shithub: rgbds

--- a/include/asm/symbol.h

+++ b/include/asm/symbol.h

@@ -120,6 +120,7 @@

 void sym_WriteAnonLabelName(char buf[MIN_NB_ELMS(MAXSYMLEN + 1)], uint32_t ofs, bool neg);

 void sym_Export(char const *symName);

 struct Symbol *sym_AddEqu(char const *symName, int32_t value);

+struct Symbol *sym_RedefEqu(char const *symName, int32_t value);

 struct Symbol *sym_AddSet(char const *symName, int32_t value);

 uint32_t sym_GetPCValue(void);

 uint32_t sym_GetConstantSymValue(struct Symbol const *sym);

--- a/src/asm/parser.y

+++ b/src/asm/parser.y

@@ -851,6 +851,7 @@

 		| warn

 		| assert

 		| def_equ

+		| redef_equ

 		| def_set

 		| def_rb

 		| def_rw

@@ -1115,6 +1116,11 @@

 def_equ		: def_id T_POP_EQU const {

 			sym_AddEqu($1, $3);

+		}

+;

+redef_equ	: redef_id T_POP_EQU const {

+			sym_RedefEqu($1, $3);

--- a/src/asm/rgbasm.5

+++ b/src/asm/rgbasm.5

@@ -967,6 +967,26 @@

 Note that colons

 .Ql \&:

 following the name are not allowed.

+.Pp

+If you

+.Em really

+need to, the

+.Ic REDEF

+keyword will define or redefine a constant symbol.

+This can be used, for example, to update a constant using a macro, without making it mutable in general.

+.Bd -literal -offset indent

+    def NUM_ITEMS equ 0

+MACRO add_item

+    redef NUM_ITEMS equ NUM_ITEMS + 1

+    def ITEM_{02x:NUM_ITEMS} equ \1

+ENDM

+    add_item 1

+    add_item 4

+    add_item 9

+    add_item 16

+    assert NUM_ITEMS == 4

+    assert ITEM_04 == 16

+.Ed

 .Ss Mutable constants

 .Ic SET ,

 or its synonym

--- a/src/asm/symbol.c

+++ b/src/asm/symbol.c

@@ -397,6 +397,30 @@

 	return sym;

+struct Symbol *sym_RedefEqu(char const *symName, int32_t value)

+{

+	struct Symbol *sym = sym_FindExactSymbol(symName);

+	if (!sym)

+		return sym_AddEqu(symName, value);

+	if (sym_IsDefined(sym) && sym->type != SYM_EQU) {

+		error("'%s' already defined as non-EQU at ", symName);

+		dumpFilename(sym);

+		putc('\n', stderr);

+		return NULL;

+	} else if (sym->isBuiltin) {

+		error("Built-in symbol '%s' cannot be redefined\n", symName);

+		return NULL;

+	}

+	updateSymbolFilename(sym);

+	sym->type = SYM_EQU;

+	sym->value = value;

+	return sym;

+}

/*

  * Add a string equated symbol.

--- a/test/asm/def.asm

+++ b/test/asm/def.asm

@@ -26,4 +26,5 @@

 redef string equs "there"

 	println "{string}"

-redef constant equ 6*9 ; syntax error

+redef constant equ 6*9

+	println constant

--- a/test/asm/def.err

+++ b/test/asm/def.err

@@ -1,5 +1,3 @@

 ERROR: def.asm(23):

     'constant' already defined at def.asm(10)

-ERROR: def.asm(29):

-    syntax error, unexpected EQU, expecting SET or = or EQUS

-error: Assembly aborted (2 errors)!

+error: Assembly aborted (1 error)!

--- a/test/asm/def.out

+++ b/test/asm/def.out

@@ -7,3 +7,4 @@

 $0 $1 $5 $9

$2A

 there

+$36

--- /dev/null

+++ b/test/asm/redef-equ.asm

@@ -1,0 +1,23 @@

+DEF n EQU 0

+REDEF n EQU 1

+; prints "$1"

+PRINTLN n

+list: MACRO

+LIST_NAME EQUS "\1"

+DEF LENGTH_{LIST_NAME} EQU 0

+ENDM

+item: MACRO

+REDEF LENGTH_{LIST_NAME} EQU LENGTH_{LIST_NAME} + 1

+DEF {LIST_NAME}_{d:LENGTH_{LIST_NAME}} EQU \1

+ENDM

+	list SQUARES

+	item 1

+	item 4

+	item 9

+	println LENGTH_SQUARES, SQUARES_1, SQUARES_2, SQUARES_3

+N EQUS "X"

+REDEF N EQU 42

--- /dev/null

+++ b/test/asm/redef-equ.err

@@ -1,0 +1,3 @@

+ERROR: redef-equ.asm(23):

+    'N' already defined as non-EQU at redef-equ.asm(22)

+error: Assembly aborted (1 error)!

--- /dev/null

+++ b/test/asm/redef-equ.out

@@ -1,0 +1,2 @@

+$1

+$3$1$4$9

--- /dev/null

+++ b/test/asm/reference-undefined-equs.asm

@@ -1,0 +1,5 @@

+SECTION "sec", ROM0[0]

+	db s1, s2

+def s1 equs "1"

+redef s2 equs "2"

--- /dev/null

+++ b/test/asm/reference-undefined-equs.err

@@ -1,0 +1,5 @@

+ERROR: reference-undefined-equs.asm(4):

+    's1' already referenced at reference-undefined-equs.asm(2)

+ERROR: reference-undefined-equs.asm(5):

+    's2' already referenced at reference-undefined-equs.asm(2)

+error: Assembly aborted (2 errors)!

--- a/test/asm/reference-undefined-sym.asm

+++ b/test/asm/reference-undefined-sym.asm

@@ -1,4 +1,7 @@

 SECTION "sec", ROM0[0]

-	db X

+	db x1, x2, y1, y2

-X = 2

+def x1 = 1

+redef x2 = 2

+def y1 equ 3

+redef y2 equ 4

--- a/test/asm/reference-undefined-sym.out.bin

+++ b/test/asm/reference-undefined-sym.out.bin

@@ -1,0 +1,1 @@

\ No newline at end of file