Move CXFA_FMParse to CFXA_FMParser

Minor nit I had with this code and want to fix.

Bug:
Change-Id: I2494667d580bf982a4359153123d9e8afb75e349
Reviewed-on: https://pdfium-review.googlesource.com/9370
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: (OOO Jul 28 - Aug 8) dsinclair <dsinclair@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>

1 files changed, 1184 insertions, 0 deletions

diff --git a/xfa/fxfa/fm2js/cxfa_fmparser.cpp b/xfa/fxfa/fm2js/cxfa_fmparser.cpp
new file mode 100644
index 0000000000..150fa5aeda
--- /dev/null
+++ b/xfa/fxfa/fm2js/cxfa_fmparser.cpp
@@ -0,0 +1,1184 @@
+// Copyright 2014 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#include "xfa/fxfa/fm2js/cxfa_fmparser.h"
+
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include "third_party/base/ptr_util.h"
+
+namespace {
+
+const int kMaxAssignmentChainLength = 12;
+
+}  // namespace
+
+CXFA_FMParser::CXFA_FMParser(const CFX_WideStringC& wsFormcalc)
+    : m_error(false) {
+  m_lexer = pdfium::MakeUnique<CXFA_FMLexer>(wsFormcalc);
+  m_token = m_lexer->NextToken();
+}
+
+CXFA_FMParser::~CXFA_FMParser() {}
+
+std::unique_ptr<CXFA_FMFunctionDefinition> CXFA_FMParser::Parse() {
+  auto expressions = ParseTopExpression();
+  if (HasError())
+    return nullptr;
+
+  std::vector<CFX_WideStringC> arguments;
+  return pdfium::MakeUnique<CXFA_FMFunctionDefinition>(
+      1, true, L"", std::move(arguments), std::move(expressions));
+}
+
+bool CXFA_FMParser::NextToken() {
+  if (HasError())
+    return false;
+  m_token = m_lexer->NextToken();
+  while (!HasError() && m_token->m_type == TOKreserver)
+    m_token = m_lexer->NextToken();
+  return !HasError();
+}
+
+bool CXFA_FMParser::CheckThenNext(XFA_FM_TOKEN op) {
+  if (HasError())
+    return false;
+
+  if (m_token->m_type != op) {
+    m_error = true;
+    return false;
+  }
+  return NextToken();
+}
+
+std::vector<std::unique_ptr<CXFA_FMExpression>>
+CXFA_FMParser::ParseTopExpression() {
+  std::unique_ptr<CXFA_FMExpression> expr;
+  std::vector<std::unique_ptr<CXFA_FMExpression>> expressions;
+  if (HasError())
+    return expressions;
+
+  while (!HasError()) {
+    if (m_token->m_type == TOKeof || m_token->m_type == TOKendfunc ||
+        m_token->m_type == TOKendif || m_token->m_type == TOKelseif ||
+        m_token->m_type == TOKelse || m_token->m_type == TOKreserver) {
+      return expressions;
+    }
+
+    expr = m_token->m_type == TOKfunc ? ParseFunction() : ParseExpression();
+    if (!expr) {
+      m_error = true;
+      expressions.clear();
+      break;
+    }
+    expressions.push_back(std::move(expr));
+  }
+  if (HasError())
+    expressions.clear();
+  return expressions;
+}
+
+std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseFunction() {
+  if (HasError())
+    return nullptr;
+
+  CFX_WideStringC ident;
+  std::vector<CFX_WideStringC> arguments;
+  std::vector<std::unique_ptr<CXFA_FMExpression>> expressions;
+  uint32_t line = m_token->m_line_num;
+  if (!NextToken())
+    return nullptr;
+  if (m_token->m_type != TOKidentifier) {
+    m_error = true;
+    return nullptr;
+  } else {
+    ident = m_token->m_string;
+    if (!NextToken())
+      return nullptr;
+  }
+  if (!CheckThenNext(TOKlparen))
+    return nullptr;
+  if (m_token->m_type == TOKrparen) {
+    if (!NextToken())
+      return nullptr;
+  } else {
+    while (1) {
+      if (m_token->m_type != TOKidentifier) {
+        m_error = true;
+        return nullptr;
+      }
+      arguments.push_back(m_token->m_string);
+      if (!NextToken())
+        return nullptr;
+      if (m_token->m_type == TOKcomma) {
+        if (!NextToken())
+          return nullptr;
+        continue;
+      }
+      if (m_token->m_type == TOKrparen) {
+        if (!NextToken())
+          return nullptr;
+      } else {
+        if (!CheckThenNext(TOKrparen))
+          return nullptr;
+      }
+      break;
+    }
+  }
+  if (!CheckThenNext(TOKdo))
+    return nullptr;
+  if (m_token->m_type == TOKendfunc) {
+    if (!NextToken())
+      return nullptr;
+  } else {
+    expressions = ParseTopExpression();
+    if (!expressions.size() || !CheckThenNext(TOKendfunc))
+      return nullptr;
+  }
+
+  return pdfium::MakeUnique<CXFA_FMFunctionDefinition>(
