[hphpd] add print_r format to print command

Summary:
We have a level limit on print command but, the '=' cmd could still
trigger a huge serialization since it could endup in print_r() with
no checking on serialization limit. But print_r() format is
generally prettier than var_dump format used by print command.

This diff adds print_r format to print command and uses it as default,
var_dump format can be used by: p v $toprint. So mostly people should
stick to print command, instead of '='. This diff also makes sure when
'=' is trying to serialize, it observe the serialization limit and fail
faster.

Test Plan:
make fast_tests
manually verified with a few cases including the error case in hphpi

Reviewers: myang, mwilliams

Reviewed By: myang

CC: ps, mwilliams, myang

Differential Revision: 342394

Task ID: 754526

src/runtime/eval/debugger/cmd/cmd_print.cpp

@@ -24,7 +24,7 @@ namespace HPHP { namespace Eval {
 ///////////////////////////////////////////////////////////////////////////////
 
 const char *CmdPrint::Formats[] = {
-  "x", "hex", "oct", "dec", "unsigned", "time", NULL
+  "x", "v", "hex", "oct", "dec", "unsigned", "time", NULL
 };
 
 std::string CmdPrint::FormatResult(const char *format, CVarRef ret) {
@@ -33,6 +33,11 @@ std::string CmdPrint::FormatResult(const char *format, CVarRef ret) {
     return string(sret.data(), sret.size());
   }
 
+  if (strcmp(format, "v") == 0) {
+    String sret = DebuggerClient::FormatVariable(ret, -1, true);
+    return string(sret.data(), sret.size());
+  }
+
   if (strcmp(format, "dec") == 0 ||
       strcmp(format, "unsigned") == 0 ||
       ret.isInteger()) {
@@ -161,7 +166,8 @@ void CmdPrint::list(DebuggerClient *client) {
 bool CmdPrint::help(DebuggerClient *client) {
   client->helpTitle("Print Command");
   client->helpCmds(
-    "[p]rint {php}",              "prints result of PHP code",
+    "[p]rint {php}",              "prints result of PHP code, (print_r)",
+    "[p]rint v {php}",            "prints result of PHP code, (var_dump)",
     "[p]rint x {php}",            "prints hex encoded string or number",
     "[p]rint [h]ex {php}",        "prints hex encoded string or number",
     "[p]rint [o]ct {php}",        "prints octal encoded string or number",

src/runtime/eval/debugger/debugger_client.cpp

@@ -272,11 +272,15 @@ bool DebuggerClient::IsValidNumber(const std::string &arg) {
   return true;
 }
 
-String DebuggerClient::FormatVariable(CVarRef v, int maxlen /* = 80 */) {
+String DebuggerClient::FormatVariable(CVarRef v, int maxlen /* = 80 */,
+                                      bool vardump /* = false */) {
   String value;
   if (maxlen <= 0) {
     try {
-      VariableSerializer vs(VariableSerializer::VarDump, 0, 2);
+      VariableSerializer::Type t = vardump ?
+                                   VariableSerializer::VarDump :
+                                   VariableSerializer::PrintR;
+      VariableSerializer vs(t, 0, 2);
       value = vs.serialize(v, true);
     } catch (StringBufferLimitException &e) {
       value = "Serialization limit reached";
@@ -1786,8 +1790,8 @@ void DebuggerClient::loadConfig() {
   }
 
   m_printFunction = (boost::format(
-    "(function_exists(\"%s\") ? %s($_) : print_r($_));")  % pprint % pprint)
-    .str();
+    "(function_exists(\"%s\") ? %s($_) : print_r(print_r($_, true)));")
+    % pprint % pprint).str();
 
   m_config["Tutorial"]["Visited"].get(m_tutorialVisited);
 

src/runtime/eval/debugger/debugger_client.h

@@ -93,7 +93,8 @@ class DebuggerClient {
   static void AdjustScreenMetrics();
   static bool Match(const char *input, const char *cmd);
   static bool IsValidNumber(const std::string &arg);
-  static String FormatVariable(CVarRef v, int maxlen = 80);
+  static String FormatVariable(CVarRef v, int maxlen = 80,
+                               bool vardump = false);
   static String FormatInfoVec(const IDebuggable::InfoVec &info,
                               int *nameLen = NULL);
   static String FormatTitle(const char *title);