[Contribs] Add command-line utility for looking up gPXE error codes.

contrib/errcode/build_errcodedb.py

@@ -0,0 +1,66 @@
+#!/usr/bin/env python
+import sys
+import re
+
+pxenv_status_files = ('../../src/include/errno.h', )
+errfile_files = ('../../src/include/gpxe/errfile.h',
+            '../../src/arch/i386/include/bits/errfile.h')
+posix_errno_files = ('../../src/include/errno.h', )
+
+PXENV_STATUS_RE = re.compile(r'^#define\s+(PXENV_STATUS_[^\s]+)\s+(.+)$')
+ERRFILE_RE = re.compile(r'^#define\s+(ERRFILE_[^\s]+)\s+(.+)$')
+POSIX_ERRNO_RE = re.compile(r'^#define\s+(E[A-Z]+)\s+.*(0x[0-9a-f]+).*$')
+
+def err(msg):
+    sys.stderr.write('%s: %s\n' % (sys.argv[0], msg))
+    sys.exit(1)
+
+def load_header_file(filename, regexp):
+    defines = {}
+    for line in open(filename, 'r'):
+        m = regexp.match(line)
+        if m:
+            key, val = m.groups()
+            defines[key] = val
+    return defines
+
+def evaluate(defines, expr):
+    pyexpr = ''
+    for token in expr.split():
+        if token in '()':
+            pass
+        elif token.startswith('/*') or token.startswith('//'):
+            break
+        elif token.startswith('0x') or token == '|':
+            pyexpr += token
+        else:
+            if token in defines:
+                pyexpr += '0x%x' % defines[token]
+            else:
+                return -1
+    if not re.match(r'^[0-9a-zA-Z_|]+$', pyexpr):
+        err('invalid expression')
+    return eval(pyexpr)
+
+def build(filenames, regexp):
+    unevaluated = {}
+    for filename in filenames:
+        unevaluated.update(load_header_file(filename, regexp))
+
+    evaluated = {}
+    changed = True
+    while changed:
+        changed = False
+        for key in list(unevaluated.keys()):
+            val = evaluate(evaluated, unevaluated[key])
+            if val != -1:
+                del unevaluated[key]
+                evaluated[key] = val
+                changed = True
+    if unevaluated:
+        err('unable to evaluate all #defines')
+    return evaluated
+
+print 'pxenv_status =', repr(build(pxenv_status_files, PXENV_STATUS_RE))
+print 'errfile =', repr(build(errfile_files, ERRFILE_RE))
+print 'posix_errno =', repr(build(posix_errno_files, POSIX_ERRNO_RE))