hphp/hhbbc/func-util.cpp

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-present Facebook, Inc. (http://www.facebook.com)  |
   6    +----------------------------------------------------------------------+
   7    | This source file is subject to version 3.01 of the PHP license,      |
   8    | that is bundled with this package in the file LICENSE, and is        |
   9    | available through the world-wide-web at the following url:           |
  10    | http://www.php.net/license/3_01.txt                                  |
  11    | If you did not receive a copy of the PHP license and are unable to   |
  12    | obtain it through the world-wide-web, please send a note to          |
  13    | license@php.net so we can mail you a copy immediately.               |
  14    +----------------------------------------------------------------------+
  15 */
  16 #include "hphp/hhbbc/func-util.h"
  17
  18 #include "hphp/hhbbc/misc.h"
  19 #include "hphp/hhbbc/representation.h"
  20
  21 #include "hphp/runtime/vm/func.h"
  22
  23 namespace HPHP { namespace HHBBC {
  24
  25 //////////////////////////////////////////////////////////////////////
  26
  27 const StaticString s_reified_generics_var("0ReifiedGenerics");
  28
  29 //////////////////////////////////////////////////////////////////////
  30
  31 uint32_t closure_num_use_vars(const php::Func* f) {
  32   // Properties on the closure object are use vars.
  33   return f->cls->properties.size();
  34 }
  35
  36 bool is_pseudomain(const php::Func* f) {
  37   return f->unit->pseudomain.get() == f;
  38 }
  39
  40 bool is_volatile_local(const php::Func* func, LocalId lid) {
  41   auto const& l = func->locals[lid];
  42   if (!l.name) return false;
  43
  44   // Named pseudomain locals are bound to $GLOBALS.
  45   if (is_pseudomain(func)) return true;
  46
  47   return (RuntimeOption::EnableArgsInBacktraces &&
  48           l.name->same(s_reified_generics_var.get())) ||
  49          l.name->same(s_86metadata.get());
  50 }
  51
  52 SString memoize_impl_name(const php::Func* func) {
  53   always_assert(func->isMemoizeWrapper);
  54   return Func::genMemoizeImplName(func->name);
  55 }
  56
  57 bool check_nargs_in_range(const php::Func* func, uint32_t nArgs) {
  58   while (nArgs < func->dvEntries.size()) {
  59     if (func->dvEntries[nArgs++] == NoBlockId) return false;
  60   }
  61   return true;
  62 }
  63
  64 int dyn_call_error_level(const php::Func* func)  {
  65   if (!(func->attrs & AttrDynamicallyCallable) ||
  66       RuntimeOption::EvalForbidDynamicCallsWithAttr) {
  67     if (func->cls) {
  68       if (func->attrs & AttrStatic)
  69         return RuntimeOption::EvalForbidDynamicCallsToClsMeth;
  70       else
  71         return RuntimeOption::EvalForbidDynamicCallsToInstMeth;
  72     }
  73     else
  74       return RuntimeOption::EvalForbidDynamicCallsToFunc;
  75   }
  76   return 0;
  77 }
  78
  79 //////////////////////////////////////////////////////////////////////
  80
  81 namespace {
  82
  83 using ExnNode = php::ExnNode;
  84
  85 void copy_into(php::FuncBase* dst, const php::FuncBase& other) {
  86   hphp_fast_map<ExnNode*, ExnNode*> processed;
  87
  88   BlockId delta = dst->blocks.size();
  89   always_assert(!dst->exnNodes.size() || !other.exnNodes.size());
  90   dst->exnNodes.reserve(dst->exnNodes.size() + other.exnNodes.size());
  91   for (auto en : other.exnNodes) {
  92     en.region.catchEntry += delta;
  93     dst->exnNodes.push_back(std::move(en));
  94   }
  95   for (auto theirs : other.blocks) {
  96     if (delta) {
  97       auto const ours = theirs.mutate();
  98       if (ours->fallthrough != NoBlockId) ours->fallthrough += delta;
  99       if (ours->throwExit != NoBlockId) ours->throwExit += delta;
 100       for (auto& bc : ours->hhbcs) {
 101         // When merging functions (used for 86xints) we have to drop
 102         // the src info, because it might reference a different unit
 103         // (and as a generated function, the src info isn't very
 104         // meaningful anyway).
 105         bc.srcLoc = -1;
 106         bc.forEachTarget([&] (BlockId& b) { b += delta; });
 107       }
 108     }
 109     dst->blocks.push_back(std::move(theirs));
 110   }
 111 }
 112
 113 //////////////////////////////////////////////////////////////////////
 114
 115 }
 116
 117 //////////////////////////////////////////////////////////////////////
 118
 119 bool append_func(php::Func* dst, const php::Func& src) {
 120   if (src.numIters || src.locals.size()) return false;
 121   if (src.exnNodes.size() && dst->exnNodes.size()) return false;
 122
 123   bool ok = false;
 124   for (auto& b : dst->blocks) {
 125     if (b->hhbcs.back().op != Op::RetC) continue;
 126     auto const blk = b.mutate();
 127     blk->hhbcs.back() = bc::PopC {};
 128     blk->fallthrough = dst->blocks.size();
 129     ok = true;
 130   }
 131   if (!ok) return false;
 132   copy_into(dst, src);
 133   return true;
 134 }
 135
 136 php::FuncBase::FuncBase(const FuncBase& other) {
 137   copy_into(this, other);
 138
 139   assertx(!other.nativeInfo);
 140 }
 141
 142 //////////////////////////////////////////////////////////////////////
 143
 144 }}