Add support for generating CGO flags

Makefile

@@ -33,6 +33,7 @@ generate:
 		--message-module-prefix "github.com/tiiuae/rclgo/$$dest_path" \
 		--license-header-path ./license-header.txt \
 		--include-go-package-deps ./... \
+		--cgo-flags-path "" \
 		|| exit 1
 	rm "$$dest_path/msgs.gen.go" || exit 1
 	go run ./cmd/rclgo-gen generate-rclgo \

cmd/rclgo-gen/cmd/generate.go

@@ -76,6 +76,9 @@ var generateCmd = &cobra.Command{
 		if err := gen.GenerateROS2AllMessagesImporter(); err != nil {
 			return fmt.Errorf("failed to generate all importer: %w", err)
 		}
+		if err := gen.GenerateCGOFlags(); err != nil {
+			return fmt.Errorf("failed to generate CGO flags: %w", err)
+		}
 		return nil
 	},
 	Args: validateGenerateArgs,
@@ -125,6 +128,7 @@ func configureFlags(cmd *cobra.Command, destPathDefault string) {
 	cmd.PersistentFlags().StringArray("include-go-package-deps", nil, "Include only packages which are dependencies of listed Go packages. Can be passed multiple times. If multiple include options are passed, the union of the matches is generated.")
 	cmd.PersistentFlags().Bool("ignore-ros-distro-mismatch", false, "If true, ignores possible mismatches in sourced and supported ROS distro")
 	cmd.PersistentFlags().String("license-header-path", "", "Path to a file containing a license header to be added to generated files. By default no license is added.")
+	cmd.PersistentFlags().String("cgo-flags-path", "cgo-flags.env", `Path to file where CGO flags are written. If empty, no flags are written. If "-", flags are written to stdout.`)
 	bindPFlags(cmd)
 }
 
@@ -188,6 +192,7 @@ func getGogenConfig(cmd *cobra.Command) (*gogen.Config, error) {
 		MessageModulePrefix: modulePrefix,
 		RootPaths:           getRootPaths(cmd),
 		DestPath:            destPath,
+		CGOFlagsPath:        getString(cmd, "cgo-flags-path"),
 
 		RegexIncludes:  rules,
 		ROSPkgIncludes: viper.GetStringSlice(getPrefix(cmd) + "include-package-deps"),

examples/custom_message_package/greeter/go.mod

@@ -10,6 +10,7 @@ replace github.com/tiiuae/rclgo v0.0.0 => ../../..
 require github.com/tiiuae/rclgo v0.0.0
 
 require (
+	github.com/alessio/shellescape v1.4.2 // indirect
 	github.com/fsnotify/fsnotify v1.6.0 // indirect
 	github.com/hashicorp/hcl v1.0.0 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect

examples/custom_message_package/greeter/go.sum

@@ -38,6 +38,8 @@ cloud.google.com/go/storage v1.14.0/go.mod h1:GrKmX003DSIwi9o29oFT7YDnHYwZoctc3f
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
+github.com/alessio/shellescape v1.4.2 h1:MHPfaU+ddJ0/bYWpgIeUnQUqKrlJ1S7BfEYPM4uEoM0=
+github.com/alessio/shellescape v1.4.2/go.mod h1:PZAiSCk0LJaZkiCSkPv8qIobYglO3FPpyFjDCtHLS30=
 github.com/bradleyjkemp/cupaloy/v2 v2.8.0 h1:any4BmKE+jGIaMpnU8YgH/I2LPiLBufr6oMMlVBbn9M=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
 github.com/chzyer/logex v1.1.10/go.mod h1:+Ywpsq7O8HXn0nuIou7OrIPyXbp3wmkHB+jjWRnGsAI=

examples/custom_message_package/greeter/main.go

@@ -12,7 +12,7 @@ import (
 	"github.com/tiiuae/rclgo/pkg/rclgo"
 )
 
