Still a lot to be done, but I'm going to bed.

Two remaining big issues:
* aplwc (the parameter passed "everywhere") - should it move or not?
* values returned from the public API should not move.

FossilOrigin-Name: 31ab3154b8f3d5ac167218496e9e204324bf0ac9d36b7bada8fe2a6c8f93d51c

8 files changed, 325 insertions, 91 deletions

diff --git a/src/bin/main.c b/src/bin/main.c
index fb75a9d..99149f6 100644
--- a/src/bin/main.c
+++ b/src/bin/main.c
@@ -4,15 +4,21 @@
 #include <errno.h>
 #include "aplwc_repl.h"
 
-#define MEMSIZE 20000
+static void *my_alloc(size_t min, size_t max, size_t *actual)
+{
+	UNUSED_PARAMETER(max);
+
+	*actual = min;
+	return malloc(min);
+}
 
 int
 main(int argc, char *argv[])
 {
+	struct aplwc_fns fns;
 	struct aplwc *aplwc;
 	struct aplwc_line *line;
 	struct aplwc_value *value;
-	uint8_t *data;
 	char *input, *src;
 	int ret, exit_code, line_number;
 	size_t input_size, src_size, i;
@@ -28,6 +34,9 @@ main(int argc, char *argv[])
 	exit_code = 0;
 	line_number = 0;
 
+	memset(&fns, 0, sizeof(fns));
+	fns.alloc = my_alloc;
+
 	while((opt = getopt(argc, argv, "x")) != -1){
 		switch(opt){
 		case 'x':
@@ -52,16 +61,9 @@ usage:
 	else
 		goto usage;
 
-	data = malloc(MEMSIZE);
-	if(data == NULL){
-		fprintf(stderr, "Couldn't allocate memory\n");
-		return 1;
-	}
-
-	ret = aplwc_new(&aplwc, data, MEMSIZE);
+	ret = aplwc_new(&aplwc, fns);
 	if(ret){
 		fprintf(stderr, "Couldn't create new aplwc instance: %s\n", aplwc_errstr_rc(ret));
-		free(data);
 		return 1;
 	}
 
@@ -152,6 +154,5 @@ exit:
 		aplwc_free_value(value);
 
 	aplwc_destroy(aplwc);
-	free(data);
 	return exit_code;
 }
diff --git a/src/include/aplwc.h b/src/include/aplwc.h
index ad640e4..843fe42 100644
--- a/src/include/aplwc.h
+++ b/src/include/aplwc.h
@@ -18,7 +18,12 @@ struct aplwc;
 struct aplwc_line;
 struct aplwc_value;
 
-enum aplwc_rc aplwc_new(struct aplwc **, uint8_t *, size_t);
+struct aplwc_fns {
+	void *(*alloc)(size_t, size_t, size_t *);
+	void (*dealloc)(void *);
+};
+
+enum aplwc_rc aplwc_new(struct aplwc **, struct aplwc_fns);
 void aplwc_destroy(struct aplwc *);
 const char *aplwc_errstr_rc(enum aplwc_rc);
 const char *aplwc_errstr(struct aplwc *);
diff --git a/src/lib/aplwc_internal.h b/src/lib/aplwc_internal.h
index 23b26f9..a7b7030 100644
--- a/src/lib/aplwc_internal.h
+++ b/src/lib/aplwc_internal.h
@@ -9,13 +9,21 @@
 #include <string.h>
 
 struct aplwc {
+	struct aplwc_fns fns;
 	enum aplwc_rc last_error;
 	struct aplwc_module *modules;
 
 	/* Memory management */
 	uint8_t *data;
+	uint8_t *unaligned_data;
 	size_t size;
-	size_t offset;
+	struct memory_ptr_frame *memptrs;
+};
+
+struct memory_ptr_frame {
+	struct memory_ptr_frame *link;
+	void ***ptrs;
+	size_t count;
 };
 
 struct aplwc_line {
@@ -79,8 +87,8 @@ struct aplwc_module {
 struct aplwc_value *eval_line(struct aplwc_line *);
 
