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It can possible improve performance

For variables of type char (1-byte int) show corresponding character, if it is printable

Add support for unions just like for structs

Try different journal modes, maybe even OFF (which required disabling all ROLLBACKs). However if something failed, content of DB doesn't matter as it is not usefule anyway

Currently only memory vars supported, add register vars

Consider using _mm_prefetch() for preloading cached and actual page data into CPU cache before comparison

Build process must run automated tests

Evaluate expression received and return result to debugger front

Create engine for executing test scripts. Script consists of test cases, each case has some JSONs to send, and can check resulted JSONs, for exact and approximate match (using regex).
If all responses match, case it passed. If all cases in script passed, the script is passed.

mapped_mem() accounts for about 12%, it just looks for memory in the linked list of regions. Consider changing region storage to either balanced tree (regions added not too often so balancing overhead is negligible) or to array (to improve caching).
Probably sorted array will be the fastest - it has logarithmic complexity and good cache locality

Pointer vars with NULL value don't displayed in VSCode correctly because are missing variable reference field

Support enum type as signed integer (because C standard doesn't specify signedness of enum)

In case of abnormal termination of the child program record signal number and the last step

According to https://microsoft.github.io/debug-adapter-protocol/implementors/tools/ Eclipse Theia IDE supports DAP protocol so VS Code debugger extension should work with Theia as well.
Test it

currently DB workers write to in-memory database which leads high memory requirements. Consider switching to using file system for temporary DBs, will prgrmas to speed things up (without journal, without sync etc.)

Especially largest regions.
As an option - create a worker thread for every region (to avoid overhead of thread creation/joining) and just trigger checks

During program execution memory addresses written in DWARF info all may be shifted to 'base address', therefore real addresses of "debug_line" entries, functions and global/static vars need to be shifted.
Calculate the offset in Recorder and store it run DB for use by Examiner.

https://microsoft.github.io/debug-adapter-protocol/specification#Requests_GotoTargets
https://microsoft.github.io/debug-adapter-protocol/specification#Requests_Goto

Script to test:

• running/continuing forward
• running/continuing backward
• step in forward
• step out forward
• step over forward
• step over backward (no other backward steps available by protocol)
• frames (stack trace)

Evaluate expression, find dependencies from variables, find the steps where variable(s) from expression change value and re-evaluate expression for these steps, until condition is true.
Pay attention that that variable(s) may change its location in memory

Add test script for viewng different kind of expressions:

• struct members
• array elements
• result of logical or math operation

mem_process_region() accounts for almost 29%, look for ways to improve it.
Make sure AVX instruction is used for memory comparison (it is not clear from profiler output).

Support Disconnect DAP request

On reverse continue debugger should stop on last hit of prev breakpoint, but it stops on first, like with regular continue

Create lex/yacc definition for parsing expressions into AST

Add script for

• setting breakpoints
• removing breakpoints
• stopping at breakpoint when running forward
• stopping at breakpoint when running backward

For pointers that alias other variables (were no allocated using malloc) find the name of the variable the pointer points to, and display in Watch.
Pointer can also point to something inside the variable, like specific struct field or array item.

Test custom (typdef'ed) types:

• aliases for standard types
• alias for pointer type
• alias for struct type
• alias for array type
• alias for function pointer type

Add support for Data breakpoints

https://microsoft.github.io/debug-adapter-protocol/specification#Requests_StepInTargets
and targetId in stepIn request

Allow to attach to running program by PID

Allow limiting recording from specific point in program (specified as source:line) and/or to specific point in program, to limit the scope of recorded

Add support for shared libs, loaded during client execution, see https://github.com/TartanLlama/dltrace

In build config add creation of artifacts

Test script to test

• list of scopes
• globals
• locals
• signed vars (different sizes)
• unsigned vars (different sizes)
• float vars (different sizes)
• pointer variables (dynamic memory - size, content, before/after allocation, NULL, invalid)
• pointer variables (pointing to other variable)
• strings
• structures
• arrays
• function pointers