Allow changing recursion depth limit at runtime

include/asm/fstack.h

@@ -77,6 +77,7 @@ void fstk_RunFor(char const *symName, int32_t start, int32_t stop, int32_t step,
 void fstk_StopRept(void);
 bool fstk_Break(void);
 
+void fstk_NewRecursionDepth(size_t newDepth);
 void fstk_Init(char const *mainPath, size_t maxDepth);
 
 #endif /* RGBDS_ASM_FSTACK_H */

include/asm/lexer.h

@@ -83,6 +83,7 @@ struct CaptureBody {
 	size_t size;
 };
 
+void lexer_CheckRecursionDepth(void);
 char const *lexer_GetFileName(void);
 uint32_t lexer_GetLineNo(void);
 uint32_t lexer_GetColNo(void);

src/asm/fstack.c

@@ -284,8 +284,9 @@ bool yywrap(void)
  */
 static void newContext(struct FileStackNode *fileInfo)
 {
-	if (++contextDepth >= maxRecursionDepth)
-		fatalerror("Recursion limit (%zu) exceeded\n", maxRecursionDepth);
+	++contextDepth;
+	fstk_NewRecursionDepth(maxRecursionDepth); // Only checks if the max depth was exceeded
+
 	struct Context *context = malloc(sizeof(*context));
 
 	if (!context)
@@ -507,6 +508,13 @@ bool fstk_Break(void)
 	return true;
 }
 
+void fstk_NewRecursionDepth(size_t newDepth)
+{
+	if (contextDepth >= newDepth)
+		fatalerror("Recursion limit (%zu) exceeded\n", newDepth);
+	maxRecursionDepth = newDepth;
+}
+
 void fstk_Init(char const *mainPath, size_t maxDepth)
 {
 	struct LexerState *state = lexer_OpenFile(mainPath);

src/asm/lexer.c

@@ -668,14 +668,8 @@ static void beginExpansion(char const *str, bool owned, char const *name)
 	if (!size)
 		return;
 
-	if (name) {
-		size_t depth = 0;
-
-		for (struct Expansion *exp = lexerState->expansions; exp; exp = exp->parent) {
-			if (depth++ >= maxRecursionDepth)
-				fatalerror("Recursion limit (%zu) exceeded\n", maxRecursionDepth);
-		}
-	}
+	if (name)
+		lexer_CheckRecursionDepth();
 
 	struct Expansion *exp = malloc(sizeof(*exp));
 
@@ -692,6 +686,16 @@ static void beginExpansion(char const *str, bool owned, char const *name)
 	lexerState->expansions = exp;
 }
 
+void lexer_CheckRecursionDepth(void)
+{
+	size_t depth = 0;
+
+	for (struct Expansion *exp = lexerState->expansions; exp; exp = exp->parent) {
+		if (depth++ >= maxRecursionDepth)
+			fatalerror("Recursion limit (%zu) exceeded\n", maxRecursionDepth);
+	}
+}
+
 static void freeExpansion(struct Expansion *expansion)
 {
 	free(expansion->name);

src/asm/opt.c

@@ -1,3 +1,4 @@
+#include <ctype.h>
 #include <errno.h>
 #include <stdbool.h>
 #include <stdint.h>
@@ -5,6 +6,7 @@
 #include <stdlib.h>
 #include <string.h>
 
+#include "asm/fstack.h"
 #include "asm/lexer.h"
 #include "asm/main.h"
 #include "asm/section.h"
@@ -17,6 +19,7 @@ struct OptStackEntry {
 	bool haltnop;
 	bool optimizeLoads;
 	bool warningsAreErrors;
+	size_t maxRecursionDepth;
 	// Don't be confused: we use the size of the **global variable** `warningStates`!
 	enum WarningState warningStates[sizeof(warningStates)];
 	struct OptStackEntry *next;
@@ -39,6 +42,12 @@ void opt_P(uint8_t fill)
 	fillByte = fill;
 }
 
+void opt_R(size_t newDepth)
+{
+	fstk_NewRecursionDepth(newDepth);
+	lexer_CheckRecursionDepth();
+}
+
 void opt_h(bool halt)
 {
 	haltnop = halt;
@@ -86,6 +95,29 @@ void opt_Parse(char *s)
 		}
 		break;
 
+	case 'r': {
+		++s; // Skip 'r'
+		while (isblank(*s))
+			++s; // Skip leading whitespace
+
+		if (s[0] == '\0') {
+			error("Missing argument to option 'r'\n");
+			break;
+		}
+
+		char *endptr;
+		unsigned long newDepth = strtoul(s, &endptr, 10);
+
+		if (*endptr != '\0') {
+			error("Invalid argument to option 'r' (\"%s\")\n", s);
+		} else if (errno == ERANGE) {
+			error("Argument to 'r' is out of range (\"%s\")\n", s);
+		} else {
+			opt_R(newDepth);
+		}
+		break;
+	}
+
 	case 'h':
 		if (s[1] == '\0')
 			opt_h(false);

src/asm/rgbasm.5

@@ -1993,6 +1993,7 @@ block, all of them but the first one are ignored.
 .Ss Changing options while assembling
 .Ic OPT
 can be used to change some of the options during assembling from within the source, instead of defining them on the command-line.
+.Pq See Xr rgbasm 1 .
 .Pp
 .Ic OPT
 takes a comma-separated list of options as its argument:
@@ -2008,8 +2009,10 @@ POPO
     LD [$FF88], A         ; optimized to use LDH by default
 .Ed
 .Pp
-The options that OPT can modify are currently:
-.Cm b , g , p , h , L ,
+The options that
+.Ic OPT
+can modify are currently:
+.Cm b , g , p , r , h , L ,
 and
 .Cm W .
 The Boolean flag options

test/asm/opt-r.asm

@@ -0,0 +1,13 @@
+OPT r34 ; :3
+OPT r 360
+
+; Invalid
+OPT r ; Missing arg
+OPT r 2a ; Bad decimal
+
+; Check that it has an effect
+OPT r 1
+MACRO m
+	m
+ENDM
+	m

test/asm/opt-r.err

@@ -0,0 +1,6 @@
+error: opt-r.asm(5):
+    Missing argument to option 'r'
+error: opt-r.asm(6):
+    Invalid argument to option 'r' ("2a")
+FATAL: opt-r.asm(13):
+    Recursion limit (1) exceeded