Supported python build in host side.

The base module handles all the common functionalites, such as version
compatibilty check, version variations split, source file format check,
source/data file duplicate check.

The library/binary module focuses on how to generate binary build actions,
such as setting up stub script, zipping, filling in __init__.py in
runfiles dir tree.

Bug: b/31676493
Test: go test under python package

Change-Id: I06608369f350f7195873d459e1c8d1bdb811e77e

1 files changed, 235 insertions, 0 deletions

diff --git a/python/binary.go b/python/binary.go
new file mode 100644
index 00000000..4b4ccc28
--- /dev/null
+++ b/python/binary.go
@@ -0,0 +1,235 @@
+// Copyright 2017 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package python
+
+// This file contains the module types for building Python binary.
+
+import (
+	"fmt"
+	"io"
+	"path/filepath"
+	"strings"
+
+	"github.com/google/blueprint"
+
+	"android/soong/android"
+)
+
+func init() {
+	android.RegisterModuleType("python_binary_host", PythonBinaryHostFactory)
+}
+
+type PythonBinaryProperties struct {
+	// the name of the source file that is the main entry point of the program.
+	// this file must also be listed in srcs.
+	// If left unspecified, module name is used instead.
+	// If name doesn’t match any filename in srcs, main must be specified.
+	Main string
+
+	// set the name of the output binary.
+	Stem string
+
+	// append to the name of the output binary.
+	Suffix string
+}
+
+type PythonBinary struct {
+	pythonBaseModule
+
+	binaryProperties PythonBinaryProperties
+
+	// soong_zip arguments from all its dependencies.
+	depsParSpecs []parSpec
+
+	// Python runfiles paths from all its dependencies.
+	depsPyRunfiles []string
+
+	// the installation path for Python binary.
+	installPath android.OutputPath
+}
+
+var _ PythonSubModule = (*PythonBinary)(nil)
+
+var (
+	stubTemplateHost = "build/soong/python/scripts/stub_template_host.txt"
+)
+
+func PythonBinaryHostFactory() (blueprint.Module, []interface{}) {
+	module := &PythonBinary{}
+
+	return InitPythonBaseModule(&module.pythonBaseModule, module, android.HostSupportedNoCross,
+		&module.binaryProperties)
+}
+
+func (p *PythonBinary) GeneratePythonBuildActions(ctx android.ModuleContext) {
+	p.pythonBaseModule.GeneratePythonBuildActions(ctx)
+
+	// no Python source file for compiling par file.
+	if len(p.pythonBaseModule.srcsPathMappings) == 0 && len(p.depsPyRunfiles) == 0 {
+		return
+	}
+
+	// the runfiles packages needs to be populated with "__init__.py".
+	newPyPkgs := []string{}
+	// the set to de-duplicate the new Python packages above.
+	newPyPkgSet := make(map[string]bool)
+	// the runfiles dirs have been treated as packages.
+	existingPyPkgSet := make(map[string]bool)
+
+	wholePyRunfiles := []string{}
+	for _, path := range p.pythonBaseModule.srcsPathMappings {
+		wholePyRunfiles = append(wholePyRunfiles, path.dest)
+	}
+	wholePyRunfiles = append(wholePyRunfiles, p.depsPyRunfiles...)
+
+	// find all the runfiles dirs which have been treated as packages.
+	for _, path := range wholePyRunfiles {
+		if filepath.Base(path) != initFileName {
+			continue
+		}
+		existingPyPkg := PathBeforeLastSlash(path)
+		if _, found := existingPyPkgSet[existingPyPkg]; found {
+			panic(fmt.Errorf("found init file path duplicates: %q for module: %q.",
+				path, ctx.ModuleName()))
+		} else {
+			existingPyPkgSet[existingPyPkg] = true
+		}
+		parentPath := PathBeforeLastSlash(existingPyPkg)
+		populateNewPyPkgs(parentPath, existingPyPkgSet, newPyPkgSet, &newPyPkgs)
+	}
+
+	// create new packages under runfiles tree.