+      line, false, ident, std::move(arguments), std::move(expressions));
+}
+
+std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseExpression() {
+  if (HasError())
+    return nullptr;
+
+  std::unique_ptr<CXFA_FMExpression> expr;
+  uint32_t line = m_token->m_line_num;
+  switch (m_token->m_type) {
+    case TOKvar:
+      expr = ParseVarExpression();
+      break;
+    case TOKnull:
+    case TOKnumber:
+    case TOKstring:
+    case TOKplus:
+    case TOKminus:
+    case TOKksnot:
+    case TOKidentifier:
+    case TOKlparen:
+      expr = ParseExpExpression();
+      break;
+    case TOKif:
+      expr = ParseIfExpression();
+      break;
+    case TOKwhile:
+      expr = ParseWhileExpression();
+      break;
+    case TOKfor:
+      expr = ParseForExpression();
+      break;
+    case TOKforeach:
+      expr = ParseForeachExpression();
+      break;
+    case TOKdo:
+      expr = ParseDoExpression();
+      break;
+    case TOKbreak:
+      expr = pdfium::MakeUnique<CXFA_FMBreakExpression>(line);
+      if (!NextToken())
+        return nullptr;
+      break;
+    case TOKcontinue:
+      expr = pdfium::MakeUnique<CXFA_FMContinueExpression>(line);
+      if (!NextToken())
+        return nullptr;
+      break;
+    default:
+      m_error = true;
+      return nullptr;
+  }
+  return expr;
+}
+
+std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseVarExpression() {
+  if (HasError())
+    return nullptr;
+
+  CFX_WideStringC ident;
+  uint32_t line = m_token->m_line_num;
+  if (!NextToken())
+    return nullptr;
+  if (m_token->m_type != TOKidentifier) {
+    m_error = true;
+    return nullptr;
+  }
+
+  ident = m_token->m_string;
+  if (!NextToken())
+    return nullptr;
+
+  std::unique_ptr<CXFA_FMExpression> expr;
+  if (m_token->m_type == TOKassign) {
+    if (!NextToken())
+      return nullptr;
+
+    expr = ParseExpExpression();
+    if (!expr)
+      return nullptr;
+  }
+
+  return pdfium::MakeUnique<CXFA_FMVarExpression>(line, ident, std::move(expr));
+}
+
+std::unique_ptr<CXFA_FMSimpleExpression>
+CXFA_FMParser::ParseSimpleExpression() {
+  if (HasError())
+    return nullptr;
+
+  uint32_t line = m_token->m_line_num;
+  std::unique_ptr<CXFA_FMSimpleExpression> pExp1 = ParseLogicalOrExpression();
+  if (!pExp1)
+    return nullptr;
+  int level = 1;
+  while (m_token->m_type == TOKassign) {
+    if (!NextToken())
+      return nullptr;
+    std::unique_ptr<CXFA_FMSimpleExpression> pExp2 = ParseLogicalOrExpression();
+    if (!pExp2)
+      return nullptr;
+    if (level++ == kMaxAssignmentChainLength) {
+      m_error = true;
+      return nullptr;
+    }
+    pExp1 = pdfium::MakeUnique<CXFA_FMAssignExpression>(
+        line, TOKassign, std::move(pExp1), std::move(pExp2));
+  }
+  return pExp1;
+}
+
+std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseExpExpression() {
+  if (HasError())
+    return nullptr;
+
+  uint32_t line = m_token->m_line_num;
+  std::unique_ptr<CXFA_FMSimpleExpression> pExp1 = ParseSimpleExpression();
+  if (!pExp1)
+    return nullptr;
+  return pdfium::MakeUnique<CXFA_FMExpExpression>(line, std::move(pExp1));
+}
+
+std::unique_ptr<CXFA_FMSimpleExpression>
+CXFA_FMParser::ParseLogicalOrExpression() {
+  if (HasError())
+    return nullptr;
+
+  uint32_t line = m_token->m_line_num;
+  std::unique_ptr<CXFA_FMSimpleExpression> e1 = ParseLogicalAndExpression();
+  if (!e1)
+    return nullptr;
+
+  for (;;) {
+    switch (m_token->m_type) {
+      case TOKor:
+      case TOKksor: {
+        if (!NextToken())
+          return nullptr;
+
+        std::unique_ptr<CXFA_FMSimpleExpression> e2(
+            ParseLogicalAndExpression());
+        if (!e2)
+          return nullptr;
+
+        e1 = pdfium::MakeUnique<CXFA_FMLogicalOrExpression>(
+            line, TOKor, std::move(e1), std::move(e2));
+        continue;
+      }
+      default:
+        break;
+    }
+    break;
+  }
+  return e1;
+}
+
+std::unique_ptr<CXFA_FMSimpleExpression>
+CXFA_FMParser::ParseLogicalAndExpression() {
+  if (HasError())
+    return nullptr;
+
+  uint32_t line = m_token->m_line_num;
+  std::unique_ptr<CXFA_FMSimpleExpression> e1 = ParseEqualityExpression();
+  if (!e1)
+    return nullptr;
+
+  for (;;) {
+    switch (m_token->m_type) {
+      case TOKand:
+      case TOKksand: {
