allow address of spin functions to be taken

Changelog.txt

@@ -10,6 +10,7 @@ Version 4.0.5
 - Print errors for function declared twice
 - Re-arranged internal code to make it possible to distinguish C vs C++ or spin1 vs spin2
 - Allow empty parameter lists in Spin
+- Allow address of function to be taken in Spin
 - Added checks for redefined constants
 
 Version 4.0.4

Test/Expect/stest184.pasm

@@ -28,24 +28,24 @@ LR__0001
 _fetchv_ret
 	ret
 
-__system___tx
-	mov	__system___tx_val, arg01
-	rdlong	__system___tx_bitcycles, ptr___system__dat__
+__system___txraw
+	mov	__system___txraw_val, arg01
+	rdlong	__system___txraw_bitcycles, ptr___system__dat__
 	or	outa, imm_1073741824_
 	or	dira, imm_1073741824_
-	or	__system___tx_val, #256
-	shl	__system___tx_val, #1
-	mov	__system___tx_nextcnt, cnt
-	mov	__system___tx__idx__90001, #10
+	or	__system___txraw_val, #256
+	shl	__system___txraw_val, #1
+	mov	__system___txraw_nextcnt, cnt
+	mov	__system___txraw__idx__90001, #10
 LR__0002
-	add	__system___tx_nextcnt, __system___tx_bitcycles
-	mov	arg01, __system___tx_nextcnt
+	add	__system___txraw_nextcnt, __system___txraw_bitcycles
+	mov	arg01, __system___txraw_nextcnt
 	waitcnt	arg01, #0
-	shr	__system___tx_val, #1 wc
+	shr	__system___txraw_val, #1 wc
 	muxc	outa, imm_1073741824_
-	djnz	__system___tx__idx__90001, #LR__0002
+	djnz	__system___txraw__idx__90001, #LR__0002
 	mov	result1, #1
-__system___tx_ret
+__system___txraw_ret
 	ret
 
 __system___gc_pageptr
@@ -204,7 +204,7 @@ LR__0008
 	add	__system___gc_errmsg_s, #1
  if_e	jmp	#LR__0009
 	mov	arg01, __system___gc_errmsg_c
-	call	#__system___tx
+	call	#__system___txraw
 	jmp	#LR__0008
 LR__0009
 	mov	result1, #0
@@ -793,13 +793,13 @@ __system___gc_tryalloc_saveptr
 	res	1
 __system___gc_tryalloc_size
 	res	1
-__system___tx__idx__90001
+__system___txraw__idx__90001
 	res	1
-__system___tx_bitcycles
+__system___txraw_bitcycles
 	res	1
-__system___tx_nextcnt
+__system___txraw_nextcnt
 	res	1
-__system___tx_val
+__system___txraw_val
 	res	1
 __system__bytemove_origdst
 	res	1

frontends/spin/spinlang.c

@@ -214,8 +214,16 @@ ScanFunctionBody(Function *fdef, AST *body, AST *upper, AST *expectType)
                         lab->flags |= (LABEL_NEEDS_EXTRA_ALIGN|LABEL_USED_IN_SPIN);
                         WARNING(body, "Label is dereferenced with greater alignment than it was declared with");
                     }
-
-                }
+                } else if (sym && sym->kind == SYM_FUNCTION) {
+                    // insert an explicit function address
+                    extern AST *FunctionAddress(AST *); // in types.c
+                    AST *getaddr = FunctionAddress(body->left);
+                    if (upper->left == body) {
+                        upper->left = getaddr;
+                        return;
+                    }
+                    WARNING(body, "Taking address of function not supported yet in Spin");
+                }                        
             }
         } else if (ast->kind == AST_RESULT) {
             /* hack to make F32.spin work: it expects all variables
@@ -264,7 +272,7 @@ ScanFunctionBody(Function *fdef, AST *body, AST *upper, AST *expectType)
             }
             // convert plain IDENTIFIER into a FUNCCALL if it is a function
             // identifier
-            if (sym->kind == SYM_FUNCTION && upper && upper->kind != AST_FUNCCALL) {
+            if (sym->kind == SYM_FUNCTION && upper && upper->kind != AST_FUNCCALL && upper->kind != AST_ADDROF) {
                 AST *funccall;
                 ASTReportInfo saveinfo;
                 AstReportAs(body, &saveinfo);

frontends/types.c

@@ -67,7 +67,8 @@ static AST *gc_free;
 
 static AST *funcptr_cmp;
 
-static AST *BuildMethodPointer(AST *ast);
+AST *BuildMethodPointer(AST *ast);
+static AST * getBasicPrimitive(const char *name);
 
 bool VerifyIntegerType(AST *astForError, AST *typ, const char *opname)
 {
@@ -1003,7 +1004,7 @@ doCast(AST *desttype, AST *srctype, AST *src)
     return NULL;
 }
 
-static AST *
+AST *
 BuildMethodPointer(AST *ast)
 {
     Symbol *sym;
@@ -1029,6 +1030,9 @@ BuildMethodPointer(AST *ast)
     // save off the current @ node
     funcaddr = NewAST(AST_ADDROF, ast->left, ast->right);
     // create a call
+    if (!make_methodptr) {
+        make_methodptr = getBasicPrimitive("_make_methodptr");
+    }
     result = MakeOperatorCall(make_methodptr, objast, funcaddr, NULL);
     return result;
 }