Coverage support.

- open source CoverageCommand.java
- add a collect-coverage.sh script
- update test-setup.sh to be compatible with the coverage collector
- update StandaloneTestStrategy to provide the necessary env variables
- update StandaloneTestStrategy to set the right command line for coverage
- add support for C++ coverage

An HTML report can then be generated with genhtml like this:
genhtml -o report/ -p "$(readlink -f bazel-<project>)" path/to/coverage.dat

Progress on #1118.

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MOS_MIGRATED_REVID=140125715

1 files changed, 15 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/runtime/commands/coverage.txt b/src/main/java/com/google/devtools/build/lib/runtime/commands/coverage.txt
new file mode 100644
index 0000000000..2ebc501d8f
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/runtime/commands/coverage.txt
@@ -0,0 +1,15 @@
+
+Usage: blaze %{command} <options> <test-targets>
+
+Builds and runs the specified test targets using the specified options while
+collecting code coverage statistics. Optionally, it also generates combined
+HTML report containing coverage results for all executed tests.
+
+This command accepts all valid options to 'test' and 'build', and inherits
+defaults for 'test' (and 'build') from your .blazerc.  If you don't use
+.blazerc, don't forget to pass all your 'build' options to '%{command}' too.
+
+See 'blaze help target-syntax' for details and examples on how to
+specify targets.
+
+%{options}