commit 1eb210637539ce71794ff49fc462c35511b8a141 Author: Nick Mathewson nickm@torproject.org Date: Tue Aug 25 11:53:20 2015 -0400

Document callgraph analysis code --- doc/HACKING | 17 +++++++++++++++++ scripts/maint/generate_callgraph.sh | 3 ++- 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/doc/HACKING b/doc/HACKING index 7ee5cf8..e92d675 100644 --- a/doc/HACKING +++ b/doc/HACKING @@ -265,6 +265,23 @@ Here are some basic instructions * "opreport -l that_dir/*" - Profit

+Generating and analyzing a callgraph +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +1. Run ./scripts/maint/generate_callgraph.sh . This will generate a + bunch of files in a new ./callgraph directory. + +2. Run ./scripts/maint/analyze_callgraph.py callgraph/src/*/* . This + will do a lot of graph operations and then dump out a new + "callgraph.pkl" file, containing data in Python's "pickle" format. + +3. Run ./scripts/maint/display_callgraph.py . It will display: + - the number of functions reachable from each function. + - all strongly-connnected components in the Tor callgraph + - the largest bottlenecks in the largest SCC in the Tor callgraph. + +Note that currently the callgraph generator can't detect calls that pass +through function pointers.

Coding conventions ------------------ diff --git a/scripts/maint/generate_callgraph.sh b/scripts/maint/generate_callgraph.sh index 97330cc..c6b33c0 100755 --- a/scripts/maint/generate_callgraph.sh +++ b/scripts/maint/generate_callgraph.sh @@ -8,6 +8,7 @@ mkdir -p callgraph/src/or mkdir -p callgraph/src/tools

for fn in $C_FILES; do + echo $fn clang $CFLAGS -S -emit-llvm -fno-inline -o - $fn | \ - opt -analyze -print-callgraph 2> "callgraph/${fn}allgraph" + opt -analyze -print-callgraph >/dev/null 2> "callgraph/${fn}allgraph" done