Commit a4a9330648

@@ -1625,6 +1625,10 @@ unsigned ZigClangFunctionDecl_getAlignedAttribute(const struct ZigClangFunctionD
     return 0;
 }
 
+ZigClangQualType ZigClangParmVarDecl_getOriginalType(const struct ZigClangParmVarDecl *self) {
+    return bitcast(reinterpret_cast<const clang::ParmVarDecl *>(self)->getOriginalType());
+}
+
 const ZigClangRecordDecl *ZigClangRecordDecl_getDefinition(const ZigClangRecordDecl *zig_record_decl) {
     const clang::RecordDecl *record_decl = reinterpret_cast<const clang::RecordDecl *>(zig_record_decl);
     const clang::RecordDecl *definition = record_decl->getDefinition();

@@ -866,6 +866,8 @@ ZIG_EXTERN_C const char* ZigClangVarDecl_getSectionAttribute(const struct ZigCla
 ZIG_EXTERN_C unsigned ZigClangVarDecl_getAlignedAttribute(const struct ZigClangVarDecl *self, const ZigClangASTContext* ctx);
 ZIG_EXTERN_C unsigned ZigClangFunctionDecl_getAlignedAttribute(const struct ZigClangFunctionDecl *self, const ZigClangASTContext* ctx);
 
+ZIG_EXTERN_C struct ZigClangQualType ZigClangParmVarDecl_getOriginalType(const struct ZigClangParmVarDecl *self);
+
 ZIG_EXTERN_C bool ZigClangRecordDecl_getPackedAttribute(const struct ZigClangRecordDecl *);
 ZIG_EXTERN_C const struct ZigClangRecordDecl *ZigClangRecordDecl_getDefinition(const struct ZigClangRecordDecl *);
 ZIG_EXTERN_C const struct ZigClangEnumDecl *ZigClangEnumDecl_getDefinition(const struct ZigClangEnumDecl *);

@@ -768,6 +768,7 @@ pub extern fn ZigClangFieldDecl_getCanonicalDecl(field_decl: ?*const struct_ZigC
 pub extern fn ZigClangEnumDecl_getCanonicalDecl(self: ?*const struct_ZigClangEnumDecl) ?*const struct_ZigClangTagDecl;
 pub extern fn ZigClangTypedefNameDecl_getCanonicalDecl(self: ?*const struct_ZigClangTypedefNameDecl) ?*const struct_ZigClangTypedefNameDecl;
 pub extern fn ZigClangFunctionDecl_getCanonicalDecl(self: ?*const struct_ZigClangFunctionDecl) ?*const struct_ZigClangFunctionDecl;
+pub extern fn ZigClangParmVarDecl_getOriginalType(self: ?*const struct_ZigClangParmVarDecl) struct_ZigClangQualType;
 pub extern fn ZigClangVarDecl_getCanonicalDecl(self: ?*const struct_ZigClangVarDecl) ?*const struct_ZigClangVarDecl;
 pub extern fn ZigClangVarDecl_getSectionAttribute(self: *const ZigClangVarDecl, len: *usize) ?[*]const u8;
 pub extern fn ZigClangFunctionDecl_getAlignedAttribute(self: *const ZigClangFunctionDecl, *const ZigClangASTContext) c_uint;

@@ -485,6 +485,7 @@ fn visitFnDecl(c: *Context, fn_decl: *const ZigClangFunctionDecl) Error!void {
     block_scope.block_node = block_node;
 
     var it = proto_node.params.iterator(0);
+    var param_id: c_uint = 0;
     while (it.next()) |p| {
         const param = @fieldParentPtr(ast.Node.ParamDecl, "base", p.*);
         const param_name = if (param.name_token) |name_tok|
@@ -498,18 +499,27 @@ fn visitFnDecl(c: *Context, fn_decl: *const ZigClangFunctionDecl) Error!void {
 
         const mangled_param_name = try block_scope.makeMangledName(c, param_name);
 
+        const c_param = ZigClangFunctionDecl_getParamDecl(fn_decl, param_id);
+        const qual_type = ZigClangParmVarDecl_getOriginalType(c_param);
+        const is_const = ZigClangQualType_isConstQualified(qual_type);
+
         const arg_name = blk: {
-            const bare_arg_name = try std.fmt.allocPrint(c.a(), "arg_{}", .{mangled_param_name});
+            const param_prefix = if (is_const) "" else "arg_";
+            const bare_arg_name = try std.fmt.allocPrint(c.a(), "{}{}", .{param_prefix, mangled_param_name});
             break :blk try block_scope.makeMangledName(c, bare_arg_name);
         };
 
-        const node = try transCreateNodeVarDecl(c, false, false, mangled_param_name);
-        node.eq_token = try appendToken(c, .Equal, "=");
-        node.init_node = try transCreateNodeIdentifier(c, arg_name);
-        node.semicolon_token = try appendToken(c, .Semicolon, ";");
-        try block_node.statements.push(&node.base);
-        param.name_token = try appendIdentifier(c, arg_name);
-        _ = try appendToken(c, .Colon, ":");
+        if (!is_const) {
+            const node = try transCreateNodeVarDecl(c, false, false, mangled_param_name);
+            node.eq_token = try appendToken(c, .Equal, "=");
+            node.init_node = try transCreateNodeIdentifier(c, arg_name);
+            node.semicolon_token = try appendToken(c, .Semicolon, ";");
+            try block_node.statements.push(&node.base);
+            param.name_token = try appendIdentifier(c, arg_name);
+            _ = try appendToken(c, .Colon, ":");
+        }
+
+        param_id += 1;
     }
 
     transCompoundStmtInline(rp, &block_scope.base, @ptrCast(*const ZigClangCompoundStmt, body_stmt), block_node) catch |err| switch (err) {

@@ -2615,4 +2615,16 @@ pub fn addCases(cases: *tests.TranslateCContext) void {
         \\    return foo((@intCast(c_int, @bitCast(i1, @intCast(u1, @boolToInt(c)))) != @intCast(c_int, @bitCast(i1, @intCast(u1, @boolToInt(b))))));
         \\}
     });
+
+    cases.add("Don't make const parameters mutable",
+        \\int max(const int x, int y) {
+        \\    return (x > y) ? x : y;
+        \\}
+    , &[_][]const u8{
+        \\pub export fn max(x: c_int, arg_y: c_int) c_int {
+        \\    var y = arg_y;
+        \\    return if (x > y) x else y;
+        \\}
+    });
+            
 }