ihonen / c-cpp-call-trace-example

Example: Tracing and logging C/C++ function calls (Linux + GCC only)

C/C++ function call trace example

This example demonstrates how to trace and log C/C++ function calls without writing extra code in the traced functions themselves. This also provides us a means of tracing the total number of function calls as well as the lengths of function call chains.

Feel free to use the provided code as you please.

Notes

• All functions compiled as part of the program are traced – even static and inline functions
• Static and inline function names can't be resolved via the method used in this example
• Calls to dynamic library functions are not traced
• C++ symbols are demangled if trace.c is compiled as C++

Future improvements

Look into the following:

• Resolve static and inline function names
• Display source file names and line numbers

The addr2line utility could be useful for this if the source code is available in the runtime environment. It is very slow, though.

Compile and run (Linux + GCC only)

Commands:

make example
./example.out

Possible output:

<TRACE> ---> main [0x564e4b8f4270] 0

---------------------------------------------------------------
C LINKAGE
---------------------------------------------------------------

*** Static functions ***

<TRACE>  ---> ??? +0x2850 [0x564e4b8f4850] 1
<TRACE>   ---> ??? +0x2820 [0x564e4b8f4820] 2
<TRACE>   <--- ??? +0x2820 [0x564e4b8f4820] 2
<TRACE>  <--- ??? +0x2850 [0x564e4b8f4850] 1

*** Inline functions ***

<TRACE>  ---> ??? +0x27a0 [0x564e4b8f47a0] 1
<TRACE>   ---> ??? +0x27f0 [0x564e4b8f47f0] 2
<TRACE>   <--- ??? +0x27f0 [0x564e4b8f47f0] 2
<TRACE>  <--- ??? +0x27a0 [0x564e4b8f47a0] 1

*** Extern functions ***

<TRACE>  ---> extern_foo [0x564e4b8f4dd0] 1
<TRACE>   ---> extern_bar [0x564e4b8f4da0] 2
<TRACE>   <--- extern_bar [0x564e4b8f4da0] 2
<TRACE>  <--- extern_foo [0x564e4b8f4dd0] 1

---------------------------------------------------------------
C++ LINKAGE
---------------------------------------------------------------

*** Throwing functions ***

<TRACE>  ---> mynamespace::throwing_foo() [0x564e4b8f4f40] 1
<TRACE>   ---> std::exception::exception() [0x564e4b8f4fc0] 2
<TRACE>   <--- std::exception::exception() [0x564e4b8f4fc0] 2
<TRACE>  <--- mynamespace::throwing_foo() [0x564e4b8f4f40] 1

*** Template functions ***

<TRACE>  ---> void mynamespace::template_foo<int>() [0x564e4b8f4890] 1
<TRACE>  <--- void mynamespace::template_foo<int>() [0x564e4b8f4890] 1

*** Constructors ***

<TRACE>  ---> mynamespace::Derived::Derived() [0x564e4b8f4900] 1
<TRACE>   ---> mynamespace::Base::Base() [0x564e4b8f48c0] 2
<TRACE>   <--- mynamespace::Base::Base() [0x564e4b8f48c0] 2
<TRACE>  <--- mynamespace::Derived::Derived() [0x564e4b8f4900] 1

*** Static member functions ***

<TRACE>  ---> mynamespace::Derived::static_foo() [0x564e4b8f4e80] 1
<TRACE>  <--- mynamespace::Derived::static_foo() [0x564e4b8f4e80] 1

*** Member functions ***

<TRACE>  ---> mynamespace::Derived::nonvirtual_foo() [0x564e4b8f4eb0] 1
<TRACE>  <--- mynamespace::Derived::nonvirtual_foo() [0x564e4b8f4eb0] 1

*** Virtual member functions ***

<TRACE>  ---> mynamespace::Base::virtual_foo() [0x564e4b8f4e50] 1
<TRACE>  <--- mynamespace::Base::virtual_foo() [0x564e4b8f4e50] 1

*** Destructors ***

<TRACE>  ---> mynamespace::Derived::~Derived() [0x564e4b8f4ee0] 1
<TRACE>   ---> mynamespace::Base::~Base() [0x564e4b8f4e20] 2
<TRACE>   <--- mynamespace::Base::~Base() [0x564e4b8f4e20] 2
<TRACE>  <--- mynamespace::Derived::~Derived() [0x564e4b8f4ee0] 1

---------------------------------------------------------------

<TRACE> <--- main [0x564e4b8f4270] 0