cmake: convert_to_cmake.py script for converting IDF GNU Make projects

diff --git a/tools/cmake/convert_to_cmake.py b/tools/cmake/convert_to_cmake.py
new file mode 100755 (executable)
index 0000000..0cfd602
--- /dev/null
+++ b/tools/cmake/convert_to_cmake.py
@@ -0,0 +1,214 @@
+#!/usr/bin/env python
+#
+# Command line tool to convert simple ESP-IDF Makefile & component.mk files to
+# CMakeLists.txt files
+#
+import argparse
+import subprocess
+import re
+import os.path
+import glob
+import sys
+
+debug = False
+
+def get_make_variables(path, makefile="Makefile", expected_failure=False, variables={}):
+    """
+    Given the path to a Makefile of some kind, return a dictionary of all variables defined in this Makefile
+
+    Uses 'make' to parse the Makefile syntax, so we don't have to!
+
+    Overrides IDF_PATH= to avoid recursively evaluating the entire project Makefile structure.
+    """
+    variable_setters = [ ("%s=%s" % (k,v)) for (k,v) in variables.items() ]
+
+    cmdline = ["make", "-rpn", "-C", path, "-f", makefile ] + variable_setters
+    if debug:
+        print("Running %s..." % (" ".join(cmdline)))
+
+    p = subprocess.Popen(cmdline, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    (output, stderr) = p.communicate("\n")
+
+    if (not expected_failure) and p.returncode != 0:
+        raise RuntimeError("Unexpected make failure, result %d" % p.returncode)
+
+    if debug:
+        print("Make stdout:")
+        print(output)
+        print("Make stderr:")
+        print(stderr)
+
+    next_is_makefile = False  # is the next line a makefile variable?
+    result = {}
+    BUILT_IN_VARS = set(["MAKEFILE_LIST", "SHELL", "CURDIR", "MAKEFLAGS"])
+
+    for line in output.decode().split("\n"):
+        if line.startswith("# makefile"):  # this line appears before any variable defined in the makefile itself
+            next_is_makefile = True
+        elif next_is_makefile:
+            next_is_makefile = False
+            m = re.match(r"(?P<var>[^ ]+) :?= (?P<val>.+)", line)
+            if m is not None:
+                if not m.group("var") in BUILT_IN_VARS:
+                    result[m.group("var")] = m.group("val").strip()
+
+    return result
+
+def get_component_variables(project_path, component_path):
+    make_vars = get_make_variables(component_path,
+                                   os.path.join(os.environ["IDF_PATH"],
+                                                "make",
+                                                "component_wrapper.mk"),
+                                   expected_failure=True,
+                                   variables = {
+                                       "COMPONENT_MAKEFILE" : os.path.join(component_path, "component.mk"),
+                                       "COMPONENT_NAME" : os.path.basename(component_path),
+                                       "PROJECT_PATH": project_path,
+                                   })
+
+    if "COMPONENT_OBJS" in make_vars:  # component.mk specifies list of object files
+        # Convert to sources
+        def find_src(obj):
+            obj = os.path.splitext(obj)[0]
+            for ext in [ "c", "cpp", "S" ]:
+                if os.path.exists(os.path.join(component_path, obj) + "." + ext):
+                    return obj + "." + ext
+            print("WARNING: Can't find source file for component %s COMPONENT_OBJS %s" % (component_path, obj))
+            return None
+
+        srcs = []
+        for obj in make_vars["COMPONENT_OBJS"].split(" "):
+            src = find_src(obj)
+            if src is not None:
+                srcs.append(src)
+        make_vars["COMPONENT_SRCS"] = " ".join(srcs)
+    else:  # Use COMPONENT_SRCDIRS
+        make_vars["COMPONENT_SRCDIRS"] = make_vars.get("COMPONENT_SRCDIRS", ".")
+
+    make_vars["COMPONENT_ADD_INCLUDEDIRS"] = make_vars.get("COMPONENT_ADD_INCLUDEDIRS", "include")
+
+    return make_vars
+
+
+def convert_project(project_path):
+    if not os.path.exists(project_path):
+        raise RuntimeError("Project directory '%s' not found" % project_path)
+    if not os.path.exists(os.path.join(project_path, "Makefile")):
+        raise RuntimeError("Directory '%s' doesn't contain a project Makefile" % project_path)
+
+    project_cmakelists = os.path.join(project_path, "CMakeLists.txt")
+    if os.path.exists(project_cmakelists):
+        raise RuntimeError("This project already has a CMakeLists.txt file")
+
+    project_vars = get_make_variables(project_path, expected_failure=True)
+    if not "PROJECT_NAME" in project_vars:
+        raise RuntimeError("PROJECT_NAME does not appear to be defined in IDF project Makefile at %s" % project_path)
+
+    component_paths = project_vars["COMPONENT_PATHS"].split(" ")
+
+    # "main" component is made special in cmake, so extract it from the component_paths list
+    try:
+        main_component_path = [ p for p in component_paths if os.path.basename(p) == "main" ][0]
+        if debug:
+            print("Found main component %s"  % main_component_path)
+        main_vars = get_component_variables(project_path, main_component_path)
+    except IndexError:
+        print("WARNING: Project has no 'main' component, but CMake-based system requires at least one file in MAIN_SRCS...")
