work on improving union initialization

Author: totalspectrum

expr.c

@@ -4048,11 +4048,12 @@ AST *FindMethodInList(AST *list, AST *ident, int *curptr)
 /* fix up an initializer list of a given type */
 /* creates an array containing the initializer expressions;
  * each of these may in turn be an array of initializers
- * returns an EXPRLIST containing the items
+ * returns an EXPRLIST containing the items; if "unionInit"
+ * is true, it adds any explicit method names
  * returns NULL if list is empty
  */
 AST *
-FixupInitList(AST *type, AST *initval)
+FixupInitList(AST *type, AST *initval, bool unionInit)
 {
     int numelems;
     AST **astarr = 0;
@@ -4163,6 +4164,7 @@ FixupInitList(AST *type, AST *initval)
         curelem = 0;
         while (initval) {
             AST *val = initval;
+            AST *methodname = NULL;
             initval = initval->right;
             val->right = NULL;
             if (val->left->kind == AST_INITMODIFIER) {
@@ -4176,7 +4178,8 @@ FixupInitList(AST *type, AST *initval)
                     ERROR(fixup, "Internal error, cannot handle nested designators");
                     newval = AstInteger(0);
                 } else {
-                    varlist = FindMethodInList(P->finalvarblock, fixup->right, &curelem);
+                    methodname = fixup->right;
+                    varlist = FindMethodInList(P->finalvarblock, methodname, &curelem);
                     if (!varlist) {
                         ERROR(fixup, "%s not found in struct", GetUserIdentifierName(fixup->right));
                         break;
@@ -4191,6 +4194,11 @@ FixupInitList(AST *type, AST *initval)
                 AST *subtype = ExprType(varlist->left);
                 val->left = NewAST(AST_CAST, subtype, val->left);
             }
+            if (is_union && unionInit && methodname) {
+                if (val->kind == AST_EXPRLIST && val->right == NULL)
+                    val = val->left;
+                val = NewAST(AST_ASSIGN_INIT, methodname, val);
+            }
             if (curelem < numelems) {
                 astarr[curelem] = val;
                 curelem++;

expr.h

@@ -190,7 +190,7 @@ AST *BuildExprlistFromObject(AST *expr, AST *typ);
 
 // fix up an initializer list of type "type"
 // handles designators like .x = n, and adds any missing 0's
-AST *FixupInitList(AST *typ, AST *initval);
+AST *FixupInitList(AST *typ, AST *initval, bool unionInit);
 
 /* get a const value as either a constant or a default value */
 int32_t const_or_default(Module *M, const char *name, int32_t defaultval);

frontends/c/clang.c

@@ -1,6 +1,6 @@
 /*
  * Spin to C/C++ converter
- * Copyright 2011-2024 Total Spectrum Software Inc.
+ * Copyright 2011-2026 Total Spectrum Software Inc. and contributors
  * See the file COPYING for terms of use
  *
  * code for C specific features

frontends/common.c

@@ -2005,7 +2005,7 @@ DeclareOneGlobalVar(Module *P, AST *ident, AST *type, int inDat)
             return; // just ignore this declaration
         } else {
             if (initializer->kind == AST_EXPRLIST) {
-                initializer = FixupInitList(rawtype, initializer);
+                initializer = FixupInitList(rawtype, initializer, false);
                 *initptr = initializer;
                 rawtype->right = AstInteger(AstListLen(initializer));
             } else if (initializer->kind == AST_STRINGPTR) {

functions.c

@@ -541,7 +541,7 @@ AddInitializers(AST *seq, AST *ident, AST *expr, AST *basetype)
         AstReportDone(&saveinfo);
         return seq;
     } else if (expr->kind == AST_EXPRLIST) {
-        expr = FixupInitList(basetype, expr);
+        expr = FixupInitList(basetype, expr, true);
         if (IsArrayType(basetype)) {
             if (!IsConstExpr(basetype->right)) {
                 ERROR(ident, "Variable length arrays not supported yet");
@@ -569,13 +569,14 @@ AddInitializers(AST *seq, AST *ident, AST *expr, AST *basetype)
             AST *decl;
             AST *subident;
             AST *curexpr;
-            while (varlist && varlist->kind == AST_LISTHOLDER) {
+            bool moreVars = true;
+            while (varlist && varlist->kind == AST_LISTHOLDER && moreVars) {
                 decl = varlist->left;
                 varlist = varlist->right;
                 if (decl && decl->kind == AST_DECLARE_VAR) {
                     subtype = decl->left;
                     decl = decl->right;
-                    while (decl) {
+                    while (decl && moreVars) {
                         if (decl->kind == AST_LISTHOLDER) {
                             subident = decl->left;
                             decl = decl->right;
@@ -594,6 +595,14 @@ AddInitializers(AST *seq, AST *ident, AST *expr, AST *basetype)
                         } else {
                             curexpr = AstInteger(0);
                         }
+                        if (curexpr && curexpr->kind == AST_ASSIGN_INIT) {
+                            subident = curexpr->left;
+                            curexpr = curexpr->right;
+                            if (curexpr && curexpr->kind == AST_CAST) {
+                                subtype = curexpr->left;
+                            }
+                            moreVars = false;
+                        }
                         sub = NewAST(AST_METHODREF, ident, subident);
                         seq = AddInitializers(seq, sub, curexpr, subtype);
                     }
@@ -671,7 +680,7 @@ findLocalsAndDeclare(Function *func, AST *ast)
             if (ident->kind == AST_ASSIGN) {
                 // check for x[] = {a, b, c} type initializers here
                 if (IsArrayType(basetype) && basetype->right == NULL) {
-                    AST *tmp = FixupInitList(basetype, ident->right);
+                    AST *tmp = FixupInitList(basetype, ident->right, false);
                     ident->right = tmp;
                     //fixupInitializer(current, ident->right, basetype);
                     if (ident->right->kind == AST_EXPRLIST) {

pasm.c

@@ -1201,7 +1201,7 @@ AssignAddresses(PASMAddresses *addr, SymbolTable *orig_symtab, AST *instrlist, i
                     }
                 }
                 if (initptr && (IsClassType(type) || IsArrayType(type)) ) {
-                    initializer = FixupInitList(type, initializer);
+                    initializer = FixupInitList(type, initializer, false);
                     *initptr = initializer;
                 }
                 ALIGNPC(typalign);