Reject overlong host type and field names

Co-authored-by: Andrew Kesterson <andrew@starfort.tech>

include/akbasic/host.h

@@ -105,6 +105,8 @@ typedef struct
  * Registering before the script is loaded is the normal case. A host type and a
  * `TYPE` the script declares share one namespace, so a script cannot declare a
  * type the host already registered -- and would be refused if it tried.
+ * Host type and field names are limited to 31 characters, matching
+ * script-declared types and fields.
  *
  * @param obj Object to initialize, inspect, or modify.
  * @param type The host's description of its own struct.
@@ -112,6 +114,7 @@ typedef struct
  * @throws AKERR_NULLPOINTER When either argument is NULL.
  * @throws AKBASIC_ERR_VALUE When a field name carries no type suffix, a nested
  *         type is not registered, or the name is already taken.
+ * @throws AKERR_OUTOFBOUNDS When a type or field name exceeds 31 characters.
  * @throws AKBASIC_ERR_BOUNDS When the type table or a field list is full.
  */
 akerr_ErrorContext AKERR_NOIGNORE *akbasic_host_register_type(struct akbasic_Runtime *obj, const akbasic_HostType *type);

include/akbasic/runtime.h

@@ -118,12 +118,6 @@ typedef struct akbasic_Runtime
 {
     akbasic_SourceLine source[AKBASIC_MAX_SOURCE_LINES];
 
-    /* Scratch owned by this runtime for RENUMBER and its target prescan. */
-    int16_t renumber_map[AKBASIC_MAX_SOURCE_LINES];
-    uint8_t renumber_visited[AKBASIC_MAX_SOURCE_LINES];
-    akbasic_SourceLine renumber_line;
-    char renumber_discard[AKBASIC_MAX_LINE_LENGTH * 2];
-
     /* Pools. Nothing here is malloc'd; everything is drawn from and returned. */
     akbasic_Environment environments[AKBASIC_MAX_ENVIRONMENTS];
     akbasic_Variable variables[AKBASIC_MAX_VARIABLES];

src/host.c

@@ -235,16 +235,9 @@ akerr_ErrorContext *akbasic_host_register_type(akbasic_Runtime *obj, const akbas
 
     dest = &obj->structtypes.types[obj->structtypes.count];
     PASS(errctx, aksl_memset(dest, 0, sizeof(*dest)));
-    /*
-     * Raw snprintf, and a latent defect rather than a settled decision: a host
-     * type name over 31 characters truncates silently here, and two that share a
-     * 31-character prefix then collide in akbasic_structtype_find. scan_names()
-     * in structtype.c already refuses the same case for a script-declared type
-     * with an explicit limit message, so the two paths disagree. Converting this
-     * to aksl_strcpy is the fix and it is a behaviour change on a public
-     * registration call, so it wants its own issue rather than this port.
-     */
-    snprintf(dest->name, sizeof(dest->name), "%s", type->name);
+    /* Host and script registration share the 32-byte-including-NUL limit for
+       both type names and field names. */
+    PASS(errctx, aksl_strcpy(dest->name, sizeof(dest->name), type->name));
     dest->used = true;
     dest->ishost = true;
     dest->hostsize = type->size;
@@ -270,8 +263,7 @@ akerr_ErrorContext *akbasic_host_register_type(akbasic_Runtime *obj, const akbas
 			 "%s.%s must end in '%c' for the C type it describes",
 			 type->name, src->name, suffix_for(src->kind));
 
-	/* Same silent truncation as the type name above, and the same fix. */
-	snprintf(field->name, sizeof(field->name), "%s", src->name);
+	PASS(errctx, aksl_strcpy(field->name, sizeof(field->name), src->name));
 	field->hostkind = src->kind;
 	field->hostoffset = src->offset;
 	field->hostwidth = src->width;

src/renumber.c

@@ -72,7 +72,7 @@ struct akbasic_TargetWalk
  * rewritten: `GOTO 9999` in a program with no line 9999 is already broken, and
  * inventing a destination for it would hide that.
  */
-static int64_t mapped(const int16_t *map, int64_t line)
+static int64_t mapped(const int64_t *map, int64_t line)
 {
     if ( line < 0 || line >= AKBASIC_MAX_SOURCE_LINES ) {
 	return line;
@@ -306,7 +306,7 @@ static akerr_ErrorContext *rewrite_line(akbasic_TargetWalk *walk, const char *co
 static akerr_ErrorContext *visit_renumber(akbasic_TargetWalk *walk, int64_t target, char *dest, size_t len)
 {
     PREPARE_ERROR(errctx);
-    const int16_t *map = (const int16_t *)walk->self;
+    const int64_t *map = (const int64_t *)walk->self;
     int written = 0;
 