 /* memory.c */
-void memory_init(struct aplwc *, uint8_t *, size_t);
-struct aplwc *memory_alloc_aplwc(struct aplwc *);
+void memory_init(struct aplwc *);
+void memory_destroy(struct aplwc *);
 struct aplwc_line *memory_alloc_aplwc_line(struct aplwc *);
 struct string *memory_alloc_string(struct aplwc *, size_t);
 struct token_list *memory_alloc_token_list(struct aplwc *, size_t);
@@ -88,6 +96,15 @@ struct aplwc_value *memory_alloc_aplwc_value(struct aplwc *);
 struct aplwc_module *memory_alloc_aplwc_module(struct aplwc *);
 struct module_imports *memory_alloc_module_imports(struct aplwc *, size_t);
 void memory_free_root(struct aplwc *, void *);
+void memptrs_add(struct aplwc *, struct memory_ptr_frame *, void ***, size_t);
+void memptrs_remove(struct aplwc *, struct memory_ptr_frame *);
+
+#define MEMPTRS(aplwc, n) \
+	void **memptrs[n]; \
+	struct memory_ptr_frame memptrs_frame; \
+	memptrs_add(aplwc, &memptrs_frame, memptrs, n);
+#define MEMPTR(n, ptr) memptrs[n] = (void **)&ptr
+#define MEMPTRS_EXIT(aplwc) memptrs_remove(aplwc, &memptrs_frame)
 
 /* string.c */
 struct string *chars_to_string(struct aplwc *, const char *, int len);
diff --git a/src/lib/eval.c b/src/lib/eval.c
index 21fb223..50c3cda 100644
--- a/src/lib/eval.c
+++ b/src/lib/eval.c
@@ -14,5 +14,6 @@ eval_line(struct aplwc_line *line)
 		value->aplwc = aplwc;
 		value->tag = VALUE_NULL;
 	}
+
 	return value;
 }
diff --git a/src/lib/main.c b/src/lib/main.c
index 81cd6bb..03c31a5 100644
--- a/src/lib/main.c
+++ b/src/lib/main.c
@@ -2,24 +2,32 @@
 #include "boot.h"
 
 enum aplwc_rc
-aplwc_new(struct aplwc **p, uint8_t *data, size_t size)
+aplwc_new(struct aplwc **p, struct aplwc_fns fns)
 {
-	struct aplwc tmp_aplwc;
-
-	memory_init(&tmp_aplwc, data, size);
-
-	*p = memory_alloc_aplwc(&tmp_aplwc);
-	if(*p == NULL)
-		return tmp_aplwc.last_error;
-	memcpy(*p, &tmp_aplwc, sizeof(tmp_aplwc));	
-
-	return aplwc_load_module(*p, "Boot", (const char *)boot_src, boot_src_len);
+	struct aplwc *aplwc;
+	size_t size;
+
+	if(fns.alloc == NULL)
+		return APLWC_OUT_OF_MEMORY;
+	aplwc = fns.alloc(sizeof(*aplwc), sizeof(*aplwc), &size);
+	if(aplwc == NULL)
+		return APLWC_OUT_OF_MEMORY;
+	*p = aplwc;
+
+	aplwc->fns = fns;
+	memory_init(aplwc);
+	return aplwc_load_module(aplwc, "Boot", (const char *)boot_src, boot_src_len);
 }
 
 void
 aplwc_destroy(struct aplwc *p)
 {
-	UNUSED_PARAMETER(p);
+	if(p == NULL)
+		return;
+	
+	memory_destroy(p);
+	if(p->fns.dealloc)
+		p->fns.dealloc(p);
 }
 
 const char *
@@ -70,26 +78,30 @@ aplwc_read(struct aplwc *aplwc, const char *line)
 	struct token_list *tokens;
 	struct aplwc_line *ret;
 
