Move to Python 3. (#218)

The impetus for this was mostly that after my Ubuntu upgrade, pylint
suddenly starting to apply python3 rules, and I suppose it's time to
adopt python 3 now that it's been released for more than a decade.

4 files changed, 78 insertions, 75 deletions

diff --git a/debug/gdbserver.py b/debug/gdbserver.py
index 84d3f1d..c34e341 100755
--- a/debug/gdbserver.py
+++ b/debug/gdbserver.py
@@ -1,8 +1,9 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import argparse
 import binascii
 import random
+import struct
 import sys
 import tempfile
 import time
@@ -11,7 +12,7 @@ import os
 import targets
 import testlib
 from testlib import assertEqual, assertNotEqual, assertIn, assertNotIn
-from testlib import assertGreater, assertRegexpMatches, assertLess
+from testlib import assertGreater, assertRegex, assertLess
 from testlib import GdbTest, GdbSingleHartTest, TestFailed
 from testlib import assertTrue, TestNotApplicable
 
@@ -52,14 +53,14 @@ def ihex_line(address, record_type, data):
     return line
 
 def srec_parse(line):
-    assert line.startswith('S')
+    assert line.startswith(b'S')
     typ = line[:2]
     count = int(line[2:4], 16)
     data = ""
-    if typ == 'S0':
+    if typ == b'S0':
         # header
         return 0, 0, 0
-    elif typ == 'S3':
+    elif typ == b'S3':
         # data with 32-bit address
         # Any higher bits were chopped off.
         address = int(line[4:12], 16)
@@ -67,7 +68,7 @@ def srec_parse(line):
             data += "%c" % int(line[2*i:2*i+2], 16)
         # Ignore the checksum.
         return 3, address, data
-    elif typ == 'S7':
+    elif typ == b'S7':
         # ignore execution start field
         return 7, 0, 0
     else:
@@ -142,9 +143,9 @@ class SimpleF18Test(SimpleRegisterTest):
                 assertEqual(size, 4)
         else:
             output = self.gdb.p_raw("$" + name)
-            assertRegexpMatches(output, r"void|Could not fetch register.*")
+            assertRegex(output, r"void|Could not fetch register.*")
             output = self.gdb.p_raw("$" + alias)
-            assertRegexpMatches(output, r"void|Could not fetch register.*")
+            assertRegex(output, r"void|Could not fetch register.*")
 
     def test(self):
         self.check_reg("f18", "fs2")
@@ -154,7 +155,7 @@ class CustomRegisterTest(SimpleRegisterTest):
         return self.target.implements_custom_test
 
     def check_custom(self, magic):
-        regs = {k: v for k, v in self.gdb.info_registers("all").iteritems()
+        regs = {k: v for k, v in self.gdb.info_registers("all").items()
                 if k.startswith("custom")}
         assertEqual(set(regs.keys()),
                 set(("custom1",
@@ -162,7 +163,7 @@ class CustomRegisterTest(SimpleRegisterTest):
                     "custom12346",
                     "custom12347",
                     "custom12348")))
-        for name, value in regs.iteritems():
+        for name, value in regs.items():
             number = int(name[6:])
             if number % 2:
                 expect = number + magic
@@ -305,11 +306,12 @@ class MemTestBlock(GdbTest):
 
     def write(self, temporary_file):
         data = ""
-        for i in range(self.length / self.line_length):
+        for i in range(self.length // self.line_length):
             line_data = "".join(["%c" % random.randrange(256)
                 for _ in range(self.line_length)])
             data += line_data
-            temporary_file.write(ihex_line(i * self.line_length, 0, line_data))
+            temporary_file.write(ihex_line(i * self.line_length, 0,
+                line_data).encode())
         temporary_file.flush()
         return data
 
