ref: 6874f694e5eadfdeb5ddfcf24dea57413c02bd46
parent: 3690546795dec9adf4a1bc36f8a8465d999ca1f1
author: Rangi <35663410+Rangi42@users.noreply.github.com>
date: Tue Dec 29 10:30:42 EST 2020
Implement `FOREACH` (#658) This acts like `REPT` with a variable automatically incremented across a range of values Fixes #432
--- a/include/asm/fstack.h
+++ b/include/asm/fstack.h
@@ -73,6 +73,8 @@
void fstk_RunInclude(char const *path);
void fstk_RunMacro(char const *macroName, struct MacroArgs *args);
void fstk_RunRept(uint32_t count, int32_t nReptLineNo, char *body, size_t size);
+void fstk_RunForeach(char const *symName, int32_t start, int32_t stop, int32_t step,
+ int32_t reptLineNo, char *body, size_t size);
void fstk_Init(char const *mainPath, size_t maxRecursionDepth);
--- a/src/asm/fstack.c
+++ b/src/asm/fstack.c
@@ -34,6 +34,9 @@
uint32_t uniqueID;
struct MacroArgs *macroArgs; /* Macro args are *saved* here */
uint32_t nbReptIters;
+ int32_t foreachValue;
+ int32_t foreachStep;
+ char *foreachName;
};
static struct Context *contextStack;
@@ -217,6 +220,15 @@
}
fileInfo->iters[0]++;
+ /* If this is a FOREACH, update the symbol value */
+ if (contextStack->foreachName) {+ contextStack->foreachValue += contextStack->foreachStep;
+ struct Symbol *sym = sym_AddSet(contextStack->foreachName,
+ contextStack->foreachValue);
+
+ if (sym->type != SYM_SET)
+ fatalerror("Failed to update FOREACH symbol value\n");+ }
/* If this wasn't the last iteration, wrap instead of popping */
if (fileInfo->iters[0] <= contextStack->nbReptIters) {lexer_RestartRept(contextStack->fileInfo->lineNo);
@@ -242,6 +254,8 @@
/* Free the file stack node */
if (!context->fileInfo->referenced)
free(context->fileInfo);
+ /* Free the FOREACH symbol name */
+ free(context->foreachName);
/* Free the entry and make its parent the current entry */
free(context);
@@ -267,6 +281,7 @@
fileInfo->referenced = false;
fileInfo->lineNo = lexer_GetLineNo();
context->fileInfo = fileInfo;
+ context->foreachName = NULL;
/*
* Link new entry to its parent so it's reachable later
* ERRORS SHOULD NOT OCCUR AFTER THIS!!
@@ -273,7 +288,6 @@
*/
context->parent = contextStack;
contextStack = context;
-
}
void fstk_RunInclude(char const *path)
@@ -386,12 +400,8 @@
macro_UseNewArgs(args);
}
-void fstk_RunRept(uint32_t count, int32_t reptLineNo, char *body, size_t size)
+static bool newReptContext(int32_t reptLineNo, char *body, size_t size)
{- dbgPrint("Running REPT(%" PRIu32 ")\n", count);- if (count == 0)
- return;
-
uint32_t reptDepth = contextStack->fileInfo->type == NODE_REPT
? ((struct FileStackReptNode *)contextStack->fileInfo)->reptDepth
: 0;
@@ -400,7 +410,7 @@
if (!fileInfo) { error("Failed to alloc file info for REPT: %s\n", strerror(errno));- return;
+ return false;
}
fileInfo->node.type = NODE_REPT;
fileInfo->reptDepth = reptDepth + 1;
@@ -420,8 +430,53 @@
fatalerror("Failed to set up lexer for rept block\n");lexer_SetStateAtEOL(contextStack->lexerState);
contextStack->uniqueID = macro_UseNewUniqueID();
+ return true;
+}
+
+void fstk_RunRept(uint32_t count, int32_t reptLineNo, char *body, size_t size)
+{+ dbgPrint("Running REPT(%" PRIu32 ")\n", count);+
+ if (count == 0)
+ return;
+ if (!newReptContext(reptLineNo, body, size))
+ return;
+
contextStack->nbReptIters = count;
+ contextStack->foreachName = NULL;
+}
+void fstk_RunForeach(char const *symName, int32_t start, int32_t stop, int32_t step,
+ int32_t reptLineNo, char *body, size_t size)
+{+ dbgPrint("Running FOREACH(\"%s\", %" PRId32 ", %" PRId32 ", %" PRId32 ")\n",+ symName, start, stop, step);
+
+ struct Symbol *sym = sym_AddSet(symName, start);
+
+ if (sym->type != SYM_SET)
+ return;
+
+ uint32_t count = 0;
+
+ if (step > 0 && start < stop)
+ count = (stop - start - 1) / step + 1;
+ else if (step < 0 && stop < start)
+ count = (start - stop - 1) / -step + 1;
+ else if (step == 0)
+ error("FOREACH cannot have a step value of 0\n");+
