Fix #139: don't fail govet on cgo

Author: jirfag

Diff for: pkg/lint/load.go

@@ -3,15 +3,18 @@ package lint
 import (
 	"context"
 	"fmt"
+	"go/ast"
 	"go/build"
 	"go/parser"
+	"go/token"
 	"os"
 	"path/filepath"
 	"strings"
 	"time"
 
 	"github.com/golangci/golangci-lint/pkg/goutils"
 	"github.com/golangci/golangci-lint/pkg/logutils"
+	"github.com/golangci/golangci-lint/pkg/result/processors"
 
 	"github.com/golangci/go-tools/ssa"
 	"github.com/golangci/go-tools/ssa/ssautil"
@@ -258,6 +261,30 @@ func separateNotCompilingPackages(lintCtx *linter.Context) {
 	}
 }
 
+func removeFakePkgFiles(info *loader.PackageInfo, fset *token.FileSet) {
+	newFiles := make([]*ast.File, 0, len(info.Files))
+	for _, f := range info.Files {
+		if !processors.IsCgoFilename(fset.Position(f.Pos()).Filename) {
+			newFiles = append(newFiles, f)
+		}
+	}
+	info.Files = newFiles
+}
+
+func removeFakePackages(prog *loader.Program) {
+	if prog.Created != nil {
+		for _, info := range prog.Created {
+			removeFakePkgFiles(info, prog.Fset)
+		}
+	}
+
+	if prog.Imported != nil {
+		for _, info := range prog.Imported {
+			removeFakePkgFiles(info, prog.Fset)
+		}
+	}
+}
+
 //nolint:gocyclo
 func LoadContext(ctx context.Context, linters []linter.Config, cfg *config.Config,
 	log logutils.Log) (*linter.Context, error) {
@@ -298,6 +325,10 @@ func LoadContext(ctx context.Context, linters []linter.Config, cfg *config.Confi
 		ssaProg = buildSSAProgram(ctx, prog, log)
 	}
 
+	if prog != nil {
+		removeFakePackages(prog)
+	}
+
 	astLog := log.Child("astcache")
 	var astCache *astcache.Cache
 	if prog != nil {

Diff for: pkg/result/processors/utils.go

@@ -2,7 +2,7 @@ package processors
 
 import (
 	"fmt"
-	"strings"
+	"path/filepath"
 
 	"github.com/golangci/golangci-lint/pkg/result"
 )
@@ -47,5 +47,5 @@ func transformIssues(issues []result.Issue, transform func(i *result.Issue) *res
 }
 
 func IsCgoFilename(f string) bool {
-	return f == "C" || strings.HasSuffix(f, "/C")
+	return filepath.Base(f) == "C"
 }

Diff for: test/run_test.go

@@ -131,6 +131,22 @@ func TestTestsAreLintedByDefault(t *testing.T) {
 	assert.Equal(t, exitcodes.Success, exitCode, out)
 }
 
+func TestCgoOk(t *testing.T) {
+	out, exitCode := runGolangciLint(t, "--enable-all", filepath.Join(testdataDir, "cgo"))
+	checkNoIssuesRun(t, out, exitCode)
+}
+
+func TestUnsafeOk(t *testing.T) {
+	out, exitCode := runGolangciLint(t, "--enable-all", filepath.Join(testdataDir, "unsafe"))
+	checkNoIssuesRun(t, out, exitCode)
+}
+
+func TestDeadcodeNoFalsePositivesInMainPkg(t *testing.T) {
+	out, exitCode := runGolangciLint(t, "--no-config", "--disable-all", "-Edeadcode",
+		filepath.Join(testdataDir, "deadcode_main_pkg"))
+	checkNoIssuesRun(t, out, exitCode)
+}
+
 func TestConfigFileIsDetected(t *testing.T) {
 	checkGotConfig := func(out string, exitCode int) {
 		assert.Equal(t, exitcodes.Success, exitCode, out)

Diff for: test/testdata/cgo/main.go

@@ -0,0 +1,19 @@
+package cgoexample
+
+/*
+#include <stdio.h>
+#include <stdlib.h>
+
+void myprint(char* s) {
+	printf("%d\n", s);
+}
+*/
+import "C"
+
+import "unsafe"
+
+func Example() {
+	cs := C.CString("Hello from stdio\n")
+	C.myprint(cs)
+	C.free(unsafe.Pointer(cs))
+}

Diff for: test/testdata/unsafe/pkg.go

@@ -0,0 +1,14 @@
+package pkg
+
+import (
+	"log"
+	"unsafe"
+)
+
+func F() {
+	x := 123 // of type int
+	p := unsafe.Pointer(&x)
+	pp := &p // of type *unsafe.Pointer
+	p = unsafe.Pointer(pp)
+	log.Print(p)
+}