Reland "[lldb] Add --all option to "memory region""

This reverts commit 3e928c4b9dfb01efd2cb968795e605760828e873.

This fixes an issue seen on Windows where we did not properly
get the section names of regions if they overlapped. Windows
has regions like:
[0x00007fff928db000-0x00007fff949a0000) ---
[0x00007fff949a0000-0x00007fff949a1000) r-- PECOFF header
[0x00007fff949a0000-0x00007fff94a3d000) r-x .hexpthk
[0x00007fff949a0000-0x00007fff94a85000) r-- .rdata
[0x00007fff949a0000-0x00007fff94a88000) rw- .data
[0x00007fff949a0000-0x00007fff94a94000) r-- .pdata
[0x00007fff94a94000-0x00007fff95250000) ---

I assumed that you could just resolve the address and get the section
name using the start of the region but here you'd always get
"PECOFF header" because they all have the same start point.

The usual command repeating loop used the end address of the previous
region when requesting the next, or getting the section name.
So I've matched this in the --all scenario.

In the example above, somehow asking for the region at
0x00007fff949a1000 would get you a region that starts at
0x00007fff949a0000 but has a different end point. Using the load
address you get (what I assume is) the correct section name.

1 files changed, 145 insertions, 50 deletions

diff --git a/lldb/source/Commands/CommandObjectMemory.cpp b/lldb/source/Commands/CommandObjectMemory.cpp
index f13f749..7005db3 100644
--- a/lldb/source/Commands/CommandObjectMemory.cpp
+++ b/lldb/source/Commands/CommandObjectMemory.cpp
@@ -1643,19 +1643,113 @@ protected:
 // CommandObjectMemoryRegion
 #pragma mark CommandObjectMemoryRegion
 
+#define LLDB_OPTIONS_memory_region
+#include "CommandOptions.inc"
+
 class CommandObjectMemoryRegion : public CommandObjectParsed {
 public:
+  class OptionGroupMemoryRegion : public OptionGroup {
+  public:
+    OptionGroupMemoryRegion() : OptionGroup(), m_all(false, false) {}
+
+    ~OptionGroupMemoryRegion() override = default;
+
+    llvm::ArrayRef<OptionDefinition> GetDefinitions() override {
+      return llvm::makeArrayRef(g_memory_region_options);
+    }
+
+    Status SetOptionValue(uint32_t option_idx, llvm::StringRef option_value,
+                          ExecutionContext *execution_context) override {
+      Status status;
+      const int short_option = g_memory_region_options[option_idx].short_option;
+
+      switch (short_option) {
+      case 'a':
+        m_all.SetCurrentValue(true);
+        m_all.SetOptionWasSet();
+        break;
+      default:
+        llvm_unreachable("Unimplemented option");
+      }
+
+      return status;
+    }
+
+    void OptionParsingStarting(ExecutionContext *execution_context) override {
+      m_all.Clear();
+    }
+
+    OptionValueBoolean m_all;
+  };
+
   CommandObjectMemoryRegion(CommandInterpreter &interpreter)
       : CommandObjectParsed(interpreter, "memory region",
                             "Get information on the memory region containing "
                             "an address in the current target process.",
-                            "memory region ADDR",
+                            "memory region <address-expression> (or --all)",
                             eCommandRequiresProcess | eCommandTryTargetAPILock |
-                                eCommandProcessMustBeLaunched) {}
+                                eCommandProcessMustBeLaunched) {
+    // Address in option set 1.
+    m_arguments.push_back(CommandArgumentEntry{CommandArgumentData(
+        eArgTypeAddressOrExpression, eArgRepeatPlain, LLDB_OPT_SET_1)});
+    // "--all" will go in option set 2.
+    m_option_group.Append(&m_memory_region_options);
+    m_option_group.Finalize();
+  }
 
   ~CommandObjectMemoryRegion() override = default;
 
