From d104270f8412381b5eb7715a775c3999f28b740c Mon Sep 17 00:00:00 2001
From: Jan Vorlicek <janvorli@microsoft.com>
Date: Thu, 22 Mar 2018 01:11:59 +0100
Subject: Remove dependency on libunwind (#17094)

* Add original source of libunwind 1.3-stable

Taken from:
https://github.com/libunwind/libunwind/tree/v1.3-stable

* Enable building of libunwind

This change enables building libunwind and removes
dependency on the libunwind package for all Unixes
except OSX. In OSX the libunwind is part of the OS
and also has support for compact unwind info that
is OSX specific, so we keep using that one.

* Disable warnings in code we don't execute
---
 src/pal/src/libunwind/src/x86/Gstep.c | 115 ++++++++++++++++++++++++++++++++++
 1 file changed, 115 insertions(+)
 create mode 100644 src/pal/src/libunwind/src/x86/Gstep.c

(limited to 'src/pal/src/libunwind/src/x86/Gstep.c')

diff --git a/src/pal/src/libunwind/src/x86/Gstep.c b/src/pal/src/libunwind/src/x86/Gstep.c
new file mode 100644
index 0000000000..129b739a3e
--- /dev/null
+++ b/src/pal/src/libunwind/src/x86/Gstep.c
@@ -0,0 +1,115 @@
+/* libunwind - a platform-independent unwind library
+   Copyright (C) 2002-2004 Hewlett-Packard Co
+        Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
+
+This file is part of libunwind.
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
+
+#include "unwind_i.h"
+#include "offsets.h"
+
+int
+unw_step (unw_cursor_t *cursor)
+{
+  struct cursor *c = (struct cursor *) cursor;
+  int ret, i;
+
+  Debug (1, "(cursor=%p, ip=0x%08x)\n", c, (unsigned) c->dwarf.ip);
+
+  /* Try DWARF-based unwinding... */
+  ret = dwarf_step (&c->dwarf);
+
+  if (ret < 0 && ret != -UNW_ENOINFO)
+    {
+      Debug (2, "returning %d\n", ret);
+      return ret;
+    }
+
+  if (unlikely (ret < 0))
+    {
+      /* DWARF failed, let's see if we can follow the frame-chain
+         or skip over the signal trampoline.  */
+      struct dwarf_loc ebp_loc, eip_loc;
+
+      /* We could get here because of missing/bad unwind information.
+         Validate all addresses before dereferencing. */
+      c->validate = 1;
+
+      Debug (13, "dwarf_step() failed (ret=%d), trying frame-chain\n", ret);
+
+      if (unw_is_signal_frame (cursor) > 0)
+        {
+          ret = x86_handle_signal_frame(cursor);
+          if (ret < 0)
+            {
+              Debug (2, "returning 0\n");
+              return 0;
+            }
+        }
+      else
+        {
+          ret = dwarf_get (&c->dwarf, c->dwarf.loc[EBP], &c->dwarf.cfa);
+          if (ret < 0)
+            {
+              Debug (2, "returning %d\n", ret);
+              return ret;
+            }
+
+          Debug (13, "[EBP=0x%x] = 0x%x\n", DWARF_GET_LOC (c->dwarf.loc[EBP]),
+                 c->dwarf.cfa);
+
+          ebp_loc = DWARF_LOC (c->dwarf.cfa, 0);
+          eip_loc = DWARF_LOC (c->dwarf.cfa + 4, 0);
+          c->dwarf.cfa += 8;
+
+          /* Mark all registers unsaved, since we don't know where
+             they are saved (if at all), except for the EBP and
+             EIP.  */
+          for (i = 0; i < DWARF_NUM_PRESERVED_REGS; ++i)
+            c->dwarf.loc[i] = DWARF_NULL_LOC;
+
+          c->dwarf.loc[EBP] = ebp_loc;
+          c->dwarf.loc[EIP] = eip_loc;
+          c->dwarf.use_prev_instr = 1;
+        }
+
+      if (!DWARF_IS_NULL_LOC (c->dwarf.loc[EBP]))
+        {
+          ret = dwarf_get (&c->dwarf, c->dwarf.loc[EIP], &c->dwarf.ip);
+          if (ret < 0)
+            {
+              Debug (13, "dwarf_get([EIP=0x%x]) failed\n", DWARF_GET_LOC (c->dwarf.loc[EIP]));
+              Debug (2, "returning %d\n", ret);
+              return ret;
+            }
+          else
+            {
+              Debug (13, "[EIP=0x%x] = 0x%x\n", DWARF_GET_LOC (c->dwarf.loc[EIP]),
+                c->dwarf.ip);
+            }
+        }
+      else
+        c->dwarf.ip = 0;
+    }
+  ret = (c->dwarf.ip == 0) ? 0 : 1;
+  Debug (2, "returning %d\n", ret);
+  return ret;
+}
-- 
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