Add tools/run_tests/run_lcov.sh

This is a tool for collecting coverage reports from our tests and
combining them with the open-source tool 'lcov'.

.gitignore

@@ -3,4 +3,5 @@ deps
 libs
 objs
 *.pyc
+*.gcno
 

Makefile

@@ -49,6 +49,15 @@ CPPFLAGS_msan = -O1 -fsanitize=memory -fno-omit-frame-pointer
 LDFLAGS_msan = -fsanitize=memory
 DEFINES_msan = NDEBUG
 
+VALID_CONFIG_gcov = 1
+CC_gcov = gcc
+CXX_gcov = g++
+LD_gcov = gcc
+LDXX_gcov = g++
+CPPFLAGS_gcov = -O0 -fprofile-arcs -ftest-coverage
+LDFLAGS_gcov = -fprofile-arcs -ftest-coverage
+DEFINES_gcov = NDEBUG
+
 # General settings.
 # You may want to change these depending on your system.
 

tools/run_tests/run_lcov.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+
+set -ex
+
+out=`realpath ${1:-coverage}`
+
+root=`realpath $(dirname $0)/../..`
+tmp=`mktemp`
+cd $root
+tools/run_tests/run_tests.py -c gcov
+lcov --capture --directory . --output-file $tmp
+genhtml $tmp --output-directory $out
+rm $tmp
+if which xdg-open > /dev/null
+then
+  xdg-open file://$out/index.html
+fi
+

tools/run_tests/run_tests.py

@@ -37,6 +37,7 @@ _CONFIGS = {
   'tsan': SimpleConfig('tsan'),
   'msan': SimpleConfig('msan'),
   'asan': SimpleConfig('asan'),
+  'gcov': SimpleConfig('gcov'),
   'valgrind': ValgrindConfig('dbg'),
   }