[REBASE & FF] patina_debugger: Fix use of crate without "alloc" and fix associated issues#1331
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Javagedes merged 2 commits intoOpenDevicePartnership:mainfrom Feb 24, 2026
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Currently the alloc feature attempts to prevent use of the alloc features but does not actually remove the use of the alloc crate. This means that it is quite easy to accidentally use the alloc crate and break this use case. Additionally, it makes it too easy to accidentally add heap allocations where they shouldn't be, such as by using `format!` in a monitor command. This feature also helps increase awareness of when heap allocations are used which is important for the debugger which runs in limited environments. The commit removes use of the `alloc` crate when the `alloc` feature is not enabled, and removes all code leveraging it.
In all cases, the GDB stub is transitioned though a constant reference and pointer before being converted back to a mutable reference for use. This can cause unexpected behavior with the compilers interpretting the type as immutable. When the `alloc` feature is disabled, the debugger uses a static buffer for the GDB stub. This buffer current defines the buffer simple as a const array of `u8`. However, the GDB stub converts this to a mutable reference leading to undefined behavior, and active causes faults if the stub is placed in a read-only section by the linker. This commit stores the GDB buffer as a NonNull pointer in the mutable internal struct, and prevents use of any const pointer to the memory. When the `alloc` feature is disabled, the static buffer the static buffer is now wrapped in an UnsafeCell to allow for interior mutability ensuring the compiler knows the memory should be treated as mutable.
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Description
Currently the alloc feature attempts to prevent use of the alloc features but does not actually remove the use of the alloc crate. This means that it is quite easy to accidentally use the alloc crate and break this use case.
Additionally, it makes it too easy to accidentally add heap allocations where they shouldn't be, such as by using
format!in a monitor command. This feature also helps increase awareness of when heap allocations are used which is important for the debugger which runs in limited environments.The commit removes use of the
alloccrate when theallocfeature is not enabled, and removes all code leveraging it.Issue #1318
How This Was Tested
Tested on local build and Q35
Integration Instructions
N/A