[Lldb-commits] [lldb] [lldb] Add SBProcess methods for get/set/use address masks (PR #83095)

[Will Hawkins via lldb-commits]

================
@@ -407,6 +407,117 @@ class LLDB_API SBProcess {
   ///     the process isn't loaded from a core file.
   lldb::SBFileSpec GetCoreFile();
 
+  /// \{
+  /// \group Mask Address Methods
+  ///
+  /// \a type
+  /// All of the methods in this group take \a type argument
+  /// which is an AddressMaskType enum value.
+  /// There can be different address masks for code addresses and
+  /// data addresses, this argument can select which to get/set,
+  /// or to use when clearing non-addressable bits from an address.
+  /// On AArch32 code with arm+thumb code, where instructions start
+  /// on even addresses, the 0th bit may be used to indicate that
+  /// a function is thumb code.  On such a target, the eAddressMaskTypeCode
+  /// may clear the 0th bit from an address to get the actual address.
+  ///
+  /// \a addr_range
+  /// Many of the methods in this group take an \a addr_range argument
+  /// which is an AddressMaskRange enum value.
+  /// Needing to specify the address range is highly unusual, and the
+  /// default argument can be used in nearly all circumstances.
+  /// On some architectures like AArch64, it is possible to have
+  /// different page table setups for low and high memory, so different
+  /// numbers of bits relevant to addressing. It is possible to have
+  /// a program running in one half of memory and accessing the other
+  /// as heap, so we need to maintain two different sets of address masks
+  /// to debug this correctly.
+
+  /// Get the current address mask that will be applied to addresses
+  /// before reading from memory.
+  ///
+  /// \param[in] type
+  ///     See \ref Mask Address Methods descripton of this argument.
+  ///     eAddressMaskTypeAny is often a suitable value when code and
+  ///     data masks are the same on a given target.
+  ///
+  /// \param[in] addr_range
+  ///     See \ref Mask Address Methods descripton of this argument.
+  ///     This will default to eAddressMaskRangeLow which is the
+  ///     only set of masks used normally.
+  ///
+  /// \return
+  ///     The address mask currently in use.  Bits which are not used
+  ///     for addressing will be set to 1 in the mask.
+  lldb::addr_t GetAddressMask(
+      lldb::AddressMaskType type,
+      lldb::AddressMaskRange addr_range = lldb::eAddressMaskRangeLow);
+
+  /// Set the current address mask that can be applied to addresses
+  /// before reading from memory.
+  ///
+  /// \param[in] type
+  ///     See \ref Mask Address Methods descripton of this argument.
+  ///     eAddressMaskTypeAll is often a suitable value when the
+  ///     same mask is being set for both code and data.
+  ///
+  /// \param[in] mask
+  ///     The address mask to set.  Bits which are not used for addressing
+  ///     should be set to 1 in the mask.
+  ///
+  /// \param[in] addr_range
+  ///     See \ref Mask Address Methods descripton of this argument.
+  ///     This will default to eAddressMaskRangeLow which is the
+  ///     only set of masks used normally.
+  void SetAddressMask(
+      lldb::AddressMaskType type, lldb::addr_t mask,
+      lldb::AddressMaskRange addr_range = lldb::eAddressMaskRangeLow);
+
+  /// Set the number of bits used for addressing in this Process.
+  ///
+  /// In some environments, the number of bits that are used for addressing
+  /// is the natural representation instead of a mask, but lldb
+  /// internally represents this as a mask.  This method calculates
+  /// the addressing mask that lldb uses that number of addressable bits.
+  ///
+  /// \param[in] type
+  ///     See \ref Mask Address Methods descripton of this argument.
+  ///     eAddressMaskTypeAll is often a suitable value when the
+  ///     same mask is being set for both code and data.
+  ///
+  /// \param[in] num_bits
+  ///     Number of bits that are used for addressing.
+  ///     A value of 42 indicates that the low 42 bits are relevant for
----------------
hawkinsw wrote:

```suggestion
  ///     For example, a value of 42 indicates that the low 42 bits are relevant for
```

https://github.com/llvm/llvm-project/pull/83095