cctime

A simple tool for measuring compilation time.

This tool was originally created to measure compiler performance of clang.

single file example

Suppose you have a cpp file called foo.cpp which you compile with g++ using:

$ g++ -c foo.cpp

To take 5 samples and output the results to foo.csv use:

$ cctime.py -n 5 foo.csv g++ -c foo.cpp
$ cat foo.csv

If you want to compare gcc 4.6 to gcc 4.7 try:

$ cctime.py -n 5 --ref=g++-4.6 foo.csv g++-4.7 -c foo.cpp
$ cat foo.csv

cmake example

Here's an example that shows building llvm using cmake and capturing the time to compile each cpp file:

1. Create a new build directory

    $ mkdir timed_build
    $ cd timed_build
   

2. Run cmake with CXX set to cctime

    $ cmake \
    	-DCMAKE_CXX_COMPILER=path/to/cctime.py \
    	-DCMAKE_CXX_COMPILER_ARG1="-n=5 /path/to/output.csv /path/to/clang++" \
    	/path/to/llvm_src
    # clear the csv file which will now include results from cmake test compiles
    $ rm /path/to/output.csv
   

3. Run make to generate the results

    $ make
   

   or you can use VERBOSE=1 to see how cctime.py is invoked:

    $ make VERBOSE=1
   

4. Go have a beer because it's going to take a while to compile llvm 5 times.

    $ cat /path/to/output.csv
   

If you want to run again just make clean and clear the existing csv file:

	$ make clean
	$ rm /path/to/output.csv
	$ make