Add the ability to disassemble "n" instructions from the current PC, or the first "n" instructions in a function.
Also added a "-p" flag that disassembles from the current pc.

git-svn-id: https://llvm.org/svn/llvm-project/llvdb/trunk@128063 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/Commands/CommandObjectDisassemble.cpp b/source/Commands/CommandObjectDisassemble.cpp
index a4dd5ac..ecfd30f 100644
--- a/source/Commands/CommandObjectDisassemble.cpp
+++ b/source/Commands/CommandObjectDisassemble.cpp
@@ -27,15 +27,19 @@
 #include "lldb/Target/Target.h"
 
 #define DEFAULT_DISASM_BYTE_SIZE 32
+#define DEFAULT_DISASM_NUM_INS  4
 
 using namespace lldb;
 using namespace lldb_private;
 
 CommandObjectDisassemble::CommandOptions::CommandOptions () :
     Options(),
+    num_lines_context(0),
+    num_instructions (0),
     m_func_name(),
     m_start_addr(),
-    m_end_addr ()
+    m_end_addr (),
+    m_at_pc (false)
 {
     ResetOptionValues();
 }
@@ -51,14 +55,24 @@
 
     char short_option = (char) m_getopt_table[option_idx].val;
 
+    bool success;
+    
     switch (short_option)
     {
     case 'm':
         show_mixed = true;
         break;
 
+    case 'x':
+        num_lines_context = Args::StringToUInt32(option_arg, 0, 0, &success);
+        if (!success)
+            error.SetErrorStringWithFormat ("Invalid num context lines string: \"%s\".\n", option_arg);
+        break;
+
     case 'c':
-        num_lines_context = Args::StringToUInt32(option_arg, 0, 0);
+        num_instructions = Args::StringToUInt32(option_arg, 0, 0, &success);
+        if (!success)
+            error.SetErrorStringWithFormat ("Invalid num of instructions string: \"%s\".\n", option_arg);
         break;
 
     case 'b':
@@ -66,26 +80,30 @@
         break;
 
     case 's':
-        m_start_addr = Args::StringToUInt64(optarg, LLDB_INVALID_ADDRESS, 0);
+        m_start_addr = Args::StringToUInt64(option_arg, LLDB_INVALID_ADDRESS, 0);
         if (m_start_addr == LLDB_INVALID_ADDRESS)
-            m_start_addr = Args::StringToUInt64(optarg, LLDB_INVALID_ADDRESS, 16);
+            m_start_addr = Args::StringToUInt64(option_arg, LLDB_INVALID_ADDRESS, 16);
 
         if (m_start_addr == LLDB_INVALID_ADDRESS)
-            error.SetErrorStringWithFormat ("Invalid start address string '%s'.\n", optarg);
+            error.SetErrorStringWithFormat ("Invalid start address string '%s'.\n", option_arg);
         break;
     case 'e':
-        m_end_addr = Args::StringToUInt64(optarg, LLDB_INVALID_ADDRESS, 0);
+        m_end_addr = Args::StringToUInt64(option_arg, LLDB_INVALID_ADDRESS, 0);
         if (m_end_addr == LLDB_INVALID_ADDRESS)
-            m_end_addr = Args::StringToUInt64(optarg, LLDB_INVALID_ADDRESS, 16);
+            m_end_addr = Args::StringToUInt64(option_arg, LLDB_INVALID_ADDRESS, 16);
 
         if (m_end_addr == LLDB_INVALID_ADDRESS)
-            error.SetErrorStringWithFormat ("Invalid end address string '%s'.\n", optarg);
+            error.SetErrorStringWithFormat ("Invalid end address string '%s'.\n", option_arg);
         break;
 
     case 'n':
         m_func_name = option_arg;
         break;
 
+    case 'p':
+        m_at_pc = true;
+        break;
+
     case 'r':
         raw = true;
         break;
@@ -110,7 +128,9 @@
     show_mixed = false;
     show_bytes = false;
     num_lines_context = 0;
+    num_instructions = 0;
     m_func_name.clear();
+    m_at_pc = false;
     m_start_addr = LLDB_INVALID_ADDRESS;
     m_end_addr = LLDB_INVALID_ADDRESS;
     raw = false;
@@ -126,16 +146,24 @@
 CommandObjectDisassemble::CommandOptions::g_option_table[] =
 {
 { LLDB_OPT_SET_ALL, false, "bytes",    'b', no_argument,       NULL, 0, eArgTypeNone,             "Show opcode bytes when disassembling."},
-{ LLDB_OPT_SET_ALL, false, "context",  'c', required_argument, NULL, 0, eArgTypeNumLines,    "Number of context lines of source to show."},
+{ LLDB_OPT_SET_ALL, false, "context",  'x', required_argument, NULL, 0, eArgTypeNumLines,    "Number of context lines of source to show."},
 { LLDB_OPT_SET_ALL, false, "mixed",    'm', no_argument,       NULL, 0, eArgTypeNone,             "Enable mixed source and assembly display."},
 { LLDB_OPT_SET_ALL, false, "raw",      'r', no_argument,       NULL, 0, eArgTypeNone,             "Print raw disassembly with no symbol information."},
 
