From edd79d76b6120186ecc4f47db322f915555555d1 Mon Sep 17 00:00:00 2001
From: Zane Duffield <zduffield@integradev.com.au>
Date: Fri, 6 Oct 2023 16:24:30 +1100
Subject: [PATCH] Correctly parse various unusual integer literals

---
 CHANGELOG.md                                  |  1 +
 .../au/com/integradev/delphi/antlr/Delphi.g   | 10 ++++----
 .../integradev/delphi/antlr/GrammarTest.java  |  5 ++++
 .../delphi/grammar/UnusualIntegerLiterals.pas | 23 +++++++++++++++++++
 4 files changed, 34 insertions(+), 5 deletions(-)
 create mode 100644 delphi-frontend/src/test/resources/au/com/integradev/delphi/grammar/UnusualIntegerLiterals.pas

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4c52ca03c..55e5d2da0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -59,6 +59,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `add` is no longer colorized as a keyword in the SonarQube web interface.
 - `remove` is no longer colorized as a keyword in the SonarQube web interface.
 - `variant` is no longer colorized as a keyword in the SonarQube web interface.
+- Parsing errors for unusual escaped character, hex integer, and binary integer literals.
 
 ## [0.40.0] - 2023-01-10
 
diff --git a/delphi-frontend/src/main/antlr3/au/com/integradev/delphi/antlr/Delphi.g b/delphi-frontend/src/main/antlr3/au/com/integradev/delphi/antlr/Delphi.g
index 731cb86f8..0ad4b759a 100644
--- a/delphi-frontend/src/main/antlr3/au/com/integradev/delphi/antlr/Delphi.g
+++ b/delphi-frontend/src/main/antlr3/au/com/integradev/delphi/antlr/Delphi.g
@@ -1201,9 +1201,9 @@ TkIntNumber             : DigitSeq (
                               )?
                           )?
                         ;
-TkHexNumber             : '$' HexDigitSeq
+TkHexNumber             : '$' ('_' | HexDigit)*
                         ;
-TkBinaryNumber          : '%' BinaryDigitSeq
+TkBinaryNumber          : '%' ('_' | BinaryDigit)*
                         ;
 TkAsmId                 : { asmMode }? => '@' '@'? (Alpha | '_' | Digit)+
                         ;
@@ -1213,9 +1213,9 @@ TkQuotedString          : '\'' ('\'\'' | ~('\''))* '\''
                         ;
 TkAsmDoubleQuotedString : { asmMode }? => '"' (~('\"'))* '"'
                         ;
-TkCharacterEscapeCode   : '#' DigitSeq
-                        | '#' '$' HexDigitSeq
-                        | '#' '%' BinaryDigitSeq
+TkCharacterEscapeCode   : '#' ('_' | Digit)+
+                        | '#' '$' ('_' | HexDigit)+
+                        | '#' '%' ('_' | BinaryDigit)+
                         ;
 //----------------------------------------------------------------------------
 // Fragments
diff --git a/delphi-frontend/src/test/java/au/com/integradev/delphi/antlr/GrammarTest.java b/delphi-frontend/src/test/java/au/com/integradev/delphi/antlr/GrammarTest.java
index b263814ac..cd6cd2a78 100644
--- a/delphi-frontend/src/test/java/au/com/integradev/delphi/antlr/GrammarTest.java
+++ b/delphi-frontend/src/test/java/au/com/integradev/delphi/antlr/GrammarTest.java
@@ -237,4 +237,9 @@ void testEmptyFileShouldThrow() {
                     DelphiFileUtils.mockConfig()))
         .isInstanceOf(DelphiFileConstructionException.class);
   }
+
+  @Test
+  void testUnusualIntegerLiterals() {
+    parseFile("UnusualIntegerLiterals.pas");
+  }
 }
diff --git a/delphi-frontend/src/test/resources/au/com/integradev/delphi/grammar/UnusualIntegerLiterals.pas b/delphi-frontend/src/test/resources/au/com/integradev/delphi/grammar/UnusualIntegerLiterals.pas
new file mode 100644
index 000000000..906dedf0c
--- /dev/null
+++ b/delphi-frontend/src/test/resources/au/com/integradev/delphi/grammar/UnusualIntegerLiterals.pas
@@ -0,0 +1,23 @@
+unit UnusualIntegerLiterals;
+
+interface
+
+const
+  HexWithoutDigits = $;
+  BinaryWithoutDigits = %;
+  HexStartingWithUnderscore = $_;
+  BinaryStartingWithUnderscore = %_;
+  HexStartingWithManyUnderscores = $__;
+  BinaryStartingWithManyUnderscores = %__;
+
+  CharHexStartingWithUnderscore = #$_;
+  CharBinaryStartingWithUnderscore = #%_;
+  CharHexStartingWithManyUnderscores = #$__;
+  CharBinaryStartingWithManyUnderscores = #%__;
+
+  CharDecimalStartingWithUnderscore = #_;
+  CharDecimalStartingWithManyUnderscores = #__;
+
+implementation
+
+end.