reflection for namespaced constants

In repo mode this does the right thing and returns the right constant, but for non-repo it thinks it is an undefined non-namespace constant. I'll have to do something more hardcore if that starts to matter

While I was in there, I made the correct name for `ReflectionParameter` that was added in 5.4 instead of the draft we copied.

hphp/compiler/expression/constant_expression.cpp

@@ -277,5 +277,5 @@ TypePtr ConstantExpression::inferTypes(AnalysisResultPtr ar, TypePtr type,
 // code generation functions
 
 void ConstantExpression::outputPHP(CodeGenerator &cg, AnalysisResultPtr ar) {
-  cg_printf("%s", m_name.c_str());
+  cg_printf("%s", getNonNSOriginalName().c_str());
 }

hphp/runtime/base/execution_context.h

@@ -671,7 +671,7 @@ public:
   bool m_dbgNoBreak;
   bool doFCall(HPHP::ActRec* ar, PC& pc);
   bool doFCallArray(PC& pc);
-  CVarRef getEvaledArg(const StringData* val);
+  CVarRef getEvaledArg(const StringData* val, CStrRef namespacedName);
 private:
   void enterVMWork(ActRec* enterFnAr);
   void enterVMPrologue(ActRec* enterFnAr);

hphp/runtime/ext/ext_reflection.cpp

@@ -449,7 +449,10 @@ static void set_function_info(Array &ret, const Func* func) {
           // undefined class constants can cause the eval() to
           // fatal. Zend lets such fatals propagate, so don't bother catching
           // exceptions here.
-          CVarRef v = g_vmContext->getEvaledArg(fpi.phpCode());
+          CVarRef v = g_vmContext->getEvaledArg(
+            fpi.phpCode(),
+            func->cls() ? func->cls()->nameRef() : func->nameRef()
+          );
           param.set(s_default, v);
         }
         param.set(s_defaultText, VarNR(fpi.phpCode()));

hphp/runtime/vm/bytecode.cpp

@@ -2479,14 +2479,29 @@ bool VMExecutionContext::evalUnit(Unit* unit, PC& pc, int funcType) {
   return ret;
 }
 
-CVarRef VMExecutionContext::getEvaledArg(const StringData* val) {
+StaticString
+  s_php_namespace("<?php namespace "),
+  s_curly_return(" { return "),
+  s_semicolon_curly("; }"),
+  s_php_return("<?php return "),
+  s_semicolon(";");
+CVarRef VMExecutionContext::getEvaledArg(const StringData* val,
+                                         CStrRef namespacedName) {
   CStrRef key = *(String*)&val;
 
   if (m_evaledArgs.get()) {
     CVarRef arg = m_evaledArgs.get()->get(key);
     if (&arg != &null_variant) return arg;
   }
-  String code = HPHP::concat3("<?php return ", key, ";");
+
+  String code;
+  int pos = namespacedName.rfind('\\');
+  if (pos != -1) {
+    auto ns = namespacedName.substr(0, pos);
+    code = s_php_namespace + ns + s_curly_return + key + s_semicolon_curly;
+  } else {
+    code = s_php_return + key + s_semicolon;
+  }
   Unit* unit = compileEvalString(code.get());
   assert(unit != nullptr);
   Variant v;

hphp/runtime/vm/func.cpp

@@ -587,7 +587,10 @@ void Func::getFuncInfo(ClassInfo::MethodInfo* mi) const {
           // that access of undefined class constants can cause the eval() to
           // fatal. Zend lets such fatals propagate, so don't bother catching
           // exceptions here.
-          CVarRef v = g_vmContext->getEvaledArg(fpi.phpCode());
+          CVarRef v = g_vmContext->getEvaledArg(
+            fpi.phpCode(),
+            cls() ? cls()->nameRef() : nameRef()
+          );
           pi->value = strdup(f_serialize(v).get()->data());
         }
         // This is a raw char*, but its lifetime should be at least as long

hphp/system/php/reflection/reflection.php

@@ -306,7 +306,25 @@ class ReflectionParameter implements Reflector {
     return $defaultValue;
   }
 
+  /**
+    * @deprecated
+    */
   public function getDefaultValueText() {
+    return $this->getDefaultValueConstantName();
+  }
+
+  // This doc comment block generated by idl/sysdoc.php
+  /**
+   * ( excerpt from
+   * http://php.net/manual/en/reflectionparameter.getdefaultvalueconstantname.php
+   * )
+   *
+   * WarningThis function is currently not documented; only its argument
+   * list is available.
+   *
+   * @return     mixed   Returns string on success or NULL on failure.
+   */
+  public function getDefaultValueConstantName() {
     if (isset($this->info['defaultText'])) {
       return $this->info['defaultText'];
     }

hphp/test/slow/namespace/const_param.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace A {
+  const B = 'c';
+  class D {
+    public function e($f = PHP_VERSION, $g = B,
+                      $h = array(PHP_VERSION), $i = array(B)) {
+    }
+  }
+  function j($k = PHP_VERSION, $l = B, $m = array(PHP_VERSION), $n = array(B)) {
+  }
+}
+
+namespace {
+  $tests = array(
+    new ReflectionMethod('A\D', 'e'),
+    new ReflectionFunction('A\j'),
+  );
+  foreach ($tests as $method) {
+    $params = $method->getParameters();
+    foreach ($params as $param) {
+      var_dump(
+        $param->getDefaultValue(),
+        $param->getDefaultValueConstantName()
+      );
+    }
+  }
+}

hphp/test/slow/namespace/const_param.php.expectf

@@ -0,0 +1,28 @@
+string(14) "5.4.999-hiphop"
+string(11) "PHP_VERSION"
+string(1) "c"
+string(1) "B"
+array(1) {
+  [0]=>
+  string(14) "5.4.999-hiphop"
+}
+string(18) "array(PHP_VERSION)"
+array(1) {
+  [0]=>
+  string(1) "c"
+}
+string(%d) "array%w(%a)"
+string(14) "5.4.999-hiphop"
+string(11) "PHP_VERSION"
+string(1) "c"
+string(1) "B"
+array(1) {
+  [0]=>
+  string(14) "5.4.999-hiphop"
+}
+string(18) "array(PHP_VERSION)"
+array(1) {
+  [0]=>
+  string(1) "c"
+}
+string(%d) "array%w(%a)"