2() == main();
fd.parent.isTemplateInstance() == template mmap(T...);
fd.parent.isTemplateInstance().tinst == template printstuffs(T...);
fd.parent.isTemplateInstance().tinst.toAlias() == void printstuffs(T...);

This is how you track the 'this' pointer for mmap to the frame of printstuffs.

Fix for gdc will happen soon.  Someone will have to look at dmd.

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https://issues.dlang.org/show_bug.cgi?id=17836

--- Comment #5 from Iain Buclaw <ibuclaw@gdcproject.org> ---
(In reply to Iain Buclaw from comment #4)
> 
> This is how you track the 'this' pointer for mmap to the frame of printstuffs.
> 

Also note that you can't trust toParent2() here, as it returns the function the
template was declared in. Parent access should be done through toParent() to
properly inspect whether a template comes from another template instance
(declared in another context).

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https://issues.dlang.org/show_bug.cgi?id=17836

Basile-z <b2.temp@gmx.com> changed:

           What    |Removed                     |Added
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             Status|NEW                         |RESOLVED
         Resolution|---                         |WORKSFORME

--- Comment #6 from Basile-z <b2.temp@gmx.com> ---
The bug as an ICE is gone now. Open another issue if the compilation is supposed to succeed.

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https://issues.dlang.org/show_bug.cgi?id=17836

Basile-z <b2.temp@gmx.com> changed:

           What    |Removed                     |Added
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                 CC|b2.temp@gmx.com             |

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