Builder now support parsing of compiler output

Author: cmaglie

Diff for: arduino/builder/builder.go

@@ -25,6 +25,7 @@ import (
 
 	"github.com/arduino/arduino-cli/arduino/builder/internal/compilation"
 	"github.com/arduino/arduino-cli/arduino/builder/internal/detector"
+	"github.com/arduino/arduino-cli/arduino/builder/internal/diagnostics"
 	"github.com/arduino/arduino-cli/arduino/builder/internal/logger"
 	"github.com/arduino/arduino-cli/arduino/builder/internal/progress"
 	"github.com/arduino/arduino-cli/arduino/builder/internal/utils"
@@ -90,6 +91,10 @@ type Builder struct {
 	buildOptions *buildOptions
 
 	libsDetector *detector.SketchLibrariesDetector
+
+	// This is a function used to parse the output of the compiler
+	// It is used to extract errors and warnings
+	compilerOutputParser diagnostics.CompilerOutputParserCB
 }
 
 // buildArtifacts contains the result of various build

Diff for: arduino/builder/compilation.go

@@ -166,6 +166,12 @@ func (b *Builder) compileFileWithRecipe(
 		}
 		b.logger.WriteStderr(commandStderr.Bytes())
 
+		// Parse the output of the compiler to gather errors and warnings...
+		if b.compilerOutputParser != nil {
+			b.compilerOutputParser(command.GetArgs(), commandStdout.Bytes())
+			b.compilerOutputParser(command.GetArgs(), commandStderr.Bytes())
+		}
+
 		// ...and then return the error
 		if err != nil {
 			return nil, errors.WithStack(err)

Diff for: arduino/builder/internal/diagnostics/parser.go

@@ -0,0 +1,20 @@
+// This file is part of arduino-cli.
+//
+// Copyright 2023 ARDUINO SA (http://www.arduino.cc/)
+//
+// This software is released under the GNU General Public License version 3,
+// which covers the main part of arduino-cli.
+// The terms of this license can be found at:
+// https://www.gnu.org/licenses/gpl-3.0.en.html
+//
+// You can be released from the requirements of the above licenses by purchasing
+// a commercial license. Buying such a license is mandatory if you want to
+// modify or otherwise use the software for commercial activities involving the
+// Arduino software without disclosing the source code of your own applications.
+// To purchase a commercial license, send an email to [email protected].
+
+package diagnostics
+
+// CompilerOutputParserCB is a callback function that is called to feed a parser
+// with the plain-text compiler output.
+type CompilerOutputParserCB func(cmdline []string, out []byte)