+  Options *GetOptions() override { return &m_option_group; }
+
 protected:
+  void DumpRegion(CommandReturnObject &result, Target &target,
+                  const MemoryRegionInfo &range_info, lldb::addr_t load_addr) {
+    lldb_private::Address addr;
+    ConstString section_name;
+    if (target.ResolveLoadAddress(load_addr, addr)) {
+      SectionSP section_sp(addr.GetSection());
+      if (section_sp) {
+        // Got the top most section, not the deepest section
+        while (section_sp->GetParent())
+          section_sp = section_sp->GetParent();
+        section_name = section_sp->GetName();
+      }
+    }
+
+    ConstString name = range_info.GetName();
+    result.AppendMessageWithFormatv(
+        "[{0:x16}-{1:x16}) {2:r}{3:w}{4:x}{5}{6}{7}{8}",
+        range_info.GetRange().GetRangeBase(),
+        range_info.GetRange().GetRangeEnd(), range_info.GetReadable(),
+        range_info.GetWritable(), range_info.GetExecutable(), name ? " " : "",
+        name, section_name ? " " : "", section_name);
+    MemoryRegionInfo::OptionalBool memory_tagged = range_info.GetMemoryTagged();
+    if (memory_tagged == MemoryRegionInfo::OptionalBool::eYes)
+      result.AppendMessage("memory tagging: enabled");
+
+    const llvm::Optional<std::vector<addr_t>> &dirty_page_list =
+        range_info.GetDirtyPageList();
+    if (dirty_page_list.hasValue()) {
+      const size_t page_count = dirty_page_list.getValue().size();
+      result.AppendMessageWithFormat(
+          "Modified memory (dirty) page list provided, %zu entries.\n",
+          page_count);
+      if (page_count > 0) {
+        bool print_comma = false;
+        result.AppendMessageWithFormat("Dirty pages: ");
+        for (size_t i = 0; i < page_count; i++) {
+          if (print_comma)
+            result.AppendMessageWithFormat(", ");
+          else
+            print_comma = true;
+          result.AppendMessageWithFormat("0x%" PRIx64,
+                                         dirty_page_list.getValue()[i]);
+        }
+        result.AppendMessageWithFormat(".\n");
+      }
+    }
+  }
+
   bool DoExecute(Args &command, CommandReturnObject &result) override {
     ProcessSP process_sp = m_exe_ctx.GetProcessSP();
     if (!process_sp) {
@@ -1672,6 +1766,13 @@ protected:
     const lldb::ABISP &abi = process_sp->GetABI();
 
     if (argc == 1) {
+      if (m_memory_region_options.m_all) {
+        result.AppendError(
+            "The \"--all\" option cannot be used when an address "
+            "argument is given");
+        return false;
+      }
+
       auto load_addr_str = command[0].ref();
       // Non-address bits in this will be handled later by GetMemoryRegion
       load_addr = OptionArgParser::ToAddress(&m_exe_ctx, load_addr_str,
@@ -1685,67 +1786,58 @@ protected:
                // When we're repeating the command, the previous end address is
                // used for load_addr. If that was 0xF...F then we must have
                // reached the end of memory.
-               (argc == 0 && load_addr == LLDB_INVALID_ADDRESS) ||
+               (argc == 0 && !m_memory_region_options.m_all &&
+                load_addr == LLDB_INVALID_ADDRESS) ||
                // If the target has non-address bits (tags, limited virtual
                // address size, etc.), the end of mappable memory will be lower
                // than that. So if we find any non-address bit set, we must be
                // at the end of the mappable range.
                (abi && (abi->FixAnyAddress(load_addr) != load_addr))) {
-      result.AppendErrorWithFormat("'%s' takes one argument:\nUsage: %s\n",
-                                   m_cmd_name.c_str(), m_cmd_syntax.c_str());
+      result.AppendErrorWithFormat(
+          "'%s' takes one argument or \"--all\" option:\nUsage: %s\n",
+          m_cmd_name.c_str(), m_cmd_syntax.c_str());
       return false;
     }
 