@@ -321,7 +323,7 @@ class MemTestBlock(GdbTest):
         self.gdb.command("monitor riscv reset_delays 50")
         self.gdb.command("restore %s 0x%x" % (a.name, self.hart.ram))
         increment = 19 * 4
-        for offset in range(0, self.length, increment) + [self.length-4]:
+        for offset in list(range(0, self.length, increment)) + [self.length-4]:
             value = self.gdb.p("*((int*)0x%x)" % (self.hart.ram + offset))
             written = ord(data[offset]) | \
                     (ord(data[offset+1]) << 8) | \
@@ -335,7 +337,7 @@ class MemTestBlock(GdbTest):
             self.hart.ram, self.hart.ram + self.length), ops=self.length / 32)
         self.gdb.command("shell cat %s" % b.name)
         highest_seen = 0
-        for line in b.xreadlines():
+        for line in b:
             record_type, address, line_data = srec_parse(line)
             if record_type == 3:
                 offset = address - (self.hart.ram & 0xffffffff)
@@ -551,7 +553,7 @@ class Hwbp1(DebugTest):
         for _ in range(2):
             output = self.gdb.c()
             self.gdb.p("$pc")
-            assertRegexpMatches(output, r"[bB]reakpoint")
+            assertRegex(output, r"[bB]reakpoint")
             assertIn("rot13 ", output)
         self.gdb.b("_exit")
         self.exit()
@@ -568,7 +570,7 @@ class Hwbp2(DebugTest):
         for expected in ("main", "rot13", "rot13"):
             output = self.gdb.c()
             self.gdb.p("$pc")
-            assertRegexpMatches(output, r"[bB]reakpoint")
+            assertRegex(output, r"[bB]reakpoint")
             assertIn("%s " % expected, output)
         self.gdb.command("delete")
         self.gdb.b("_exit")
@@ -598,14 +600,14 @@ class Registers(DebugTest):
             for reg in ('zero', 'ra', 'sp', 'gp', 'tp'):
                 assertIn(reg, output)
             for line in output.splitlines():
-                assertRegexpMatches(line, r"^\S")
+                assertRegex(line, r"^\S")
 
         #TODO
         # mcpuid is one of the few registers that should have the high bit set
         # (for rv64).
         # Leave this commented out until gdb and spike agree on the encoding of
         # mcpuid (which is going to be renamed to misa in any case).
-        #assertRegexpMatches(output, ".*mcpuid *0x80")
+        #assertRegex(output, ".*mcpuid *0x80")
 
         #TODO:
         # The instret register should always be changing.
@@ -884,9 +886,9 @@ class SmpSimultaneousRunHalt(GdbTest):
             old_mtime.update(mtime_value)
 
             mtime_spread = max(mtime_value) - min(mtime_value)
-            print "mtime_spread:", mtime_spread
+            print("mtime_spread:", mtime_spread)
             counter_spread = max(counter) - min(counter)
-            print "counter_spread:", counter_spread
+            print("counter_spread:", counter_spread)
 
             assertLess(mtime_spread, 101 * (len(self.target.harts) - 1),
                     "Harts don't halt around the same time.")
@@ -935,9 +937,9 @@ class JumpHbreak(GdbSingleHartTest):
         self.gdb.b("read_loop")
         self.gdb.command("hbreak just_before_read_loop")
         output = self.gdb.command("jump just_before_read_loop")
-        assertRegexpMatches(output, r"Breakpoint \d, just_before_read_loop ")
+        assertRegex(output, r"Breakpoint \d, just_before_read_loop ")
         output = self.gdb.c()
-        assertRegexpMatches(output, r"Breakpoint \d, read_loop ")
+        assertRegex(output, r"Breakpoint \d, read_loop ")
 
 class TriggerTest(GdbSingleHartTest):
     compile_args = ("programs/trigger.S", )
@@ -1131,24 +1133,24 @@ class DownloadTest(GdbTest):
         length = min(2**14, max(2**10, self.hart.ram_size - 2048))
         self.download_c = tempfile.NamedTemporaryFile(prefix="download_",
                 suffix=".c", delete=False)
-        self.download_c.write("#include <stdint.h>\n")
+        self.download_c.write(b"#include <stdint.h>\n")
         self.download_c.write(
-                "unsigned int crc32a(uint8_t *message, unsigned int size);\n")
-        self.download_c.write("uint32_t length = %d;\n" % length)
-        self.download_c.write("uint8_t d[%d] = {\n" % length)
+                b"unsigned int crc32a(uint8_t *message, unsigned int size);\n")
+        self.download_c.write(b"uint32_t length = %d;\n" % length)
+        self.download_c.write(b"uint8_t d[%d] = {\n" % length)
         self.crc = 0
         assert length % 16 == 0
-        for i in range(length / 16):
-            self.download_c.write("  /* 0x%04x */ " % (i * 16))
+        for i in range(length // 16):
+            self.download_c.write(("  /* 0x%04x */ " % (i * 16)).encode())
             for _ in range(16):
                 value = random.randrange(1<<8)
-                self.download_c.write("0x%02x, " % value)
-                self.crc = binascii.crc32("%c" % value, self.crc)
-            self.download_c.write("\n")
-        self.download_c.write("};\n")
-        self.download_c.write("uint8_t *data = &d[0];\n")
+                self.download_c.write(("0x%02x, " % value).encode())
+                self.crc = binascii.crc32(struct.pack("B", value), self.crc)
+            self.download_c.write(b"\n")
+        self.download_c.write(b"};\n")
+        self.download_c.write(b"uint8_t *data = &d[0];\n")
         self.download_c.write(
-                "uint32_t main() { return crc32a(data, length); }\n")
+                b"uint32_t main() { return crc32a(data, length); }\n")
         self.download_c.flush()
 