-	text = chars_to_string(aplwc, line, -1);
-	if(text == NULL)
-		return NULL;
+	MEMPTRS(aplwc, 2);
+
+	ret = NULL;
 
-	tokens = scan_string(aplwc, text, 1);
-	if(tokens == NULL)
-		return NULL;
+	if((text = chars_to_string(aplwc, line, -1)) == NULL)
+		goto end;
+	MEMPTR(0, text);
 
-	aplwc->last_error = check_tokens(tokens);
-	if(aplwc->last_error != APLWC_OK)
-		return NULL;
+	if((tokens = scan_string(aplwc, text, 1)) == NULL)
+		goto end;
+	MEMPTR(1, tokens);
 
-	ret = memory_alloc_aplwc_line(aplwc);
-	if(ret == NULL)
-		return NULL;
+	if((aplwc->last_error = check_tokens(tokens)) != APLWC_OK)
+		goto end;
+
+	if((ret = memory_alloc_aplwc_line(aplwc)) == NULL)
+		goto end;
 	
 	ret->aplwc = aplwc;
 	ret->text = text;
 	ret->tokens = tokens;
 
+end:
+	MEMPTRS_EXIT(aplwc);
 	return ret;
 }
 
@@ -131,16 +143,22 @@ aplwc_load_module(struct aplwc *aplwc, const char *name, const char *src, int sr
 	struct string *text, *namestr;
 	struct token_list *tokens;
 
+	MEMPTRS(aplwc, 3);
+
 	if((namestr = chars_to_string(aplwc, name, -1)) == NULL)
-		goto error;
+		goto end;
+	MEMPTR(0, namestr);
+
 	if((text = chars_to_string(aplwc, src, srclen)) == NULL)
-		goto error;
+		goto end;
+	MEMPTR(1, text);
+
 	if((tokens = scan_string(aplwc, text, 0)) == NULL)
-		goto error;
-	if(load_module(aplwc, namestr, tokens) != APLWC_OK){
-error:
-		return aplwc_last_error(aplwc);
-	}
+		goto end;
+	MEMPTR(2, tokens);
 
-	return APLWC_OK;
+	aplwc->last_error = load_module(aplwc, namestr, tokens);
+end:
+	MEMPTRS_EXIT(aplwc);
+	return aplwc_last_error(aplwc);
 }
diff --git a/src/lib/memory.c b/src/lib/memory.c
index 94f903c..8a91d2d 100644
--- a/src/lib/memory.c
+++ b/src/lib/memory.c
@@ -1,41 +1,201 @@
 #include "aplwc_internal.h"
 
+#define ALIGNMENT 8
+#define HEADER_SIZE (sizeof(struct chunk) + (sizeof(struct chunk) % ALIGNMENT))
+
+enum chunk_tag {
+	CHUNK_TAG_FREE,
+	CHUNK_TAG_APLWC_LINE,
+	CHUNK_TAG_STRING,
+	CHUNK_TAG_TOKEN_LIST,
+	CHUNK_TAG_APLWC_VALUE,
+	CHUNK_TAG_APLWC_MODULE
+};
+
+struct chunk {
+	struct chunk *next;
+	size_t size;
+	enum chunk_tag tag;
+	uint8_t *data;
+};
+
 void
-memory_init(struct aplwc *aplwc, uint8_t *data , size_t size)
+memory_init(struct aplwc *aplwc)
 {
-	aplwc->data = data;
-	aplwc->size = size;
-	aplwc->offset = 0;
+	aplwc->data = NULL;
+	aplwc->unaligned_data = NULL;
+	aplwc->size = 0;
+	aplwc->memptrs = NULL;
 }
 
-static void *
-alloc(struct aplwc *aplwc, size_t size, size_t align)
+void
+memory_destroy(struct aplwc *aplwc)
 {
-	uintptr_t ptr;
-	size_t alloc_size, adjust;
-	void *p;
+	if(aplwc->fns.dealloc)
+		aplwc->fns.dealloc(aplwc->unaligned_data);
+}
 
