Subject: -gcolumn-info and PR 14106
Date: Thursday 26th June 2014 16:46:12 UTC (over 3 years ago)
For -Rpass, and other related uses, I am looking at enabling column info by default. David pointed me at PR 14106, which seems to be the original motivation for introducing -gcolumn-info. However, I am finding no differences when using it on this test. I've tried building with/without -gcolumn-info and found almost no difference in compile time (+0.4%): $ /usr/bin/time clang -w -fno-builtin -O2 -g -gcolumn-info test-tgmath2.i 474.38user 2.10system 7:58.00elapsed 99%CPU $ /usr/bin/time clang -w -fno-builtin -O2 -g test-tgmath2.i 472.63user 2.02system 7:56.11elapsed 99%CPU I'm running clang from trunk @211693. The size of all debug sections (according to readelf) are: - with -g -gcolumn-info: 836,177 bytes - with -g: 826,552 bytes That's a growth of about 1% in debug info size. These numbers are in line with a comparative build I did of our internal codebase. The build included a massive number of C and C++ files. For C files, total file size grows by 1% on average. For C++ files the average growth is around 0.2%. Build times are unchanged as well. Does anyone remember any other edge case I may want to try? It seems to me that these differences are not really worth the effort of having a flag controlling column information. Thanks. Diego.