+ if (count == 0)
+ return;
+ if (!newReptContext(reptLineNo, body, size))
+ return;
+
+ contextStack->nbReptIters = count;
+ contextStack->foreachValue = start;
+ contextStack->foreachStep = step;
+ contextStack->foreachName = strdup(symName);
+ if (!contextStack->foreachName)
+ fatalerror("Not enough memory for FOREACH name: %s\n", strerror(errno));}
void fstk_Init(char const *mainPath, size_t maxRecursionDepth)
@@ -453,6 +508,9 @@
context->uniqueID = 0;
macro_SetUniqueID(0);
context->nbReptIters = 0;
+ context->foreachValue = 0;
+ context->foreachStep = 0;
+ context->foreachName = NULL;
/* Now that it's set up properly, register the context */
contextStack = context;
--- a/src/asm/lexer.c
+++ b/src/asm/lexer.c
@@ -238,6 +238,7 @@
{"SHIFT", T_POP_SHIFT}, {"REPT", T_POP_REPT},+ {"FOREACH", T_POP_FOREACH}, {"ENDR", T_POP_ENDR}, {"LOAD", T_POP_LOAD},@@ -453,7 +454,7 @@
void lexer_RestartRept(uint32_t lineNo)
{- dbgPrint("Restarting REPT\n");+ dbgPrint("Restarting REPT/FOREACH\n");lexerState->offset = 0;
initState(lexerState);
lexerState->lineNo = lineNo;
@@ -479,7 +480,7 @@
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[341] = {0}; /* Make sure to keep this correct when adding keywords! */+} keywordDict[347] = {0}; /* Make sure to keep this correct when adding keywords! *//* Convert a char into its index into the dict */
static inline uint8_t dictIndex(char c)
@@ -2161,10 +2162,11 @@
do { /* Discard initial whitespace */c = nextChar();
} while (isWhitespace(c));
- /* Now, try to match either `REPT` or `ENDR` as a **whole** identifier */
+ /* Now, try to match `REPT`, `FOREACH` or `ENDR` as a **whole** identifier */
if (startsIdentifier(c)) { switch (readIdentifier(c)) {case T_POP_REPT:
+ case T_POP_FOREACH:
level++;
/* Ignore the rest of that line */
break;
@@ -2188,7 +2190,7 @@
/* Just consume characters until EOL or EOF */
for (;;) { if (c == EOF) {- error("Unterminated REPT block\n");+ error("Unterminated REPT/FOREACH block\n");lexerState->capturing = false;
goto finish;
} else if (c == '\n' || c == '\r') {@@ -2246,7 +2248,7 @@
do { /* Discard initial whitespace */c = nextChar();
} while (isWhitespace(c));
- /* Now, try to match either `REPT` or `ENDR` as a **whole** identifier */
+ /* Now, try to match `ENDM` as a **whole** identifier */
if (startsIdentifier(c)) { if (readIdentifier(c) == T_POP_ENDM) {/* Read (but don't capture) until EOL or EOF */
--- a/src/asm/parser.y
+++ b/src/asm/parser.y
@@ -205,6 +205,11 @@
struct SectionSpec sectSpec;
struct MacroArgs *macroArg;
enum AssertionType assertType;
+ struct {+ int32_t start;
+ int32_t stop;
+ int32_t step;
+ } foreachArgs;
}
%type <sVal> relocexpr
@@ -296,7 +301,7 @@
%token T_POP_ENDM
%token T_POP_RSRESET T_POP_RSSET
%token T_POP_UNION T_POP_NEXTU T_POP_ENDU
-%token T_POP_INCBIN T_POP_REPT
+%token T_POP_INCBIN T_POP_REPT T_POP_FOREACH
%token T_POP_CHARMAP
%token T_POP_NEWCHARMAP
%token T_POP_SETCHARMAP
@@ -321,6 +326,8 @@
%type <sectMod> sectmod
%type <macroArg> macroargs
+%type <foreachArgs> foreach_args
+
%token T_Z80_ADC T_Z80_ADD T_Z80_AND
%token T_Z80_BIT
%token T_Z80_CALL T_Z80_CCF T_Z80_CP T_Z80_CPL
@@ -522,6 +529,7 @@
| popc
| load
| rept
+ | foreach
| shift
| fail
| warn
@@ -642,6 +650,31 @@
size_t size;
lexer_CaptureRept(&body, &size);
fstk_RunRept($2, nDefinitionLineNo, body, size);
+ }
+;
+
+foreach : T_POP_FOREACH T_ID T_COMMA foreach_args {+ uint32_t nDefinitionLineNo = lexer_GetLineNo();
+ char *body;
+ size_t size;
+ lexer_CaptureRept(&body, &size);
+ fstk_RunForeach($2, $4.start, $4.stop, $4.step, nDefinitionLineNo, body, size);
+ }
+
+foreach_args : const {+ $$.start = 0;
+ $$.stop = $1;
+ $$.step = 1;
+ }
+ | const T_COMMA const {+ $$.start = $1;
+ $$.stop = $3;
+ $$.step = 1;
+ }
+ | const T_COMMA const T_COMMA const {+ $$.start = $1;
+ $$.stop = $3;
+ $$.step = $5;
}
;
--- a/src/asm/rgbasm.5
+++ b/src/asm/rgbasm.5
@@ -1470,6 +1470,73 @@
.Ic \[rs]@ .
