From 97f2cd76dac1440fe3d69b1cd63a82c2959ee6f1 Mon Sep 17 00:00:00 2001
From: zufuliu <zufuliu@gmail.com>
Date: Sat, 2 Nov 2024 14:28:05 +0800
Subject: [PATCH] [VBA] Handle line continuation in comment, issue #716.

---
 scintilla/include/SciLexer.iface | 11 ++++++-----
 scintilla/lexers/LexVB.cxx       | 24 ++++++++++++++++++++++--
 2 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/scintilla/include/SciLexer.iface b/scintilla/include/SciLexer.iface
index c8d7499494..5307f33f3e 100644
--- a/scintilla/include/SciLexer.iface
+++ b/scintilla/include/SciLexer.iface
@@ -522,13 +522,9 @@ val SCE_RB_LIKE_CLASS=
 val SCE_RB_BUILTIN_CONSTANT=
 val SCE_RB_BUILTIN_FUNCTION=
 val SCE_RB_UPPER_BOUND=
-# Lexical states for SCLEX_VISUALBASIC, SCLEX_VBSCRIPT, SCLEX_POWERBASIC, SCLEX_BLITZBASIC, SCLEX_PUREBASIC, SCLEX_FREEBASIC
+# Lexical states for SCLEX_VISUALBASIC, SCLEX_VBSCRIPT
 lex VisualBasic=SCLEX_VISUALBASIC SCE_VB_
 lex VBScript=SCLEX_VBSCRIPT SCE_VB_
-#lex PowerBasic=SCLEX_POWERBASIC SCE_B_
-#lex BlitzBasic=SCLEX_BLITZBASIC SCE_B_
-#lex PureBasic=SCLEX_PUREBASIC SCE_B_
-#lex FreeBasic=SCLEX_FREEBASIC SCE_B_
 val SCE_VB_DEFAULT=
 val SCE_VB_COMMENTLINE=
 val SCE_VB_LINE_CONTINUATION=
@@ -554,6 +550,11 @@ val SCE_VB_BASIC_FUNCTION=
 val SCE_VB_PREPROCESSOR=
 val SCE_VB_PREPROCESSOR_WORD=
 val SCE_VB_LABEL=
+# Lexical states for SCLEX_POWERBASIC, SCLEX_BLITZBASIC, SCLEX_PUREBASIC, SCLEX_FREEBASIC
+#lex PowerBasic=SCLEX_POWERBASIC SCE_B_
+#lex BlitzBasic=SCLEX_BLITZBASIC SCE_B_
+#lex PureBasic=SCLEX_PUREBASIC SCE_B_
+#lex FreeBasic=SCLEX_FREEBASIC SCE_B_
 # Lexical states for SCLEX_PROPERTIES
 lex Properties=SCLEX_PROPERTIES SCE_PROPS_
 val SCE_PROPS_DEFAULT=0
diff --git a/scintilla/lexers/LexVB.cxx b/scintilla/lexers/LexVB.cxx
index 07f5539212..b307260468 100644
--- a/scintilla/lexers/LexVB.cxx
+++ b/scintilla/lexers/LexVB.cxx
@@ -36,6 +36,10 @@ enum class Language {
 	VBScript,
 };
 
+enum {
+	VBLineStateLineContinuation = 1 << 1,
+};
+
 #define LexCharAt(pos)	styler.SafeGetCharAt(pos)
 
 // https://learn.microsoft.com/en-us/dotnet/visual-basic/reference/language-specification/lexical-grammar#type-characters
@@ -84,6 +88,7 @@ void ColouriseVBDoc(Sci_PositionU startPos, Sci_Position length, int initStyle,
 	const WordList &keywords5 = keywordLists[4];
 	const WordList &keywords6 = keywordLists[5];
 
+	int lineState = 0;
 	int fileNbDigits = 0;
 	int visibleChars = 0;
 	int chPrevNonWhite = 0;
@@ -93,12 +98,15 @@ void ColouriseVBDoc(Sci_PositionU startPos, Sci_Position length, int initStyle,
 	const Language language = static_cast<Language>(styler.GetPropertyInt("lexer.lang"));
 
 	StyleContext sc(startPos, length, initStyle, styler);
+	if (sc.currentLine > 0) {
+		lineState = styler.GetLineState(sc.currentLine - 1);
+		lineState &= VBLineStateLineContinuation;
+	}
 	if (startPos != 0 && IsSpaceEquiv(initStyle)) {
 		LookbackNonWhite(styler, startPos, SCE_VB_LINE_CONTINUATION, chPrevNonWhite, stylePrevNonWhite);
 	}
 
 	while (sc.More()) {
-
 		switch (sc.state) {
 		case SCE_VB_OPERATOR:
 		case SCE_VB_LINE_CONTINUATION:
@@ -156,6 +164,7 @@ void ColouriseVBDoc(Sci_PositionU startPos, Sci_Position length, int initStyle,
 						} else if (keywords6.InList(s)) {
 							sc.ChangeState(SCE_VB_CONSTANT);
 						}
+						stylePrevNonWhite = sc.state;
 					}
 					sc.SetState(SCE_VB_DEFAULT);
 				}
@@ -186,7 +195,17 @@ void ColouriseVBDoc(Sci_PositionU startPos, Sci_Position length, int initStyle,
 
 		case SCE_VB_COMMENTLINE:
 			if (sc.atLineStart) {
-				sc.SetState(SCE_VB_DEFAULT);
+				if (lineState == VBLineStateLineContinuation) {
+					lineState = 0;
+				} else {
+					sc.SetState(SCE_VB_DEFAULT);
+				}
+			} else if (language == Language::VBA && sc.ch == '_' && sc.chPrev <= ' ') {
+				if (sc.GetLineNextChar(true) == '\0') {
+					lineState |= VBLineStateLineContinuation;
+					sc.SetState(SCE_VB_LINE_CONTINUATION);
+					sc.ForwardSetState(SCE_VB_COMMENTLINE);
+				}
 			}
 			break;
 
@@ -255,6 +274,7 @@ void ColouriseVBDoc(Sci_PositionU startPos, Sci_Position length, int initStyle,
 			}
 		}
 		if (sc.atLineEnd) {
+			styler.SetLineState(sc.currentLine, lineState);
 			isIfThenPreprocessor = false;
 			isEndPreprocessor = false;
 			visibleChars = 0;