+        main_vars = { "COMPONENT_SRCS" : ""} # dummy for MAIN_SRCS
+
+    # Remove main component from list of components we're converting to cmake
+    component_paths = [ p for p in component_paths if os.path.basename(p) != "main" ]
+
+    # Convert components as needed
+    for p in component_paths:
+        convert_component(project_path, p)
+
+    # Look up project variables before we start writing the file, so nothing
+    # is created if there is an error
+
+    main_srcs = main_vars["COMPONENT_SRCS"].split(" ")
+    # convert from component-relative to absolute paths
+    main_srcs = [ os.path.normpath(os.path.join(main_component_path, m)) for m in main_srcs ]
+    # convert to make relative to the project directory
+    main_srcs = [ os.path.relpath(m, project_path) for m in main_srcs ]
+
+    project_name = project_vars["PROJECT_NAME"]
+
+    # Generate the project CMakeLists.txt file
+    with open(project_cmakelists, "w") as f:
+        f.write("""
+# (Automatically converted from project Makefile by convert_to_cmake.py.)
+
+# The following four lines of boilerplate have to be in your project's CMakeLists
+# in this exact order for cmake to work correctly
+cmake_minimum_required(VERSION 3.5)
+
+""")
+        f.write("set(MAIN_SRCS %s)\n" % " ".join(main_srcs))
+        f.write("""
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+""")
+        f.write("project(%s)\n" % project_name)
+
+    print("Converted project %s" % project_cmakelists)
+
+def convert_component(project_path, component_path):
+    if debug:
+        print("Converting %s..." % (component_path))
+    cmakelists_path = os.path.join(component_path, "CMakeLists.txt")
+    if os.path.exists(cmakelists_path):
+        print("Skipping already-converted component %s..." % cmakelists_path)
+        return
+    v = get_component_variables(project_path, component_path)
+
+    # Look up all the variables before we start writing the file, so it's not
+    # created if there's an erro
+    component_srcs = v.get("COMPONENT_SRCS", None)
+    component_srcdirs = None
+    if component_srcs is not None:
+        # see if we should be using COMPONENT_SRCS or COMPONENT_SRCDIRS, if COMPONENT_SRCS is everything in SRCDIRS
+        component_allsrcs = []
+        for d in v.get("COMPONENT_SRCDIRS", "").split(" "):
+            component_allsrcs += glob.glob(os.path.normpath(os.path.join(component_path, d, "*.[cS]")))
+            component_allsrcs += glob.glob(os.path.normpath(os.path.join(component_path, d, "*.cpp")))
+        abs_component_srcs = [os.path.normpath(os.path.join(component_path, p)) for p in component_srcs.split(" ")]
+        if set(component_allsrcs) == set(abs_component_srcs):
+            component_srcdirs = v.get("COMPONENT_SRCDIRS")
+
+    component_add_includedirs = v["COMPONENT_ADD_INCLUDEDIRS"]
+    cflags = v.get("CFLAGS", None)
+
+    with open(cmakelists_path, "w") as f:
+        f.write("set(COMPONENT_ADD_INCLUDEDIRS %s)\n\n" % component_add_includedirs)
+        if component_srcdirs is not None:
+            f.write("set(COMPONENT_SRCDIRS %s)\n\n" % component_srcdirs)
+            f.write("register_component()\n")
+        elif component_srcs is not None:
+            f.write("set(COMPONENT_SRCS %s)\n\n" % component_srcs)
+            f.write("register_component()\n")
+        else:
+            f.write("register_config_only_component()\n")
+        if cflags is not None:
+            f.write("component_compile_options(%s)\n" % cflags)
+
+    print("Converted %s" % cmakelists_path)
+
+
+def main():
+    global debug
+
+    parser = argparse.ArgumentParser(description='convert_to_cmake.py - ESP-IDF Project Makefile to CMakeLists.txt converter', prog='convert_to_cmake')
+
+    parser.add_argument('--debug', help='Display debugging output',
+                        action='store_true')
+
+    parser.add_argument('project', help='Path to project to convert (defaults to CWD)', default=os.getcwd(), metavar='project path', nargs='?')
+
+    args = parser.parse_args()
+    debug = args.debug
+    print("Converting %s..." % args.project)
+    convert_project(args.project)
+
+
+if __name__ == "__main__":
+    main()