[breaking] Fixed regression in library discovery (#1741)

* Fixed libraries-set selection for discovery

Fix #1740

* removed useless variable

* Added tests

* Updated readme

Author: cmaglie

arduino/libraries/librariesresolver/cpp.go

@@ -20,6 +20,7 @@ import (
 	"path/filepath"
 	"strings"
 
+	"github.com/arduino/arduino-cli/arduino/cores"
 	"github.com/arduino/arduino-cli/arduino/libraries"
 	"github.com/arduino/arduino-cli/arduino/libraries/librariesmanager"
 	"github.com/arduino/arduino-cli/arduino/utils"
@@ -53,6 +54,49 @@ func (resolver *Cpp) ScanFromLibrariesManager(lm *librariesmanager.LibrariesMana
 	return nil
 }
 
+// ScanIDEBuiltinLibraries reads ide-builtin librariers loaded in the LibrariesManager to find
+// and cache all C++ headers for later retrieval.
+func (resolver *Cpp) ScanIDEBuiltinLibraries(lm *librariesmanager.LibrariesManager) error {
+	for _, libAlternatives := range lm.Libraries {
+		for _, lib := range libAlternatives.Alternatives {
+			if lib.Location == libraries.IDEBuiltIn {
+				resolver.ScanLibrary(lib)
+			}
+		}
+	}
+	return nil
+}
+
+// ScanUserAndUnmanagedLibraries reads user/unmanaged librariers loaded in the LibrariesManager to find
+// and cache all C++ headers for later retrieval.
+func (resolver *Cpp) ScanUserAndUnmanagedLibraries(lm *librariesmanager.LibrariesManager) error {
+	for _, libAlternatives := range lm.Libraries {
+		for _, lib := range libAlternatives.Alternatives {
+			if lib.Location == libraries.User || lib.Location == libraries.Unmanaged {
+				resolver.ScanLibrary(lib)
+			}
+		}
+	}
+	return nil
+}
+
+// ScanPlatformLibraries reads platform-bundled libraries for a specific platform loaded in the LibrariesManager
+// to find and cache all C++ headers for later retrieval.
+func (resolver *Cpp) ScanPlatformLibraries(lm *librariesmanager.LibrariesManager, platform *cores.PlatformRelease) error {
+	for _, libAlternatives := range lm.Libraries {
+		for _, lib := range libAlternatives.Alternatives {
+			if lib.Location != libraries.PlatformBuiltIn && lib.Location != libraries.ReferencedPlatformBuiltIn {
+				continue
+			}
+			if lib.ContainerPlatform != platform {
+				continue
+			}
+			resolver.ScanLibrary(lib)
+		}
+	}
+	return nil
+}
+
 // ScanLibrary reads a library to find and cache C++ headers for later retrieval
 func (resolver *Cpp) ScanLibrary(lib *libraries.Library) error {
 	cppHeaders, err := lib.SourceHeaders()

docs/UPGRADING.md

@@ -4,6 +4,15 @@ Here you can find a list of migration guides to handle breaking changes between
 
 ## 0.23.0
 
+### Arduino IDE builtin libraries are now excluded from the build when running `arduino-cli` standalone
+
+Previously the "builtin libraries" in the Arduino IDE 1.8.x were always included in the build process. This wasn't the
+intended behaviour, `arduino-cli` should include them only if run as a daemon from the Arduino IDE. Now this is fixed,
+but since it has been the default behaviour from a very long time we decided to report it here as a breaking change.
+
+If a compilation fail for a missing bundled library, you can fix it just by installing the missing library from the
+library manager as usual.
+
 ### golang API: PackageManager.DownloadPlatformRelease no longer need `label` parameter
 
 ```go

legacy/builder/libraries_loader.go

@@ -38,12 +38,10 @@ func (s *LibrariesLoader) Run(ctx *types.Context) error {
 			lm.AddLibrariesDir(folder, libraries.IDEBuiltIn)
 		}
 
-		actualPlatform := ctx.ActualPlatform
-		platform := ctx.TargetPlatform
-		if actualPlatform != platform {
-			lm.AddPlatformReleaseLibrariesDir(actualPlatform, libraries.ReferencedPlatformBuiltIn)
+		if ctx.ActualPlatform != ctx.TargetPlatform {
+			lm.AddPlatformReleaseLibrariesDir(ctx.ActualPlatform, libraries.ReferencedPlatformBuiltIn)
 		}
-		lm.AddPlatformReleaseLibrariesDir(platform, libraries.PlatformBuiltIn)
+		lm.AddPlatformReleaseLibrariesDir(ctx.TargetPlatform, libraries.PlatformBuiltIn)
 
 		librariesFolders := ctx.OtherLibrariesDirs
 		if err := librariesFolders.ToAbs(); err != nil {
@@ -72,9 +70,20 @@ func (s *LibrariesLoader) Run(ctx *types.Context) error {
 	}
 
 	resolver := librariesresolver.NewCppResolver()
-	if err := resolver.ScanFromLibrariesManager(ctx.LibrariesManager); err != nil {
+	if err := resolver.ScanIDEBuiltinLibraries(ctx.LibrariesManager); err != nil {
 		return errors.WithStack(err)
 	}
+	if err := resolver.ScanUserAndUnmanagedLibraries(ctx.LibrariesManager); err != nil {
+		return errors.WithStack(err)
+	}
+	if err := resolver.ScanPlatformLibraries(ctx.LibrariesManager, ctx.TargetPlatform); err != nil {
+		return errors.WithStack(err)
+	}
+	if ctx.ActualPlatform != ctx.TargetPlatform {
+		if err := resolver.ScanPlatformLibraries(ctx.LibrariesManager, ctx.ActualPlatform); err != nil {
+			return errors.WithStack(err)
+		}
+	}
 	ctx.LibrariesResolver = resolver
 
 	return nil

test/test_profiles.py

@@ -28,3 +28,22 @@ def test_compile_with_profiles(run_command, copy_sketch):
     # use profile with the required library -> should succeed
     result = run_command(["compile", "-m", "avr2", sketch_path])
     assert result.ok
+
+
+def test_builder_did_not_catch_libs_from_unused_platforms(run_command, copy_sketch):
+    # Init the environment explicitly
+    run_command(["core", "update-index"])
+
+    sketch_path = copy_sketch("sketch_with_error_including_wire")
+
+    # install two platforms with the Wire library bundled
+    assert run_command(["core", "install", "arduino:avr"])
+    assert run_command(["core", "install", "arduino:samd"])
+
+    # compile for AVR
+    result = run_command(["compile", "-b", "arduino:avr:uno", sketch_path])
+    assert result.failed
+
+    # check that the libary resolver did not take the SAMD bundled Wire library into account
+    assert "samd" not in result.stdout
+    assert "samd" not in result.stderr

test/testdata/sketch_with_error_including_wire/sketch_with_error_including_wire.ino

@@ -0,0 +1,3 @@
+#include <Wire.h>
+
+this sketch has syntax errors