c_debugging.txt

Program flow tracing (with source modification)
===============================================
* assert()
  Instead of
    if (variable < 0)
        printf(...);
    else
        printf(...);
  use
    assert(variable > 0);

* __func__
  Formerly gcc-specific __FUNC__, nowadays part of the C standard.
  Trace program flow by adding
    printf("### %s\n", __func__);
  at the beginning of each relevant function.

  Vim: %s/^{/{\r\l\tprintf("### %s\\n", __func__);/g

* backtrace()
  http://man7.org/linux/man-pages/man3/backtrace.3.html
  http://stackoverflow.com/questions/77005/how-to-generate-a-stacktrace-when-my-gcc-c-app-crashes

  Linux kernel: dump_stack

* Determine exact source of function error return code
  int fce(void) {
    ...
    if (...)
        return -EINVAL;

    if (...)
        ...
    else
        return -EINVAL;

    if (...)
        return -EINVAL;
  }

  Reaplace each relevant return value with __LINE__
  Vim: %s/EINVAL/__LINE__/g


Program flow tracing (without source modification)
==================================================
* strace

* ltrace

* gdb


Source code tracing
===================
* Vim + ctags
  apt-get install vim exuberant-ctags
  find . | egrep -i "*\.c|*\.h" | ctags -L-
  vim main.c
    ^]
    ^t

* grep/egrep
  egrep -irn "tlb_write_indexed" .
  ./arch/mips/cpu/cpu.c:37:	tlb_write_indexed();
  ./arch/mips/include/asm/mipsregs.h:1304:static inline void tlb_write_indexed(void)

  vim ./arch/mips/cpu/cpu.c +37