-    lldb_private::MemoryRegionInfo range_info;
-    error = process_sp->GetMemoryRegionInfo(load_addr, range_info);
-    if (error.Success()) {
-      lldb_private::Address addr;
-      ConstString name = range_info.GetName();
-      ConstString section_name;
-      if (process_sp->GetTarget().ResolveLoadAddress(load_addr, addr)) {
-        SectionSP section_sp(addr.GetSection());
-        if (section_sp) {
-          // Got the top most section, not the deepest section
-          while (section_sp->GetParent())
-            section_sp = section_sp->GetParent();
-          section_name = section_sp->GetName();
+    // Is is important that we track the address used to request the region as
+    // this will give the correct section name in the case that regions overlap.
+    // On Windows we get mutliple regions that start at the same place but are
+    // different sizes and refer to different sections.
+    std::vector<std::pair<lldb_private::MemoryRegionInfo, lldb::addr_t>>
+        region_list;
+    if (m_memory_region_options.m_all) {
+      // We don't use GetMemoryRegions here because it doesn't include unmapped
+      // areas like repeating the command would. So instead, emulate doing that.
+      lldb::addr_t addr = 0;
+      while (error.Success() && addr != LLDB_INVALID_ADDRESS &&
+             // When there are non-address bits the last range will not extend
+             // to LLDB_INVALID_ADDRESS but to the max virtual address.
+             // This prevents us looping forever if that is the case.
+             (abi && (abi->FixAnyAddress(addr) == addr))) {
+        lldb_private::MemoryRegionInfo region_info;
+        error = process_sp->GetMemoryRegionInfo(addr, region_info);
+
+        if (error.Success()) {
+          region_list.push_back({region_info, addr});
+          addr = region_info.GetRange().GetRangeEnd();
         }
       }
 
-      result.AppendMessageWithFormatv(
-          "[{0:x16}-{1:x16}) {2:r}{3:w}{4:x}{5}{6}{7}{8}",
-          range_info.GetRange().GetRangeBase(),
-          range_info.GetRange().GetRangeEnd(), range_info.GetReadable(),
-          range_info.GetWritable(), range_info.GetExecutable(), name ? " " : "",
-          name, section_name ? " " : "", section_name);
-      MemoryRegionInfo::OptionalBool memory_tagged =
-          range_info.GetMemoryTagged();
-      if (memory_tagged == MemoryRegionInfo::OptionalBool::eYes)
-        result.AppendMessage("memory tagging: enabled");
-
-      const llvm::Optional<std::vector<addr_t>> &dirty_page_list =
-          range_info.GetDirtyPageList();
-      if (dirty_page_list.hasValue()) {
-        const size_t page_count = dirty_page_list.getValue().size();
-        result.AppendMessageWithFormat(
-            "Modified memory (dirty) page list provided, %zu entries.\n",
-            page_count);
-        if (page_count > 0) {
-          bool print_comma = false;
-          result.AppendMessageWithFormat("Dirty pages: ");
-          for (size_t i = 0; i < page_count; i++) {
-            if (print_comma)
-              result.AppendMessageWithFormat(", ");
-            else
-              print_comma = true;
-            result.AppendMessageWithFormat("0x%" PRIx64,
-                                           dirty_page_list.getValue()[i]);
-          }
-          result.AppendMessageWithFormat(".\n");
-        }
+      // Even if we read nothing, don't error for --all
+      error.Clear();
+    } else {
+      lldb_private::MemoryRegionInfo region_info;
+      error = process_sp->GetMemoryRegionInfo(load_addr, region_info);
+      if (error.Success())
+        region_list.push_back({region_info, load_addr});
+    }
+
+    if (error.Success()) {
+      for (std::pair<MemoryRegionInfo, addr_t> &range : region_list) {
+        DumpRegion(result, process_sp->GetTarget(), range.first, range.second);
+        m_prev_end_addr = range.first.GetRange().GetRangeEnd();
       }
 
-      m_prev_end_addr = range_info.GetRange().GetRangeEnd();
       result.SetStatus(eReturnStatusSuccessFinishResult);
       return true;
     }
@@ -1762,6 +1854,9 @@ protected:
   }
 
   lldb::addr_t m_prev_end_addr = LLDB_INVALID_ADDRESS;
+
+  OptionGroupOptions m_option_group;
+  OptionGroupMemoryRegion m_memory_region_options;
 };
 
 // CommandObjectMemory