Skip dependency detection if library is fully precompiled (#1139)

* Skip dependency detection if library is fully precompiled

Precompiled bits of a library should not depend on any link time dependency (we cannot assure ABI stability).
Fixes https://github.com/arduino/ArduinoCore-mbed/issues/119

* Add output when skipping deps detection for precompiled libs
Co-authored-by: Silvano Cerza <silvanocerza@gmail.com>

legacy/builder/constants/constants.go

@@ -89,6 +89,7 @@ const MSG_BOOTLOADER_FILE_MISSING = "Bootloader file specified but missing: {0}"
 const MSG_BUILD_OPTIONS_CHANGED = "Build options changed, rebuilding all"
 const MSG_CANT_FIND_SKETCH_IN_PATH = "Unable to find {0} in {1}"
 const MSG_FQBN_INVALID = "{0} is not a valid fully qualified board name. Required format is targetPackageName:targetPlatformName:targetBoardName."
+const MSG_SKIP_PRECOMPILED_LIBRARY = "Skipping dependencies detection for precompiled library {0}"
 const MSG_FIND_INCLUDES_FAILED = "Error while detecting libraries included by {0}"
 const MSG_LIB_LEGACY = "(legacy)"
 const MSG_LIBRARIES_MULTIPLE_LIBS_FOUND_FOR = "Multiple libraries were found for \"{0}\""

legacy/builder/container_find_includes.go

@@ -316,8 +316,21 @@ func findIncludesUntilDone(ctx *types.Context, cache *includeCache, sourceFile t
 		if library, ok := sourceFile.Origin.(*libraries.Library); ok && library.UtilityDir != nil {
 			includes = append(includes, library.UtilityDir)
 		}
+
+		if library, ok := sourceFile.Origin.(*libraries.Library); ok {
+			if library.Precompiled && library.PrecompiledWithSources {
+				// Fully precompiled libraries should have no dependencies
+				// to avoid ABI breakage
+				if ctx.Verbose {
+					ctx.GetLogger().Println(constants.LOG_LEVEL_DEBUG, constants.MSG_SKIP_PRECOMPILED_LIBRARY, library.Name)
+				}
+				return nil
+			}
+		}
+
 		var preproc_err error
 		var preproc_stderr []byte
+
 		if unchanged && cache.valid {
 			include = cache.Next().Include
 			if first && ctx.Verbose {

test/test_compile.py

@@ -590,3 +590,42 @@ def test_compile_with_archives_and_long_paths(run_command):
     sketch_path = Path(lib_output[0]["library"]["install_dir"], "examples", "ArduinoIoTCloud-Advanced")
 
     assert run_command(f"compile -b esp8266:esp8266:huzzah {sketch_path}")
+
+
+def test_compile_with_precompiled_library(run_command, data_dir):
+    assert run_command("update")
+
+    assert run_command("core install arduino:samd@1.8.11")
+    fqbn = "arduino:samd:mkrzero"
+
+    # Install precompiled library
+    # For more information see:
+    # https://arduino.github.io/arduino-cli/latest/library-specification/#precompiled-binaries
+    assert run_command('lib install "BSEC Software Library@1.5.1474"')
+    sketch_folder = Path(data_dir, "libraries", "BSEC_Software_Library", "examples", "basic")
+
+    # Compile and verify dependencies detection for fully precompiled library is not skipped
+    result = run_command(f"compile -b {fqbn} {sketch_folder} -v")
+    assert result.ok
+    assert "Skipping dependencies detection for precompiled library BSEC Software Library" not in result.stdout
+
+
+def test_compile_with_fully_precompiled_library(run_command, data_dir):
+    assert run_command("update")
+
+    assert run_command("core install arduino:mbed@1.3.1")
+    fqbn = "arduino:mbed:nano33ble"
+
+    # Install fully precompiled library
+    # For more information see:
+    # https://arduino.github.io/arduino-cli/latest/library-specification/#precompiled-binaries
+    assert run_command("lib install Arduino_TensorFlowLite@2.1.1-ALPHA-precompiled")
+    sketch_folder = Path(data_dir, "libraries", "Arduino_TensorFlowLite", "examples", "hello_world")
+
+    # Install example dependency
+    # assert run_command("lib install Arduino_LSM9DS1")
+
+    # Compile and verify dependencies detection for fully precompiled library is skipped
+    result = run_command(f"compile -b {fqbn} {sketch_folder} -v")
+    assert result.ok
+    assert "Skipping dependencies detection for precompiled library Arduino_TensorFlowLite" in result.stdout