 { LLDB_OPT_SET_1, true, "start-address",  's', required_argument, NULL, 0, eArgTypeStartAddress,      "Address at which to start disassembling."},
 { LLDB_OPT_SET_1, false, "end-address",  'e', required_argument, NULL, 0, eArgTypeEndAddress,      "Address at which to end disassembling."},
 
-{ LLDB_OPT_SET_2, true, "name",     'n', required_argument, NULL, CommandCompletions::eSymbolCompletion, eArgTypeFunctionName,             "Disassemble entire contents of the given function name."},
+{ LLDB_OPT_SET_2, true, "start-address",  's', required_argument, NULL, 0, eArgTypeStartAddress,      "Address at which to start disassembling."},
+{ LLDB_OPT_SET_2, false, "instruction-count",  'c', required_argument, NULL, 0, eArgTypeNumLines,      "Number of instructions to display."},
 
-{ LLDB_OPT_SET_3, true, "current-frame", 'f',  no_argument, NULL, 0, eArgTypeNone,             "Disassemble entire contents of the current frame's function."},
+{ LLDB_OPT_SET_3, true, "name",     'n', required_argument, NULL, CommandCompletions::eSymbolCompletion, eArgTypeFunctionName,             "Disassemble entire contents of the given function name."},
+{ LLDB_OPT_SET_3, false, "instruction-count",  'c', required_argument, NULL, 0, eArgTypeNumLines,      "Number of instructions to display."},
+
+{ LLDB_OPT_SET_4, true, "current-frame", 'f',  no_argument, NULL, 0, eArgTypeNone,             "Disassemble from the start of the current frame's function."},
+{ LLDB_OPT_SET_4, false, "instruction-count",  'c', required_argument, NULL, 0, eArgTypeNumLines,      "Number of instructions to display."},
+
+{ LLDB_OPT_SET_5, true, "current-pc", 'p',  no_argument, NULL, 0, eArgTypeNone,             "Disassemble from the current pc."},
+{ LLDB_OPT_SET_5, false, "instruction-count",  'c', required_argument, NULL, 0, eArgTypeNumLines,      "Number of instructions to display."},
 
 { 0, false, NULL, 0, 0, NULL, 0, eArgTypeNone, NULL }
 };
@@ -202,11 +230,12 @@
         result.SetStatus (eReturnStatusFailed);
         return false;
     }
-    ExecutionContext exe_ctx(m_interpreter.GetDebugger().GetExecutionContext());
-
+    
     if (m_options.show_mixed && m_options.num_lines_context == 0)
         m_options.num_lines_context = 1;
 
