Sebastian Neubauer c33b9395b1 [BitcodeReader] Allow reading pointer types from old IR ... When opaque pointers are enabled and old IR with typed pointers is read, the BitcodeReader automatically upgrades all typed pointers to opaque pointers. This is a lossy conversion, i.e. when a function argument is a pointer and unused, it’s impossible to reconstruct the original type behind the pointer. There are cases where the type information of pointers is needed. One is reading DXIL, which is bitcode of old LLVM IR and makes a lot of use of pointers in function signatures. We’d like to keep using up-to-date llvm to read in and process DXIL, so in the face of opaque pointers, we need some way to access the type information of pointers from the read bitcode. This patch allows extracting type information by supplying functions to parseBitcodeFile that get called for each function signature or metadata value. The function can access the type information via the reader’s type IDs and the getTypeByID and getContainedTypeID functions. The tests exemplarily shows how type info from pointers can be stored in metadata for use after the BitcodeReader finished. Differential Revision: https://reviews.llvm.org/D127728		2023-01-18 13:20:15 +01:00
..
CMakeLists.txt
IRReader.cpp	[BitcodeReader] Allow reading pointer types from old IR	2023-01-18 13:20:15 +01:00