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path: root/llvm/lib/ExecutionEngine/JITLink/JITLinkMemoryManager.cpp
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* [JITLink] Switch to slab allocation for InProcessMemoryManager, re-enable test.Lang Hames2019-10-151-10/+40
| | | | | | | | | | | | | | InProcessMemoryManager used to make separate memory allocation calls for each permission level (RW, RX, RO), which could lead to target-out-of-range errors if data and code were placed too far apart (this was the source of failures in the JITLink/AArch64 testcase when it was first landed). This patch updates InProcessMemoryManager to allocate a single slab which is subdivided between text and data. This should guarantee that accesses remain in-range provided that individual object files do not exceed 1Mb in size. This patch also re-enables the JITLink/AArch64 testcase. llvm-svn: 374948
* [JITLink] Switch from an atom-based model to a "blocks and symbols" model.Lang Hames2019-10-041-10/+7
| | | | | | | | | | | | | | | | | | | | | | | | In the Atom model the symbols, content and relocations of a relocatable object file are represented as a graph of atoms, where each Atom represents a contiguous block of content with a single name (or no name at all if the content is anonymous), and where edges between Atoms represent relocations. If more than one symbol is associated with a contiguous block of content then the content is broken into multiple atoms and layout constraints (represented by edges) are introduced to ensure that the content remains effectively contiguous. These layout constraints must be kept in mind when examining the content associated with a symbol (it may be spread over multiple atoms) or when applying certain relocation types (e.g. MachO subtractors). This patch replaces the Atom model in JITLink with a blocks-and-symbols model. The blocks-and-symbols model represents relocatable object files as bipartite graphs, with one set of nodes representing contiguous content (Blocks) and another representing named or anonymous locations (Symbols) within a Block. Relocations are represented as edges from Blocks to Symbols. This scheme removes layout constraints (simplifying handling of MachO alt-entry symbols, and hopefully ELF sections at some point in the future) and simplifies some relocation logic. llvm-svn: 373689
* [JITLink] Move JITLinkMemoryManager into its own header.Lang Hames2019-06-141-0/+105
llvm-svn: 363444
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