Refactor GetSoftwareBreakpointTrapOpcode

This patch aims to reduce the code duplication among all of the platforms in GetSoftwareBreakpointTrapOpcode by pushing all common code into the Platform base class.

Differential Revision: http://reviews.llvm.org/D17395

llvm-svn: 261536

1 files changed, 103 insertions, 0 deletions

diff --git a/lldb/source/Target/Platform.cpp b/lldb/source/Target/Platform.cpp
index f92338e061f..bcf5241c50f 100644
--- a/lldb/source/Target/Platform.cpp
+++ b/lldb/source/Target/Platform.cpp
@@ -20,6 +20,7 @@
 // Project includes
 #include "lldb/Target/Platform.h"
 #include "lldb/Breakpoint/BreakpointIDList.h"
+#include "lldb/Breakpoint/BreakpointLocation.h"
 #include "lldb/Core/DataBufferHeap.h"
 #include "lldb/Core/Debugger.h"
 #include "lldb/Core/Error.h"
@@ -2046,3 +2047,105 @@ Platform::ConnectToWaitingProcesses(lldb_private::Debugger& debugger, lldb_priva
     error.Clear();
     return 0;
 }
+
+size_t
+Platform::GetSoftwareBreakpointTrapOpcode(Target &target, BreakpointSite *bp_site)
+{
+    ArchSpec arch = target.GetArchitecture();
+    const uint8_t *trap_opcode = nullptr;
+    size_t trap_opcode_size = 0;
+
+    switch (arch.GetMachine())
+    {
+    case llvm::Triple::aarch64:
+        {
+            static const uint8_t g_aarch64_opcode[] = {0x00, 0x00, 0x20, 0xd4};
+            trap_opcode = g_aarch64_opcode;
+            trap_opcode_size = sizeof(g_aarch64_opcode);
+        }
+        break;
+
+    // TODO: support big-endian arm and thumb trap codes.
+    case llvm::Triple::arm:
+        {
+            // The ARM reference recommends the use of 0xe7fddefe and 0xdefe
+            // but the linux kernel does otherwise.
+            static const uint8_t g_arm_breakpoint_opcode[] = {0xf0, 0x01, 0xf0, 0xe7};
+            static const uint8_t g_thumb_breakpoint_opcode[] = {0x01, 0xde};
+
+            lldb::BreakpointLocationSP bp_loc_sp(bp_site->GetOwnerAtIndex(0));
+            AddressClass addr_class = eAddressClassUnknown;
+
+            if (bp_loc_sp)
+            {
+                addr_class = bp_loc_sp->GetAddress().GetAddressClass();
+                if (addr_class == eAddressClassUnknown && (bp_loc_sp->GetAddress().GetFileAddress() & 1))
+                    addr_class = eAddressClassCodeAlternateISA;
+            }
+
+            if (addr_class == eAddressClassCodeAlternateISA)
+            {
+                trap_opcode = g_thumb_breakpoint_opcode;
+                trap_opcode_size = sizeof(g_thumb_breakpoint_opcode);
+            }
+            else
+            {
+                trap_opcode = g_arm_breakpoint_opcode;
+                trap_opcode_size = sizeof(g_arm_breakpoint_opcode);
+            }
+        }
+        break;
+
+    case llvm::Triple::mips64:
+        {
+            static const uint8_t g_hex_opcode[] = {0x00, 0x00, 0x00, 0x0d};
+            trap_opcode = g_hex_opcode;
+            trap_opcode_size = sizeof(g_hex_opcode);
+        }
+        break;
+
+    case llvm::Triple::mips64el:
+        {
+            static const uint8_t g_hex_opcode[] = {0x0d, 0x00, 0x00, 0x00};
+            trap_opcode = g_hex_opcode;
+            trap_opcode_size = sizeof(g_hex_opcode);
+        }
+        break;
+
+    case llvm::Triple::hexagon:
+        {
+            static const uint8_t g_hex_opcode[] = {0x0c, 0xdb, 0x00, 0x54};
+            trap_opcode = g_hex_opcode;
+            trap_opcode_size = sizeof(g_hex_opcode);
+        }
+        break;
+
+    case llvm::Triple::ppc:
+    case llvm::Triple::ppc64:
+        {
+            static const uint8_t g_ppc_opcode[] = {0x7f, 0xe0, 0x00, 0x08};
+            trap_opcode = g_ppc_opcode;
+            trap_opcode_size = sizeof(g_ppc_opcode);
+        }
+        break;
+
+    case llvm::Triple::x86:
+    case llvm::Triple::x86_64:
+        {
+            static const uint8_t g_i386_opcode[] = {0xCC};
+            trap_opcode = g_i386_opcode;
+            trap_opcode_size = sizeof(g_i386_opcode);
+        }
+        break;
+
+    default:
+        assert(!"Unhandled architecture in Platform::GetSoftwareBreakpointTrapOpcode");
+        break;
+    }
+
+    assert(bp_site);
+    if (bp_site->SetTrapOpcode(trap_opcode, trap_opcode_size))
+        return trap_opcode_size;
+
+    return 0;
+}