Go: improve output of check formatting in makefile

go/Makefile

@@ -32,7 +32,12 @@ autoformat:
 	find . -path '**/vendor' -prune -or -type f -iname '*.go' ! -empty -print0 | xargs -0 grep -L "//\s*autoformat-ignore" | xargs gofmt -w
 
 check-formatting:
-	test -z "$$(find . -path '**/vendor' -prune -or -type f -iname '*.go' ! -empty -print0 | xargs -0 grep -L "//\s*autoformat-ignore" | xargs gofmt -l)"
+	@output=$$(find . -path '**/vendor' -prune -or -type f -iname '*.go' ! -empty -print0 | xargs -0 grep -L "//\s*autoformat-ignore" | xargs gofmt -l 2>&1); \
+	if [ -n "$$output" ]; then \
+		echo "The following files need to be reformatted using gofmt or have compilation errors:"; \
+		echo "$$output"; \
+	fi; \
+	test -z "$$output"
 
 ifeq ($(QHELP_OUT_DIR),)
 # If not otherwise specified, compile qhelp to markdown in place

go/ql/src/experimental/CWE-203/timingBad.go

@@ -1,4 +1,11 @@
-func bad(w http.ResponseWriter, req *http.Request, []byte secret) (interface{}, error) {
+package main
+
+import (
+	"fmt"
+	"net/http"
+)
+
+func bad(w http.ResponseWriter, req *http.Request, secret []byte) (interface{}, error) {
 
 	secretHeader := "X-Secret"
 
@@ -8,4 +15,4 @@ func bad(w http.ResponseWriter, req *http.Request, []byte secret) (interface{},
 		return nil, fmt.Errorf("header %s=%s did not match expected secret", secretHeader, headerSecret)
 	}
 	return nil, nil
-}
+}

go/ql/src/experimental/CWE-203/timingGood.go

@@ -1,4 +1,12 @@
-func good(w http.ResponseWriter, req *http.Request, []byte secret) (interface{}, error) {
+package main
+
+import (
+	"crypto/subtle"
+	"fmt"
+	"net/http"
+)
+
+func good(w http.ResponseWriter, req *http.Request, secret []byte) (interface{}, error) {
 
 	secretHeader := "X-Secret"
 
@@ -7,4 +15,4 @@ func good(w http.ResponseWriter, req *http.Request, []byte secret) (interface{},
 		return nil, fmt.Errorf("header %s=%s did not match expected secret", secretHeader, headerSecret)
 	}
 	return nil, nil
-}
+}

go/ql/src/experimental/CWE-74/DsnBad.go

@@ -1,3 +1,10 @@
+package main
+
+import (
+	"database/sql"
+	"fmt"
+	"os"
+)
 
 func bad() interface{} {
 	name := os.Args[1:]

go/ql/src/experimental/CWE-74/DsnGood.go

@@ -1,3 +1,13 @@
+package main
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+	"os"
+	"regexp"
+)
+
 func good() (interface{}, error) {
 	name := os.Args[1]
 	hasBadChar, _ := regexp.MatchString(".*[?].*", name)