+        if (!NextToken())
+          return nullptr;
+
+        std::unique_ptr<CXFA_FMSimpleExpression> e2 = ParseEqualityExpression();
+        if (!e2)
+          return nullptr;
+
+        e1 = pdfium::MakeUnique<CXFA_FMLogicalAndExpression>(
+            line, TOKand, std::move(e1), std::move(e2));
+        continue;
+      }
+      default:
+        break;
+    }
+    break;
+  }
+  return e1;
+}
+
+std::unique_ptr<CXFA_FMSimpleExpression>
+CXFA_FMParser::ParseEqualityExpression() {
+  if (HasError())
+    return nullptr;
+
+  uint32_t line = m_token->m_line_num;
+  std::unique_ptr<CXFA_FMSimpleExpression> e1 = ParseRelationalExpression();
+  if (!e1)
+    return nullptr;
+  for (;;) {
+    std::unique_ptr<CXFA_FMSimpleExpression> e2;
+    switch (m_token->m_type) {
+      case TOKeq:
+      case TOKkseq:
+        if (!NextToken())
+          return nullptr;
+
+        e2 = ParseRelationalExpression();
+        if (!e2)
+          return nullptr;
+
+        e1 = pdfium::MakeUnique<CXFA_FMEqualityExpression>(
+            line, TOKeq, std::move(e1), std::move(e2));
+        continue;
+      case TOKne:
+      case TOKksne:
+        if (!NextToken())
+          return nullptr;
+
+        e2 = ParseRelationalExpression();
+        if (!e2)
+          return nullptr;
+
+        e1 = pdfium::MakeUnique<CXFA_FMEqualityExpression>(
+            line, TOKne, std::move(e1), std::move(e2));
+        continue;
+      default:
+        break;
+    }
+    break;
+  }
+  return e1;
+}
+
+std::unique_ptr<CXFA_FMSimpleExpression>
+CXFA_FMParser::ParseRelationalExpression() {
+  if (HasError())
+    return nullptr;
+
+  uint32_t line = m_token->m_line_num;
+  std::unique_ptr<CXFA_FMSimpleExpression> e1 = ParseAddtiveExpression();
+  if (!e1)
+    return nullptr;
+
+  for (;;) {
+    std::unique_ptr<CXFA_FMSimpleExpression> e2;
+    switch (m_token->m_type) {
+      case TOKlt:
+      case TOKkslt:
+        if (!NextToken())
+          return nullptr;
+
+        e2 = ParseAddtiveExpression();
+        if (!e2)
+          return nullptr;
+
+        e1 = pdfium::MakeUnique<CXFA_FMRelationalExpression>(
+            line, TOKlt, std::move(e1), std::move(e2));
+        continue;
+      case TOKgt:
+      case TOKksgt:
+        if (!NextToken())
+          return nullptr;
+
+        e2 = ParseAddtiveExpression();
+        if (!e2)
+          return nullptr;
+
+        e1 = pdfium::MakeUnique<CXFA_FMRelationalExpression>(
+            line, TOKgt, std::move(e1), std::move(e2));
+        continue;
+      case TOKle:
+      case TOKksle:
+        if (!NextToken())
+          return nullptr;
+
+        e2 = ParseAddtiveExpression();
+        if (!e2)
+          return nullptr;
+
+        e1 = pdfium::MakeUnique<CXFA_FMRelationalExpression>(
+            line, TOKle, std::move(e1), std::move(e2));
+        continue;
+      case TOKge:
+      case TOKksge:
+        if (!NextToken())
+          return nullptr;
+
+        e2 = ParseAddtiveExpression();
+        if (!e2)
+          return nullptr;
+
+        e1 = pdfium::MakeUnique<CXFA_FMRelationalExpression>(
+            line, TOKge, std::move(e1), std::move(e2));
+        continue;
+      default:
+        break;
+    }
+    break;
+  }
+  return e1;
+}
+
+std::unique_ptr<CXFA_FMSimpleExpression>
+CXFA_FMParser::ParseAddtiveExpression() {
+  if (HasError())
+    return nullptr;
+
+  uint32_t line = m_token->m_line_num;
+  std::unique_ptr<CXFA_FMSimpleExpression> e1 = ParseMultiplicativeExpression();
+  if (!e1)
+    return nullptr;
+
+  for (;;) {
+    std::unique_ptr<CXFA_FMSimpleExpression> e2;
+    switch (m_token->m_type) {
+      case TOKplus:
+        if (!NextToken())
+          return nullptr;
+
+        e2 = ParseMultiplicativeExpression();
+        if (!e2)
+          return nullptr;
+
+        e1 = pdfium::MakeUnique<CXFA_FMAdditiveExpression>(
+            line, TOKplus, std::move(e1), std::move(e2));
+        continue;
+      case TOKminus:
+        if (!NextToken())
+          return nullptr;
+
+        e2 = ParseMultiplicativeExpression();
+        if (!e2)
+          return nullptr;
+
+        e1 = pdfium::MakeUnique<CXFA_FMAdditiveExpression>(
+            line, TOKminus, std::move(e1), std::move(e2));
+        continue;
+      default:
+        break;
+    }
+    break;
+  }
+  return e1;
+}
+
+std::unique_ptr<CXFA_FMSimpleExpression>
+CXFA_FMParser::ParseMultiplicativeExpression() {
+  if (HasError())
+    return nullptr;
+
+  uint32_t line = m_token->m_line_num;
+  std::unique_ptr<CXFA_FMSimpleExpression> e1 = ParseUnaryExpression();
+  if (!e1)
+    return nullptr;
+
+  for (;;) {
+    std::unique_ptr<CXFA_FMSimpleExpression> e2;
+    switch (m_token->m_type) {
+      case TOKmul:
+        if (!NextToken())
+          return nullptr;
+
+        e2 = ParseUnaryExpression();
+        if (!e2)
+          return nullptr;
+
+        e1 = pdfium::MakeUnique<CXFA_FMMultiplicativeExpression>(
+            line, TOKmul, std::move(e1), std::move(e2));
+        continue;
+      case TOKdiv:
+        if (!NextToken())
+          return nullptr;
+
+        e2 = ParseUnaryExpression();
+        if (!e2)
+          return nullptr;
+
+        e1 = pdfium::MakeUnique<CXFA_FMMultiplicativeExpression>(
+            line, TOKdiv, std::move(e1), std::move(e2));
+        continue;
+      default:
+        break;
+    }
+    break;
+  }
+  return e1;
+}
+
+std::unique_ptr<CXFA_FMSimpleExpression> CXFA_FMParser::ParseUnaryExpression() {
+  if (HasError())
+    return nullptr;
+
+  std::unique_ptr<CXFA_FMSimpleExpression> expr;
+  uint32_t line = m_token->m_line_num;
+  switch (m_token->m_type) {
+    case TOKplus:
+      if (!NextToken())
+        return nullptr;
+
+      expr = ParseUnaryExpression();
+      if (!expr)
+        return nullptr;
+
+      expr = pdfium::MakeUnique<CXFA_FMPosExpression>(line, std::move(expr));
+      break;
+    case TOKminus:
+      if (!NextToken())
+        return nullptr;
+
+      expr = ParseUnaryExpression();
+      if (!expr)
+        return nullptr;
+
+      expr = pdfium::MakeUnique<CXFA_FMNegExpression>(line, std::move(expr));
+      break;
+    case TOKksnot:
+      if (!NextToken())
+        return nullptr;
+
+      expr = ParseUnaryExpression();
+      if (!expr)
+        return nullptr;
+
+      expr = pdfium::MakeUnique<CXFA_FMNotExpression>(line, std::move(expr));
+      break;
+    default:
+      expr = ParsePrimaryExpression();
+      if (!expr)
+        return nullptr;
+      break;
+  }
+  return expr;
+}
+
+std::unique_ptr<CXFA_FMSimpleExpression>
+CXFA_FMParser::ParsePrimaryExpression() {
+  if (HasError())
+    return nullptr;
+
+  std::unique_ptr<CXFA_FMSimpleExpression> expr;
+  uint32_t line = m_token->m_line_num;
+  switch (m_token->m_type) {
+    case TOKnumber:
+      expr =
+          pdfium::MakeUnique<CXFA_FMNumberExpression>(line, m_token->m_string);
+      if (!NextToken())
+        return nullptr;
+      break;
+    case TOKstring:
+      expr =
+          pdfium::MakeUnique<CXFA_FMStringExpression>(line, m_token->m_string);
+      if (!NextToken())
+        return nullptr;
+      break;
+    case TOKidentifier: {
+      CFX_WideStringC wsIdentifier(m_token->m_string);
+      if (!NextToken())
+        return nullptr;
+      if (m_token->m_type == TOKlbracket) {
+        std::unique_ptr<CXFA_FMSimpleExpression> s = ParseIndexExpression();
+        if (!s)
+          return nullptr;
+
+        expr = pdfium::MakeUnique<CXFA_FMDotAccessorExpression>(
+            line, nullptr, TOKdot, wsIdentifier, std::move(s));
+        if (!expr)
+          return nullptr;
+        if (!NextToken())
+          return nullptr;
+      } else {
+        expr =
+            pdfium::MakeUnique<CXFA_FMIdentifierExpression>(line, wsIdentifier);
+      }
+      break;
+    }
+    case TOKif:
+      expr = pdfium::MakeUnique<CXFA_FMIdentifierExpression>(line,
+                                                             m_token->m_string);
+      if (!expr || !NextToken())
+        return nullptr;
+      break;
+    case TOKnull:
+      expr = pdfium::MakeUnique<CXFA_FMNullExpression>(line);
+      if (!expr || !NextToken())
+        return nullptr;
+      break;
+    case TOKlparen:
+      expr = ParseParenExpression();
+      if (!expr)
+        return nullptr;
+      break;
+    default:
+      m_error = true;
+      return nullptr;
+  }
+  expr = ParsePostExpression(std::move(expr));
+  if (!expr)
+    return nullptr;
+  return expr;
+}
+
+std::unique_ptr<CXFA_FMSimpleExpression> CXFA_FMParser::ParsePostExpression(
