executor: make flatrpc build for C++

9 files changed, 48 insertions, 57 deletions

diff --git a/Makefile b/Makefile
index 0990b00ee..584336822 100644
--- a/Makefile
+++ b/Makefile
@@ -282,10 +282,11 @@ configs: kconf
 	bin/syz-kconf -config dashboard/config/linux/main.yml -sourcedir $(SOURCEDIR)
 
 tidy: descriptions
-	clang-tidy -quiet -header-filter=.* -warnings-as-errors=* \
+	clang-tidy -quiet -header-filter=executor/.* -warnings-as-errors=* \
 		-checks=-*,misc-definitions-in-headers,bugprone-macro-parentheses,clang-analyzer-*,-clang-analyzer-security.insecureAPI*,-clang-analyzer-optin.performance* \
 		-extra-arg=-DGOOS_$(TARGETOS)=1 -extra-arg=-DGOARCH_$(TARGETARCH)=1 \
 		-extra-arg=-DHOSTGOOS_$(HOSTOS)=1 -extra-arg=-DGIT_REVISION=\"$(REV)\" \
+		--extra-arg=-I. --extra-arg=-Ivendor \
 		executor/*.cc
 
 ifdef CI
diff --git a/executor/common_ext_test.go b/executor/common_ext_test.go
index 00bca4494..d92eff00c 100644
--- a/executor/common_ext_test.go
+++ b/executor/common_ext_test.go
@@ -5,7 +5,6 @@ package executor
 
 import (
 	"bytes"
-	"os"
 	"testing"
 	"time"
 
@@ -26,11 +25,7 @@ func TestCommonExt(t *testing.T) {
 	if sysTarget.BrokenCompiler != "" {
 		t.Skipf("skipping, broken cross-compiler: %v", sysTarget.BrokenCompiler)
 	}
-	bin, err := csource.BuildFile(target, "executor.cc", "-DSYZ_TEST_COMMON_EXT_EXAMPLE=1")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.Remove(bin)
+	bin := csource.BuildExecutor(t, target, "..", "-DSYZ_TEST_COMMON_EXT_EXAMPLE=1")
 	out, err := osutil.RunCmd(time.Minute, "", bin, "setup")
 	if err != nil {
 		t.Fatal(err)
diff --git a/executor/executor.cc b/executor/executor.cc
index f9ec7f1b5..6ac777ad6 100644
--- a/executor/executor.cc
+++ b/executor/executor.cc
@@ -3,6 +3,9 @@
 
 // +build
 
+// Currently this is unused (included only to test building).
+#include "pkg/flatrpc/flatrpc.h"
+
 #include <algorithm>
 #include <errno.h>
 #include <limits.h>
diff --git a/pkg/cover/report_test.go b/pkg/cover/report_test.go
index e93d43eda..07ae439ac 100644
--- a/pkg/cover/report_test.go
+++ b/pkg/cover/report_test.go
@@ -17,6 +17,7 @@ import (
 	"reflect"
 	"regexp"
 	"runtime"
+	"slices"
 	"strconv"
 	"strings"
 	"testing"
@@ -224,7 +225,10 @@ func buildTestBinary(t *testing.T, target *targets.Target, test *Test, dir strin
 		aslrExtraLibs = []string{"-ldl"}
 	}
 
-	kcovFlags := append([]string{"-c", "-fpie", "-w", "-x", "c", "-o", kcovObj, kcovSrc, aslrDefine}, target.CFlags...)
+	targetCFlags := slices.DeleteFunc(slices.Clone(target.CFlags), func(flag string) bool {
+		return strings.HasPrefix(flag, "-std=c++")
+	})
+	kcovFlags := append([]string{"-c", "-fpie", "-w", "-x", "c", "-o", kcovObj, kcovSrc, aslrDefine}, targetCFlags...)
 	src := filepath.Join(dir, "main.c")
 	obj := filepath.Join(dir, "main.o")
 	bin := filepath.Join(dir, target.KernelObject)
@@ -240,7 +244,7 @@ func buildTestBinary(t *testing.T, target *targets.Target, test *Test, dir strin
 	// -fsanitize-coverage=trace-pc is provided during linking and
 	// ubsan runtime is missing for arm/arm64/riscv arches in the llvm packages.
 	// So we first compile with -fsanitize-coverage and then link w/o it.
-	cflags := append(append([]string{"-w", "-c", "-o", obj, src}, target.CFlags...), test.CFlags...)
+	cflags := append(append([]string{"-w", "-c", "-o", obj, src}, targetCFlags...), test.CFlags...)
 	if test.DebugInfo {
 		// TODO: pkg/cover doesn't support DWARF5 yet, which is the default in Clang.
 		cflags = append([]string{"-g", "-gdwarf-4"}, cflags...)
@@ -257,7 +261,7 @@ func buildTestBinary(t *testing.T, target *targets.Target, test *Test, dir strin
 	}
 
