That’s kind of right, but incomplete. -g requests that the compiler and linker generate and retain source-level debugging/symbol information in the executable itself. If… the program happens to later crash and produce a core file (which suggests some problem in the actual code), or a deliberate OS command forced it to core (e.g. kill -SIGQUIT pid), or the program … Read more
You need the /t switch which works with both p and x: See help x for more info on the FMT (format) switches.
In addition to Michael’s explanation of breakpoints, that are probably the best way to solve your problem, there are actually also are “until” and “advance” commands, that do just what you require/suggest. Basically you can do “until 60” or “until main.c:60” or “advance 60” or similar, depending if you want to limit temporary breakpoint to … Read more
info frame to show the stack frame info To read the memory at given addresses you should take a look at x x/x $esp for hex x/d $esp for signed x/u $esp for unsigned etc. x uses the format syntax, you could also take a look at the current instruction via x/i $eip etc.
You can use the finish command. finish: Continue running until just after function in the selected stack frame returns. Print the returned value (if any). This command can be abbreviated as fin. (See 5.2 Continuing and Stepping.)
If you’re on Sierra , that’s expected. GDB isn’t compatible with macOS Sierra , even the last release (7.12). We should maybe wait for another release of GDB , or for another update for macOS in order to get the bug fixed.
You just need a binary (with debugging symbols included) that is identical to the one that generated the core dump file. Then you can run gdb path/to/the/binary path/to/the/core/dump/file to debug it. When it starts up, you can use bt (for backtrace) to get a stack trace from the time of the crash. In the backtrace, each function invocation is … Read more
stepi is more detailed than nexti. if you call sum() from main() function then doing stepi reaches you inside the sum() function, but nexti doesn’t. Below is the screenshot when you call stepi when you were at call of sum() instruction (i.e., => 0x08048403 <+40>: call 0x8048419 <sum>). The stepi instuction routes you inside the … Read more
I am trying to debug a simple “hello world” C++ program on Ubuntu 16.04 but gdb is not able to recognize the executable file format. However, I am able to successfully run the executable on the command line. Here is the code I compile the program file TestProject.cpp using the command Then to debug, I … Read more
In Snow Leopard and later Mac OS versions, it isn’t enough to codesign the gdb executable. You have to follow this guide to make it work: http://www.opensource.apple.com/source/lldb/lldb-69/docs/code-signing.txt The guide explains how to do it for lldb, but the process is exactly the same for gdb.