Initial revision

1 files changed, 122 insertions, 0 deletions

diff --git a/deheader b/deheader
new file mode 100755
index 0000000..e9a5429
--- /dev/null
+++ b/deheader
@@ -0,0 +1,122 @@
+#!/usr/bin/env python
+"""\
+deheader -- find (optionally remove) unneeded includes in C or C++ sourcefiles.
+
+Usage: deheader [-h] [-v] [-r] [-i str] sourcefiles
+    -h, --help     Emit this help message and quit.
+    -i, --ignore   Ignore (don't remove) headers containing the arg string
+    -r, --remove   Remove the final set of unneeded headers
+    -v, --verbose  Be chatty about what you're doing.
+
+This tool takes a list of C or C++ sourcefiles and generates a report
+on which #includes can be omitted from them -- the test, for each foo.c
+or foo.cc or foo.cpp, is simply whether 'rm foo.o; make foo.o' returns a
+zero status. Optionally, with the -r option, the unneeded headers are removed.
+
+The original sourcefile is moved to a name with an .orig suffix and restored
+on interrupt or after processing with its original timestamp, unless the
+-r option was given and headers removed.
+"""
+
+import sys, os, tempfile, getopt, time
+
+def trim(line):
+    "Get file reference from an #include, retaining <> if a system header."
+    trimmed = line[9:].strip()
+    if trimmed[0] in '"':
+        return '"' + trimmed.split('"')[1] + '"'
+    elif trimmed[0] == '<':
+        return trimmed.split('>')[0] + ">"
+    else:
+        return `line`
+
+def compile(source, msg=""):
+    (stem, suffix) = os.path.splitext(source)
+    derived = stem + ".o"
+    if os.path.exists(derived):
+        os.remove(derived)
+    command = "make " + derived
+    if verbose < 2:
+        command += " >/dev/null 2>&1"
+    start = time.time()
+    status = os.system(command)
+    end = time.time()
+    if status:
+        explain = "failed"
+        if verbose >= 2:
+            explain += " (%d)" % status
+    else:
+        explain = "succeeded"
+    if verbose:
+        print "deheader: %s%s %s in %2.2f sec." \
+          % (sourcefile, msg, explain, end-start)
+    return (status, end - start)
+
+if __name__ == "__main__":
+    (options, arguments) = getopt.getopt(sys.argv[1:], "hrvi:",
+                                         ["help", "ignore",
+                                          "remove", "verbose",])
+    verbose = 0
+    remove = False
+    ignores = []
+    for (switch, val) in options:
+        if switch in ('-h', '--help'):
+            sys.stderr.write(__doc__)
+            sys.exit(0)
+        elif switch in ('-i', '--ignore'):
+            ignores.append(val)
+        elif switch in ('-r', '--remove'):
+            remove = True
+        elif switch in ('-v', '--verbose'):
+            verbose += 1
+
+    for sourcefile in arguments:
+        (st, t) = compile(sourcefile)
+        if st != 0:
+            continue
+        includes = []
+        for line in open(sourcefile):
+            if line.startswith("#include"):
+                if verbose:
+                    print "deheader: %s requires %s" % (sourcefile, `line`)
+                for stopper in ignores:
+                    if stopper in line:
+                        break
+                else:
+                    includes.append(line)
+        # We'll remove headers in reverse order, because later unnecessary
+        # headers might depend on earlier ones
+        includes.reverse()
+        unneeded = []
+        original = sourcefile + ".orig"
+        try:
+            os.rename(sourcefile, original)
+            while True:                
+                keepgoing = False
+                for header in includes:
+                    ofp = open(sourcefile, "w")
+                    for line in open(original):
+                        if line != header:
+                            ofp.write(line)
+                    ofp.close()
+                    (st, t) = compile(sourcefile, " without %s" % trim(header))
+                    if st == 0:
+                        unneeded.append(header)
+                        includes.remove(header)
+                        keepgoing = True
+                if not keepgoing:
+                    break
+        finally:
+            os.remove(sourcefile)
+            os.rename(original, sourcefile)
+        if unneeded:
+            print "deheader: the following headers may be omitted from %s:" % sourcefile
+            print "\n".join(map(trim, unneeded))
+            if remove:
+                os.rename(sourcefile, original)
+                for header in includes:
+                    ofp = open(sourcefile, "w")
+                    for line in open(original):
+                        if line not in unneeded:
+                            ofp.write(line)
+                    ofp.close()