 	ldflags := append(append(append([]string{"-o", bin, obj, kcovObj}, aslrExtraLibs...),
-		target.CFlags...), test.LDFlags...)
+		targetCFlags...), test.LDFlags...)
 	staticIdx, pieIdx := -1, -1
 	for i, arg := range ldflags {
 		switch arg {
diff --git a/pkg/csource/build.go b/pkg/csource/build.go
index 35d97d023..5dd1234a7 100644
--- a/pkg/csource/build.go
+++ b/pkg/csource/build.go
@@ -7,7 +7,11 @@ import (
 	"bytes"
 	"fmt"
 	"os"
+	"path/filepath"
 	"runtime"
+	"slices"
+	"strings"
+	"testing"
 
 	"github.com/google/syzkaller/pkg/osutil"
 	"github.com/google/syzkaller/prog"
@@ -16,7 +20,7 @@ import (
 
 // Build builds a C program from source src and returns name of the resulting binary.
 func Build(target *prog.Target, src []byte) (string, error) {
-	return build(target, src, "")
+	return build(target, src, "", "")
 }
 
 // BuildNoWarn is the same as Build, but ignores all compilation warnings.
@@ -24,15 +28,24 @@ func Build(target *prog.Target, src []byte) (string, error) {
 // using an old repro with newer compiler, or a compiler that we never seen before.
 // In these cases it's more important to build successfully.
 func BuildNoWarn(target *prog.Target, src []byte) (string, error) {
-	return build(target, src, "", "-fpermissive", "-w")
+	return build(target, src, "", "", "-fpermissive", "-w")
 }
 
-// BuildFile builds a C/C++ program from file src and returns name of the resulting binary.
-func BuildFile(target *prog.Target, src string, cflags ...string) (string, error) {
-	return build(target, nil, src, cflags...)
+// BuildExecutor builds the executor binary for tests.
+// rootDir must point to syzkaller root directory in slash notation.
+func BuildExecutor(t *testing.T, target *prog.Target, rootDir string, cflags ...string) string {
+	bin, err := build(target, nil, filepath.FromSlash(rootDir),
+		filepath.FromSlash("executor/executor.cc"), cflags...)
+	if err != nil {
+		t.Fatalf("failed to build executor: %v", err)
+	}
+	t.Cleanup(func() {
+		os.Remove(bin)
+	})
+	return bin
 }
 
-func build(target *prog.Target, src []byte, file string, cflags ...string) (string, error) {
+func build(target *prog.Target, src []byte, dir, file string, cflags ...string) (string, error) {
 	sysTarget := targets.Get(target.OS, target.Arch)
 	compiler := sysTarget.CCompiler
 	// We call the binary syz-executor because it sometimes shows in bug titles,
@@ -59,7 +72,14 @@ func build(target *prog.Target, src []byte, file string, cflags ...string) (stri
 		flags = append(flags, "-Wno-overflow")
 	}
 	flags = append(flags, cflags...)
+	if file == "" || strings.HasSuffix(file, ".c") {
+		// Building C source, so remove C++ flags.
+		flags = slices.DeleteFunc(flags, func(flag string) bool {
+			return strings.HasPrefix(flag, "-std=c++")
+		})
+	}
 	cmd := osutil.Command(compiler, flags...)
+	cmd.Dir = dir
 	if file == "" {
 		cmd.Stdin = bytes.NewReader(src)
 	}
diff --git a/pkg/fuzzer/fuzzer_test.go b/pkg/fuzzer/fuzzer_test.go
index 5e275851a..13eb5609b 100644
--- a/pkg/fuzzer/fuzzer_test.go
+++ b/pkg/fuzzer/fuzzer_test.go
@@ -9,8 +9,6 @@ import (
 	"fmt"
 	"hash/crc32"
 	"math/rand"
-	"os"
-	"path/filepath"
 	"regexp"
 	"runtime"
 	"strings"
@@ -41,7 +39,7 @@ func TestFuzz(t *testing.T) {
 	if sysTarget.BrokenCompiler != "" {
 		t.Skipf("skipping, broken cross-compiler: %v", sysTarget.BrokenCompiler)
 	}
-	executor := buildExecutor(t, target)
+	executor := csource.BuildExecutor(t, target, "../..", "-fsanitize-coverage=trace-pc", "-g")
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 
@@ -318,18 +316,6 @@ func (proc *executorProc) execute(req *Request) (*Result, string, error) {
 	return &Result{Info: info}, "", nil
 }
 
