Module memory_utils

An analysis to compute symbols that escape out from a function. This could be into another function, or via ptr_to_int etc. Any transformations involving such symbols are unsafe.

Enums

• EscapedSymbols
• ReferredSymbols
  Provides Symbols, both Symbol::Locals and Symbol::Args, reachable from a certain Value via chain of InstOp::GetElemPtr (GEP) instructions or via InstOp::IntToPtr and InstOp::PtrToInt instruction patterns specific to references, both referencing (&) and dereferencing (*), and raw pointers, via __addr_of.
• Symbol

Constants

• ESCAPED_SYMBOLS_NAME

Functions

• combine_indices
  Combine a series of GEPs into one.
• compute_escaped_symbols
• compute_escaped_symbols_pass
• create_escaped_symbols_pass
• get_gep_referred_symbols
  Get Symbols, both Symbol::Locals and Symbol::Args, reachable from the val via chain of InstOp::GetElemPtr (GEP) instructions. A val can, via GEP instructions, refer indirectly to none, or one or more symbols.
• get_gep_symbol
• get_loaded_ptr_values
  Pointers that may possibly be loaded from the instruction inst.
• get_loaded_symbols
  Symbols that may possibly, directly or indirectly, be loaded from the instruction inst.
• get_memory_offsets
  Given a memory pointer instruction, compute the offset of indexed element, for each symbol that it may alias to. If for any symbol we can’t compute it, return None.
• get_referred_symbol
  Return Symbol referred by val if there is exactly one symbol referred, or None if there are no Symbols referred or if there is more then one referred.
• get_referred_symbols
  Get Symbols, both Symbol::Locals and Symbol::Args, reachable from the val via chain of InstOp::GetElemPtr (GEP) instructions or via InstOp::IntToPtr and InstOp::PtrToInt instruction patterns specific to references, both referencing (&) and dereferencing (*), and raw pointers, via __addr_of. A val can, via these instructions, refer indirectly to none, or one or more symbols.
• get_stored_ptr_values
  Pointers that may possibly be stored to the instruction inst.
• get_stored_symbols
  Symbols that may possibly, directly or indirectly, be stored to the instruction inst.
• may_alias
  Can memory ranges [val1, val1+len1] and [val2, val2+len2] overlap? Conservatively returns true if cannot statically determine.
• must_alias
  Are memory ranges [val1, val1+len1] and [val2, val2+len2] exactly the same? Conservatively returns false if cannot statically determine.
• pointee_size
  For a pointer argument ptr_val, what’s the size of its pointee.