Implement SIZEOF("Section") and STARTOF("Section") (#766)

Updates the object file revision to 8

Fixes #765

src/asm/lexer.c

@@ -180,6 +180,9 @@ static struct KeywordMapping {
 	{"BANK", T_OP_BANK},
 	{"ALIGN", T_OP_ALIGN},
 
+	{"SIZEOF", T_OP_SIZEOF},
+	{"STARTOF", T_OP_STARTOF},
+
 	{"ROUND", T_OP_ROUND},
 	{"CEIL", T_OP_CEIL},
 	{"FLOOR", T_OP_FLOOR},
@@ -592,7 +595,7 @@ struct KeywordDictNode {
 	uint16_t children[0x60 - ' '];
 	struct KeywordMapping const *keyword;
 /* Since the keyword structure is invariant, the min number of nodes is known at compile time */
-} keywordDict[357] = {0}; /* Make sure to keep this correct when adding keywords! */
+} keywordDict[365] = {0}; /* Make sure to keep this correct when adding keywords! */
 
 /* Convert a char into its index into the dict */
 static uint8_t dictIndex(char c)

src/asm/output.c

@@ -354,6 +354,22 @@ static void writerpn(uint8_t *rpnexpr, uint32_t *rpnptr, uint8_t *rpn,
 			} while (b != 0);
 			break;
 
+		case RPN_SIZEOF_SECT:
+			writebyte(RPN_SIZEOF_SECT);
+			do {
+				b = popbyte();
+				writebyte(b);
+			} while (b != 0);
+			break;
+
+		case RPN_STARTOF_SECT:
+			writebyte(RPN_STARTOF_SECT);
+			do {
+				b = popbyte();
+				writebyte(b);
+			} while (b != 0);
+			break;
+
 		default:
 			writebyte(rpndata);
 			break;

src/asm/parser.y

@@ -514,6 +514,7 @@ enum {
 %token	T_OP_DEF "DEF"
 %token	T_OP_BANK "BANK"
 %token	T_OP_ALIGN "ALIGN"
+%token	T_OP_SIZEOF "SIZEOF" T_OP_STARTOF "STARTOF"
 %token	T_OP_SIN "SIN" T_OP_COS "COS" T_OP_TAN "TAN"
 %token	T_OP_ASIN "ASIN" T_OP_ACOS "ACOS" T_OP_ATAN "ATAN" T_OP_ATAN2 "ATAN2"
 %token	T_OP_FDIV "FDIV"
@@ -1419,6 +1420,8 @@ relocexpr_no_str : scoped_anon_id	{ rpn_Symbol(&$$, $1); }
 			rpn_BankSymbol(&$$, $3);
 		}
 		| T_OP_BANK T_LPAREN string T_RPAREN	{ rpn_BankSection(&$$, $3); }
+		| T_OP_SIZEOF T_LPAREN string T_RPAREN	{ rpn_SizeOfSection(&$$, $3); }
+		| T_OP_STARTOF T_LPAREN string T_RPAREN	{ rpn_StartOfSection(&$$, $3); }
 		| T_OP_DEF {
 			lexer_ToggleStringExpansion(false);
 		} T_LPAREN scoped_anon_id T_RPAREN {

src/asm/rgbasm.5

@@ -461,6 +461,12 @@ is a label, it returns the bank number the label is in.
 The result may be constant if
 .Nm
 is able to compute it.
+.It Fn SIZEOF arg Ta Returns the size of the section named
+.Ar arg .
+The result is not constant, since only RGBLINK can compute its value.
+.It Fn STARTOF arg Ta Returns the starting address of the section named
+.Ar arg .
+The result is not constant, since only RGBLINK can compute its value.
 .It Fn DEF symbol Ta Returns TRUE (1) if
 .Ar symbol
 has been defined, FALSE (0) otherwise.

src/asm/rpn.c

@@ -201,6 +201,34 @@ void rpn_BankSection(struct Expression *expr, char const *tzSectionName)
 	}
 }
 
+void rpn_SizeOfSection(struct Expression *expr, char const *tzSectionName)
+{
+	rpn_Init(expr);
+
+	makeUnknown(expr, "Section \"%s\"'s size is not known", tzSectionName);
+
+	size_t nameLen = strlen(tzSectionName) + 1; /* Room for NUL! */
+	uint8_t *ptr = reserveSpace(expr, nameLen + 1);
+
+	expr->nRPNPatchSize += nameLen + 1;
+	*ptr++ = RPN_SIZEOF_SECT;
+	memcpy(ptr, tzSectionName, nameLen);
+}
+
+void rpn_StartOfSection(struct Expression *expr, char const *tzSectionName)
+{
+	rpn_Init(expr);
+
+	makeUnknown(expr, "Section \"%s\"'s start is not known", tzSectionName);
+
+	size_t nameLen = strlen(tzSectionName) + 1; /* Room for NUL! */
+	uint8_t *ptr = reserveSpace(expr, nameLen + 1);
+
+	expr->nRPNPatchSize += nameLen + 1;
+	*ptr++ = RPN_STARTOF_SECT;
+	memcpy(ptr, tzSectionName, nameLen);
+}
+
 void rpn_CheckHRAM(struct Expression *expr, const struct Expression *src)
 {
 	*expr = *src;
@@ -396,6 +424,8 @@ void rpn_BinaryOp(enum RPNCommand op, struct Expression *expr,
 		case RPN_BANK_SYM:
 		case RPN_BANK_SECT:
 		case RPN_BANK_SELF:
+		case RPN_SIZEOF_SECT:
+		case RPN_STARTOF_SECT:
 		case RPN_HRAM:
 		case RPN_RST:
 		case RPN_CONST: