[libfuzzer] in-vcs corpus support.

testing/libfuzzer/fuzzer_test.gni

Index: testing/libfuzzer/fuzzer_test.gni
diff --git a/testing/libfuzzer/fuzzer_test.gni b/testing/libfuzzer/fuzzer_test.gni
index 9fc5c6a5e5d0e09db1f75537cbfe056c96fb245b..5445b2e4764442aca62815cd714de15bffa2ec68 100644
--- a/testing/libfuzzer/fuzzer_test.gni
+++ b/testing/libfuzzer/fuzzer_test.gni
@@ -16,6 +16,7 @@ import("//testing/test.gni")
 # - additional_configs - additional configs to be used for compilation
 # - dict - a dictionary file for the fuzzer.
 # - libfuzzer_options - options for the fuzzer (e.g. -max_len or -timeout).
+# - corpus - a directory with seed corpus.

[mmoroz, 2016/03/07 14:08:55]

May be let's use |seed_corpus| option name and the same suffix for zip-archive
name (line 55)? Just to make more explicit that it is a "seed corpus" - some
testcases stored in repository, not all "corpus" we have and we use.

[aizatsky, 2016/03/07 21:42:54]

Done.

 #
 # If use_libfuzzer gn flag is defined, then proper fuzzer would be build.
 # Without use_libfuzzer a unit-test style binary would be built on linux
@@ -49,6 +50,30 @@ template("fuzzer_test") {
       test_deps += [ ":" + target_name + "_libfuzzer_options_copy" ]
     }
 
+    if (defined(invoker.corpus)) {
+      depfile = "$root_build_dir/$target_name" + ".corpus.d"
+      out = "$root_build_dir/$target_name" + "_corpus.zip"
+
+      action(target_name + "_corpus") {
+        script = "//testing/libfuzzer/archive_corpus.py"
+        args = [
+          "--depfile",
+          rebase_path(depfile),
+          "--corpus",
+          rebase_path(invoker.corpus),
+          "--output",
+          rebase_path(out),
+        ]
+
+        depfile = depfile
+        outputs = [
+          out,
+        ]
+      }
+
+      test_deps += [ ":" + target_name + "_corpus" ]
+    }
+
     if (defined(invoker.dict)) {
       # Copy dictionary to output.
       copy(target_name + "_dict_copy") {