Implement interactive command interruption

The core of this change is the new CommandInterpreter::m_command_state,
which models the state transitions for interactive commands, including
an "interrupted" state transition.

In general, command interruption requires cooperation from the code
executing the command, which needs to poll for interruption requests
through CommandInterpreter::WasInterrupted().

CommandInterpreter::PrintCommandOutput() implements an optionally
interruptible printing of the command output, which for large outputs 
was likely the longest blocking part.
(ex. target modules dump symtab on a complex binary could take 10+ minutes)

Differential Revision: https://reviews.llvm.org/D37923

llvm-svn: 315037

1 files changed, 14 insertions, 0 deletions

diff --git a/lldb/source/Commands/CommandObjectTarget.cpp b/lldb/source/Commands/CommandObjectTarget.cpp
index bb1b3f8ae7d..4eaec5b4cea 100644
--- a/lldb/source/Commands/CommandObjectTarget.cpp
+++ b/lldb/source/Commands/CommandObjectTarget.cpp
@@ -2053,6 +2053,8 @@ protected:
               result.GetOutputStream().EOL();
               result.GetOutputStream().EOL();
             }
+            if (m_interpreter.WasInterrupted())
+              break;
             num_dumped++;
             DumpModuleSymtab(
                 m_interpreter, result.GetOutputStream(),
@@ -2081,6 +2083,8 @@ protected:
                   result.GetOutputStream().EOL();
                   result.GetOutputStream().EOL();
                 }
+                if (m_interpreter.WasInterrupted())
+                  break;
                 num_dumped++;
                 DumpModuleSymtab(m_interpreter, result.GetOutputStream(),
                                  module, m_options.m_sort_order);
@@ -2146,6 +2150,8 @@ protected:
                                           " modules.\n",
                                           (uint64_t)num_modules);
           for (size_t image_idx = 0; image_idx < num_modules; ++image_idx) {
+            if (m_interpreter.WasInterrupted())
+              break;
             num_dumped++;
             DumpModuleSections(
                 m_interpreter, result.GetOutputStream(),
@@ -2167,6 +2173,8 @@ protected:
               FindModulesByName(target, arg_cstr, module_list, true);
           if (num_matches > 0) {
             for (size_t i = 0; i < num_matches; ++i) {
+              if (m_interpreter.WasInterrupted())
+                break;
               Module *module = module_list.GetModulePointerAtIndex(i);
               if (module) {
                 num_dumped++;
@@ -2239,6 +2247,8 @@ protected:
                                           " modules.\n",
                                           (uint64_t)num_modules);
           for (uint32_t image_idx = 0; image_idx < num_modules; ++image_idx) {
+            if (m_interpreter.WasInterrupted())
+              break;
             if (DumpModuleSymbolVendor(
                     result.GetOutputStream(),
                     target_modules.GetModulePointerAtIndexUnlocked(image_idx)))
@@ -2260,6 +2270,8 @@ protected:
               FindModulesByName(target, arg_cstr, module_list, true);
           if (num_matches > 0) {
             for (size_t i = 0; i < num_matches; ++i) {
+              if (m_interpreter.WasInterrupted())
+                break;
               Module *module = module_list.GetModulePointerAtIndex(i);
               if (module) {
                 if (DumpModuleSymbolVendor(result.GetOutputStream(), module))
@@ -2327,6 +2339,8 @@ protected:
         if (num_modules > 0) {
           uint32_t num_dumped = 0;
           for (uint32_t i = 0; i < num_modules; ++i) {
+            if (m_interpreter.WasInterrupted())
+              break;
             if (DumpCompileUnitLineTable(
                     m_interpreter, result.GetOutputStream(),
                     target_modules.GetModulePointerAtIndexUnlocked(i),