Avoid calling malloc/free in the library code.

FossilOrigin-Name: 3e7c2c1b4beda2a729c880caf1a41c441e0a8387d40b666ac7163eb1346653b5

8 files changed, 85 insertions, 28 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index fd1839b..29f567b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -31,7 +31,7 @@ target_link_options(common INTERFACE
 add_library(aplwc
 	src/errors.c
 	src/libmain.c
-	src/malloc.c
+	src/memory.c
 )
 target_link_libraries(aplwc PRIVATE common)
 
diff --git a/src/aplwc.h b/src/aplwc.h
index 7a90147..e01e38c 100644
--- a/src/aplwc.h
+++ b/src/aplwc.h
@@ -1,15 +1,18 @@
 #ifndef APLWC_H
 #define APLWC_H
 
+#include <stdint.h>
+#include <stddef.h>
+
 typedef enum {
 	APLWC_OK,
 	APLWC_NOT_IMPLEMENTED,
-	APLWC_MALLOC_FAILED,
+	APLWC_OUT_OF_MEMORY,
 } AplwcRc;
 
 typedef struct Aplwc Aplwc;
 
-AplwcRc aplwc_new(Aplwc **);
+AplwcRc aplwc_new(Aplwc **, uint8_t *, size_t);
 AplwcRc aplwc_destroy(Aplwc *);
 const char *aplwc_errstr(Aplwc *);
 
diff --git a/src/aplwc_internal.h b/src/aplwc_internal.h
index f80c8ab..ccf600f 100644
--- a/src/aplwc_internal.h
+++ b/src/aplwc_internal.h
@@ -1,6 +1,8 @@
 #ifndef APLWC_INTERNAL_H
 #define APLWC_INTERNAL_H
 
+#include <aplwc.h>
+
 #define UNUSED_PARAMETER(arg) ((void)arg)
 
 #define RETURN_ERROR(aplwc, rc, msg) do{ \
@@ -12,21 +14,32 @@
 
 #define NELEM(x) (sizeof(x)/sizeof(x[0]))
 
-#include <stddef.h>
-#include <stdint.h>
+#include <stdalign.h>
+#include <stdbool.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
 
+typedef struct Memory Memory;
+
+struct Memory {
+	uint8_t *data;
+	size_t size;
+	size_t offset;
+};
+
 struct Aplwc {
 	AplwcRc last_error;
 	char last_error_msg[64];
+	Memory memory;
 };
 
 /* errors.c */
 const char *rc_to_string(AplwcRc);
 
-/* malloc.c */
-void *malloc_zero(size_t);
+/* memory.c */
+Memory memory_init(uint8_t *, size_t);
+Aplwc *memory_alloc_aplwc(Memory *);
+void memory_free_aplwc(Memory *, Aplwc *);
 
 #endif /* APLWC_INTERNAL_H */
diff --git a/src/errors.c b/src/errors.c
index 014f859..cd93df4 100644
--- a/src/errors.c
+++ b/src/errors.c
@@ -1,4 +1,3 @@
-#include <aplwc.h>
 #include <aplwc_internal.h>
 
 static const char *errors[] = {
@@ -6,8 +5,6 @@ static const char *errors[] = {
 		"",
 	[APLWC_NOT_IMPLEMENTED] =
 		"Not yet implemented",
-	[APLWC_MALLOC_FAILED] =
-		"Could not allocate memory",
 };
 
 const char *
diff --git a/src/libmain.c b/src/libmain.c
index 1458bf8..93ad2a0 100644
--- a/src/libmain.c
+++ b/src/libmain.c
@@ -1,13 +1,14 @@
-#include <aplwc.h>
 #include <aplwc_internal.h>
 
 AplwcRc
-aplwc_new(Aplwc **p)
+aplwc_new(Aplwc **p, uint8_t *data, size_t size)
 {
-	*p = malloc_zero(sizeof(Aplwc));
+	Memory m = memory_init(data, size);
+	*p = memory_alloc_aplwc(&m);
 	if(*p == NULL)
-		RETURN_ERROR(*p, MALLOC_FAILED, "");
-	
+		RETURN_ERROR(*p, OUT_OF_MEMORY, "");
+	(*p)->memory = m;
+
 	return APLWC_OK;
 }
 
@@ -15,7 +16,7 @@ AplwcRc
 aplwc_destroy(Aplwc *p)
 {
 	if(p)
-		free(p);
+		memory_free_aplwc(&p->memory, p);
 
 	return APLWC_OK;
 }
diff --git a/src/main.c b/src/main.c
index 209c88a..1e46fbf 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,12 +1,21 @@
 #include <stdio.h>
+#include <stdlib.h>
 #include <aplwc.h>
 
+#define MEMORY (1024*1024)
+
 int
 main(void)
 {
 	Aplwc *aplwc;
 
-	int ret = aplwc_new(&aplwc);
+	uint8_t *data = malloc(MEMORY);
+	if(data == NULL){
+		fprintf(stderr, "Couldn't allocate memory\n");
+		return 1;
+	}
+
+	int ret = aplwc_new(&aplwc, data, MEMORY);
 	if(ret){
 		fprintf(stderr, "Couldn't create new aplwc instance: %s\n", aplwc_errstr(aplwc));
 		return 1;
@@ -19,5 +28,7 @@ main(void)
 		return 1;
 	}
 
+	free(data);
+
 	return 0;
 }
diff --git a/src/malloc.c b/src/malloc.c
deleted file mode 100644
index abf0884..0000000
--- a/src/malloc.c
+++ /dev/null
@@ -1,11 +0,0 @@
-#include <aplwc.h>
-#include <aplwc_internal.h>
-
-void *
-malloc_zero(size_t size)
-{
-	void *p = malloc(size);
-	if(p)
-		memset(p, 0, size);
-	return p;
-}
diff --git a/src/memory.c b/src/memory.c
new file mode 100644
index 0000000..c2216b2
--- /dev/null
+++ b/src/memory.c
@@ -0,0 +1,43 @@
+#include <aplwc_internal.h>
+
+Memory
+memory_init(uint8_t *data , size_t size)
+{
+	Memory mem = {
+		.data = data,
+		.size = size,
+		.offset = 0,
+	};
+	return mem;
+}
+
+static void *
+alloc(Memory *m, size_t size, size_t align)
+{
+	uintptr_t ptr = (uintptr_t)m->data;
+	size_t alloc_size = size;
+	if((ptr % align) != 0)
+		alloc_size += align - (ptr % align);
+
+	void *p = NULL;
+	if((m->size - m->offset) >= alloc_size){
+		p = m->data+m->offset+alloc_size-size;
+		m->offset += alloc_size;
+		memset(p, 0, size);
+	}
+	return p;
+}
+
+Aplwc *
+memory_alloc_aplwc(Memory *m)
+{
+	Aplwc *p = alloc(m, sizeof(Aplwc), alignof(Aplwc));
+	return p;
+}
+
+void
+memory_free_aplwc(Memory *m, Aplwc *p)
+{
+	UNUSED_PARAMETER(m);
+	UNUSED_PARAMETER(p);
+}