Support for compiling c++ source file.

Makefile

@@ -467,6 +467,7 @@ endif
 	@$(MD5SUM) test.hex
 ifneq ($(OS),Windows_NT)
 	$(TINYGO) build -o test.elf -gc=leaking -scheduler=none examples/serial
+	$(TINYGO) build -o test.elf                             examples/callcpp
 endif
 
 

builder/build.go

@@ -538,6 +538,21 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 			}
 			linkerDependencies = append(linkerDependencies, job)
 		}
+		for _, filename := range pkg.CXXFiles {
+			abspath := filepath.Join(pkg.Dir, filename)
+			flags := make([]string, len(pkg.CFlags)+len(pkg.CXXFlags))
+			copy(flags, pkg.CFlags)
+			copy(flags[len(pkg.CFlags):], pkg.CXXFlags)
+			job := &compileJob{
+				description: "compile CGo C++ file " + abspath,
+				run: func(job *compileJob) error {
+					result, err := compileAndCacheCFile(abspath, dir, flags, config.Options.PrintCommands)
+					job.result = result
+					return err
+				},
+			}
+			linkerDependencies = append(linkerDependencies, job)
+		}
 	}
 
 	// Linker flags from CGo lines:

compileopts/config.go

@@ -223,6 +223,14 @@ func (c *Config) CFlags() []string {
 	return cflags
 }
 
+func (c *Config) CXXFlags() []string {
+	var cxxflags []string
+	for _, flag := range c.Target.CXXFlags {
+		cxxflags = append(cxxflags, strings.ReplaceAll(flag, "{root}", goenv.Get("TINYGOROOT")))
+	}
+	return cxxflags
+}
+
 // LDFlags returns the flags to pass to the linker. A few more flags are needed
 // (like the one for the compiler runtime), but this represents the majority of
 // the flags.

compileopts/target.go

@@ -38,6 +38,7 @@ type TargetSpec struct {
 	AutoStackSize    *bool    `json:"automatic-stack-size"` // Determine stack size automatically at compile time.
 	DefaultStackSize uint64   `json:"default-stack-size"`   // Default stack size if the size couldn't be determined at compile time.
 	CFlags           []string `json:"cflags"`
+	CXXFlags         []string `json:"cxxflags"`
 	LDFlags          []string `json:"ldflags"`
 	LinkerScript     string   `json:"linkerscript"`
 	ExtraFiles       []string `json:"extra-files"`

loader/loader.go

@@ -51,6 +51,7 @@ type PackageJSON struct {
 	GoFiles  []string
 	CgoFiles []string
 	CFiles   []string
+	CXXFiles []string
 
 	// Dependency information
 	Imports   []string
@@ -72,6 +73,7 @@ type Package struct {
 	Files      []*ast.File
 	FileHashes map[string][]byte
 	CFlags     []string // CFlags used during CGo preprocessing (only set if CGo is used)
+	CXXFlags   []string
 	CGoHeaders []string // text above 'import "C"' lines
 	Pkg        *types.Package
 	info       types.Info
@@ -400,6 +402,7 @@ func (p *Package) parseFiles() ([]*ast.File, error) {
 		}
 		generated, headerCode, cflags, ldflags, accessedFiles, errs := cgo.Process(files, p.program.workingDir, p.program.fset, initialCFlags)
 		p.CFlags = append(initialCFlags, cflags...)
+		p.CXXFlags = append(p.CXXFlags, p.program.config.CXXFlags()...)
 		p.CGoHeaders = headerCode
 		for path, hash := range accessedFiles {
 			p.FileHashes[path] = hash

src/examples/callcpp/add.cpp

@@ -0,0 +1,9 @@
+template <typename T>
+T add(T a, T b) {
+    return a + b;
+}
+
+extern "C" int add(int a, int b) {
+    return add<int>(a, b);
+}
+

src/examples/callcpp/main.go

@@ -0,0 +1,12 @@
+package main
+
+/*
+int add(int a, int b);
+*/
+import "C"
+import "fmt"
+
+func main() {
+	a := C.add(C.int(1), C.int(2))
+	fmt.Println(a)
+}