-func buildExecutor(t *testing.T, target *prog.Target) string {
-	executor, err := csource.BuildFile(target,
-		filepath.FromSlash("../../executor/executor.cc"),
-		"-fsanitize-coverage=trace-pc", "-g",
-	)
-	if err != nil {
-		t.Fatal(err)
-	}
-	t.Cleanup(func() { os.Remove(executor) })
-	return executor
-}
-
 func checkGoroutineLeaks() {
 	// Inspired by src/net/http/main_test.go.
 	buf := make([]byte, 2<<20)
diff --git a/pkg/ipc/ipc_test.go b/pkg/ipc/ipc_test.go
index fcc8b5dcd..a50fca9af 100644
--- a/pkg/ipc/ipc_test.go
+++ b/pkg/ipc/ipc_test.go
@@ -6,8 +6,6 @@ package ipc_test
 import (
 	"fmt"
 	"math/rand"
-	"os"
-	"path/filepath"
 	"runtime"
 	"testing"
 	"time"
@@ -23,15 +21,6 @@ import (
 	"github.com/google/syzkaller/sys/targets"
 )
 
-func buildExecutor(t *testing.T, target *prog.Target) string {
-	src := filepath.FromSlash("../../executor/executor.cc")
-	bin, err := csource.BuildFile(target, src)
-	if err != nil {
-		t.Fatal(err)
-	}
-	return bin
-}
-
 func initTest(t *testing.T) (*prog.Target, rand.Source, int, bool, bool, targets.Timeouts) {
 	t.Parallel()
 	iters := 100
@@ -65,8 +54,7 @@ func TestExecutor(t *testing.T) {
 			if err != nil {
 				t.Fatal(err)
 			}
-			bin := buildExecutor(t, target)
-			defer os.Remove(bin)
+			bin := csource.BuildExecutor(t, target, "../..")
 			// qemu-user may allow us to run some cross-arch binaries.
 			if _, err := osutil.RunCmd(time.Minute, "", bin, "test"); err != nil {
 				if sysTarget.Arch == runtime.GOARCH || sysTarget.VMArch == runtime.GOARCH {
@@ -89,8 +77,7 @@ func prepareTestProgram(target *prog.Target) *prog.Prog {
 func TestExecute(t *testing.T) {
 	target, _, _, useShmem, useForkServer, timeouts := initTest(t)
 
-	bin := buildExecutor(t, target)
-	defer os.Remove(bin)
+	bin := csource.BuildExecutor(t, target, "../..")
 
 	flags := []ExecFlags{0, FlagThreaded}
 	for _, flag := range flags {
@@ -134,8 +121,7 @@ func TestExecute(t *testing.T) {
 
 func TestParallel(t *testing.T) {
 	target, _, _, useShmem, useForkServer, timeouts := initTest(t)
-	bin := buildExecutor(t, target)
-	defer os.Remove(bin)
+	bin := csource.BuildExecutor(t, target, "../..")
 	cfg := &Config{
 		Executor:      bin,
 		UseShmem:      useShmem,
@@ -203,8 +189,7 @@ func TestZlib(t *testing.T) {
 		t.Fatal(err)
 	}
 	opts.EnvFlags |= FlagDebug
-	cfg.Executor = buildExecutor(t, target)
-	defer os.Remove(cfg.Executor)
+	cfg.Executor = csource.BuildExecutor(t, target, "../..")
 	env, err := MakeEnv(cfg, 0)
 	if err != nil {
 		t.Fatalf("failed to create env: %v", err)
diff --git a/pkg/runtest/run_test.go b/pkg/runtest/run_test.go
index 00bf343d7..6377876d6 100644
--- a/pkg/runtest/run_test.go
+++ b/pkg/runtest/run_test.go
@@ -54,13 +54,7 @@ func test(t *testing.T, sysTarget *targets.Target) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	executor, err := csource.BuildFile(target,
-		filepath.FromSlash("../../executor/executor.cc"),
-		"-fsanitize-coverage=trace-pc")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.Remove(executor)
+	executor := csource.BuildExecutor(t, target, "../../", "-fsanitize-coverage=trace-pc")
 	features, err := host.Check(target)
 	if err != nil {
 		t.Fatalf("failed to detect host features: %v", err)
diff --git a/sys/targets/targets.go b/sys/targets/targets.go
index 02a26028b..3635eb023 100644
--- a/sys/targets/targets.go
+++ b/sys/targets/targets.go
@@ -584,6 +584,9 @@ var oses = map[string]osCommon{
 
 var (
 	commonCFlags = []string{
+		"-std=c++11",
+		"-I.",
+		"-Ivendor",
 		"-O2",
 		"-pthread",
 		"-Wall",