+	for _, path := range wholePyRunfiles {
+		if filepath.Base(path) == initFileName {
+			continue
+		}
+		parentPath := PathBeforeLastSlash(path)
+		populateNewPyPkgs(parentPath, existingPyPkgSet, newPyPkgSet, &newPyPkgs)
+	}
+
+	main := p.getPyMainFile(ctx)
+	if main == "" {
+		return
+	}
+	interp := p.getInterpreter(ctx)
+	if interp == "" {
+		return
+	}
+
+	// we need remove "runfiles/" suffix since stub script starts
+	// searching for main file in each sub-dir of "runfiles" directory tree.
+	binFile := registerBuildActionForParFile(ctx, p.getInterpreter(ctx),
+		strings.TrimPrefix(main, runFiles+"/"), p.getStem(ctx),
+		newPyPkgs, append(p.depsParSpecs, p.pythonBaseModule.parSpec))
+
+	// install par file.
+	p.installPath = ctx.InstallFile(
+		android.PathForModuleInstall(ctx, "bin"), binFile)
+}
+
+// get interpreter path.
+func (p *PythonBinary) getInterpreter(ctx android.ModuleContext) string {
+	var interp string
+	switch p.pythonBaseModule.properties.ActualVersion {
+	case pyVersion2:
+		interp = "python2"
+	case pyVersion3:
+		interp = "python3"
+	default:
+		panic(fmt.Errorf("unknown Python actualVersion: %q for module: %q.",
+			p.properties.ActualVersion, ctx.ModuleName()))
+	}
+
+	return interp
+}
+
+// find main program path within runfiles tree.
+func (p *PythonBinary) getPyMainFile(ctx android.ModuleContext) string {
+	var main string
+	if p.binaryProperties.Main == "" {
+		main = p.BaseModuleName() + pyExt
+	} else {
+		main = p.binaryProperties.Main
+	}
+
+	for _, path := range p.pythonBaseModule.srcsPathMappings {
+		if main == path.src.Rel() {
+			return path.dest
+		}
+	}
+	ctx.PropertyErrorf("main", "%q is not listed in srcs.", main)
+
+	return ""
+}
+
+func (p *PythonBinary) getStem(ctx android.ModuleContext) string {
+	stem := ctx.ModuleName()
+	if p.binaryProperties.Stem != "" {
+		stem = p.binaryProperties.Stem
+	}
+
+	return stem + p.binaryProperties.Suffix
+}
+
+// Sets the given directory and all its ancestor directories as Python packages.
+func populateNewPyPkgs(pkgPath string, existingPyPkgSet,
+	newPyPkgSet map[string]bool, newPyPkgs *[]string) {
+	for pkgPath != "" {
+		if _, found := existingPyPkgSet[pkgPath]; found {
+			break
+		}
+		if _, found := newPyPkgSet[pkgPath]; !found {
+			newPyPkgSet[pkgPath] = true
+			*newPyPkgs = append(*newPyPkgs, pkgPath)
+			// Gets its ancestor directory by trimming last slash.
+			pkgPath = PathBeforeLastSlash(pkgPath)
+		} else {
+			break
+		}
+	}
+}
+
+// filepath.Dir("abc") -> "." and filepath.Dir("/abc") -> "/". However,
+// the PathBeforeLastSlash() will return "" for both cases above.
+func PathBeforeLastSlash(path string) string {
+	if idx := strings.LastIndex(path, "/"); idx != -1 {
+		return path[:idx]
+	}
+	return ""
+}
+
+func (p *PythonBinary) GeneratePythonAndroidMk() (ret android.AndroidMkData, err error) {
+	// Soong installation is only supported for host modules. Have Make
+	// installation trigger Soong installation.
+	if p.pythonBaseModule.Target().Os.Class == android.Host {
+		ret.OutputFile = android.OptionalPathForPath(p.installPath)
+	}
+	ret.Class = "EXECUTABLES"
+
+	ret.Extra = append(ret.Extra, func(w io.Writer, outputFile android.Path) error {
+		path := p.installPath.RelPathString()
+		dir, file := filepath.Split(path)
+		stem := strings.TrimSuffix(file, filepath.Ext(file))
+
+		fmt.Fprintln(w, "LOCAL_MODULE_SUFFIX := "+filepath.Ext(file))
+		fmt.Fprintln(w, "LOCAL_MODULE_PATH := $(OUT_DIR)/"+filepath.Clean(dir))
+		fmt.Fprintln(w, "LOCAL_MODULE_STEM := "+stem)
+
+		return nil
+	})
+
+	return
+
+}