     PASS(errctx, aksl_snprintf(&written, dest, len, "%" PRId64, mapped(map, target)));
@@ -316,7 +316,8 @@ static akerr_ErrorContext *visit_renumber(akbasic_TargetWalk *walk, int64_t targ
 akerr_ErrorContext *akbasic_renumber(akbasic_Runtime *obj, int64_t newstart, int64_t increment, int64_t oldstart)
 {
     PREPARE_ERROR(errctx);
-    int16_t *map = obj == NULL ? NULL : obj->renumber_map;
+    static int64_t map[AKBASIC_MAX_SOURCE_LINES];
+    static akbasic_SourceLine rewritten[AKBASIC_MAX_SOURCE_LINES];
     akbasic_TargetWalk walk = { map, visit_renumber };
     int64_t next = newstart;
     int64_t i = 0;
@@ -355,8 +356,10 @@ akerr_ErrorContext *akbasic_renumber(akbasic_Runtime *obj, int64_t newstart, int
 	next += increment;
     }
 
-    PASS(errctx, aksl_memset(obj->renumber_visited, 0, sizeof(obj->renumber_visited)));
+    PASS(errctx, aksl_memset(rewritten, 0, sizeof(rewritten)));
     for ( i = 0; i < AKBASIC_MAX_SOURCE_LINES; i++ ) {
+	int64_t target = 0;
+
 	if ( obj->source[i].code[0] == '\0' ) {
 	    continue;
 	}
@@ -364,62 +367,20 @@ akerr_ErrorContext *akbasic_renumber(akbasic_Runtime *obj, int64_t newstart, int
 	 * Every line is rewritten, not just the moved ones: a line before
 	 * `oldstart` can branch into the region that moved.
 	 */
+	target = mapped(map, i);
 	PASS(errctx, rewrite_line(&walk, obj->source[i].code,
-				  obj->renumber_line.code, sizeof(obj->renumber_line.code)));
-	obj->renumber_line.lineno = i;
+				  rewritten[target].code, sizeof(rewritten[target].code)));
+	rewritten[target].lineno = target;
 	/*
 	 * Every line comes out numbered, whether or not it went in that way.
 	 * Asking for numbers is what RENUMBER is, and a program that has been
 	 * through it can be branched into by number -- which is the whole point
 	 * of running it over source that arrived without any.
 	 */
-	obj->renumber_line.numbered = true;
-	PASS(errctx, aksl_memcpy(&obj->source[i], &obj->renumber_line,
-				 sizeof(obj->source[i])));
+	rewritten[target].numbered = true;
     }
 
-    /* Move the already-rewritten lines in place. The map is a partial
-     * permutation: a chain ends at an empty slot, while a cycle closes back
-     * on its starting line. A single displaced line is sufficient for both. */
-    for ( i = 0; i < AKBASIC_MAX_SOURCE_LINES; i++ ) {
-	int64_t current = i;
-	akbasic_SourceLine displaced;
-	akbasic_SourceLine next_line;
-
-	if ( map[i] < 0 || obj->renumber_visited[i] ) {
-	    continue;
-	}
-	PASS(errctx, aksl_memcpy(&displaced, &obj->source[i], sizeof(displaced)));
-	for ( ;; ) {
-	    int64_t destination = map[current];
-
-	    obj->renumber_visited[current] = 1;
-	    if ( destination == i ) {
-		displaced.lineno = destination;
-		PASS(errctx, aksl_memcpy(&obj->source[destination], &displaced,
-					 sizeof(displaced)));
-		break;
-	    }
-	    if ( map[destination] < 0 ) {
-		displaced.lineno = destination;
-		PASS(errctx, aksl_memcpy(&obj->source[destination], &displaced,
-					 sizeof(displaced)));
-		PASS(errctx, aksl_memset(&obj->source[current], 0,
-					 sizeof(obj->source[current])));
-		break;
-	    }
-	    PASS(errctx, aksl_memcpy(&next_line, &obj->source[destination],
-				     sizeof(displaced)));
-	    displaced.lineno = destination;
-	    PASS(errctx, aksl_memcpy(&obj->source[destination], &displaced,
-				     sizeof(obj->renumber_line)));
-	    PASS(errctx, aksl_memset(&obj->source[current], 0,
-				     sizeof(obj->source[current])));
-	    PASS(errctx, aksl_memcpy(&displaced, &next_line,
-				     sizeof(displaced)));
-	    current = destination;
-	}
-    }
+    PASS(errctx, aksl_memcpy(obj->source, rewritten, sizeof(obj->source)));
     SUCCEED_RETURN(errctx);
 }
 
@@ -474,6 +435,7 @@ akerr_ErrorContext *akbasic_runtime_check_targets(akbasic_Runtime *obj)
      * step(). Nothing is read back out of it -- the walk needs somewhere to put
      * the text it would have written, and this is it.
      */
+    static char discard[AKBASIC_MAX_LINE_LENGTH * 2];
     CheckState state = { NULL, 0 };
     akbasic_TargetWalk walk = { &state, visit_check };
     int64_t entry = 0;
@@ -501,8 +463,7 @@ akerr_ErrorContext *akbasic_runtime_check_targets(akbasic_Runtime *obj)
 	 * the whole point of setting it.
 	 */
 	obj->environment->lineno = i;
-	PASS(errctx, rewrite_line(&walk, obj->source[i].code,
-				 obj->renumber_discard, sizeof(obj->renumber_discard)));
+	PASS(errctx, rewrite_line(&walk, obj->source[i].code, discard, sizeof(discard)));
     }
     /* Nothing was refused, so leave the cursor as the caller had it. */
     obj->environment->lineno = entry;

tests/hoststruct.c

@@ -208,6 +208,72 @@ static void test_suffix_must_match_the_c_type(void)
     harness_stop();
 }
 