-//go:generate go run github.com/tiiuae/rclgo/cmd/rclgo-gen generate -d msgs --include-go-package-deps ./...
+//go:generate go run github.com/tiiuae/rclgo/cmd/rclgo-gen generate -d msgs --include-go-package-deps ./... --cgo-flags-path ""
 
 func run() error {
 	rclArgs, restArgs, err := rclgo.ParseArgs(os.Args[1:])

go.mod

@@ -3,6 +3,7 @@ module github.com/tiiuae/rclgo
 go 1.20
 
 require (
+	github.com/alessio/shellescape v1.4.2
 	github.com/bradleyjkemp/cupaloy/v2 v2.8.0
 	github.com/kivilahtio/go-re v0.1.8
 	github.com/mitchellh/go-homedir v1.1.0

go.sum

@@ -38,6 +38,8 @@ cloud.google.com/go/storage v1.14.0/go.mod h1:GrKmX003DSIwi9o29oFT7YDnHYwZoctc3f
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20190408044501-666a987793e9/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
+github.com/alessio/shellescape v1.4.2 h1:MHPfaU+ddJ0/bYWpgIeUnQUqKrlJ1S7BfEYPM4uEoM0=
+github.com/alessio/shellescape v1.4.2/go.mod h1:PZAiSCk0LJaZkiCSkPv8qIobYglO3FPpyFjDCtHLS30=
 github.com/bradleyjkemp/cupaloy/v2 v2.8.0 h1:any4BmKE+jGIaMpnU8YgH/I2LPiLBufr6oMMlVBbn9M=
 github.com/bradleyjkemp/cupaloy/v2 v2.8.0/go.mod h1:bm7JXdkRd4BHJk9HpwqAI8BoAY1lps46Enkdqw6aRX0=
 github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=

pkg/gogen/gogen.go

@@ -12,6 +12,7 @@ package gogen
 import (
 	"errors"
 	"fmt"
+	"io"
 	"io/fs"
 	"os"
 	"path"
@@ -21,6 +22,7 @@ import (
 	"strings"
 	"text/template"
 
+	"github.com/alessio/shellescape"
 	"github.com/kivilahtio/go-re/v0"
 )
 
@@ -52,6 +54,7 @@ type Config struct {
 	MessageModulePrefix string
 	RootPaths           []string
 	DestPath            string
+	CGOFlagsPath        string
 
 	RegexIncludes  RuleSet
 	ROSPkgIncludes []string
@@ -103,7 +106,7 @@ func (g *Generator) GenerateRclgoFlags() error {
 		"rclgo flags",
 		filepath.Join(g.config.DestPath, "pkg/rclgo/flags.gen.go"),
 		rclgoFlags,
-		nil,
+		templateData{"ROSIncludes": rclgoROSIncludes},
 	)
 }
 
@@ -142,6 +145,75 @@ func (g *Generator) GenerateROS2AllMessagesImporter() error {
 	)
 }
 