         if self.crc < 0:
diff --git a/debug/pylint.rc b/debug/pylint.rc
index 0d9a640..cf07149 100644
--- a/debug/pylint.rc
+++ b/debug/pylint.rc
@@ -48,7 +48,8 @@ extension-pkg-whitelist=
 # no Warning level messages displayed, use"--disable=all --enable=classes
 # --disable=W"
 disable=bad-continuation, missing-docstring, invalid-name, locally-disabled,
-    too-few-public-methods, too-many-arguments, fixme, duplicate-code
+    too-few-public-methods, too-many-arguments, fixme, duplicate-code,
+    no-else-return
 
 
 [REPORTS]
diff --git a/debug/targets.py b/debug/targets.py
index d83e84b..d797f64 100644
--- a/debug/targets.py
+++ b/debug/targets.py
@@ -5,7 +5,7 @@ import tempfile
 
 import testlib
 
-class Hart(object):
+class Hart:
     # XLEN of the hart. May be overridden with --32 or --64 command line
     # options.
     xlen = 0
@@ -45,7 +45,7 @@ class Hart(object):
             return self.misa & (1 << (ord(letter.upper()) - ord('A')))
         return False
 
-class Target(object):
+class Target:
     # pylint: disable=too-many-instance-attributes
 
     # List of Hart object instances, one for each hart in the target.
@@ -117,7 +117,6 @@ class Target(object):
 
     def create(self):
         """Create the target out of thin air, eg. start a simulator."""
-        pass
 
     def server(self):
         """Start the debug server that gdb connects to, eg. OpenOCD."""
diff --git a/debug/testlib.py b/debug/testlib.py
index 60cb897..1aa0e5b 100644
--- a/debug/testlib.py
+++ b/debug/testlib.py
@@ -38,17 +38,17 @@ def compile(args): # pylint: disable=redefined-builtin
         else:
             cmd.append(arg)
     header("Compile")
-    print "+", " ".join(cmd)
+    print("+", " ".join(cmd))
     process = subprocess.Popen(cmd, stdout=subprocess.PIPE,
                                stderr=subprocess.PIPE)
     stdout, stderr = process.communicate()
     if process.returncode:
-        print stdout,
-        print stderr,
+        print(stdout, end=" ")
+        print(stderr, end=" ")
         header("")
         raise Exception("Compile failed!")
 
-class Spike(object):
+class Spike:
     # pylint: disable=too-many-instance-attributes
     # pylint: disable=too-many-locals
     def __init__(self, target, halted=False, timeout=None, with_jtag_gdb=True,
@@ -81,7 +81,7 @@ class Spike(object):
         self.logname = self.logfile.name
         if print_log_names:
             real_stdout.write("Temporary spike log: %s\n" % self.logname)
-        self.logfile.write("+ %s\n" % " ".join(cmd))
+        self.logfile.write(("+ %s\n" % " ".join(cmd)).encode())
         self.logfile.flush()
         self.process = subprocess.Popen(cmd, stdin=subprocess.PIPE,
                 stdout=self.logfile, stderr=self.logfile)
@@ -170,7 +170,7 @@ class Spike(object):
     def wait(self, *args, **kwargs):
         return self.process.wait(*args, **kwargs)
 
-class VcsSim(object):
+class VcsSim:
     logfile = tempfile.NamedTemporaryFile(prefix='simv', suffix='.log')
     logname = logfile.name
 