+/** @brief Host names use the same bounded storage as script-declared names. */
+static void test_registration_name_limits(void)
+{
+    static const akbasic_HostField SHORT_FIELD[] = {
+	AKBASIC_HOST_FIELD( test_Enemy, hp, "ABCDEFGHIJKLMNOPQRSTUVWXYZ1234#",
+			   AKBASIC_HOSTFIELD_INT32 )
+    };
+    static const akbasic_HostField LONG_FIELD_A[] = {
+	AKBASIC_HOST_FIELD( test_Enemy, hp, "ABCDEFGHIJKLMNOPQRSTUVWXYZ123456A#",
+			   AKBASIC_HOSTFIELD_INT32 )
+    };
+    static const akbasic_HostField LONG_FIELD_B[] = {
+	AKBASIC_HOST_FIELD( test_Enemy, hp, "ABCDEFGHIJKLMNOPQRSTUVWXYZ123456B#",
+			   AKBASIC_HOSTFIELD_INT32 )
+    };
+    static const akbasic_HostType SHORT_TYPE = {
+	"ABCDEFGHIJKLMNOPQRSTUVWXYZ12345", sizeof(test_Enemy), SHORT_FIELD, 1
+    };
+    static const akbasic_HostType LONG_TYPE_A = {
+	"ABCDEFGHIJKLMNOPQRSTUVWXYZ123456A", sizeof(test_Enemy), SHORT_FIELD, 1
+    };
+    static const akbasic_HostType LONG_TYPE_B = {
+	"ABCDEFGHIJKLMNOPQRSTUVWXYZ123456B", sizeof(test_Enemy), SHORT_FIELD, 1
+    };
+    static const akbasic_HostType LONG_FIELD_TYPE_A = {
+	"LONGFIELDA", sizeof(test_Enemy), LONG_FIELD_A, 1
+    };
+    static const akbasic_HostType LONG_FIELD_TYPE_B = {
+	"LONGFIELDB", sizeof(test_Enemy), LONG_FIELD_B, 1
+    };
+    akerr_ErrorContext *raised = NULL;
+
+	TEST_REQUIRE_OK(harness_start(NULL));
+	TEST_REQUIRE_OK(akbasic_host_register_type(&HARNESS_RUNTIME, &SHORT_TYPE));
+	harness_stop();
+
+	TEST_REQUIRE_OK(harness_start(NULL));
+	raised = akbasic_host_register_type(&HARNESS_RUNTIME, &LONG_TYPE_A);
+	TEST_REQUIRE(raised != NULL, "an overlong type name must be refused");
+	TEST_REQUIRE_INT(raised->status, AKERR_OUTOFBOUNDS);
+	test_discard_error(raised);
+	raised = akbasic_host_register_type(&HARNESS_RUNTIME, &LONG_TYPE_B);
+	TEST_REQUIRE(raised != NULL, "a second long type name must fail cleanly");
+	TEST_REQUIRE_INT(raised->status, AKERR_OUTOFBOUNDS);
+	test_discard_error(raised);
+	harness_stop();
+
+	TEST_REQUIRE_OK(harness_start(NULL));
+	TEST_REQUIRE_OK(akbasic_host_register_type(&HARNESS_RUNTIME,
+						  &(akbasic_HostType){
+						      "SHORTFIELDS", sizeof(test_Enemy), SHORT_FIELD, 1
+						  }));
+	harness_stop();
+
+	TEST_REQUIRE_OK(harness_start(NULL));
+	raised = akbasic_host_register_type(&HARNESS_RUNTIME, &LONG_FIELD_TYPE_A);
+	TEST_REQUIRE(raised != NULL, "an overlong field name must be refused");
+	TEST_REQUIRE_INT(raised->status, AKERR_OUTOFBOUNDS);
+	test_discard_error(raised);
+	raised = akbasic_host_register_type(&HARNESS_RUNTIME, &LONG_FIELD_TYPE_B);
+	TEST_REQUIRE(raised != NULL, "a second long field name must fail cleanly");
+	TEST_REQUIRE_INT(raised->status, AKERR_OUTOFBOUNDS);
+	test_discard_error(raised);
+	harness_stop();
+}
+
 /**
  * @brief After unbinding, the name is refused rather than read.
  *
@@ -258,6 +324,7 @@ int main(void)
     test_conversion_refuses_rather_than_truncates();
     test_copy_versus_point();
     test_suffix_must_match_the_c_type();
+    test_registration_name_limits();
     test_unbind_refuses_later_reads();
     test_registration_survives_a_rerun();