+var rclgoROSIncludes = []string{
+	"rcl",
+	"rmw",
+	"rosidl_runtime_c",
+	"rosidl_typesupport_interface",
+	"rcutils",
+	"rcl_action",
+	"action_msgs",
+	"unique_identifier_msgs",
+	"builtin_interfaces",
+	"rcl_yaml_param_parser",
+}
+
+func includeDirFlag(rootPath, rosPkg string) string {
+	return fmt.Sprintf("-I%s", filepath.Join(rootPath, "include", rosPkg))
+}
+
+func libDirFlag(rootPath string) string {
+	return fmt.Sprintf("-L%[1]s -Wl,-rpath=%[1]s", filepath.Join(rootPath, "lib"))
+}
+
+func prependFlagEnv(envVar string, flags []string) string {
+	return strings.Join(flags, " ") + " " + os.Getenv(envVar)
+}
+
+func writeFlagEnv(w io.Writer, envVar string, flags stringSet) error {
+	_, err := fmt.Fprintf(w, "export CGO_%s=%s\n", envVar, shellescape.Quote(prependFlagEnv(envVar, flags.ToSortedSlice())))
+	return err
+}
+
+func (g *Generator) GenerateCGOFlags() error {
+	if g.config.CGOFlagsPath == "" {
+		return nil
+	}
+	PrintErrln("Generating CGO flags:", g.config.CGOFlagsPath)
+	libDirs := stringSet{}
+	includes := stringSet{}
+	for _, rootPath := range g.config.RootPaths {
+		libDirs.Add(libDirFlag(rootPath))
+		for _, dep := range rclgoROSIncludes {
+			includes.Add(includeDirFlag(rootPath, dep))
+		}
+		for pkgAndType, imports := range g.cImportsByPkgAndType {
+			pkg, _, err := parsePkgAndType(pkgAndType)
+			if err != nil {
+				PrintErrf("Failed to parse package and type from %s: %v\n", pkgAndType, err)
+				continue
+			}
+			includes.Add(includeDirFlag(rootPath, pkg))
+			for imp := range imports {
+				includes.Add(includeDirFlag(rootPath, imp))
+			}
+		}
+	}
+	var err error
+	out := os.Stdout
+	if g.config.CGOFlagsPath != "-" {
+		out, err = mkdir_p(g.config.CGOFlagsPath)
+		if err != nil {
+			return err
+		}
+		defer out.Close()
+	}
+	if err := writeFlagEnv(out, "CFLAGS", includes); err != nil {
+		return err
+	}
+	return writeFlagEnv(out, "LDFLAGS", libDirs)
+}
+
 type rosPkgRef struct {
 	Interfaces map[Metadata]string
 	Generated  bool
@@ -443,12 +515,10 @@ func (g *Generator) generateServiceGoFiles(parser *parser, srv *ROS2Service) err
 }
 
 func (g *Generator) generateCommonPackageGoFile(pkgAndType string, cImports stringSet) error {
-	i := strings.LastIndex(pkgAndType, "_")
-	if i < 0 || i > len(pkgAndType)-1 {
-		return errors.New("package type suffix is missing or incorrect")
+	cPkg, pkgType, err := parsePkgAndType(pkgAndType)
+	if err != nil {
+		return err
 	}
-	cPkg := pkgAndType[:i]
-	pkgType := pkgAndType[i+1:]
 	return g.generateGoFile(
 		filepath.Join(g.config.DestPath, cPkg, pkgType, "common.gen.go"),
 		ros2PackageCommonTemplate,
@@ -459,3 +529,11 @@ func (g *Generator) generateCommonPackageGoFile(pkgAndType string, cImports stri
 		},
 	)
 }
+
+func parsePkgAndType(pkgAndType string) (pkg string, typ string, err error) {
+	i := strings.LastIndex(pkgAndType, "_")
+	if i < 0 || i > len(pkgAndType)-1 {
+		return "", "", errors.New("package type suffix is missing or incorrect")
+	}
+	return pkgAndType[:i], pkgAndType[i+1:], nil
+}

pkg/gogen/util.go

@@ -16,11 +16,13 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+	"sort"
 	"strings"
 	"unicode"
 	"unicode/utf8"
 
 	"github.com/kivilahtio/go-re/v0"
+	"golang.org/x/exp/maps"
 	"golang.org/x/exp/slices"
 	"golang.org/x/tools/go/packages"
 )
@@ -200,6 +202,14 @@ func (s stringSet) AddFrom(s2 stringSet) {
 	}
 }
 
+func (s stringSet) ToSlice() []string { return maps.Keys(s) }
+
+func (s stringSet) ToSortedSlice() []string {
+	vals := s.ToSlice()
+	sort.Strings(vals)
+	return vals
+}
+
 func actionHasSuffix(msg *ROS2Message, suffixes ...string) bool {
 	if msg.Type == "action" {
 		for _, suffix := range suffixes {