Modify pnacl subzero to be able to read pnacl bitcode files.

llvm2iceinsts.py

Index: llvm2iceinsts.py
diff --git a/llvm2iceinsts.py b/llvm2iceinsts.py
new file mode 100755
index 0000000000000000000000000000000000000000..ebdd4578fb739e6a801045ddb9ce8f8b34b5547a
--- /dev/null
+++ b/llvm2iceinsts.py
@@ -0,0 +1,66 @@
+#!/usr/bin/env python2
+
+import argparse
+import itertools
+import os
+import re
+import subprocess
+import sys
+
+for p in sys.path:
+    if p.endswith('/toolchain_build/src/pnacl-subzero'):
+        sys.path.insert(0, p + '/pydir')
+        break

[JF, 2014/05/19 18:10:25]

Shouldn't that be in main?

[Karl, 2014/05/19 21:34:39]

Can't be. It is used to find module utils.

+
+from utils import shellcmd
+
+if __name__ == '__main__':
+    """Runs commands to convert llvm source file into ICE instructions.
+
+    Runs in two modes, depending on whether the flag '--pnacl' is specified.
+
+    If flag '--pnacl' is omitted, it runs llvm2ice to (directly) generate
+    the corresponding ICE instructions.
+
+    If flag '--pnacl' is given, it first assembles and freezes the
+    llvm source file generating the corresponding PNaCl bitcode
+    file. The PNaCl bitcode file is then piped into llvm2ice to
+    generate the corresponding ICE instructions.

[JF, 2014/05/19 18:10:25]

I think this docstring would be better as --help content for argparse (I'd drop
the docstring entirely).

[Karl, 2014/05/19 21:34:39]

Added as epilog.

+    """
+    desc = 'Run llvm2ice on llvm file to produce ICE instructions.'
+    argparser = argparse.ArgumentParser(description=desc)
+    argparser.add_argument(
+        '--llvm2ice', required=False, default='./llvm2ice', metavar='LLVM2ICE',
+        help='Path to llvm2ice driver program [default ./llvm2ice]')

[JF, 2014/05/19 18:10:25]

I think you should use this for default instead of specifying it manually:
https://docs.python.org/dev/library/argparse.html#argparse.ArgumentDefaultsHe...

[Karl, 2014/05/19 21:34:39]

Done.

+    argparser.add_argument('--llvm-bin-path', required=False,
+                           default=None, metavar='LLVM_BIN_PATH',
+                           help='Path to LLVM executables ' +
+                                '(for building PNaCl files)')
+    argparser.add_argument('--pnacl', required=False,
+                           action='store_true',
+                           help='Convert llvm source to PNaCl bitcode ' +
+                                'file first')
+    argparser.add_argument('--echo-cmd', required=False,
+                           action='store_true',
+                           help='Trace command that generates ICE instructions')
+    argparser.add_argument('llfile', nargs=1,
+                           metavar='LLVM_FILE',
+                           help='Llvm source file')
+    args = argparser.parse_args()
+    llvm_bin_path = args.llvm_bin_path
+    llfile = args.llfile[0]
+
+    cmd = []
+    if args.pnacl:
+      cmd = [os.path.join(llvm_bin_path, 'llvm-as'), llfile, '-o', '-', '|',
+             os.path.join(llvm_bin_path, 'pnacl-freeze'),
+             '--allow-local-symbol-tables', '|']
+    cmd += [args.llvm2ice, '-verbose', 'inst', '-notranslate']
+    if args.pnacl:
+      cmd += ['--allow-local-symbol-tables', '--bitcode-format=pnacl']
+    else:
+      cmd.append(llfile)
+
+    stdout_result = shellcmd(cmd, echo=args.echo_cmd)
+    if not args.echo_cmd:
+      sys.stdout.write(stdout_result)