[dev.cc] runtime: convert signal handlers from C to Go

This code overused macros and could not be
converted automatically. Instead a new sigctxt
type had to be defined for each os/arch combination,
with a common (implicit) interface used by the
arch-specific signal handler code.

[This CL is part of the removal of C code from package runtime.
See golang.org/s/dev.cc for an overview.]

LGTM=r
R=r
CC=austin, dvyukov, golang-codereviews, iant, khr
https://golang.org/cl/168500044

1 files changed, 48 insertions, 0 deletions

diff --git a/src/runtime/signal_linux_arm.go b/src/runtime/signal_linux_arm.go
new file mode 100644
index 0000000000..4a5670e740
--- /dev/null
+++ b/src/runtime/signal_linux_arm.go
@@ -0,0 +1,48 @@
+// Copyright 2013 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package runtime
+
+import "unsafe"
+
+type sigctxt struct {
+	info *siginfo
+	ctxt unsafe.Pointer
+}
+
+func (c *sigctxt) regs() *sigcontext { return &(*ucontext)(c.ctxt).uc_mcontext }
+func (c *sigctxt) r0() uint32        { return c.regs().r0 }
+func (c *sigctxt) r1() uint32        { return c.regs().r1 }
+func (c *sigctxt) r2() uint32        { return c.regs().r2 }
+func (c *sigctxt) r3() uint32        { return c.regs().r3 }
+func (c *sigctxt) r4() uint32        { return c.regs().r4 }
+func (c *sigctxt) r5() uint32        { return c.regs().r5 }
+func (c *sigctxt) r6() uint32        { return c.regs().r6 }
+func (c *sigctxt) r7() uint32        { return c.regs().r7 }
+func (c *sigctxt) r8() uint32        { return c.regs().r8 }
+func (c *sigctxt) r9() uint32        { return c.regs().r9 }
+func (c *sigctxt) r10() uint32       { return c.regs().r10 }
+func (c *sigctxt) fp() uint32        { return c.regs().fp }
+func (c *sigctxt) ip() uint32        { return c.regs().ip }
+func (c *sigctxt) sp() uint32        { return c.regs().sp }
+func (c *sigctxt) lr() uint32        { return c.regs().lr }
+func (c *sigctxt) pc() uint32        { return c.regs().pc }
+func (c *sigctxt) cpsr() uint32      { return c.regs().cpsr }
+func (c *sigctxt) fault() uint32     { return c.regs().fault_address }
+func (c *sigctxt) trap() uint32      { return c.regs().trap_no }
+func (c *sigctxt) error() uint32     { return c.regs().error_code }
+func (c *sigctxt) oldmask() uint32   { return c.regs().oldmask }
+
+func (c *sigctxt) sigcode() uint32 { return uint32(c.info.si_code) }
+func (c *sigctxt) sigaddr() uint32 { return uint32(*(*uintptr)(add(unsafe.Pointer(c.info), 2*ptrSize))) }
+
+func (c *sigctxt) set_pc(x uint32)  { c.regs().pc = x }
+func (c *sigctxt) set_sp(x uint32)  { c.regs().sp = x }
+func (c *sigctxt) set_lr(x uint32)  { c.regs().lr = x }
+func (c *sigctxt) set_r10(x uint32) { c.regs().r10 = x }
+
+func (c *sigctxt) set_sigcode(x uint32) { c.info.si_code = int32(x) }
+func (c *sigctxt) set_sigaddr(x uint32) {
+	*(*uintptr)(add(unsafe.Pointer(c.info), 2*ptrSize)) = uintptr(x)
+}