+    std::unique_ptr<CXFA_FMSimpleExpression> expr) {
+  if (HasError())
+    return nullptr;
+
+  uint32_t line = m_token->m_line_num;
+  while (1) {
+    switch (m_token->m_type) {
+      case TOKlparen: {
+        if (!NextToken())
+          return nullptr;
+        std::vector<std::unique_ptr<CXFA_FMSimpleExpression>> expressions;
+        if (m_token->m_type != TOKrparen) {
+          while (m_token->m_type != TOKrparen) {
+            if (std::unique_ptr<CXFA_FMSimpleExpression> expr =
+                    ParseSimpleExpression())
+              expressions.push_back(std::move(expr));
+            if (m_token->m_type == TOKcomma) {
+              if (!NextToken())
+                return nullptr;
+            } else if (m_token->m_type == TOKeof ||
+                       m_token->m_type == TOKreserver) {
+              break;
+            }
+          }
+          if (m_token->m_type != TOKrparen) {
+            m_error = true;
+            return nullptr;
+          }
+        }
+        expr = pdfium::MakeUnique<CXFA_FMCallExpression>(
+            line, std::move(expr), std::move(expressions), false);
+        if (!NextToken())
+          return nullptr;
+        if (m_token->m_type != TOKlbracket)
+          continue;
+
+        std::unique_ptr<CXFA_FMSimpleExpression> s = ParseIndexExpression();
+        if (!s)
+          return nullptr;
+
+        expr = pdfium::MakeUnique<CXFA_FMDotAccessorExpression>(
+            line, std::move(expr), TOKcall, L"", std::move(s));
+        break;
+      }
+      case TOKdot: {
+        if (!NextToken())
+          return nullptr;
+        if (m_token->m_type != TOKidentifier) {
+          m_error = true;
+          return nullptr;
+        }
+        CFX_WideStringC tempStr = m_token->m_string;
+        uint32_t tempLine = m_token->m_line_num;
+        if (!NextToken())
+          return nullptr;
+        if (m_token->m_type == TOKlparen) {
+          std::unique_ptr<CXFA_FMSimpleExpression> pExpCall;
+          if (!NextToken())
+            return nullptr;
+
+          std::vector<std::unique_ptr<CXFA_FMSimpleExpression>> expressions;
+          if (m_token->m_type != TOKrparen) {
+            while (m_token->m_type != TOKrparen) {
+              std::unique_ptr<CXFA_FMSimpleExpression> exp =
+                  ParseSimpleExpression();
+              if (!exp)
+                return nullptr;
+
+              expressions.push_back(std::move(exp));
+              if (m_token->m_type == TOKcomma) {
+                if (!NextToken())
+                  return nullptr;
+              } else if (m_token->m_type == TOKeof ||
+                         m_token->m_type == TOKreserver) {
+                break;
+              }
+            }
+            if (m_token->m_type != TOKrparen) {
+              m_error = true;
+              return nullptr;
+            }
+          }
+          std::unique_ptr<CXFA_FMSimpleExpression> pIdentifier =
+              pdfium::MakeUnique<CXFA_FMIdentifierExpression>(tempLine,
+                                                              tempStr);
+          pExpCall = pdfium::MakeUnique<CXFA_FMCallExpression>(
+              line, std::move(pIdentifier), std::move(expressions), true);
+          expr = pdfium::MakeUnique<CXFA_FMMethodCallExpression>(
+              line, std::move(expr), std::move(pExpCall));
+          if (!NextToken())
+            return nullptr;
+          if (m_token->m_type != TOKlbracket)
+            continue;
+
+          std::unique_ptr<CXFA_FMSimpleExpression> s = ParseIndexExpression();
+          if (!s)
+            return nullptr;
+
+          expr = pdfium::MakeUnique<CXFA_FMDotAccessorExpression>(
+              line, std::move(expr), TOKcall, L"", std::move(s));
+        } else if (m_token->m_type == TOKlbracket) {
+          std::unique_ptr<CXFA_FMSimpleExpression> s = ParseIndexExpression();
+          if (!s)
+            return nullptr;
+
+          expr = pdfium::MakeUnique<CXFA_FMDotAccessorExpression>(
+              tempLine, std::move(expr), TOKdot, tempStr, std::move(s));
+        } else {
+          std::unique_ptr<CXFA_FMSimpleExpression> s =
+              pdfium::MakeUnique<CXFA_FMIndexExpression>(
+                  tempLine, ACCESSOR_NO_INDEX, nullptr, false);
