Preprocessor calls to gcc are now saved into the NULL file: "nul" on Windows,

"/dev/null" on Linux & OSX

Signed-off-by: Federico Fissore <f.fissore@arduino.cc>

Author: Federico Fissore

src/arduino.cc/builder/container_find_includes.go

@@ -33,9 +33,7 @@ import (
 	"arduino.cc/builder/constants"
 	"arduino.cc/builder/types"
 	"arduino.cc/builder/utils"
-	"math/rand"
 	"path/filepath"
-	"strconv"
 )
 
 type ContainerFindIncludes struct{}
@@ -100,12 +98,12 @@ func runCommand(context map[string]interface{}, command types.Command) error {
 }
 
 func findIncludesUntilDone(context map[string]interface{}, sourceFilePath string) error {
-	targetFileName := filepath.Base(sourceFilePath) + "_" + strconv.Itoa(rand.Int()) + "_preprocessed.cpp"
+	targetFilePath := utils.NULLFile()
 	importedLibraries := context[constants.CTX_IMPORTED_LIBRARIES].([]*types.Library)
 	done := false
 	for !done {
 		commands := []types.Command{
-			&GCCPreprocRunnerForDiscoveringIncludes{SourceFilePath: sourceFilePath, TargetFileName: targetFileName},
+			&GCCPreprocRunnerForDiscoveringIncludes{SourceFilePath: sourceFilePath, TargetFilePath: targetFilePath},
 			&IncludesFinderWithRegExp{ContextField: constants.CTX_GCC_MINUS_E_SOURCE},
 			&IncludesToIncludeFolders{},
 		}

src/arduino.cc/builder/gcc_preproc_runner.go

@@ -65,11 +65,11 @@ func (s *GCCPreprocRunner) Run(context map[string]interface{}) error {
 
 type GCCPreprocRunnerForDiscoveringIncludes struct {
 	SourceFilePath string
-	TargetFileName string
+	TargetFilePath string
 }
 
 func (s *GCCPreprocRunnerForDiscoveringIncludes) Run(context map[string]interface{}) error {
-	properties, _, err := prepareGCCPreprocRecipeProperties(context, s.SourceFilePath, s.TargetFileName)
+	properties, _, err := prepareGCCPreprocRecipeProperties(context, s.SourceFilePath, s.TargetFilePath)
 	if err != nil {
 		return utils.WrapError(err)
 	}
@@ -86,13 +86,15 @@ func (s *GCCPreprocRunnerForDiscoveringIncludes) Run(context map[string]interfac
 	return nil
 }
 
-func prepareGCCPreprocRecipeProperties(context map[string]interface{}, sourceFilePath string, targetFileName string) (map[string]string, string, error) {
-	preprocPath := context[constants.CTX_PREPROC_PATH].(string)
-	err := utils.EnsureFolderExists(preprocPath)
-	if err != nil {
-		return nil, "", utils.WrapError(err)
+func prepareGCCPreprocRecipeProperties(context map[string]interface{}, sourceFilePath string, targetFilePath string) (map[string]string, string, error) {
+	if !filepath.IsAbs(targetFilePath) {
+		preprocPath := context[constants.CTX_PREPROC_PATH].(string)
+		err := utils.EnsureFolderExists(preprocPath)
+		if err != nil {
+			return nil, "", utils.WrapError(err)
+		}
+		targetFilePath = filepath.Join(preprocPath, targetFilePath)
 	}
-	targetFilePath := filepath.Join(preprocPath, targetFileName)
 
 	buildProperties := utils.GetMapStringStringOrDefault(context, constants.CTX_BUILD_PROPERTIES)
 	properties := utils.MergeMapsOfStrings(make(map[string]string), buildProperties)

src/arduino.cc/builder/utils/utils.go

@@ -462,3 +462,10 @@ func TagHasAtLeastOneField(tag map[string]string, fields []string) (string, bool
 	}
 	return "", false
 }
+
+func NULLFile() string {
+	if runtime.GOOS == "windows" {
+		return "nul"
+	}
+	return "/dev/null"
+}