syscall_emul: [patch 2/22] move SyscallDesc into its own .hh and .cc

The class was crammed into syscall_emul.hh which has tons of forward
declarations and template definitions. To clean it up a bit, moved the
class into separate files and commented the class with doxygen style
comments. Also, provided some encapsulation by adding some accessors and
a mutator.

The syscallreturn.hh file was renamed syscall_return.hh to make it consistent
with other similarly named files in the src/sim directory.

The DPRINTF_SYSCALL macro was moved into its own header file with the
include the Base and Verbose flags as well.

--HG--
rename : src/sim/syscallreturn.hh => src/sim/syscall_return.hh

1 files changed, 88 insertions, 0 deletions

diff --git a/src/sim/syscall_desc.cc b/src/sim/syscall_desc.cc
new file mode 100644
index 000000000..34fb43dae
--- /dev/null
+++ b/src/sim/syscall_desc.cc
@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2016 Advanced Micro Devices, Inc.
+ * Copyright (c) 2003-2005 The Regents of The University of Michigan
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Steve Reinhardt
+ *          Ali Saidi
+ *          Brandon Potter
+ */
+
+#include "sim/syscall_desc.hh"
+
+#include "base/trace.hh"
+#include "config/the_isa.hh"
+#include "cpu/base.hh"
+#include "cpu/thread_context.hh"
+#include "sim/process.hh"
+#include "sim/syscall_debug_macros.hh"
+#include "sim/syscall_return.hh"
+
+void
+SyscallDesc::doSyscall(int callnum, LiveProcess *process, ThreadContext *tc)
+{
+    TheISA::IntReg arg[6] M5_VAR_USED;
+
+    /**
+     * Step through the first six parameters for the system call and
+     * retrieve their values. Note that index is incremented as a
+     * side-effect of the calling method.
+     */
+    for (int index = 0; index < 6; )
+        arg[index] = process->getSyscallArg(tc, index);
+
+    /**
+     * Linux supports up to six system call arguments through registers
+     * so we want to print all six. Check to the relevant man page to
+     * verify how many are actually used by a given system call.
+     */
+    DPRINTF_SYSCALL(Base, "%s called w/arguments %d, %d, %d, %d, %d, %d\n",
+                    _name, arg[0], arg[1], arg[2], arg[3], arg[4], arg[5]);
+
+    /** Invoke the system call */
+    SyscallReturn retval = (*executor)(this, callnum, process, tc);
+
+    /**
+     * If the system call needs to be restarted, most likely due to
+     * blocking behavior, warn that the system call will retry;
+     * alternatively, print the return value.
+     */
+    if (retval.needsRetry())
+        DPRINTF_SYSCALL(Base, "%s needs retry\n", _name);
+    else
+        DPRINTF_SYSCALL(Base, "%s returns %d\n", _name, retval.encodedValue());
+
+    if (!(_flags & SyscallDesc::SuppressReturnValue) && !retval.needsRetry())
+        process->setSyscallReturn(tc, retval);
+}
+
+bool
+SyscallDesc::needWarning()
+{
+    bool suppress_warning = warnOnce() && _warned;
+    _warned = true;
+    return !suppress_warning;
+}