+          expr = pdfium::MakeUnique<CXFA_FMDotAccessorExpression>(
+              line, std::move(expr), TOKdot, tempStr, std::move(s));
+          continue;
+        }
+      } break;
+      case TOKdotdot: {
+        if (!NextToken())
+          return nullptr;
+        if (m_token->m_type != TOKidentifier) {
+          m_error = true;
+          return nullptr;
+        }
+        CFX_WideStringC tempStr = m_token->m_string;
+        uint32_t tempLine = m_token->m_line_num;
+        if (!NextToken())
+          return nullptr;
+        if (m_token->m_type == TOKlbracket) {
+          std::unique_ptr<CXFA_FMSimpleExpression> s = ParseIndexExpression();
+          if (!s)
+            return nullptr;
+
+          expr = pdfium::MakeUnique<CXFA_FMDotDotAccessorExpression>(
+              tempLine, std::move(expr), TOKdotdot, tempStr, std::move(s));
+        } else {
+          std::unique_ptr<CXFA_FMSimpleExpression> s =
+              pdfium::MakeUnique<CXFA_FMIndexExpression>(
+                  tempLine, ACCESSOR_NO_INDEX, nullptr, false);
+          expr = pdfium::MakeUnique<CXFA_FMDotDotAccessorExpression>(
+              line, std::move(expr), TOKdotdot, tempStr, std::move(s));
+          continue;
+        }
+      } break;
+      case TOKdotscream: {
+        if (!NextToken())
+          return nullptr;
+        if (m_token->m_type != TOKidentifier) {
+          m_error = true;
+          return nullptr;
+        }
+        CFX_WideStringC tempStr = m_token->m_string;
+        uint32_t tempLine = m_token->m_line_num;
+        if (NextToken())
+          return nullptr;
+        if (m_token->m_type != TOKlbracket) {
+          std::unique_ptr<CXFA_FMSimpleExpression> s =
+              pdfium::MakeUnique<CXFA_FMIndexExpression>(
+                  tempLine, ACCESSOR_NO_INDEX, nullptr, false);
+          expr = pdfium::MakeUnique<CXFA_FMDotAccessorExpression>(
+              line, std::move(expr), TOKdotscream, tempStr, std::move(s));
+          continue;
+        }
+        std::unique_ptr<CXFA_FMSimpleExpression> s = ParseIndexExpression();
+        if (!s)
+          return nullptr;
+
+        expr = pdfium::MakeUnique<CXFA_FMDotAccessorExpression>(
+            tempLine, std::move(expr), TOKdotscream, tempStr, std::move(s));
+        break;
+      }
+      case TOKdotstar: {
+        std::unique_ptr<CXFA_FMSimpleExpression> s =
+            pdfium::MakeUnique<CXFA_FMIndexExpression>(line, ACCESSOR_NO_INDEX,
+                                                       nullptr, false);
+        expr = pdfium::MakeUnique<CXFA_FMDotAccessorExpression>(
+            line, std::move(expr), TOKdotstar, L"*", std::move(s));
+        break;
+      }
+      default:
+        return expr;
+    }
+    if (!NextToken())
+      return nullptr;
+  }
+  return expr;
+}
+
+std::unique_ptr<CXFA_FMSimpleExpression> CXFA_FMParser::ParseIndexExpression() {
+  if (HasError())
+    return nullptr;
+
+  uint32_t line = m_token->m_line_num;
+  if (!NextToken())
+    return nullptr;
+
+  std::unique_ptr<CXFA_FMSimpleExpression> s;
+  XFA_FM_AccessorIndex accessorIndex = ACCESSOR_NO_RELATIVEINDEX;
+  std::unique_ptr<CXFA_FMSimpleExpression> pExp;
+  if (m_token->m_type == TOKmul) {
+    pExp = pdfium::MakeUnique<CXFA_FMIndexExpression>(line, accessorIndex,
+                                                      std::move(s), true);
+    if (!pExp || !NextToken())
+      return nullptr;
+    if (m_token->m_type != TOKrbracket) {
+      m_error = true;
+      return nullptr;
+    }
+    return pExp;
+  }
+  if (m_token->m_type == TOKplus) {
+    accessorIndex = ACCESSOR_POSITIVE_INDEX;
+    if (!NextToken())
+      return nullptr;
+  } else if (m_token->m_type == TOKminus) {
+    accessorIndex = ACCESSOR_NEGATIVE_INDEX;
+    if (!NextToken())
+      return nullptr;
+  }
+  s = ParseSimpleExpression();
+  if (!s)
+    return nullptr;
+  if (m_token->m_type != TOKrbracket) {
+    m_error = true;
+    return nullptr;
+  }
+  return pdfium::MakeUnique<CXFA_FMIndexExpression>(line, accessorIndex,
+                                                    std::move(s), false);
+}
+
+std::unique_ptr<CXFA_FMSimpleExpression> CXFA_FMParser::ParseParenExpression() {
+  if (!CheckThenNext(TOKlparen))
