[llvm-commits] [llvm-gcc-4.2] r45757 - in /llvm-gcc-4.2/trunk/gcc: llvm-types.cpp tree.c tree.h

[Dale Johannesen]

On Jan 8, 2008, at 2:28 PM, Chris Lattner wrote:

> On Jan 8, 2008, at 1:08 PM, Dale Johannesen wrote:
>> URL: http://llvm.org/viewvc/llvm-project?rev=45757&view=rev
>> Log:
>> Fix gcc->llvm translation for virtual base classes.  pr1746
>
> Yay, very nice Dale.
>
>> +/// Mapping from type to type-used-as-base-class and back.
>> +static DenseMap<tree, tree> BaseTypesMap;
>
> Does this play well with PCH?  Please add a comment above this that  
> says that the trees are kept pinned for the GC by the  
> llvm_types_used map.
>
> If this doesn't work with PCH (Devang, thoughts?) it might be better  
> to use the GCC splay tree or whatever they use for tree->tree  
> mappings.

I haven't tried it (except that there are no failures in the PCH part  
of the gcc testsuite, which probably doesn't prove much).
It should be OK for the map to be zeroes after a PCH read; all that  
will happen is some trees get rebuilt when this might be avoidable.
It should also be OK for it to contain tree's, since all such trees  
are referred to from GTY'd storage.