Migrating notes from Notion - Initial stage

content/notes/Notion/Debugging GDB.md

@@ -0,0 +1,70 @@
+---
+Status: Ready
+Created by: Trude EH
+tags:
+  - notes
+  - programming
+author: TrudeEH
+draft: false
+searchHidden: false
+showToc: true
+title: Debugging [GDB]
+---
+
+## GDB Debugging
+
+### Compile with Debug Information
+
+To allow `gdb` access to the source code (Provides debug symbols - Do not share publicly as it contains the source code).
+
+```Shell
+gcc -g <file>
+```
+
+### Look for / Fix Bugs
+
+First, initialize `gdb` with the executable to debug.
+
+```Shell
+gdb ./<executable> --tui
+```
+
+After `gdb` is ready, we can use the following commands:  
+
+|Command|Description|
+|---|---|
+|`lay next`|Switch to the next layout (Enables TUI mode if disabled - Allows for reading the code while debugging both in `C` and `ASM`).|
+|`ref`|Refresh (if a program prints to the terminal, it can break `gdb`'s interface).`|
+|`q`|Quit `gdb`.|
+|||
+|`b main`|Add a breakpoint at the main function.|
+|`b`|Place a breakpoint at the current line.|
+|`b <N>`|Place a breakpoint at line `N`.|
+|`b +<N>`|Place a breakpoint N lines down.|
+|`b <fn>`|Place a breakpoint at `fn` function.|
+|`d`|Delete all breakpoints.|
+|`d <N>`|Delete breakpoint number `N`.|
+|`clear <fn>`|Clear the breakpoint set to `fn` function.|
+|||
+|`n`|Execute up to the next line in `C`. If a function call is found, execute the function completely.|
+|`s`|Execute up to the next line in `C`. (Jump over)|
+|`s <N>`|Run `N` lines.|
+|`u`|Same as `n`, but if in a loop, execute until the loop exits.|
+|`nexti`|Execute up to the next instruction (line in `ASM`).|
+|`r`|Run the program until a breakpoint or error is reached.|
+|`c`|Continue running the program until a breakpoint or error is reached.|
+|||
+|`x/i $pc`|Examine the previous instruction (View memory).|
+|`info registers`|Read the CPU registers used by the program.|
+|`bt`|See the call stack up to the current line. (How we got here, so to speak)|
+|`print sizeof(<variable>)`|Check the size of a struct/variable/pointer.|
+|`p <var>`|Print variable `var` value.|
+|`info break`|List breakpoints.|
+
+## Check for Memory Leaks
+
+Use `valgrind` to check for lost memory.
+
+```Shell
+valgrind --leak-check=full ./<executable>
+```