Add step to correct tags data C linkage

src/arduino.cc/builder/ctags/ctags_has_issues.go

@@ -0,0 +1,139 @@
+/*
+ * This file is part of Arduino Builder.
+ *
+ * Arduino Builder is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction.  Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License.  This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * Copyright 2015 Arduino LLC (http://www.arduino.cc/)
+ */
+
+package ctags
+
+import (
+	"bufio"
+	"os"
+	"strings"
+
+	"arduino.cc/builder/types"
+)
+
+func (p *CTagsParser) FixCLinkageTagsDeclarations(tags []*types.CTag) {
+
+	linesMap := p.FindCLinkageLines(tags)
+	for i, _ := range tags {
+
+		if sliceContainsInt(linesMap[tags[i].Filename], tags[i].Line) &&
+			!strings.Contains(tags[i].PrototypeModifiers, EXTERN) {
+			tags[i].PrototypeModifiers = tags[i].PrototypeModifiers + " " + EXTERN
+		}
+	}
+}
+
+func sliceContainsInt(s []int, e int) bool {
+	for _, a := range s {
+		if a == e {
+			return true
+		}
+	}
+	return false
+}
+
+/* This function scans the source files searching for "extern C" context
+ * It save the line numbers in a map filename -> {lines...}
+ */
+func (p *CTagsParser) FindCLinkageLines(tags []*types.CTag) map[string][]int {
+
+	lines := make(map[string][]int)
+
+	for _, tag := range tags {
+
+		if lines[tag.Filename] != nil {
+			break
+		}
+
+		file, err := os.Open(tag.Filename)
+		if err == nil {
+			defer file.Close()
+
+			lines[tag.Filename] = append(lines[tag.Filename], 0)
+
+			scanner := bufio.NewScanner(file)
+
+			// we can't remove the comments otherwise the line number will be wrong
+			// there are three cases:
+			// 1 - extern "C" void foo()
+			// 2 - extern "C" {
+			//		void foo();
+			//		void bar();
+			//	}
+			// 3 - extern "C"
+			//	{
+			//		void foo();
+			//		void bar();
+			//	}
+			// case 1 and 2 can be simply recognized with string matching and indent level count
+			// case 3 needs specia attention: if the line ONLY contains `extern "C"` string, don't bail out on indent level = 0
+
+			inScope := false
+			enteringScope := false
+			indentLevels := 0
+			line := 0
+
+			externCDecl := removeSpacesAndTabs(EXTERN)
+
+			for scanner.Scan() {
+				line++
+				str := removeSpacesAndTabs(scanner.Text())
+
+				if len(str) == 0 {
+					continue
+				}
+
+				// check if we are on the first non empty line after externCDecl in case 3
+				if enteringScope == true {
+					enteringScope = false
+				}
+
+				// check if the line contains externCDecl
+				if strings.Contains(str, externCDecl) {
+					inScope = true
+					if len(str) == len(externCDecl) {
+						// case 3
+						enteringScope = true
+					}
+				}
+				if inScope == true {
+					lines[tag.Filename] = append(lines[tag.Filename], line)
+				}
+				indentLevels += strings.Count(str, "{") - strings.Count(str, "}")
+
+				// Bail out if indentLevel is zero and we are not in case 3
+				if indentLevels == 0 && enteringScope == false {
+					inScope = false
+				}
+			}
+		}
+
+	}
+	return lines
+}

src/arduino.cc/builder/ctags_runner.go

@@ -75,6 +75,8 @@ func (s *CTagsRunner) Run(ctx *types.Context) error {
 
 	parser := &ctags.CTagsParser{}
 	ctx.CTagsOfPreprocessedSource = parser.Parse(ctx.CTagsOutput)
+
+	parser.FixCLinkageTagsDeclarations(ctx.CTagsOfPreprocessedSource)
 	protos, line := parser.GeneratePrototypes()
 	if line != -1 {
 		ctx.PrototypesLineWhereToInsert = line