-	ptr = ((uintptr_t)aplwc->data) + aplwc->offset;
-	alloc_size = size;
+static void
+fixrefs(struct aplwc *aplwc, uint8_t *new, uint8_t *old)
+{
+#define FIX(ptr) do{ \
+	if(ptr){ \
+		(ptr) = (void*)(((uint8_t*)(ptr))+add); \
+		(ptr) = (void*)(((uint8_t*)(ptr))-sub); \
+	} \
+}while(0)
 
-	if(NEVER(align == 0))
-		return NULL;
-	adjust = ptr % align;
+#define FIX_DATA(type, ptr) FIX(((type *)c->data)->ptr)
 
-	if(adjust)
-		alloc_size += align - adjust;
+	struct chunk *c;
+	struct memory_ptr_frame *frame;
+	size_t add, sub, i;
 
-	if((aplwc->size - aplwc->offset) >= alloc_size){
-		p = aplwc->data+aplwc->offset+alloc_size-size;
-		assert((((uintptr_t)p) % align) == 0);
-		aplwc->offset += alloc_size;
-		memset(p, 0, size);
+	if(new > old){
+		add = new-old;
+		sub = 0;
 	}else{
-		p = NULL;
-		aplwc->last_error = APLWC_OUT_OF_MEMORY;
+		add = 0;
+		sub = old-new;
 	}
 
-	return p;
+	for(c = (struct chunk *)new; c; c = c->next){
+		FIX(c->next);
+		FIX(c->data);
+
+		switch(c->tag){
+		case CHUNK_TAG_APLWC_LINE:
+			FIX_DATA(struct aplwc_line, text);
+			FIX_DATA(struct aplwc_line, tokens);
+			break;
+		case CHUNK_TAG_STRING:
+			break;
+		case CHUNK_TAG_TOKEN_LIST:
+			FIX_DATA(struct token_list, text);
+			break;
+		case CHUNK_TAG_APLWC_VALUE:
+			break;
+		case CHUNK_TAG_APLWC_MODULE:
+			FIX_DATA(struct aplwc_module, name);
+			FIX_DATA(struct aplwc_module, tokens);
+			FIX_DATA(struct aplwc_module, link);
+			break;
+		case CHUNK_TAG_FREE:
+			break;
+		}
+	}
+
+	for(frame = aplwc->memptrs; frame; frame = frame->link)
+		for(i = 0; i < frame->count; i++)
+			if(frame->ptrs[i])
+				FIX(*frame->ptrs[i]);
+
+#undef FIX
+#undef FIX_DATA
+}
+
+static enum aplwc_rc
+grow(struct aplwc *aplwc, size_t extra)
+{
+	uint8_t *unaligned_data, *aligned_data;
+	size_t unaligned_newsize, aligned_newsize, adjust;
+	struct chunk **free;
+
+	if(aplwc->fns.alloc == NULL)
+		goto error;
+
+	unaligned_data = aplwc->fns.alloc(aplwc->size + extra + HEADER_SIZE + 2*ALIGNMENT, 0, &unaligned_newsize);
+	if(unaligned_data == NULL)
+		goto error;
+
+	adjust = ((uintptr_t)unaligned_data) % ALIGNMENT;
+	if(adjust)
+		adjust = ALIGNMENT - adjust;
+	aligned_newsize = unaligned_newsize - adjust;
+	aligned_data = unaligned_data + adjust;
+
+	aligned_newsize -= aligned_newsize % ALIGNMENT;
+
+	assert(aligned_newsize >= (aplwc->size + extra));
+
+	if(aplwc->data){
+		memmove(aligned_data, aplwc->data, aplwc->size);
+		fixrefs(aplwc, aligned_data, aplwc->data);
+		if(aplwc->fns.dealloc)
+			aplwc->fns.dealloc(aplwc->unaligned_data);
+		for(free = (struct chunk **)&aligned_data; (*free); free = &(*free)->next)
+			assert((*free)->tag != CHUNK_TAG_FREE);
+	}else
+		free = (struct chunk **)&aligned_data;
+
+
+	(*free) = (struct chunk *)(aligned_data + aplwc->size);
+	(*free)->tag = CHUNK_TAG_FREE;
+	(*free)->data = NULL;
+	(*free)->size = aligned_newsize - aplwc->size;
+	(*free)->next = NULL;
+
+	aplwc->unaligned_data = unaligned_data;
+	aplwc->data = aligned_data;
+	aplwc->size = aligned_newsize;
+	return 1;
+
+error:
+	aplwc->last_error = APLWC_OUT_OF_MEMORY;
+	return 0;
+}
+
+static struct chunk *
+find_free(struct aplwc *aplwc, size_t min)
+{
+	struct chunk *c;
+
+	min += HEADER_SIZE;
+
+	if(aplwc->data == NULL)
+		return NULL;
+	
+	for(c = (struct chunk *)aplwc->data; c; c = c->next){
+		if((c->tag == CHUNK_TAG_FREE) && (c->size >= min))
+			break;
+	}
+
+	return c;
+}
+
+static void *
+alloc(struct aplwc *aplwc, size_t size, enum chunk_tag tag)
+{
+	struct chunk *free;
+	struct chunk *new;
+
+retry:
+	free = find_free(aplwc, size);
+	if(!free){
+		if(grow(aplwc, size))
+			goto retry;
+		else
+			return NULL;
+	}
+
+	assert(free->data == NULL);
+
+	new = free;
+
+	if(free->size > (size + 2*HEADER_SIZE)){
+		free = (struct chunk *)(((uint8_t*)free) + HEADER_SIZE + size);
+		free->tag = CHUNK_TAG_FREE;
+		free->size = new->size - (HEADER_SIZE + size);
+		free->data = NULL;
+	}
+
+	new->tag = tag;
+	new->size = sizeof(struct chunk) + size;
+	new->data = ((uint8_t*)new) + sizeof(struct chunk);
+
+	new->data += ((uintptr_t)new->data) % ALIGNMENT;
+
+	return new->data;
 }
 
