infra: have timeout per fuzz target for coverage (#7831)

* infra: have timeout per fuzz target for coverage

As is done for other languages

* ngolo-fuzzing: remove temporary workaround

now that https://github.com/golang/go/issues/53190 is closed

* ngolo-fuzzing: use built go toolchain in its directory

without copying it to /root/.go/

in order to get coverage for std lib in the end

* infra: ability to get coverage for additional golang package

And uses it with ngolo-fuzzing :
ngolo-fuzzing fuzz targets live in a different repository than
the code being fuzzed, and we we want to get the coverage, for
both the fuzz target and the package being fuzzed

* fixup bash unbound

* fixup ngolo-fuzzing only match at beginning for std package

* stricter check for every additional go package

3 files changed, 21 insertions, 13 deletions

diff --git a/infra/base-images/base-builder/compile_go_fuzzer b/infra/base-images/base-builder/compile_go_fuzzer
index dd8c9f6a..df7d3e24 100755
--- a/infra/base-images/base-builder/compile_go_fuzzer
+++ b/infra/base-images/base-builder/compile_go_fuzzer
@@ -48,7 +48,16 @@ if [[ $SANITIZER = *coverage* ]]; then
   abspath_repo=`go list -m $tags -f {{.Dir}} $fuzzed_repo || go list $tags -f {{.Dir}} $fuzzed_repo`
   # give equivalence to absolute paths in another file, as go test -cover uses golangish pkg.Dir
   echo "s=$fuzzed_repo"="$abspath_repo"= > $OUT/$fuzzer.gocovpath
-  go test -run Test${function}Corpus -v $tags -coverpkg $fuzzed_repo/... -c -o $OUT/$fuzzer $path
+  # Additional packages for which to get coverage.
+  pkgaddcov=""
+  # to prevent bash from failing about unbound variable
+  GO_COV_ADD_PKG_SET=${GO_COV_ADD_PKG:-}
+  if [[ -n "${GO_COV_ADD_PKG_SET}" ]]; then
+    pkgaddcov=","$GO_COV_ADD_PKG
+    abspath_repo=`go list -m $tags -f {{.Dir}} $GO_COV_ADD_PKG || go list $tags -f {{.Dir}} $GO_COV_ADD_PKG`
+    echo "s=^$GO_COV_ADD_PKG"="$abspath_repo"= >> $OUT/$fuzzer.gocovpath
+  fi
+  go test -run Test${function}Corpus -v $tags -coverpkg $fuzzed_repo/...$pkgaddcov -c -o $OUT/$fuzzer $path
 else
   # Compile and instrument all Go files relevant to this fuzz target.
   echo "Running go-fuzz $tags -func $function -o $fuzzer.a $path"
diff --git a/infra/base-images/base-runner/coverage b/infra/base-images/base-runner/coverage
index 6b662dbf..fa2292ca 100755
--- a/infra/base-images/base-runner/coverage
+++ b/infra/base-images/base-runner/coverage
@@ -138,9 +138,13 @@ function run_go_fuzz_target {
   echo "Running go target $target"
   export FUZZ_CORPUS_DIR="$CORPUS_DIR/${target}/"
   export FUZZ_PROFILE_NAME="$DUMPS_DIR/$target.perf"
-  
-  $OUT/$target -test.coverprofile $DUMPS_DIR/$target.profdata &> $LOGS_DIR/$target.log
-  
+
+  timeout $TIMEOUT $OUT/$target -test.coverprofile $DUMPS_DIR/$target.profdata &> $LOGS_DIR/$target.log
+  if (( $? != 0 )); then
+    echo "Error occured while running $target:"
+    cat $LOGS_DIR/$target.log
+  fi
+
   # The Go 1.18 fuzzers are renamed to "*_fuzz_.go" during "infra/helper.py build_fuzzers".
   # They are are therefore refered to as "*_fuzz_.go" in the profdata files.
   # Since the copies named "*_fuzz_.go" do not exist in the file tree during
diff --git a/projects/ngolo-fuzzing/build.sh b/projects/ngolo-fuzzing/build.sh
index e2abec43..7c06d1f0 100755
--- a/projects/ngolo-fuzzing/build.sh
+++ b/projects/ngolo-fuzzing/build.sh
@@ -18,15 +18,10 @@
 # compile latest go from git
 (
 cd $SRC/goroot/src
-(
-# temporary workaround for https://github.com/golang/go/issues/53190
-cd runtime
-grep nosplit libfuzzer.go || sed -i 's/func libfuzzerTraceConstCmp/\n\/\/go:nosplit\nfunc libfuzzerTraceConstCmp/' libfuzzer.go
-)
 ./make.bash
 )
 rm -Rf /root/.go/
-mv $SRC/goroot /root/.go
+export PATH=$PATH:$SRC/goroot/bin/
 
 compile_package () {
     pkg=$1
@@ -53,7 +48,7 @@ compile_package () {
             continue
         fi
         cd fuzz_ng_$pkg_flat
-        compile_go_fuzzer . FuzzNG_unsure fuzz_ngo_$pkg_flat
+        GO_COV_ADD_PKG="$pkg" compile_go_fuzzer . FuzzNG_unsure fuzz_ngo_$pkg_flat
         )
     else
         (
@@ -75,8 +70,8 @@ go build
 )
 
 # maybe we should git clone --depth 1 https://github.com/golang/go.git
-find /root/.go/src/ -type d | cut -d/ -f5- | while read pkg; do
-    if [[ `ls /root/.go/src/$pkg/*.go | wc -l` == '0' ]]; then
+find $SRC/goroot/src/ -type d | cut -d/ -f5- | while read pkg; do
+    if [[ `ls $SRC/goroot/src/$pkg/*.go | wc -l` == '0' ]]; then
         continue
     fi
     if [[ `echo $pkg | grep internal | wc -l` == '1' ]]; then