forked from OSchip/llvm-project
f88a9497a2
This patches modifies PDT runtime type info generation so that it is easier to handle derived type descriptor in lowering. It changes three aspects: 1. The symbol name suffix of runtime type info for PDT instantiation is changed from a serial number unrelated to the types to an encoding of the instantiated KIND parameters. 2. New runtime type info is not created for each instantiation of PDT without KIND parameters (only length parameters). Instead, the runtime type info of the type definition is always used. It is updated to contain the component descriptions. 3. Runtime type info of PDT instantiation is now always generated in the scope where the type is defined. If several PDT type instantiation are made in different scope with the same kind parameters, they will use the same runtime type info. Rational of the change: In lowering, derived type descriptors are not mapped when instantiating derived type objects. They are mapped later when symbol knowledge is not available anymore. This mapping is based on the FIR representation of derived types. For PDT, the FIR type information does not allow deducing the instantiation scope, it only allows retrieving the type name, the type _definition_ scope, and the kind parameter values. Therefore, in order to be able to retrieve the derived type descriptor from a FIR type, the derived type descriptor must be generated in the definition scope and must reflect the kind parameters. This justifies the need for changes 1. and 3. above (suffix and scope change). Changes 2. comes from the fact that all runtime type info of type without kind parameters can be generated from the type definition, and that because of the suffix change, the symbol name for type definition and type instantiation are the same. Although this change is first motivated by how lowering handles derived types, I believe it is also an improvement from a functional point of view since this change will allow reducing the number of generated runtime type info for PDTs, since redundant information (different instantiations with same kind parameters) will only be generated once. Differential Revision: https://reviews.llvm.org/D120801 |
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| .. | ||
| Driver | ||
| Evaluate | ||
| Examples | ||
| Fir | ||
| Frontend | ||
| Lower | ||
| NonGtestUnit | ||
| Parser | ||
| Preprocessing | ||
| Runtime | ||
| Semantics | ||
| Unit | ||
| CMakeLists.txt | ||
| lit.cfg.py | ||
| lit.site.cfg.py.in | ||