1 files changed, 159 insertions, 0 deletions
diff --git a/python/makefile.py b/python/makefile.py
new file mode 100644
index 0000000000..10c73df72d
--- /dev/null
+++ b/python/makefile.py
@@ -0,0 +1,159 @@
+#!/usr/bin/python3
+#
+# FRR extended automake/Makefile functionality helper
+#
+# This script is executed on/after generating Makefile to add some pieces for
+# clippy.
+
+import sys
+import os
+import subprocess
+import re
+import argparse
+from string import Template
+from makevars import MakeReVars
+
+argp = argparse.ArgumentParser(description="FRR Makefile extensions")
+argp.add_argument(
+    "--dev-build",
+    action="store_const",
+    const=True,
+    help="run additional developer checks",
+)
+args = argp.parse_args()
+
+with open("Makefile", "r") as fd:
+    before = fd.read()
+
+mv = MakeReVars(before)
+
+clippy_scan = mv["clippy_scan"].strip().split()
+for clippy_file in clippy_scan:
+    assert clippy_file.endswith(".c")
+
+# check for files using clippy but not listed in clippy_scan
+if args.dev_build:
+    basepath = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+    if os.path.exists(os.path.join(basepath, ".git")):
+        clippy_ref = subprocess.check_output(
+            [
+                "git",
+                "-C",
+                basepath,
+                "grep",
+                "-l",
+                "-P",
+                "^#\s*include.*_clippy.c",
+                "--",
+                "**.c",
+            ]
+        ).decode("US-ASCII")
+
+        clippy_ref = set(clippy_ref.splitlines())
+        missing = clippy_ref - set(clippy_scan)
+
+        if len(missing) > 0:
+            sys.stderr.write(
+                'error: files seem to be using clippy, but not listed in "clippy_scan" in subdir.am:\n\t%s\n'
+                % ("\n\t".join(sorted(missing)))
+            )
+            sys.exit(1)
+
+clippydep = Template(
+    """
+${clippybase}.$$(OBJEXT): ${clippybase}_clippy.c
+${clippybase}.lo: ${clippybase}_clippy.c
+${clippybase}_clippy.c: $$(CLIPPY_DEPS)"""
+)
+
+clippyauxdep = Template(
+    """# clippy{
+# auxiliary clippy target
+${target}: ${clippybase}_clippy.c
+# }clippy"""
+)
+
+lines = before.splitlines()
+autoderp = "#AUTODERP# "
+out_lines = []
+bcdeps = []
+make_rule_re = re.compile("^([^:\s]+):\s*([^:\s]+)\s*($|\n)")
+
+while lines:
+    line = lines.pop(0)
+    if line.startswith(autoderp):
+        line = line[len(autoderp) :]
+
+    if line == "# clippy{":
+        while lines:
+            line = lines.pop(0)
+            if line == "# }clippy":
+                break
+        continue
+
+    if line.startswith("#"):
+        out_lines.append(line)
+        continue
+
+    full_line = line
+    full_lines = lines[:]
+    while full_line.endswith("\\"):
+        full_line = full_line[:-1] + full_lines.pop(0)
+
+    m = make_rule_re.match(full_line)
+    if m is None:
+        out_lines.append(line)
+        continue
+
+    line, lines = full_line, full_lines
+
+    target, dep = m.group(1), m.group(2)
+
+    if target.endswith(".lo") or target.endswith(".o"):
+        if not dep.endswith(".h"):
+            bcdeps.append("%s.bc: %s" % (target, target))
+            bcdeps.append("\t$(AM_V_LLVM_BC)$(COMPILE) -emit-llvm -c -o $@ %s" % (dep))
+    if m.group(2) in clippy_scan:
+        out_lines.append(
+            clippyauxdep.substitute(target=m.group(1), clippybase=m.group(2)[:-2])
+        )
+
+    out_lines.append(line)
+
+out_lines.append("# clippy{\n# main clippy targets")
+for clippy_file in clippy_scan:
+    out_lines.append(clippydep.substitute(clippybase=clippy_file[:-2]))
+
+out_lines.append("")
+out_lines.extend(bcdeps)
+out_lines.append("")
+bc_targets = []
+for varname in [
+    "bin_PROGRAMS",
+    "sbin_PROGRAMS",
+    "lib_LTLIBRARIES",
+    "module_LTLIBRARIES",
+    "noinst_LIBRARIES",
+]:
+    bc_targets.extend(mv[varname].strip().split())
+for target in bc_targets:
+    amtgt = target.replace("/", "_").replace(".", "_").replace("-", "_")
+    objs = mv[amtgt + "_OBJECTS"].strip().split()
+    objs = [obj + ".bc" for obj in objs]
+    deps = mv.get(amtgt + "_DEPENDENCIES", "").strip().split()
+    deps = [d + ".bc" for d in deps if d.endswith(".a")]
+    objs.extend(deps)
+    out_lines.append("%s.bc: %s" % (target, " ".join(objs)))
+    out_lines.append("\t$(AM_V_LLVM_LD)$(LLVM_LINK) -o $@ $^")
+    out_lines.append("")
+
+out_lines.append("# }clippy")
+out_lines.append("")
+
+after = "\n".join(out_lines)
+if after == before:
+    sys.exit(0)
+
+with open("Makefile.pyout", "w") as fd:
+    fd.write(after)
+os.rename("Makefile.pyout", "Makefile")