Move Builder and BuildEnv in specific module.

Introduce also a "NeutralEnv", a build environment independent of the
targeted platform. All `Source` now build using the neutralEnv.

Most of toolchains are also using neutralEnv except android_ndk who is
specific to a platform.

As toolchain are neutral, platform specific environment variables are now
set by the platformInfo directly instead of the toolchain.

kiwixbuild/builder.py

@@ -0,0 +1,97 @@
+
+import sys
+from collections import OrderedDict
+from .buildenv import *
+
+from .utils import remove_duplicates, StopBuild
+from .dependencies import Dependency
+
+class Builder:
+    def __init__(self, options):
+        self.options = options
+        self.targets = OrderedDict()
+        self.neutralEnv = PlatformNeutralEnv(options)
+        self.buildEnv = BuildEnv(options, self.neutralEnv, self.targets)
+
+        _targets = {}
+        targetDef = options.targets
+        self.add_targets(targetDef, _targets)
+        dependencies = self.order_dependencies(_targets, targetDef)
+        dependencies = list(remove_duplicates(dependencies))
+
+        if options.build_nodeps:
+            self.targets[targetDef] = _targets[targetDef]
+        else:
+            for dep in dependencies:
+                if self.options.build_deps_only and dep == targetDef:
+                    continue
+                self.targets[dep] = _targets[dep]
+
+    def add_targets(self, targetName, targets):
+        if targetName in targets:
+            return
+        targetClass = Dependency.all_deps[targetName]
+        target = targetClass(self.neutralEnv, self.buildEnv)
+        targets[targetName] = target
+        for dep in target.dependencies:
+            self.add_targets(dep, targets)
+
+    def order_dependencies(self, _targets, targetName):
+        target = _targets[targetName]
+        for depName in target.dependencies:
+            yield from self.order_dependencies(_targets, depName)
+        yield targetName
+
+    def prepare_sources(self):
+        if self.options.skip_source_prepare:
+            print("SKIP")
+            return
+
+        toolchain_sources = (tlc.source for tlc in self.buildEnv.toolchains if tlc.source)
+        for toolchain_source in toolchain_sources:
+            print("prepare sources for toolchain {} :".format(toolchain_source.name))
+            toolchain_source.prepare()
+
+        sources = (dep.source for dep in self.targets.values() if not dep.skip)
+        sources = remove_duplicates(sources, lambda s: s.__class__)
+        for source in sources:
+            print("prepare sources {} :".format(source.name))
+            source.prepare()
+
+    def build(self):
+        toolchain_builders = (tlc.builder for tlc in self.buildEnv.toolchains if tlc.builder)
+        for toolchain_builder in toolchain_builders:
+            print("build toolchain {} :".format(toolchain_builder.name))
+            toolchain_builder.build()
+
+        builders = (dep.builder for dep in self.targets.values() if (dep.builder and not dep.skip))
+        for builder in builders:
+            if self.options.make_dist and builder.name == self.options.targets:
+                continue
+            print("build {} :".format(builder.name))
+            builder.build()
+
+        if self.options.make_dist:
+            dep = self.targets[self.options.targets]
+            builder = dep.builder
+            print("make dist {}:".format(builder.name))
+            builder.make_dist()
+
+    def run(self):
+        try:
+            print("[INSTALL PACKAGES]")
+            self.buildEnv.install_packages()
+            self.buildEnv.finalize_setup()
+            print("[PREPARE]")
+            self.prepare_sources()
+            print("[BUILD]")
+            self.build()
+            # No error, clean intermediate file at end of build if needed.
+            print("[CLEAN]")
+            if self.buildEnv.options.clean_at_end:
+                self.buildEnv.clean_intermediate_directories()
+            else:
+                print("SKIP")
+        except StopBuild:
+            sys.exit("Stopping build due to errors")
+