Report compiler errors in machine readable format

.prettierignore

@@ -4,6 +4,7 @@
 .vs/
 .ionide/
 
+testdata
 /arduino/libraries/librariesindex/testdata/invalid.json
 /arduino/security/testdata/
 /.licenses/

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"
@@ -36,6 +37,7 @@ import (
 	rpc "github.com/arduino/arduino-cli/rpc/cc/arduino/cli/commands/v1"
 	"github.com/arduino/go-paths-helper"
 	"github.com/arduino/go-properties-orderedmap"
+	"github.com/sirupsen/logrus"
 )
 
 // ErrSketchCannotBeLocatedInBuildPath fixdoc
@@ -90,6 +92,12 @@ 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
+	// and here are the diagnostics parsed from the compiler
+	compilerDiagnostics diagnostics.Diagnostics
 }
 
 // buildArtifacts contains the result of various build
@@ -189,7 +197,7 @@ func NewBuilder(
 		logger.Warn(string(verboseOut))
 	}
 
-	return &Builder{
+	b := &Builder{
 		sketch:                        sk,
 		buildProperties:               buildProperties,
 		buildPath:                     buildPath,
@@ -226,7 +234,26 @@ func NewBuilder(
 			buildProperties.GetPath("runtime.platform.path"),
 			buildProperties.GetPath("build.core.path"), // TODO can we buildCorePath ?
 		),
-	}, nil
+	}
+
+	b.compilerOutputParser = func(cmdline []string, out []byte) {
+		compiler := diagnostics.DetectCompilerFromCommandLine(
+			cmdline,
+			false, // at the moment compiler-probing is not required
+		)
+		if compiler == nil {
+			logrus.Warnf("Could not detect compiler from: %s", cmdline)
+			return
+		}
+		diags, err := diagnostics.ParseCompilerOutput(compiler, out)
+		if err != nil {
+			logrus.Warnf("Error parsing compiler output: %s", err)
+			return
+		}
+		b.compilerDiagnostics = append(b.compilerDiagnostics, diags...)
+	}
+
+	return b, nil
 }
 
 // GetBuildProperties returns the build properties for running this build
@@ -249,6 +276,11 @@ func (b *Builder) ImportedLibraries() libraries.List {
 	return b.libsDetector.ImportedLibraries()
 }
 
+// CompilerDiagnostics returns the parsed compiler diagnostics
+func (b *Builder) CompilerDiagnostics() diagnostics.Diagnostics {
+	return b.compilerDiagnostics
+}
+
 // Preprocess fixdoc
 func (b *Builder) Preprocess() ([]byte, error) {
 	b.Progress.AddSubSteps(6)

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)

arduino/builder/internal/diagnostics/compiler_detection.go

@@ -0,0 +1,85 @@
+// 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 license@arduino.cc.
+
+package diagnostics
+
+import (
+	"bytes"
+	"path/filepath"
+	"strings"
+
+	"github.com/arduino/arduino-cli/executils"
+	semver "go.bug.st/relaxed-semver"
+)
+
+// DetectedCompiler represents a compiler detected from a given command line
+type DetectedCompiler struct {
+	Name            string
+	Family          string
+	Version         *semver.Version
+	DetailedVersion []string
+}
+
+// This function is overridden for mocking unit tests
+var runProcess = func(args ...string) []string {
+	if cmd, err := executils.NewProcess(nil, args...); err == nil {
+		out := &bytes.Buffer{}
+		cmd.RedirectStdoutTo(out)
+		cmd.Run()
+		return splitLines(out.Bytes())
+	}
+	return nil
+}
+
+// DetectCompilerFromCommandLine tries to detect a compiler from a given command line.
+// If probeCompiler is true, the compiler may be executed with different flags to
+// infer the version or capabilities.
+func DetectCompilerFromCommandLine(args []string, probeCompiler bool) *DetectedCompiler {
+	if len(args) == 0 {
+		return nil
+	}
+	basename := filepath.Base(args[0])
+	family := ""
+	if strings.Contains(basename, "g++") || strings.Contains(basename, "gcc") {
+		family = "gcc"
+	}
+	res := &DetectedCompiler{
+		Name:   basename,
+		Family: family,
+	}
+
+	if family == "gcc" && probeCompiler {
+		// Run "gcc --version" to obtain more info
+		res.DetailedVersion = runProcess(args[0], "--version")
+
+		// Usually on the first line we get the compiler architecture and
+		// version (as last field), followed by the compiler license, for
+		// example:
+		//
+		//   g++ (Ubuntu 12.2.0-3ubuntu1) 12.2.0
+		//   Copyright (C) 2022 Free Software Foundation, Inc.
+		//   This is free software; see the source for copying conditions.  There is NO
+		//   warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+		//
+		if len(res.DetailedVersion) > 0 {
+			split := strings.Split(res.DetailedVersion[0], " ")
+			if len(split) >= 3 {
+				res.Name = split[0]
+				res.Version, _ = semver.Parse(split[len(split)-1])
+			}
+		}
+	}
+	return res
+}