 void
@@ -47,13 +207,25 @@ memory_free_root(struct aplwc *aplwc, void *p)
 	UNUSED_PARAMETER(aplwc);
 }
 
-struct aplwc *
-memory_alloc_aplwc(struct aplwc *aplwc)
+void
+memptrs_add(struct aplwc *aplwc, struct memory_ptr_frame *frame, void ***ptrs, size_t count)
 {
-	struct aplwc *p;
+	size_t i;
 
-	p = alloc(aplwc, sizeof(struct aplwc), alignof(struct aplwc));
-	return p;
+	frame->ptrs = ptrs;
+	frame->link = aplwc->memptrs;	
+	frame->count = count;
+	aplwc->memptrs = frame;
+
+	for(i = 0; i < count; i++)
+		frame->ptrs[i] = NULL;
+}
+
+void
+memptrs_remove(struct aplwc *aplwc, struct memory_ptr_frame *frame)
+{
+	assert(aplwc->memptrs == frame);
+	aplwc->memptrs = frame->link;
 }
 
 struct aplwc_line *
@@ -61,7 +233,7 @@ memory_alloc_aplwc_line(struct aplwc *aplwc)
 {
 	struct aplwc_line *p;
 
-	p = alloc(aplwc, sizeof(struct aplwc_line), alignof(struct aplwc_line));
+	p = alloc(aplwc, sizeof(struct aplwc_line), CHUNK_TAG_APLWC_LINE);
 	return p;
 }
 
@@ -70,7 +242,8 @@ memory_alloc_string(struct aplwc *aplwc, size_t bytes)
 {
 	struct string *p;
 
-	p = alloc(aplwc, sizeof(struct string) + bytes, alignof(struct string));
+	p = alloc(aplwc, sizeof(struct string) + bytes, CHUNK_TAG_STRING);
+
 	return p;
 }
 
