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, 125 insertions, 0 deletions

diff --git a/src/sim/syscall_desc.hh b/src/sim/syscall_desc.hh
new file mode 100644
index 000000000..4c3ae0463
--- /dev/null
+++ b/src/sim/syscall_desc.hh
@@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 2012-2013, 2015 ARM Limited
+ * Copyright (c) 2015-2016 Advanced Micro Devices, Inc.
+ * All rights reserved
+ *
+ * The license below extends only to copyright in the software and shall
+ * not be construed as granting a license to any other intellectual
+ * property including but not limited to intellectual property relating
+ * to a hardware implementation of the functionality of the software
+ * licensed hereunder.  You may use the software subject to the license
+ * terms below provided that you ensure that this notice is replicated
+ * unmodified and in its entirety in all distributions of the software,
+ * modified or unmodified, in source code or in binary form.
+ *
+ * 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
+ *          Kevin Lim
+ *          Brandon Potter
+ */
+
+#ifndef __SIM_SYSCALL_DESC_HH__
+#define __SIM_SYSCALL_DESC_HH__
+
+#include <string>
+
+class LiveProcess;
+class SyscallReturn;
+class ThreadContext;
+
+/**
+ * This class provides the wrapper interface for the system call
+ * implementations which are defined in the sim/syscall_emul files and
+ * bound to the ISAs in the architecture specific code
+ * (i.e. arch/X86/linux/process.cc).
+ */
+class SyscallDesc {
+  public:
+    /** Typedef the function pointer here to clean up code below */
+    typedef SyscallReturn (*SyscallExecutor)(SyscallDesc*, int num,
+                                             LiveProcess*, ThreadContext*);
+
+    SyscallDesc(const char *name, SyscallExecutor sys_exec, int flags = 0)
+        : _name(name), executor(sys_exec), _flags(flags), _warned(false)
+    {
+    }
+
+    /** Provide a mechanism to specify behavior for abnormal system calls */
+    enum Flags {
+        /**
+         * Do not set return registers according to executor return value.
+         * Used for system calls with non-standard return conventions that
+         * explicitly set the thread context regs (e.g., sigreturn, clone)
+         */
+        SuppressReturnValue = 1,
+        /** Warn only once for unimplemented system calls */
+        WarnOnce = 2
+        /* X2 = 4, // Remove these comments when the next field is added; */
+        /* X3 = 8, // point is to make it obvious that this defines vector */
+    };
+
+    /**
+     * Interface for invoking the system call funcion pointer. Note that
+     * this acts as a gateway for all system calls and serves a good point
+     * to add filters for behaviors or apply checks for all system calls.
+     * @param callnum Number associated with call (by operating system)
+     * @param proc Handle for the owning Process to pass information
+     * @param tc Handle for owning ThreadContext to pass information
+     */
+    void doSyscall(int callnum, LiveProcess *proc, ThreadContext *tc);
+
+    /**
+     * Return false if WarnOnce is set and a warning has already been issued.
+     * Otherwise, return true. Updates state as a side effect to help
+     * keep track of issued warnings.
+     */
+    bool needWarning();
+
+    bool warnOnce() const { return (_flags & WarnOnce); }
+
+    std::string name() { return _name; }
+
+  private:
+    /** System call name (e.g., open, mmap, clone, socket, etc.) */
+    std::string _name;
+
+    /** Mechanism for ISAs to connect to the emul function definitions */
+    SyscallExecutor executor;
+
+    /**
+     * Holds values set with the preceding enum; note that this has been
+     * used primarily for features that are mutually exclusive, but there's
+     * no reason that this needs to be true going forward.
+     */
+    int _flags;
+
+    /** Set if WarnOnce is specified in flags AFTER first call */
+    bool _warned;
+};
+
+#endif // __SIM_SYSCALL_DESC_HH__