[formcalc] Split literal parsing to its own method

This Cl moves the code to create literals in the AST from
ParsePrimaryExpression to ParseLiteral.

Change-Id: I41ba20f28f1cb1d76d753c5baec790872acdf1da
Reviewed-on: https://pdfium-review.googlesource.com/27411
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>

2 files changed, 22 insertions, 18 deletions

diff --git a/xfa/fxfa/fm2js/cxfa_fmparser.cpp b/xfa/fxfa/fm2js/cxfa_fmparser.cpp
index 93fa44fedd..1805c119b6 100644
--- a/xfa/fxfa/fm2js/cxfa_fmparser.cpp
+++ b/xfa/fxfa/fm2js/cxfa_fmparser.cpp
@@ -592,21 +592,12 @@ CXFA_FMParser::ParsePrimaryExpression() {
   if (HasError() || !IncrementParseDepthAndCheck())
     return nullptr;
 
-  std::unique_ptr<CXFA_FMSimpleExpression> expr;
+  std::unique_ptr<CXFA_FMSimpleExpression> expr = ParseLiteral();
+  if (expr)
+    return NextToken() ? std::move(expr) : nullptr;
+
   uint32_t line = m_lexer->GetCurrentLine();
   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: {
       WideStringView wsIdentifier(m_token.m_string);
       if (!NextToken())
@@ -628,11 +619,6 @@ CXFA_FMParser::ParsePrimaryExpression() {
       }
       break;
     }
-    case TOKnull:
-      expr = pdfium::MakeUnique<CXFA_FMNullExpression>(line);
-      if (!expr || !NextToken())
-        return nullptr;
-      break;
     case TOKlparen:
       expr = ParseParenExpression();
       if (!expr)
@@ -648,6 +634,23 @@ CXFA_FMParser::ParsePrimaryExpression() {
   return expr;
 }
 
+// Literal := String | Number | Null
+std::unique_ptr<CXFA_FMSimpleExpression> CXFA_FMParser::ParseLiteral() {
+  uint32_t line = m_lexer->GetCurrentLine();
+  switch (m_token.m_type) {
+    case TOKnumber:
+      return pdfium::MakeUnique<CXFA_FMNumberExpression>(line,
+                                                         m_token.m_string);
+    case TOKstring:
+      return pdfium::MakeUnique<CXFA_FMStringExpression>(line,
+                                                         m_token.m_string);
+    case TOKnull:
+      return pdfium::MakeUnique<CXFA_FMNullExpression>(line);
+    default:
+      return nullptr;
+  }
+}
+
 std::unique_ptr<CXFA_FMSimpleExpression> CXFA_FMParser::ParsePostExpression(
     std::unique_ptr<CXFA_FMSimpleExpression> expr) {
   AutoRestorer<unsigned long> restorer(&m_parse_depth);
diff --git a/xfa/fxfa/fm2js/cxfa_fmparser.h b/xfa/fxfa/fm2js/cxfa_fmparser.h
index c2da48496f..e78495309e 100644
--- a/xfa/fxfa/fm2js/cxfa_fmparser.h
+++ b/xfa/fxfa/fm2js/cxfa_fmparser.h
@@ -55,6 +55,7 @@ class CXFA_FMParser {
   std::unique_ptr<CXFA_FMSimpleExpression> ParsePostExpression(
       std::unique_ptr<CXFA_FMSimpleExpression> e);
   std::unique_ptr<CXFA_FMSimpleExpression> ParseIndexExpression();
+  std::unique_ptr<CXFA_FMSimpleExpression> ParseLiteral();
 
   std::unique_ptr<CXFA_FMLexer> m_lexer;
   CXFA_FMToken m_token;