@@ -79,7 +252,7 @@ memory_alloc_token_list(struct aplwc *aplwc, size_t tokens)
 {
 	struct token_list *p;
 
-	p = alloc(aplwc, sizeof(struct token_list) + (tokens * sizeof(struct token)), alignof(struct token_list));
+	p = alloc(aplwc, sizeof(struct token_list) + (tokens * sizeof(struct token)), CHUNK_TAG_TOKEN_LIST);
 	return p;
 }
 
@@ -88,7 +261,7 @@ memory_alloc_aplwc_value(struct aplwc *aplwc)
 {
 	struct aplwc_value *p;
 
-	p = alloc(aplwc, sizeof(struct aplwc_value), alignof(struct aplwc_value));
+	p = alloc(aplwc, sizeof(struct aplwc_value), CHUNK_TAG_APLWC_VALUE);
 	return p;
 }
 
@@ -97,6 +270,6 @@ memory_alloc_aplwc_module(struct aplwc *aplwc)
 {
 	struct aplwc_module *p;
 
-	p = alloc(aplwc, sizeof(struct aplwc_module), alignof(struct aplwc_module));
+	p = alloc(aplwc, sizeof(struct aplwc_module), CHUNK_TAG_APLWC_MODULE);
 	return p;
 }
diff --git a/src/lib/module.c b/src/lib/module.c
index f559f00..3bca396 100644
--- a/src/lib/module.c
+++ b/src/lib/module.c
@@ -58,9 +58,17 @@ load_module(struct aplwc *aplwc, struct string *name, struct token_list *tokens)
 	enum aplwc_rc rc;
 	struct aplwc_module *module;
 
+	MEMPTRS(aplwc, 2);
+
+	MEMPTR(0, name);
+	MEMPTR(1, tokens);
+
 	module = memory_alloc_aplwc_module(aplwc);
-	if(module == NULL)
-		return aplwc->last_error;
+	if(module == NULL){
+		rc = aplwc_last_error(aplwc);
+		goto end;
+	}
+
 	module->aplwc = aplwc;
 	module->name = name;
 	module->tokens = tokens;
@@ -70,8 +78,11 @@ load_module(struct aplwc *aplwc, struct string *name, struct token_list *tokens)
 	if(rc == APLWC_OK){
 		module->link = aplwc->modules;
 		aplwc->modules = module;
-	}
+	}else
+		aplwc->last_error = rc;
 
+end:
+	MEMPTRS_EXIT(aplwc);
 	return rc;
 }
 
diff --git a/src/lib/syntax.c b/src/lib/syntax.c
index 75d6c14..ae52343 100644
--- a/src/lib/syntax.c
+++ b/src/lib/syntax.c
@@ -240,15 +240,17 @@ scan_string(struct aplwc *aplwc, struct string *text, int oneline)
 	struct token_list *tokens;
 	size_t n, i;
 
+	MEMPTRS(aplwc, 1);
+	MEMPTR(0, text);
+
+	tokens = NULL;
 	rc = check(text, &n);
-	if(rc != APLWC_OK){
-		aplwc->last_error = rc;
-		return NULL;
-	}
+	if(rc != APLWC_OK)
+		goto end;
 
 	tokens = memory_alloc_token_list(aplwc, n);
 	if(tokens == NULL)
-		return NULL;
+		goto end;
 	tokens->text = text;
 	tokens->length = n;
 	scan(text, tokens);
@@ -258,11 +260,17 @@ scan_string(struct aplwc *aplwc, struct string *text, int oneline)
 			continue;
 
 		for(i++; i < n; i++){
-			if(tokens->tokens[i].tag != TOKEN_TAG_NEWLINE)
-				return NULL;
+			if(tokens->tokens[i].tag != TOKEN_TAG_NEWLINE){
+				rc = APLWC_INVALID_SYNTAX;
+				tokens = NULL;
+				goto end;
+			}
 		}
 	}
 
+end:
+	aplwc->last_error = rc;
+	MEMPTRS_EXIT(aplwc);
 	return tokens;
 }