Simplify prefix stripping logic and consolidate

Author: fredrikhr

sources/ClangSharp.PInvokeGenerator/PInvokeGenerator.VisitDecl.cs

@@ -297,9 +297,7 @@ private void VisitEnumConstantDecl(EnumConstantDecl enumConstantDecl)
 
         if (Config.StripEnumMemberTypeName)
         {
-            Regex stripParentNameRegex = new($"^{Regex.Escape(parentName)}_*", RegexOptions.IgnoreCase);
-            var strippedName = stripParentNameRegex.Replace(escapedName, string.Empty);
-            escapedName = strippedName;
+            escapedName = PrefixAndStrip(escapedName, parentName, trimChar: '_');
         }
 
         var kind = isAnonymousEnum ? ValueKind.Primitive : ValueKind.Enumerator;
@@ -543,12 +541,12 @@ private void VisitFunctionDecl(FunctionDecl functionDecl)
         if ((cxxMethodDecl is not null) && cxxMethodDecl.IsVirtual)
         {
             isVirtual = true;
-            escapedName = PrefixAndStripName(name, GetOverloadIndex(cxxMethodDecl));
+            escapedName = PrefixAndStripMethodName(name, GetOverloadIndex(cxxMethodDecl));
         }
         else
         {
             isVirtual = false;
-            escapedName = EscapeAndStripName(name);
+            escapedName = EscapeAndStripMethodName(name);
         }
 
         var returnType = functionDecl.ReturnType;
@@ -2032,7 +2030,7 @@ void OutputMarkerInterface(CXXRecordDecl cxxRecordDecl, CXXMethodDecl cxxMethodD
 
             var desc = new FunctionOrDelegateDesc {
                 AccessSpecifier = AccessSpecifier.Public,
-                EscapedName = EscapeAndStripName(name),
+                EscapedName = EscapeAndStripMethodName(name),
                 IsMemberFunction = true,
                 NativeTypeName = nativeTypeName,
                 HasFnPtrCodeGen = !_config.ExcludeFnptrCodegen,
@@ -2120,7 +2118,7 @@ void OutputVtblEntry(CXXRecordDecl cxxRecordDecl, CXXMethodDecl cxxMethodDecl)
             }
 
             var remappedName = FixupNameForMultipleHits(cxxMethodDecl);
-            var escapedName = EscapeAndStripName(remappedName);
+            var escapedName = EscapeAndStripMethodName(remappedName);
 
             var desc = new FieldDesc
             {
@@ -2189,7 +2187,7 @@ void OutputVtblHelperMethod(CXXRecordDecl cxxRecordDecl, CXXMethodDecl cxxMethod
             var desc = new FunctionOrDelegateDesc {
                 AccessSpecifier = AccessSpecifier.Public,
                 IsAggressivelyInlined = _config.GenerateAggressiveInlining,
-                EscapedName = EscapeAndStripName(name),
+                EscapedName = EscapeAndStripMethodName(name),
                 ParentName = parentName,
                 IsMemberFunction = true,
                 IsInherited = isInherited,
@@ -2269,7 +2267,7 @@ void OutputVtblHelperMethod(CXXRecordDecl cxxRecordDecl, CXXMethodDecl cxxMethod
             {
                 body.Write("Marshal.GetDelegateForFunctionPointer<");
                 body.BeginMarker("delegate");
-                body.Write(PrefixAndStripName(name, GetOverloadIndex(cxxMethodDecl)));
+                body.Write(PrefixAndStripMethodName(name, GetOverloadIndex(cxxMethodDecl)));
                 body.EndMarker("delegate");
                 body.Write(">(");
             }
@@ -2278,7 +2276,7 @@ void OutputVtblHelperMethod(CXXRecordDecl cxxRecordDecl, CXXMethodDecl cxxMethod
             {
                 body.Write("lpVtbl->");
                 body.BeginMarker("vtbl", new KeyValuePair<string, object>("explicit", true));
-                body.Write(EscapeAndStripName(remappedName));
+                body.Write(EscapeAndStripMethodName(remappedName));
                 body.EndMarker("vtbl");
             }
             else

sources/ClangSharp.PInvokeGenerator/PInvokeGenerator.VisitStmt.cs

@@ -970,7 +970,7 @@ private void VisitDeclRefExpr(DeclRefExpr declRefExpr)
 
             if (declRefExpr.Decl is FunctionDecl)
             {
-                escapedName = EscapeAndStripName(name);
+                escapedName = EscapeAndStripMethodName(name);
             }
         }
 

sources/ClangSharp.PInvokeGenerator/PInvokeGenerator.cs

@@ -2326,13 +2326,9 @@ private static string EscapeName(string name)
         }
     }
 
-    private string EscapeAndStripName(string name)
+    private string EscapeAndStripMethodName(string name)
     {
-        if (name.StartsWith(_config.MethodPrefixToStrip, StringComparison.Ordinal))
-        {
-            name = name[_config.MethodPrefixToStrip.Length..];
-        }
-
+        name = PrefixAndStrip(name, _config.MethodPrefixToStrip);
         return EscapeName(name);
     }
 
@@ -6198,13 +6194,32 @@ private void ParenthesizeStmt(Stmt stmt)
         }
     }
 
-    private string PrefixAndStripName(string name, uint overloadIndex)
+    /// <summary>
+    /// Checks whether the specified name starts with a prefix, optionally trims a separator character following the prefix and returns the remainder.
+    /// </summary>
+    /// <param name="name">The name to strip.</param>
+    /// <param name="prefix">The prefix to strip from <paramref name="name"/>.</param>
+    /// <param name="trimChar">Additional separator that may follow <paramref name="prefix"/> which should also be trimmed away.</param>
+    /// <returns>
+    /// <paramref name="name"/> if it does not start with <paramref name="prefix"/>;
+    /// otherwise,
+    /// the remainder of <paramref name="name"/> after stripping <paramref name="prefix"/> and all immediate following occurences of <paramref name="trimChar"/> from it beginning.
+    /// </returns>
+    private static string PrefixAndStrip(string name, string prefix, char trimChar = '\0')
     {
-        if (name.StartsWith(_config.MethodPrefixToStrip, StringComparison.Ordinal))
+        var nameSpan = name.AsSpan();
+        if (nameSpan.StartsWith(prefix, StringComparison.Ordinal))
         {
-            name = name[_config.MethodPrefixToStrip.Length..];
+            nameSpan = nameSpan[prefix.Length..];
+            nameSpan = nameSpan.TrimStart(trimChar);
+            return nameSpan.ToString();
+        }
+        return name;
         }
 
+    private string PrefixAndStripMethodName(string name, uint overloadIndex)
+    {
+        name = PrefixAndStrip(name, _config.MethodPrefixToStrip);
         return $"_{name}{((overloadIndex != 0) ? overloadIndex.ToString(CultureInfo.InvariantCulture) : "")}";
     }