+    ExecutionContext exe_ctx(m_interpreter.GetDebugger().GetExecutionContext());
+
     if (!m_options.m_func_name.empty())
     {
         ConstString name(m_options.m_func_name.c_str());
@@ -216,6 +245,7 @@
                                        exe_ctx,
                                        name,
                                        NULL,    // Module *
+                                       m_options.num_instructions,
                                        m_options.show_mixed ? m_options.num_lines_context : 0,
                                        m_options.show_bytes,
                                        m_options.raw,
@@ -231,61 +261,132 @@
     } 
     else
     {
-        AddressRange range;
-        if (m_options.m_start_addr != LLDB_INVALID_ADDRESS)
+        Address start_addr;
+        lldb::addr_t range_byte_size = DEFAULT_DISASM_BYTE_SIZE;
+        
+        if (m_options.m_at_pc)
         {
-            range.GetBaseAddress().SetOffset (m_options.m_start_addr);
-            if (m_options.m_end_addr != LLDB_INVALID_ADDRESS)
+            if (exe_ctx.frame == NULL)
             {
-                if (m_options.m_end_addr < m_options.m_start_addr)
-                {
-                    result.AppendErrorWithFormat ("End address before start address.\n");
-                    result.SetStatus (eReturnStatusFailed);
-                    return false;            
-                }
-                range.SetByteSize (m_options.m_end_addr - m_options.m_start_addr);
-            }
-            else
-                range.SetByteSize (DEFAULT_DISASM_BYTE_SIZE);
-        } 
-        else
-        {
-            // The default action is to disassemble the current frame function.
-            if (exe_ctx.frame)
-            {
-                SymbolContext sc(exe_ctx.frame->GetSymbolContext(eSymbolContextFunction | eSymbolContextSymbol));
-                if (sc.function)
-                    range = sc.function->GetAddressRange();
-                else if (sc.symbol && sc.symbol->GetAddressRangePtr())
-                    range = *sc.symbol->GetAddressRangePtr();
-                else
-                    range.GetBaseAddress() = exe_ctx.frame->GetFrameCodeAddress();
-            }
-            else
-            {
-                result.AppendError ("invalid frame");
+                result.AppendError ("Cannot disassemble around the current PC without a selected frame.\n");
                 result.SetStatus (eReturnStatusFailed);
                 return false;
             }
-        }
-        if (range.GetByteSize() == 0)
-            range.SetByteSize(DEFAULT_DISASM_BYTE_SIZE);
-
-        if (Disassembler::Disassemble (m_interpreter.GetDebugger(), 
-                                       arch,
-                                       exe_ctx,
-                                       range,
-                                       m_options.show_mixed ? m_options.num_lines_context : 0,
-                                       m_options.show_bytes,
-                                       m_options.raw,
-                                       result.GetOutputStream()))
-        {
-            result.SetStatus (eReturnStatusSuccessFinishResult);
+            start_addr = exe_ctx.frame->GetFrameCodeAddress();
+            if (m_options.num_instructions == 0)
+            {
+                // Disassembling at the PC always disassembles some number of instructions (not the whole function).
+                m_options.num_instructions = DEFAULT_DISASM_NUM_INS;
+            }
         }
         else
         {
-            result.AppendErrorWithFormat ("Failed to disassemble memory at 0x%8.8llx.\n", m_options.m_start_addr);
-            result.SetStatus (eReturnStatusFailed);            
+            start_addr.SetOffset (m_options.m_start_addr);
+            if (start_addr.IsValid())
+            {
+                if (m_options.m_end_addr != LLDB_INVALID_ADDRESS)
+                {
+                    if (m_options.m_end_addr < m_options.m_start_addr)
+                    {
+                        result.AppendErrorWithFormat ("End address before start address.\n");
+                        result.SetStatus (eReturnStatusFailed);
+                        return false;            
+                    }
+                    range_byte_size = m_options.m_end_addr - m_options.m_start_addr;
+                }
+            }
+        }
+        
+        if (m_options.num_instructions != 0)
+        {
+            if (!start_addr.IsValid())
+            {
+                // The default action is to disassemble the current frame function.
+                if (exe_ctx.frame)
+                {
+                    SymbolContext sc(exe_ctx.frame->GetSymbolContext(eSymbolContextFunction | eSymbolContextSymbol));
+                    if (sc.function)
+                        start_addr = sc.function->GetAddressRange().GetBaseAddress();
+                    else if (sc.symbol && sc.symbol->GetAddressRangePtr())
+                        start_addr = sc.symbol->GetAddressRangePtr()->GetBaseAddress();
+                    else
+                        start_addr = exe_ctx.frame->GetFrameCodeAddress();
+                }
+                
+                if (!start_addr.IsValid())
+                {
+                    result.AppendError ("invalid frame");
+                    result.SetStatus (eReturnStatusFailed);
+                    return false;
+                }
+            }
+
+            if (Disassembler::Disassemble (m_interpreter.GetDebugger(), 
+                                           arch,
+                                           exe_ctx,
+                                           start_addr,
+                                           m_options.num_instructions,
+                                           m_options.show_mixed ? m_options.num_lines_context : 0,
+                                           m_options.show_bytes,
+                                           m_options.raw,
+                                           result.GetOutputStream()))
+            {
+                result.SetStatus (eReturnStatusSuccessFinishResult);
+            }
+            else
+            {
+                result.AppendErrorWithFormat ("Failed to disassemble memory at 0x%8.8llx.\n", m_options.m_start_addr);
+                result.SetStatus (eReturnStatusFailed);            
+            }
+        }
+        else
+        {
+            AddressRange range;
+            if (start_addr.IsValid())
+            {
+                range.GetBaseAddress() = start_addr;
+                range.SetByteSize (range_byte_size);
+            } 
+            else
+            {
+                // The default action is to disassemble the current frame function.
+                if (exe_ctx.frame)
+                {
+                    SymbolContext sc(exe_ctx.frame->GetSymbolContext(eSymbolContextFunction | eSymbolContextSymbol));
+                    if (sc.function)
+                        range = sc.function->GetAddressRange();
+                    else if (sc.symbol && sc.symbol->GetAddressRangePtr())
+                        range = *sc.symbol->GetAddressRangePtr();
+                    else
+                        range.GetBaseAddress() = exe_ctx.frame->GetFrameCodeAddress();
+                }
+                else
+                {
+                    result.AppendError ("invalid frame");
+                    result.SetStatus (eReturnStatusFailed);
+                    return false;
+                }
+            }
+            if (range.GetByteSize() == 0)
+                range.SetByteSize(DEFAULT_DISASM_BYTE_SIZE);
+
+            if (Disassembler::Disassemble (m_interpreter.GetDebugger(), 
+                                           arch,
+                                           exe_ctx,
+                                           range,
+                                           m_options.num_instructions,
+                                           m_options.show_mixed ? m_options.num_lines_context : 0,
+                                           m_options.show_bytes,
+                                           m_options.raw,
+                                           result.GetOutputStream()))
+            {
+                result.SetStatus (eReturnStatusSuccessFinishResult);
+            }
+            else
+            {
+                result.AppendErrorWithFormat ("Failed to disassemble memory at 0x%8.8llx.\n", m_options.m_start_addr);
+                result.SetStatus (eReturnStatusFailed);            
+            }
         }
     }