TCG frontend coverage

c2t.py

@@ -5,6 +5,7 @@
     stderr
 )
 from os.path import (
+    abspath,
     getmtime,
     relpath,
     dirname,
@@ -13,6 +14,8 @@
     basename
 )
 from os import (
+    walk,
+    remove,
     makedirs,
     killpg,
     setpgrp
@@ -68,6 +71,7 @@
     pypath
 )
 from debug import (
+    create_dwarf_cache,
     get_elffile_loading,
     InMemoryELFFile,
     DWARFInfoCache,
@@ -92,6 +96,10 @@
     DebugServer,
     TestBuilder
 )
+from qemu import (
+    qemu_build_dir_by_dwarf,
+    qemu_target_dir_by_dwarf
+)
 
 C2T_ERRMSG_FORMAT = "{prog}:\x1b[31m error:\x1b[0m {msg}\n"
 
@@ -767,6 +775,23 @@ def main():
         metavar = "N",
         help = "stop on N-th error, 0 - no stop mode"
     )
+    parser.add_argument("-q", "--qemu",
+        nargs = "?",
+        metavar = "executable",
+        help = "ignore the option in config"
+    )
+    parser.add_argument("-c", "--lcov",
+        action = "store_true",
+        help = "estimate TCG frontend coverage by this test session"
+    )
+    parser.add_argument("--coverage-output",
+        default = "c2t.coverage",
+        help = "directory for genhtml (lcov) coverage report"
+    )
+    parser.add_argument("-b", "--build",
+        nargs = "?",
+        help = "explicitly set QEMU build directory"
+    )
 
     args = parser.parse_args()
 
@@ -813,6 +838,9 @@ def main():
 
     verify_config_components(config)
 
+    if args.qemu:
+        c2t_cfg.qemu.run.executable = args.qemu
+
     incl, regexp, tests = args.regexps.find_files(C2T_TEST_DIR)
     if not tests:
         parser.error("no matches in {dir} with {var} {regexp}".format(
@@ -825,6 +853,52 @@ def main():
     if jobs < 1:
         parser.error("wrong number of jobs: %s" % jobs)
 
+    lcov = args.lcov
+    if lcov:
+        # XXX: Coverage estimation is a monkey style code. But it's better
+        # than working with lcov manually.
+
+        # Here we looking for TCG frontend build directory because estimation
+        # of whole Qemu coverage is time consuming and is not a point of c2t.
+        qemu_exe = c2t_cfg.qemu.run.executable
+        dic = create_dwarf_cache(qemu_exe)
+
+        build_dir = args.build
+        if not build_dir:
+            try:
+                build_dir = qemu_build_dir_by_dwarf(dic)
+            except RuntimeError:
+                print("Use -b option to set QEMU build directory explicitly")
+                raise
+
+        arch = qemu_exe.split('-')[-1]
+        if "system" in qemu_exe:
+            build_dir_suffix = arch + "-softmmu"
+        else:
+            build_dir_suffix = arch + "-linux-user"
+
+        target_build_dir = join(build_dir, build_dir_suffix)
+
+        # find TCG frontend build directory
+        for frontend_build_dir, __, files in walk(target_build_dir):
+            # TCG frontend build directory normally contains translate.o.
+            # Name of the directory may vary between qemu version.
+            if "translate.o" in files:
+                break
+        else:
+            print("c2t cannot find TCG frontend build directory")
+            return
+
+        # reset previous coverage
+        lcov = Popen(["lcov",
+            "--zerocounters",
+            "--directory", frontend_build_dir
+        ])
+        if lcov.wait():
+            # lcov likely print an error message, so we only conclude...
+            print("c2t stopped because of lcov failure")
+            return
+
     # creates tests subdirectories if they don't exist
     for sub_dir in (C2T_TEST_IR_DIR, C2T_TEST_BIN_DIR):
         if not exists(sub_dir):
@@ -833,6 +907,34 @@ def main():
     start_cpu_testing(tests, jobs, args.reuse, args.verbose,
         errors2stop = args.errors
     )
+
+    if lcov:
+        target_dir = qemu_target_dir_by_dwarf(dic.di)
+        lcov = Popen(["lcov",
+            "--output-file", "c2t.coverage.info",
+            "--capture",
+            "--base-directory", target_dir,
+            "--no-external", # TCG frontend coverage only
+            "--directory", frontend_build_dir
+        ])
+        if lcov.wait():
+            print("Failed to build coverage report")
+            return
+
+        genhtml = Popen(["genhtml",
+            "--output-directory", args.coverage_output,
+            "c2t.coverage.info"
+        ])
+        if genhtml.wait():
+            print("HTML coverage report generation has failed")
+        else:
+            # Note, genhtml prints some coverage statistic to stdout
+            print("HTML coverage report: "
+                + abspath(join(args.coverage_output, "index.html"))
+            )
+
+        remove("c2t.coverage.info")
+
     killpg(0, SIGTERM)
 
 

c2t/config.py

@@ -24,10 +24,13 @@
     "C2TConfig",
     "rsp_target qemu gdbserver target_compiler oracle_compiler"
 )
-Run = namedtuple(
-    "Run",
-    "executable args"
-)
+
+
+class Run(object):
+
+    def __init__(self, executable, args):
+        self.executable = executable
+        self.args = args
 
 
 def get_new_rsp(regs, pc, regsize, little_endian = True):
@@ -69,7 +72,8 @@ def __init__(self, run):
 
     @property
     def run_script(self):
-        return ' '.join(self.run)
+        run = self.run
+        return run.executable + " " + run.args
 
 
 class TestBuilder(tuple):
@@ -81,4 +85,4 @@ def __new__(cls, *runs):
     @property
     def run_script(self):
         for run in self:
-            yield ' '.join(run)
+            yield run.executable + " " + run.args

qemu/dwarf_hacks.py

@@ -0,0 +1,58 @@
+__all__ = [
+    "qemu_build_dir_by_dwarf"
+  , "qemu_target_dir_by_dwarf"
+]
+
+from os.path import (
+    abspath,
+    dirname
+)
+from six import (
+    PY3
+)
+from common import (
+    bsep
+)
+
+
+def qemu_build_dir_by_dwarf(dia):
+    # Sometimes trace-root.h is included by its absolute path:
+    # /path/to/build/directory/./trace-root.h
+    for cu in dia.di.iter_CUs():
+        for f in dia.get_CU_files(cu):
+            #           v--- because of /./
+            if len(f) > 2 and f[-1] == b"trace-root.h":
+                break
+        else:
+            continue
+        break
+    else:
+        raise RuntimeError(
+            "Nothing includes trace-root.h by absolute path"
+        )
+
+    f = bsep.join(f)
+
+    if PY3:
+        # TODO: Is DWARF file name encoding always utf-8?
+        f = f.decode("utf-8")
+
+    return dirname(abspath(f))
+
+
+def qemu_target_dir_by_dwarf(dwarf_info):
+    # There is a convention that TCG frontend (qemu target) has
+    # translate.c file in its directory.
+    # Also, there is only one TCG frontend per qemu binary.
+    for cu in dwarf_info.iter_CUs():
+        src_file = cu.get_top_DIE().attributes["DW_AT_name"].value
+        if src_file.endswith(b"translate.c"):
+            break
+    else:
+        raise RuntimeError("No compile unit for translate.c found")
+
+    if PY3:
+        # TODO: Is DWARF file name encoding always utf-8?
+        src_file = src_file.decode("utf-8")
+
+    return dirname(abspath(src_file))