.Ic REPT
blocks can be nested.
+.Pp
+A common pattern is to repeat a block for each value in some range.
+.Ic FOREACH
+is simpler than
+.Ic REPT
+for that purpose.
+Everything between
+.Ic FOREACH
+and the matching
+.Ic ENDR
+will be repeated for each value of a given symbol.
+For example, this code will produce a table of squared values from 0 to 255:
+.Bd -literal -offset indent
+FOREACH N, 256
+ dw N * N
+ENDR
+.Ed
+.Pp
+It acts just as if you had done:
+.Bd -literal -offset ident
+N = 0
+ dw N * N
+N = 1
+ dw N * N
+N = 2
+ dw N * N
+; ...
+N = 255
+ dw N * N
+N = 256
+.Ed
+.Pp
+You can customize the range of
+.Ic FOREACH
+values:
+.Bl -column "FOREACH V, start, stop, step"
+.It Sy Code Ta Sy Range
+.It Ic FOREACH Ar V , stop Ta Ar V No increments from 0 to Ar stop No
+.It Ic FOREACH Ar V , start , stop Ta Ar V No increments from Ar start No to Ar stop No
+.It Ic FOREACH Ar V , start , stop , step Ta Ar V No goes from Ar start No to Ar stop No by Ar step No
+.El
+.Pp
+The
+.Ic FOREACH
+value will be updated by
+.Ar step
+until it reaches or exceeds
+.Ar stop.
+For example:
+.Bd -literal -offset indent
+FOREACH V, 4, 25, 5
+ PRINTT "{d:V} "+ENDR
+ PRINTT "done {d:V}\n"+.Ed
+This will print:
+.Bd -literal -offset indent
+4 9 14 19 24 done 29
+.Ed
+.Pp
+Just like with
+.Ic REPT
+blocks, you can use the escape sequence
+.Ic \[rs]@
+inside of
+.Ic FOREACH
+blocks, and they can be nested.
.Ss Aborting the assembly process
.Ic FAIL
and
--- /dev/null
+++ b/test/asm/foreach.asm
@@ -1,0 +1,48 @@
+foreach n, 10
+ printt "{d:n} "+endr
+ printt "-> {d:n}\n"+
+foreach v, 0
+ printt "unreached"
+endr
+
+foreach v, 2, 1
+ printt "unreached"
+endr
+
+foreach v, 1, 2, 0
+ printt "unreached"
+endr
+
+foreach x, 1, 5+1
+ printt "{d:x} "+endr
+ printt "-> {d:x}\n"+
+foreach v, 10, -1, -1
+ printt "{d:v} "+v = 42
+endr
+ printt "-> {d:v}\n"+
+foreach q, 5, 21, 5
+ printt "{d:q} "+purge q
+endr
+ printt "-> {d:q}\n"+
+s EQUS "x"
+foreach s, 3, 30, 3
+ printt "{d:x} "+endr
+ printt "-> {d:x}\n"+
+foreach v, 10
+ printt "{d:v}\n"+if v == 3
+purge v
+v equ 42 ; causes a fatal error
+endc
+endr
+ printt "-> {d:v}\n"--- /dev/null
+++ b/test/asm/foreach.err
@@ -1,0 +1,6 @@
+ERROR: foreach.asm(16):
+ FOREACH cannot have a step value of 0
+ERROR: foreach.asm(41) -> foreach.asm::REPT~5(47):
+ 'v' already defined as constant at foreach.asm(41) -> foreach.asm::REPT~4(45)
+FATAL: foreach.asm(41) -> foreach.asm::REPT~5(47):
+ Failed to update FOREACH symbol value
--- /dev/null
+++ b/test/asm/foreach.out
@@ -1,0 +1,9 @@
+0 1 2 3 4 5 6 7 8 9 -> 10
+1 2 3 4 5 -> 6
+10 9 8 7 6 5 4 3 2 1 0 -> -1
+5 10 15 20 -> 25
+3 6 9 12 15 18 21 24 27 -> 30
+0
+1
+2
+3