Stop treating '\' as an escape character in strings.

Detect character literals and assign SCE_VHDL_STRING to them.

2 files changed, 29 insertions, 7 deletions

diff --git a/doc/ScintillaHistory.html b/doc/ScintillaHistory.html
index 051baf916..36039a5b4 100644
--- a/doc/ScintillaHistory.html
+++ b/doc/ScintillaHistory.html
@@ -538,6 +538,9 @@
 	Django tag inside of a {# #} Django comment does not break highlighting of rest of file
 	</li>
 	<li>
+	Improve VHDL lexer's handling of character literals and escape characters in strings.
+	</li>
+	<li>
 	Fix failure on Cocoa with animated find indicator in large files with macOS 10.13
 	by disabling animation on 10.13.
 	</li>
diff --git a/lexers/LexVHDL.cxx b/lexers/LexVHDL.cxx
index e0fc428fb..de87d2792 100644
--- a/lexers/LexVHDL.cxx
+++ b/lexers/LexVHDL.cxx
@@ -72,8 +72,9 @@ static void ColouriseVHDLDoc(
   StyleContext sc(startPos, length, initStyle, styler);
   bool isExtendedId = false;    // true when parsing an extended identifier
 
-  for (; sc.More(); sc.Forward())
+  while (sc.More())
   {
+    bool advance = true;
 
     // Determine if the current state should terminate.
     if (sc.state == SCE_VHDL_OPERATOR) {
@@ -106,24 +107,28 @@ static void ColouriseVHDLDoc(
         // extended identifiers are terminated by backslash, check for end of line in case we have invalid syntax
         isExtendedId = false;
         sc.ForwardSetState(SCE_VHDL_DEFAULT);
+        advance = false;
       }
     } else if (sc.state == SCE_VHDL_COMMENT || sc.state == SCE_VHDL_COMMENTLINEBANG) {
       if (sc.atLineEnd) {
         sc.SetState(SCE_VHDL_DEFAULT);
       }
     } else if (sc.state == SCE_VHDL_STRING) {
-      if (sc.ch == '\\') {
-        if (sc.chNext == '\"' || sc.chNext == '\'' || sc.chNext == '\\') {
+      if (sc.ch == '"') {
+        advance = false;
+        sc.Forward();
+        if (sc.ch == '"')
           sc.Forward();
-        }
-      } else if (sc.ch == '\"') {
-        sc.ForwardSetState(SCE_VHDL_DEFAULT);
+        else
+          sc.SetState(SCE_VHDL_DEFAULT);
       } else if (sc.atLineEnd) {
+        advance = false;
         sc.ChangeState(SCE_VHDL_STRINGEOL);
         sc.ForwardSetState(SCE_VHDL_DEFAULT);
       }
     } else if (sc.state == SCE_VHDL_BLOCK_COMMENT){
       if(sc.ch == '*' && sc.chNext == '/'){
+        advance = false;
         sc.Forward();
         sc.ForwardSetState(SCE_VHDL_DEFAULT);
       }
@@ -142,8 +147,19 @@ static void ColouriseVHDLDoc(
           sc.SetState(SCE_VHDL_COMMENT);
       } else if (sc.Match('/', '*')){
         sc.SetState(SCE_VHDL_BLOCK_COMMENT);
-      } else if (sc.ch == '\"') {
+      } else if (sc.ch == '"') {
         sc.SetState(SCE_VHDL_STRING);
+      } else if (sc.ch == '\'') {
+        if (sc.GetRelative(2) == '\''){
+          if (sc.chNext != '(' || sc.GetRelative(4) != '\''){
+            // Can only be a character literal
+            sc.SetState(SCE_VHDL_STRING);
+            sc.Forward();
+            sc.Forward();
+            sc.ForwardSetState(SCE_VHDL_DEFAULT);
+            advance = false;
+          } // else can be a tick or a character literal, need more context, eg.: identifier'('x')
+        } // else can only be a tick
       } else if (sc.ch == '\\') {
         isExtendedId = true;
         sc.SetState(SCE_VHDL_IDENTIFIER);
@@ -151,6 +167,9 @@ static void ColouriseVHDLDoc(
         sc.SetState(SCE_VHDL_OPERATOR);
       }
     }
+    
+    if (advance)
+      sc.Forward();
   }
   sc.Complete();
 }