Make mediasoup work with Python 3 (related to #207)

Note that gyp source code has been manually modified within the worker/deps/gyp
folder (credits to @saghul)

doc/Building.md

@@ -95,7 +95,6 @@ Read the [Fuzzer](Fuzzer.md) documentation for detailed information.
 Builds a Xcode project for the mediasoup-worker subproject.
 
 
-
 ### `make lint`
 
 Validates mediasoup-worker C++ files using [clang-format](https://clang.llvm.org/docs/ClangFormat.html) and rules in `worker/.clang-format`.

worker/Makefile

@@ -2,10 +2,13 @@
 # make tasks for mediasoup-worker.
 #
 
-# Best effort to get Python 2 executable and also allow custom PYTHON
-# environment variable set by the user.
-PYTHON ?= $(shell command -v python2 2> /dev/null || echo python)
+PYTHON ?= python
+LCOV = ./deps/lcov/bin/lcov
 GULP = ../node_modules/.bin/gulp
+BEAR ?= bear
+JQ ?= jq
+SED ?= sed
+DOCKER ?= docker
 MEDIASOUP_BUILDTYPE ?= Release
 
 .PHONY:	\
@@ -22,7 +25,7 @@ test:
 ifeq ($(MEDIASOUP_WORKER_BIN),)
 	$(PYTHON) ./scripts/configure.py -R mediasoup-worker-test
 	$(MAKE) BUILDTYPE=$(MEDIASOUP_BUILDTYPE) -C out
-	./deps/lcov/bin/lcov --directory ./ --zerocounters
+	$(LCOV) --directory ./ --zerocounters
 	./out/$(MEDIASOUP_BUILDTYPE)/mediasoup-worker-test --invisibles --use-colour=yes $(MEDIASOUP_TEST_TAGS)
 endif
 
@@ -43,13 +46,13 @@ format:
 
 bear:
 	$(MAKE) clean
-	bear -o compile_commands_template.tmp.json $(MAKE)
-	jq 'del(.[] | select(.file == "$(PWD)/src/Utils/IP.cpp"))' compile_commands_template.tmp.json > compile_commands_template.json
-	rm compile_commands_template.tmp.json
-	sed -i "s|$(PWD)|PATH|g" compile_commands_template.json
+	$(BEAR) -o compile_commands_template.tmp.json $(MAKE)
+	$(JQ) 'del(.[] | select(.file == "$(PWD)/src/Utils/IP.cpp"))' compile_commands_template.tmp.json > compile_commands_template.json
+	$(RM) -f compile_commands_template.tmp.json
+	$(SED) -i "s|$(PWD)|PATH|g" compile_commands_template.json
 
 tidy:
-	sed "s|PATH|$(PWD)|g" compile_commands_template.json > compile_commands.json
+	$(SED) "s|PATH|$(PWD)|g" compile_commands_template.json > compile_commands.json
 	$(PYTHON) ./scripts/clang-tidy.py \
 		-clang-tidy-binary=../node_modules/.bin/clang-tidy \
 		-clang-apply-replacements-binary=../node_modules/.bin/clang-apply-replacements \
@@ -81,13 +84,13 @@ clean-all:
 
 docker-build:
 ifeq ($(DOCKER_NO_CACHE),true)
-	docker build -f Dockerfile --no-cache --tag mediasoup/docker:latest .
+	$(DOCKER) build -f Dockerfile --no-cache --tag mediasoup/docker:latest .
 else
-	docker build -f Dockerfile --tag mediasoup/docker:latest .
+	$(DOCKER) build -f Dockerfile --tag mediasoup/docker:latest .
 endif
 
 docker-run:
-	docker run \
+	$(DOCKER) run \
 		--name=mediasoupDocker -it --rm \
 		--cap-add SYS_PTRACE \
 		-v $(shell pwd)/../:/mediasoup \

worker/deps/gyp/pylib/gyp/xcode_emulation.py

@@ -526,7 +526,7 @@ def _XcodeSdkPath(self, sdk_root):
       XcodeSettings._sdk_path_cache[sdk_root] = sdk_path
       if sdk_root:
         XcodeSettings._sdk_root_cache[sdk_path] = sdk_root
-    return XcodeSettings._sdk_path_cache[sdk_root]
+    return XcodeSettings._sdk_path_cache[sdk_root].decode()
 
   def _AppendPlatformVersionMinFlags(self, lst):
     self._Appendf(lst, 'MACOSX_DEPLOYMENT_TARGET', '-mmacosx-version-min=%s')
@@ -1413,7 +1413,7 @@ def XcodeVersion():
   version = version_list[0]
   build = version_list[-1]
   # Be careful to convert "4.2" to "0420":
-  version = version.split()[-1].replace('.', '')
+  version = version.split()[-1].decode().replace('.', '')
   version = (version + '0' * (3 - len(version))).zfill(4)
   if build:
     build = build.split()[-1]
@@ -1450,9 +1450,9 @@ def GetStdout(cmdlist):
   job = subprocess.Popen(cmdlist, stdout=subprocess.PIPE)
   out = job.communicate()[0]
   if job.returncode != 0:
-    sys.stderr.write(out + '\n')
+    sys.stderr.write(out + b'\n')
     raise GypError('Error %d running %s' % (job.returncode, cmdlist[0]))
-  return out.rstrip('\n')
+  return out.rstrip(b'\n')
 
 
 def MergeGlobalXcodeSettingsToSpec(global_dict, spec):

worker/scripts/configure.py

@@ -10,11 +10,6 @@
 import subprocess
 import sys
 
-version = sys.version_info[0]
-
-if version != 2:
-  raise RuntimeError('gyp requires Python 2, but this is Python ' + str(version) + ', ensure your python2 or python command points to the Python 2 executable')
-
 CC = os.environ.get('CC', 'cc')
 script_dir = os.path.dirname(__file__)
 root = os.path.normpath(os.path.join(script_dir, '..'))