1 files changed, 133 insertions, 0 deletions
diff --git a/bpfix/bpfix/bpfix.go b/bpfix/bpfix/bpfix.go
index 4300e81b..4ab42a4e 100644
--- a/bpfix/bpfix/bpfix.go
+++ b/bpfix/bpfix/bpfix.go
@@ -26,11 +26,27 @@ import (
 	"github.com/google/blueprint/parser"
 )
 
+// Reformat takes a blueprint file as a string and returns a formatted version
+func Reformat(input string) (string, error) {
+	tree, err := parse("<string>", bytes.NewBufferString(input))
+	if err != nil {
+		return "", err
+	}
+
+	res, err := parser.Print(tree)
+	if err != nil {
+		return "", err
+	}
+
+	return string(res), nil
+}
+
 // A FixRequest specifies the details of which fixes to apply to an individual file
 // A FixRequest doesn't specify whether to do a dry run or where to write the results; that's in cmd/bpfix.go
 type FixRequest struct {
 	simplifyKnownRedundantVariables    bool
 	rewriteIncorrectAndroidmkPrebuilts bool
+	mergeMatchingModuleProperties      bool
 }
 
 func NewFixRequest() FixRequest {
@@ -41,6 +57,7 @@ func (r FixRequest) AddAll() (result FixRequest) {
 	result = r
 	result.simplifyKnownRedundantVariables = true
 	result.rewriteIncorrectAndroidmkPrebuilts = true
+	result.mergeMatchingModuleProperties = true
 	return result
 }
 
@@ -136,6 +153,13 @@ func (f *Fixer) fixTreeOnce(config FixRequest) error {
 			return err
 		}
 	}
+
+	if config.mergeMatchingModuleProperties {
+		err := f.mergeMatchingModuleProperties()
+		if err != nil {
+			return err
+		}
+	}
 	return nil
 }
 
@@ -179,6 +203,115 @@ func (f *Fixer) rewriteIncorrectAndroidmkPrebuilts() error {
 	return nil
 }
 
+func (f *Fixer) mergeMatchingModuleProperties() error {
+	// Make sure all the offsets are accurate
+	buf, err := f.reparse()
+	if err != nil {
+		return err
+	}
+
+	var patchlist parser.PatchList
+	for _, def := range f.tree.Defs {
+		mod, ok := def.(*parser.Module)
+		if !ok {
+			continue
+		}
+
+		err := mergeMatchingProperties(&mod.Properties, buf, &patchlist)
+		if err != nil {
+			return err
+		}
+	}
+
+	newBuf := new(bytes.Buffer)
+	err = patchlist.Apply(bytes.NewReader(buf), newBuf)
+	if err != nil {
+		return err
+	}
+
+	newTree, err := parse(f.tree.Name, newBuf)
+	if err != nil {
+		return err
+	}
+
+	f.tree = newTree
+
+	return nil
+}
+
+func mergeMatchingProperties(properties *[]*parser.Property, buf []byte, patchlist *parser.PatchList) error {
+	seen := make(map[string]*parser.Property)
+	for i := 0; i < len(*properties); i++ {
+		property := (*properties)[i]
+		if prev, exists := seen[property.Name]; exists {
+			err := mergeProperties(prev, property, buf, patchlist)
+			if err != nil {
+				return err
+			}
+			*properties = append((*properties)[:i], (*properties)[i+1:]...)
+		} else {
+			seen[property.Name] = property
+			if mapProperty, ok := property.Value.(*parser.Map); ok {
+				err := mergeMatchingProperties(&mapProperty.Properties, buf, patchlist)
+				if err != nil {
+					return err
+				}
+			}
+		}
+	}
+	return nil
+}
+
+func mergeProperties(a, b *parser.Property, buf []byte, patchlist *parser.PatchList) error {
+	if a.Value.Type() != b.Value.Type() {
+		return fmt.Errorf("type mismatch when merging properties %q: %s and %s", a.Name, a.Value.Type(), b.Value.Type())
+	}
+
+	switch a.Value.Type() {
+	case parser.StringType:
+		return fmt.Errorf("conflicting definitions of string property %q", a.Name)
+	case parser.ListType:
+		return mergeListProperties(a, b, buf, patchlist)
+	}
+
+	return nil
+}
+
+func mergeListProperties(a, b *parser.Property, buf []byte, patchlist *parser.PatchList) error {
+	aval, oka := a.Value.(*parser.List)
+	bval, okb := b.Value.(*parser.List)
+	if !oka || !okb {
+		// Merging expressions not supported yet
+		return nil
+	}
+
+	s := string(buf[bval.LBracePos.Offset+1 : bval.RBracePos.Offset])
+	if bval.LBracePos.Line != bval.RBracePos.Line {
+		if s[0] != '\n' {
+			panic("expected \n")
+		}
+		// If B is a multi line list, skip the first "\n" in case A already has a trailing "\n"
+		s = s[1:]
+	}
+	if aval.LBracePos.Line == aval.RBracePos.Line {
+		// A is a single line list with no trailing comma
+		if len(aval.Values) > 0 {
+			s = "," + s
+		}
+	}
+
+	err := patchlist.Add(aval.RBracePos.Offset, aval.RBracePos.Offset, s)
+	if err != nil {
+		return err
+	}
+	err = patchlist.Add(b.NamePos.Offset, b.End().Offset+2, "")
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
 // removes from <items> every item present in <removals>
 func filterExpressionList(items *parser.List, removals *parser.List) {
 	writeIndex := 0