@@ -223,7 +223,7 @@ class VcsSim(object):
         except OSError:
             pass
 
-class Openocd(object):
+class Openocd:
     logfile = tempfile.NamedTemporaryFile(prefix='openocd', suffix='.log')
     logname = logfile.name
 
@@ -255,7 +255,7 @@ class Openocd(object):
         if config:
             self.config_file = find_file(config)
             if self.config_file is None:
-                print "Unable to read file " + config
+                print("Unable to read file", config)
                 exit(1)
 
             cmd += ["-f", self.config_file]
@@ -306,7 +306,7 @@ class Openocd(object):
 
                 if not messaged and time.time() - start > 1:
                     messaged = True
-                    print "Waiting for OpenOCD to start..."
+                    print("Waiting for OpenOCD to start...")
                 if (time.time() - start) > self.timeout:
                     raise Exception("Timed out waiting for OpenOCD to "
                             "listen for gdb")
@@ -330,12 +330,12 @@ class Openocd(object):
     def smp(self):
         """Return true iff OpenOCD internally sees the harts as part of an SMP
         group."""
-        for line in file(self.config_file, "r"):
+        for line in open(self.config_file, "r"):
             if "target smp" in line:
                 return True
         return False
 
-class OpenocdCli(object):
+class OpenocdCli:
     def __init__(self, port=4444):
         self.child = pexpect.spawn(
                 "sh -c 'telnet localhost %d | tee openocd-cli.log'" % port)
@@ -346,7 +346,7 @@ class OpenocdCli(object):
         self.child.expect(cmd)
         self.child.expect("\n")
         self.child.expect("> ")
-        return self.child.before.strip("\t\r\n \0")
+        return self.child.before.strip("\t\r\n \0").decode("utf-8")
 
     def reg(self, reg=''):
         output = self.command("reg %s" % reg)
@@ -383,7 +383,7 @@ def parse_rhs(text):
         if all([isinstance(p, dict) for p in parsed]):
             dictionary = {}
             for p in parsed:
-                for k, v in p.iteritems():
+                for k, v in p.items():
                     dictionary[k] = v
             parsed = dictionary
         return parsed
@@ -394,12 +394,12 @@ def parse_rhs(text):
         return {lhs: parse_rhs(rhs)}
     elif re.match(r"-?(\d+\.\d+(e-?\d+)?|inf)", text):
         return float(text)
-    elif re.match(r"-nan\(0x[a-f0-9]+\)", text):
+    elif re.match(r"-?nan\(0x[a-f0-9]+\)", text):
         return float("nan")
     else:
         return int(text, 0)
 
-class Gdb(object):
+class Gdb:
     """A single gdb class which can interact with one or more gdb instances."""
 
     # pylint: disable=too-many-public-methods
@@ -428,7 +428,7 @@ class Gdb(object):
                 real_stdout.write("Temporary gdb log: %s\n" % logfile.name)
             child = pexpect.spawn(cmd)
             child.logfile = logfile
-            child.logfile.write("+ %s\n" % cmd)
+            child.logfile.write(("+ %s\n" % cmd).encode())
             self.children.append(child)
         self.active_child = self.children[0]
 
@@ -468,7 +468,7 @@ class Gdb(object):
             del child
 
     def one_hart_per_gdb(self):
-        return all(h['solo'] for h in self.harts.itervalues())
+        return all(h['solo'] for h in self.harts.values())
 
     def lognames(self):
         return [logfile.name for logfile in self.logfiles]
@@ -504,7 +504,7 @@ class Gdb(object):
         self.active_child.sendline(command)
         self.active_child.expect("\n", timeout=timeout)
         self.active_child.expect(r"\(gdb\)", timeout=timeout)
-        return self.active_child.before.strip()
+        return self.active_child.before.strip().decode("utf-8")
 
     def global_command(self, command):
         """Execute this command on every gdb that we control."""
@@ -559,7 +559,7 @@ class Gdb(object):
     def interrupt(self, ops=1):
         self.active_child.send("\003")
         self.active_child.expect(r"\(gdb\)", timeout=self.timeout * ops)
-        return self.active_child.before.strip()
+        return self.active_child.before.strip().decode()
 
     def interrupt_all(self):
         for child in self.children:
@@ -678,7 +678,7 @@ class Gdb(object):
     def where(self):
         return self.command("where 1")
 
