Can I see the instrumented code?
You cannot see the instrumented data like gcda files .
How Gcov works ?
GCOV works in four phases:
1. Code instrumentation during compilation
2. Data collection during code execution
3. Data extraction at program exit time
4. Coverage analysis and presentation post-mortem.
to know more about individual steps u can go through this pdf.
http://ltp.sourceforge.net/documentation/technical_papers/gcov-ols2003.pdf