arduino/builder/internal/diagnostics/compiler_detection_test.go

@@ -0,0 +1,79 @@
+// 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 license@arduino.cc.
+
+package diagnostics
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func init() {
+	runProcess = mockedRunProcessToGetCompilerVersion
+}
+
+func mockedRunProcessToGetCompilerVersion(args ...string) []string {
+	if strings.HasSuffix(args[0], "7.3.0-atmel3.6.1-arduino7/bin/avr-g++") && args[1] == "--version" {
+		return []string{
+			"avr-g++ (GCC) 7.3.0",
+			"Copyright (C) 2017 Free Software Foundation, Inc.",
+			"This is free software; see the source for copying conditions.  There is NO",
+			"warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.",
+			"",
+		}
+	}
+	if strings.HasSuffix(args[0], "7.3.0-atmel3.6.1-arduino7/bin/avr-gcc") && args[1] == "--version" {
+		return []string{
+			"avr-gcc (GCC) 7.3.0",
+			"Copyright (C) 2017 Free Software Foundation, Inc.",
+			"This is free software; see the source for copying conditions.  There is NO",
+			"warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.",
+			"",
+		}
+	}
+	if strings.HasSuffix(args[0], "xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/xtensa-esp32-elf-g++") && args[1] == "--version" {
+		return []string{
+			"xtensa-esp32-elf-g++ (crosstool-NG esp-2021r2-patch3) 8.4.0",
+			"Copyright (C) 2018 Free Software Foundation, Inc.",
+			"This is free software; see the source for copying conditions.  There is NO",
+			"warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.",
+			"",
+		}
+	}
+
+	panic("missing mock for command line: " + strings.Join(args, " "))
+}
+
+func TestCompilerDetection(t *testing.T) {
+	comp := DetectCompilerFromCommandLine([]string{"~/.arduino15/packages/arduino/tools/avr-gcc/7.3.0-atmel3.6.1-arduino7/bin/avr-g++"}, true)
+	require.NotNil(t, comp)
+	require.Equal(t, "gcc", comp.Family)
+	require.Equal(t, "avr-g++", comp.Name)
+	require.Equal(t, "7.3.0", comp.Version.String())
+
+	comp = DetectCompilerFromCommandLine([]string{"~/.arduino15/packages/arduino/tools/avr-gcc/7.3.0-atmel3.6.1-arduino7/bin/avr-gcc"}, true)
+	require.NotNil(t, comp)
+	require.Equal(t, "gcc", comp.Family)
+	require.Equal(t, "avr-gcc", comp.Name)
+	require.Equal(t, "7.3.0", comp.Version.String())
+
+	comp = DetectCompilerFromCommandLine([]string{"/home/megabug/.arduino15/packages/esp32/tools/xtensa-esp32-elf-gcc/gcc8_4_0-esp-2021r2-patch3/bin/xtensa-esp32-elf-g++"}, true)
+	require.NotNil(t, comp)
+	require.Equal(t, "gcc", comp.Family)
+	require.Equal(t, "xtensa-esp32-elf-g++", comp.Name)
+	require.Equal(t, "8.4.0", comp.Version.String())
+}