Add a go-gen-dbscheme for generating dbschemes

Makefile

@@ -18,7 +18,7 @@ CODEQL_TOOLS = $(addprefix codeql-tools/,autobuild.cmd autobuild.sh index.cmd in
 
 EXTRACTOR_PACK_OUT = build/codeql-extractor-go
 
-BINARIES = go-extractor go-tokenizer go-autobuilder go-bootstrap
+BINARIES = go-extractor go-tokenizer go-autobuilder go-bootstrap go-gen-dbscheme
 
 .PHONY: tools tools-codeql tools-codeql-full clean \
 	tools-linux64 tools-osx64 tools-win64
@@ -81,8 +81,8 @@ tools/net/sourceforge/pmd/cpd/GoLanguage.class: extractor/net/sourceforge/pmd/cp
 	rm tools/net/sourceforge/pmd/cpd/TokenEntry.class
 	rm tools/net/sourceforge/pmd/cpd/Tokenizer.class
 
-ql/src/go.dbscheme: tools/$(CODEQL_PLATFORM)/go-extractor$(EXE)
-	env TRAP_FOLDER=/tmp $< --dbscheme $@
+ql/src/go.dbscheme: tools/$(CODEQL_PLATFORM)/go-gen-dbscheme$(EXE)
+	$< $@
 
 build/stats/src.stamp:
 	mkdir -p $(@D)/src

extractor/cli/go-extractor/go-extractor.go

@@ -8,8 +8,6 @@ import (
 	"runtime/pprof"
 	"strings"
 
-	"github.com/github/codeql-go/extractor/dbscheme"
-
 	"github.com/github/codeql-go/extractor"
 )
 
@@ -20,12 +18,10 @@ func usage() {
 	fmt.Fprintf(os.Stderr, "Usage:\n\n  %s [<flag>...] [<buildflag>...] [--] <file>...\n\n", os.Args[0])
 	fmt.Fprintf(os.Stderr, "Flags:\n\n")
 	fmt.Fprintf(os.Stderr, "--help                Print this help.\n")
-	fmt.Fprintf(os.Stderr, "--dbscheme string     Write dbscheme to this file.\n")
 }
 
-func parseFlags(args []string) ([]string, []string, string) {
+func parseFlags(args []string) ([]string, []string) {
 	i := 0
-	var dumpDbscheme string
 	buildFlags := []string{}
 	for i < len(args) && strings.HasPrefix(args[i], "-") {
 		if args[i] == "--" {
@@ -33,12 +29,7 @@ func parseFlags(args []string) ([]string, []string, string) {
 			break
 		}
 
-		if strings.HasPrefix(args[i], "--dbscheme=") {
-			dumpDbscheme = strings.TrimPrefix(args[i], "--dbscheme=")
-		} else if args[i] == "--dbscheme" {
-			i++
-			dumpDbscheme = args[i]
-		} else if args[i] == "--help" {
+		if args[i] == "--help" {
 			usage()
 			os.Exit(0)
 		} else {
@@ -51,21 +42,11 @@ func parseFlags(args []string) ([]string, []string, string) {
 	cpuprofile = os.Getenv("CODEQL_EXTRACTOR_GO_CPU_PROFILE")
 	memprofile = os.Getenv("CODEQL_EXTRACTOR_GO_MEM_PROFILE")
 
-	return buildFlags, args[i:], dumpDbscheme
+	return buildFlags, args[i:]
 }
 
 func main() {
-	buildFlags, patterns, dumpDbscheme := parseFlags(os.Args[1:])
-
-	if dumpDbscheme != "" {
-		f, err := os.Create(dumpDbscheme)
-		if err != nil {
-			log.Fatalf("Unable to open file %s for writing.", dumpDbscheme)
-		}
-		dbscheme.PrintDbScheme(f)
-		f.Close()
-		log.Printf("Dbscheme written to file %s.", dumpDbscheme)
-	}
+	buildFlags, patterns := parseFlags(os.Args[1:])
 
 	if cpuprofile != "" {
 		f, err := os.Create(cpuprofile)

extractor/cli/go-gen-dbscheme/go-gen-dbscheme.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/github/codeql-go/extractor/dbscheme"
+)
+
+func usage() {
+	fmt.Fprintf(os.Stderr, "%s is a program for generating the dbscheme for CodeQL Go databases.\n\n", os.Args[0])
+	fmt.Fprintf(os.Stderr, "Usage:\n\n  %s <output file>\n\n", os.Args[0])
+}
+
+func main() {
+	if len(os.Args) != 2 {
+		usage()
+		os.Exit(2)
+	}
+
+	out := os.Args[1]
+
+	f, err := os.Create(out)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Unable to open file %s for writing.", out)
+		os.Exit(1)
+	}
+	dbscheme.PrintDbScheme(f)
+	f.Close()
+	fmt.Printf("Dbscheme written to file %s.", out)
+}