Setup the build directory with gprof flags
   meson setup build -Dc_args="-pg" -Dc_link_args="-pg"

Compile the project
   meson compile -C build

Run the testcase to generate 'gmon.out'
   ./build/thunar/thunar

Analyze with gprof
   gprof ./build/thunar/thunar gmon.out > analysis.txt