+    return nullptr;
+
+  if (m_token->m_type == TOKrparen) {
+    m_error = true;
+    return nullptr;
+  }
+
+  uint32_t line = m_token->m_line_num;
+  std::unique_ptr<CXFA_FMSimpleExpression> pExp1 = ParseLogicalOrExpression();
+  if (!pExp1)
+    return nullptr;
+
+  int level = 1;
+  while (m_token->m_type == TOKassign) {
+    if (!NextToken())
+      return nullptr;
+
+    std::unique_ptr<CXFA_FMSimpleExpression> pExp2 = ParseLogicalOrExpression();
+    if (!pExp2)
+      return nullptr;
+    if (level++ == kMaxAssignmentChainLength) {
+      m_error = true;
+      return nullptr;
+    }
+
+    pExp1 = pdfium::MakeUnique<CXFA_FMAssignExpression>(
+        line, TOKassign, std::move(pExp1), std::move(pExp2));
+  }
+  if (!CheckThenNext(TOKrparen))
+    return nullptr;
+  return pExp1;
+}
+
+std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseBlockExpression() {
+  if (HasError())
+    return nullptr;
+
+  uint32_t line = m_token->m_line_num;
+  std::vector<std::unique_ptr<CXFA_FMExpression>> expressions;
+  while (1) {
+    std::unique_ptr<CXFA_FMExpression> expr;
+    switch (m_token->m_type) {
+      case TOKeof:
+      case TOKendif:
+      case TOKelseif:
+      case TOKelse:
+      case TOKendwhile:
+      case TOKendfor:
+      case TOKend:
+      case TOKendfunc:
+      case TOKreserver:
+        break;
+      case TOKfunc:
+        expr = ParseFunction();
+        if (!expr)
+          return nullptr;
+
+        expressions.push_back(std::move(expr));
+        continue;
+      default:
+        expr = ParseExpression();
+        if (!expr)
+          return nullptr;
+
+        expressions.push_back(std::move(expr));
+        continue;
+    }
+    break;
+  }
+  return pdfium::MakeUnique<CXFA_FMBlockExpression>(line,
+                                                    std::move(expressions));
+}
+
+std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseIfExpression() {
+  if (HasError())
+    return nullptr;
+
+  uint32_t line = m_token->m_line_num;
+  const wchar_t* pStartPos = m_lexer->GetPos();
+  if (!NextToken() || !CheckThenNext(TOKlparen))
+    return nullptr;
+
+  std::unique_ptr<CXFA_FMSimpleExpression> pExpression;
+  while (m_token->m_type != TOKrparen) {
+    pExpression = ParseSimpleExpression();
+    if (!pExpression)
+      return nullptr;
+    if (m_token->m_type != TOKcomma)
+      break;
+    if (!NextToken())
+      return nullptr;
+  }
+  if (!CheckThenNext(TOKrparen))
+    return nullptr;
+  if (m_token->m_type != TOKthen) {
+    m_lexer->SetCurrentLine(line);
+    auto pNewToken = pdfium::MakeUnique<CXFA_FMToken>(line);
+    m_token = std::move(pNewToken);
+    m_token->m_type = TOKidentifier;
+    m_token->m_string = L"if";
+    m_lexer->SetPos(pStartPos);
+    return ParseExpExpression();
+  }
+  if (!CheckThenNext(TOKthen))
+    return nullptr;
+
+  std::unique_ptr<CXFA_FMExpression> pIfExpression = ParseBlockExpression();
+  if (!pIfExpression)
+    return nullptr;
+
+  std::unique_ptr<CXFA_FMExpression> pElseExpression;
+  switch (m_token->m_type) {
+    case TOKeof:
+    case TOKendif:
+      if (!CheckThenNext(TOKendif))
+        return nullptr;
+      break;
+    case TOKif:
+      pElseExpression = ParseIfExpression();
+      if (!pElseExpression || !CheckThenNext(TOKendif))
+        return nullptr;
+      break;
+    case TOKelseif:
+      pElseExpression = ParseIfExpression();
+      if (!pElseExpression)
+        return nullptr;
+      break;
+    case TOKelse:
+      if (!NextToken())
+        return nullptr;
+      pElseExpression = ParseBlockExpression();
+      if (!pElseExpression || !CheckThenNext(TOKendif))
+        return nullptr;
+      break;
+    default:
+      m_error = true;
+      return nullptr;
+  }
+  return pdfium::MakeUnique<CXFA_FMIfExpression>(line, std::move(pExpression),
+                                                 std::move(pIfExpression),
+                                                 std::move(pElseExpression));
+}
+
+std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseWhileExpression() {
+  if (HasError())
+    return nullptr;
+
+  uint32_t line = m_token->m_line_num;
+  if (!NextToken())
+    return nullptr;
+
+  std::unique_ptr<CXFA_FMSimpleExpression> pCondition = ParseParenExpression();