-class PrivateState(object):
+class PrivateState:
     def __init__(self, gdb):
         self.gdb = gdb
 
@@ -706,9 +706,9 @@ def run_all_tests(module, target, parsed):
     for hart in target.harts:
         if parsed.misaval:
             hart.misa = int(parsed.misaval, 16)
-            print "Using $misa from command line: 0x%x" % hart.misa
+            print("Using $misa from command line: 0x%x" % hart.misa)
         elif hart.misa:
-            print "Using $misa from hart definition: 0x%x" % hart.misa
+            print("Using $misa from hart definition: 0x%x" % hart.misa)
         elif not examine_added:
             todo.append(("ExamineTarget", ExamineTarget, None))
             examine_added = True
@@ -735,7 +735,7 @@ def run_tests(parsed, target, todo):
         log_name = os.path.join(parsed.logs, "%s-%s-%s.log" %
                 (time.strftime("%Y%m%d-%H%M%S"), type(target).__name__, name))
         log_fd = open(log_name, 'w')
-        print "[%s] Starting > %s" % (name, log_name)
+        print("[%s] Starting > %s" % (name, log_name))
         instance = definition(target, hart)
         sys.stdout.flush()
         log_fd.write("Test: %s\n" % name)
@@ -754,7 +754,7 @@ def run_tests(parsed, target, todo):
             sys.stdout = real_stdout
             log_fd.write("Time elapsed: %.2fs\n" % (time.time() - start))
             log_fd.flush()
-        print "[%s] %s in %.2fs" % (name, result, time.time() - start)
+        print("[%s] %s in %.2fs" % (name, result, time.time() - start))
         if result not in good_results and parsed.print_failures:
             sys.stdout.write(open(log_name).read())
         sys.stdout.flush()
@@ -767,12 +767,12 @@ def run_tests(parsed, target, todo):
 
 def print_results(results):
     result = 0
-    for key, value in results.iteritems():
-        print "%d tests returned %s" % (len(value), key)
+    for key, value in results.items():
+        print("%d tests returned %s" % (len(value), key))
         if key not in good_results:
             result = 1
             for name, log_name in value:
-                print "   %s > %s" % (name, log_name)
+                print("   %s > %s" % (name, log_name))
 
     return result
 
@@ -797,22 +797,22 @@ def add_test_run_options(parser):
 def header(title, dash='-', length=78):
     if title:
         dashes = dash * (length - 4 - len(title))
-        before = dashes[:len(dashes)/2]
-        after = dashes[len(dashes)/2:]
-        print "%s[ %s ]%s" % (before, title, after)
+        before = dashes[:len(dashes)//2]
+        after = dashes[len(dashes)//2:]
+        print("%s[ %s ]%s" % (before, title, after))
     else:
-        print dash * length
+        print(dash * length)
 
 def print_log_handle(name, handle):
     header(name)
     for l in handle:
         sys.stdout.write(l)
-    print
+    print()
 
 def print_log(path):
     print_log_handle(path, open(path, "r"))
 
-class BaseTest(object):
+class BaseTest:
     compiled = {}
 
     def __init__(self, target, hart=None):
@@ -893,15 +893,16 @@ class BaseTest(object):
             else:
                 result = "exception"
             if isinstance(e, TestFailed):
+                # pylint: disable=no-member
                 header("Message")
-                print e.message
+                print(e.message)
             header("Traceback")
             traceback.print_exc(file=sys.stdout)
             try:
                 self.postMortem()
             except Exception as e:  # pylint: disable=broad-except
                 header("postMortem Exception")
-                print e
+                print(e)
                 traceback.print_exc(file=sys.stdout)
             return result
 
@@ -1007,7 +1008,7 @@ class ExamineTarget(GdbTest):
             for i in range(26):
                 if hart.misa & (1<<i):
                     txt += chr(i + ord('A'))
-            print txt,
+            print(txt, end=" ")
 
 class TestFailed(Exception):
     def __init__(self, message, comment=None):
@@ -1049,6 +1050,6 @@ def assertTrue(a):
     if not a:
         raise TestFailed("%r is not True" % a)
 
-def assertRegexpMatches(text, regexp):
+def assertRegex(text, regexp):
     if not re.search(regexp, text):
         raise TestFailed("can't find %r in %r" % (regexp, text))