Add a JSON producer to LLDB - this is a set of classes that encapsulate JSON objects and allow you to write them to a Stream for subsequent processing

Using this JSON producer, write a little tool that expands its own command-line arguments and dumps them to stdout as a JSON array

llvm-svn: 228636

lldb/source/Utility/JSON.cpp

@@ -0,0 +1,217 @@
+//===--------------------- JSON.cpp -----------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "lldb/Utility/JSON.h"
+
+using namespace lldb_private;
+
+std::string
+JSONString::json_string_quote_metachars (const std::string &s)
+{
+    if (s.find('"') == std::string::npos)
+        return s;
+    
+    std::string output;
+    const size_t s_size = s.size();
+    const char *s_chars = s.c_str();
+    for (size_t i = 0; i < s_size; i++)
+    {
+        unsigned char ch = *(s_chars + i);
+        if (ch == '"')
+        {
+            output.push_back ('\\');
+        }
+        output.push_back (ch);
+    }
+    return output;
+}
+
+JSONString::JSONString () :
+JSONValue(JSONValue::Kind::String),
+m_data()
+{
+}
+
+JSONString::JSONString (const char* s) :
+JSONValue(JSONValue::Kind::String),
+m_data(s ? s : "")
+{
+}
+
+JSONString::JSONString (const std::string& s) :
+JSONValue(JSONValue::Kind::String),
+m_data(s)
+{
+}
+
+void
+JSONString::Write (Stream& s)
+{
+    s.Printf("\"%s\"", json_string_quote_metachars(m_data).c_str());
+}
+
+JSONNumber::JSONNumber () :
+JSONValue(JSONValue::Kind::Number),
+m_data(0)
+{
+}
+
+JSONNumber::JSONNumber (int64_t i) :
+JSONValue(JSONValue::Kind::Number),
+m_data(i)
+{
+}
+
+void
+JSONNumber::Write (Stream& s)
+{
+    s.Printf("%" PRId64, m_data);
+}
+
+JSONTrue::JSONTrue () :
+JSONValue(JSONValue::Kind::True)
+{
+}
+
+void
+JSONTrue::Write(Stream& s)
+{
+    s.Printf("true");
+}
+
+JSONFalse::JSONFalse () :
+JSONValue(JSONValue::Kind::False)
+{
+}
+
+void
+JSONFalse::Write(Stream& s)
+{
+    s.Printf("false");
+}
+
+JSONNull::JSONNull () :
+JSONValue(JSONValue::Kind::Null)
+{
+}
+
+void
+JSONNull::Write(Stream& s)
+{
+    s.Printf("null");
+}
+
+JSONObject::JSONObject () :
+JSONValue(JSONValue::Kind::Object)
+{
+}
+
+void
+JSONObject::Write (Stream& s)
+{
+    bool first = true;
+    s.PutChar('{');
+    auto iter = m_elements.begin(), end = m_elements.end();
+    for (;iter != end; iter++)
+    {
+        if (first)
+            first = false;
+        else
+            s.PutChar(',');
+        JSONString key(iter->first);
+        JSONValue::SP value(iter->second);
+        key.Write(s);
+        s.PutChar(':');
+        value->Write(s);
+    }
+    s.PutChar('}');
+}
+
+bool
+JSONObject::SetObject (const std::string& key,
+                       JSONValue::SP value)
+{
+    if (key.empty() || nullptr == value.get())
+        return false;
+    m_elements[key] = value;
+    return true;
+}
+
+JSONValue::SP
+JSONObject::GetObject (const std::string& key)
+{
+    auto iter = m_elements.find(key), end = m_elements.end();
+    if (iter == end)
+        return JSONValue::SP();
+    return iter->second;
+}
+
+JSONArray::JSONArray () :
+JSONValue(JSONValue::Kind::Array)
+{
+}
+
+void
+JSONArray::Write (Stream& s)
+{
+    bool first = true;
+    s.PutChar('[');
+    auto iter = m_elements.begin(), end = m_elements.end();
+    for (;iter != end; iter++)
+    {
+        if (first)
+            first = false;
+        else
+            s.PutChar(',');
+        (*iter)->Write(s);
+    }
+    s.PutChar(']');
+}
+
+bool
+JSONArray::SetObject (Index i,
+                      JSONValue::SP value)
+{
+    if (value.get() == nullptr)
+        return false;
+    if (i < m_elements.size())
+    {
+        m_elements[i] = value;
+        return true;
+    }
+    if (i == m_elements.size())
+    {
+        m_elements.push_back(value);
+        return true;
+    }
+    return false;
+}
+
+bool
+JSONArray::AppendObject (JSONValue::SP value)
+{
+    if (value.get() == nullptr)
+        return false;
+    m_elements.push_back(value);
+    return true;
+}
+
+JSONValue::SP
+JSONArray::GetObject (Index i)
+{
+    if (i < m_elements.size())
+        return m_elements[i];
+    return JSONValue::SP();
+}
+
+JSONArray::Size
+JSONArray::GetNumElements ()
+{
+    return m_elements.size();
+}