+  if (!pCondition || !CheckThenNext(TOKdo))
+    return nullptr;
+
+  std::unique_ptr<CXFA_FMExpression> pExpression = ParseBlockExpression();
+  if (!pExpression || !CheckThenNext(TOKendwhile))
+    return nullptr;
+  return pdfium::MakeUnique<CXFA_FMWhileExpression>(line, std::move(pCondition),
+                                                    std::move(pExpression));
+}
+
+std::unique_ptr<CXFA_FMSimpleExpression>
+CXFA_FMParser::ParseSubassignmentInForExpression() {
+  if (HasError())
+    return nullptr;
+
+  if (m_token->m_type != TOKidentifier) {
+    m_error = true;
+    return nullptr;
+  }
+  std::unique_ptr<CXFA_FMSimpleExpression> expr = ParseSimpleExpression();
+  if (!expr)
+    return nullptr;
+  return expr;
+}
+
+std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseForExpression() {
+  if (HasError())
+    return nullptr;
+
+  CFX_WideStringC wsVariant;
+  uint32_t line = m_token->m_line_num;
+  if (!NextToken())
+    return nullptr;
+  if (m_token->m_type != TOKidentifier) {
+    m_error = true;
+    return nullptr;
+  }
+
+  wsVariant = m_token->m_string;
+  if (!NextToken())
+    return nullptr;
+  if (m_token->m_type != TOKassign) {
+    m_error = true;
+    return nullptr;
+  }
+  if (!NextToken())
+    return nullptr;
+
+  std::unique_ptr<CXFA_FMSimpleExpression> pAssignment =
+      ParseSimpleExpression();
+  if (!pAssignment)
+    return nullptr;
+
+  int32_t iDirection = 0;
+  if (m_token->m_type == TOKupto) {
+    iDirection = 1;
+  } else if (m_token->m_type == TOKdownto) {
+    iDirection = -1;
+  } else {
+    m_error = true;
+    return nullptr;
+  }
+
+  if (!NextToken())
+    return nullptr;
+
+  std::unique_ptr<CXFA_FMSimpleExpression> pAccessor = ParseSimpleExpression();
+  if (!pAccessor)
+    return nullptr;
+
+  std::unique_ptr<CXFA_FMSimpleExpression> pStep;
+  if (m_token->m_type == TOKstep) {
+    if (!NextToken())
+      return nullptr;
+    pStep = ParseSimpleExpression();
+    if (!pStep)
+      return nullptr;
+  }
+  if (!CheckThenNext(TOKdo))
+    return nullptr;
+
+  std::unique_ptr<CXFA_FMExpression> pList = ParseBlockExpression();
+  if (!pList || !CheckThenNext(TOKendfor))
+    return nullptr;
+
+  std::unique_ptr<CXFA_FMExpression> expr;
+  if (!expr)
+    return nullptr;
+  return pdfium::MakeUnique<CXFA_FMForExpression>(
+      line, wsVariant, std::move(pAssignment), std::move(pAccessor), iDirection,
+      std::move(pStep), std::move(pList));
+}
+
+std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseForeachExpression() {
+  if (HasError())
+    return nullptr;
+
+  std::unique_ptr<CXFA_FMExpression> expr;
+  CFX_WideStringC wsIdentifier;
+  std::vector<std::unique_ptr<CXFA_FMSimpleExpression>> pAccessors;
+  std::unique_ptr<CXFA_FMExpression> pList;
+  uint32_t line = m_token->m_line_num;
+  if (!NextToken())
+    return nullptr;
+  if (m_token->m_type != TOKidentifier) {
+    m_error = true;
+    return nullptr;
+  }
+
+  wsIdentifier = m_token->m_string;
+  if (!NextToken() || !CheckThenNext(TOKin) || !CheckThenNext(TOKlparen))
+    return nullptr;
+  if (m_token->m_type == TOKrparen) {
+    m_error = true;
+    return nullptr;
+  }
+
+  while (m_token->m_type != TOKrparen) {
+    std::unique_ptr<CXFA_FMSimpleExpression> s = ParseSimpleExpression();
+    if (!s)
+      return nullptr;
+
+    pAccessors.push_back(std::move(s));
+    if (m_token->m_type != TOKcomma)
+      break;
+    if (!NextToken())
+      return nullptr;
+  }
+  if (!CheckThenNext(TOKrparen) || !CheckThenNext(TOKdo))
+    return nullptr;
+
+  pList = ParseBlockExpression();
+  if (!pList || !CheckThenNext(TOKendfor))
+    return nullptr;
+  return pdfium::MakeUnique<CXFA_FMForeachExpression>(
+      line, wsIdentifier, std::move(pAccessors), std::move(pList));
+}
+
+std::unique_ptr<CXFA_FMExpression> CXFA_FMParser::ParseDoExpression() {
+  if (HasError())
+    return nullptr;
+
+  uint32_t line = m_token->m_line_num;
+  if (!NextToken())
+    return nullptr;
+
+  std::unique_ptr<CXFA_FMExpression> expr = ParseBlockExpression();
+  if (!expr || !CheckThenNext(TOKend))
+    return nullptr;
+  return pdfium::MakeUnique<CXFA_FMDoExpression>(line, std::move(expr));
+}
+
+bool CXFA_FMParser::HasError() const {
+  return m_error || m_token == nullptr;
+}