From 0e3c5739c3478c3c55fc7bef5c6c4f70e60e8f16 Mon Sep 17 00:00:00 2001
From: Avril <flanchan@cumallover.me>
Date: Mon, 16 Nov 2020 14:30:14 +0000
Subject: [PATCH] initial commit

---
 .gitignore   |  4 +++
 Makefile     | 39 +++++++++++++++++++++++++++
 README       |  1 +
 include/rc.h | 27 +++++++++++++++++++
 src/rc.c     | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 145 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 Makefile
 create mode 100644 README
 create mode 100644 include/rc.h
 create mode 100644 src/rc.c

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..5812b96
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+*.o
+*~
+*.a
+*.so
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..762f9ff
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,39 @@
+SRC = $(wildcard src/*.c)
+INCLUDE = include
+
+CFLAGS = -Wall $(addprefix -I,$(INCLUDE)) --std=gnu11 -pedantic
+CFLAGS+= -O3 -flto -fgraphite
+
+LDFLAGS = -O3 -flto
+
+OBJ:= obj
+
+STATIC = $(addprefix $(OBJ)/static/,$(SRC:.c=.o))
+SHARED = $(addprefix $(OBJ)/shared/,$(SRC:.c=.o))
+
+BUILD = librc
+
+.PHONY: all
+all: dirs $(BUILD)
+
+dirs:
+	@mkdir -p obj/{shared,static}/src
+
+obj/static/%.o: %.c
+	$(CC) -c $< $(CFLAGS) -o $@
+
+obj/shared/%.o: %.c
+	$(CC) -fPIC -c $< $(CFLAGS) -o $@
+
+$(BUILD).a: $(STATIC)
+	ar rcs $@ $^
+
+$(BUILD).so: $(SHARED)
+	$(CC) -shared $^ $(CFLAGS) -o $@ $(LDFLAGS)
+	strip $@
+
+$(BUILD): $(BUILD).a $(BUILD).so
+
+clean:
+	rm -f $(BUILD).{a,so}
+	rm -rf obj
diff --git a/README b/README
new file mode 100644
index 0000000..f60294b
--- /dev/null
+++ b/README
@@ -0,0 +1 @@
+Owned pointers in C
diff --git a/include/rc.h b/include/rc.h
new file mode 100644
index 0000000..f23cb2a
--- /dev/null
+++ b/include/rc.h
@@ -0,0 +1,27 @@
+#ifndef _RC_H
+#define _RC_H
+
+#ifdef __cplusplus
+#define _rc_restrict __restrict
+extern "C" {
+#else
+#define _rc_restrict restrict
+#endif
+
+#ifndef __GNUC__
+#define _rc_attr(_)
+#else
+#define _rc_attr(v) __attribute__(v)
+#endif
+
+typedef struct rc* rc_t;
+
+void* _rc_restrict rc_malloc(size_t sz) _rc_attr((malloc, alloc_size(1), returns_nonnull));
+void rc_free(void* ptr) _rc_attr((nonnull));
+void* _rc_attr((may_alias)) rc_clone(void* ptr) _rc_attr((pure, nonnull, returns_nonnull)); 
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _RC_H */
diff --git a/src/rc.c b/src/rc.c
new file mode 100644
index 0000000..530ac2e
--- /dev/null
+++ b/src/rc.c
@@ -0,0 +1,74 @@
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdarg.h>
+
+#include <rc.h>
+
+#define RC_CHK 0xabadcafe
+
+struct rc {
+	uint32_t check;
+	_Atomic size_t refs;
+
+	uint8_t ptr[];
+};
+
+_rc_attr((noreturn)) static void panic(const char* string, ...)
+{
+	va_list args;
+	va_start(args, string);
+	fprintf(stderr, "(librc) Fatal error: ");
+	vfprintf(stderr, string, args);
+	va_end(args);
+	fprintf(stderr, "\n");
+	abort();
+}
+
+_rc_attr((noinline, noreturn, cold)) static void _fail_invptr() 
+{
+	panic("Invalid RC pointer");
+}
+
+ _rc_attr((noinline, noreturn, cold)) static void _fail_malloc(size_t sz)
+{
+	panic("malloc() failed to allocate %d bytes (%d + sizeof(struct rc))", sz+sizeof(struct rc), sz);
+}
+
+_rc_attr((artificial, always_inline)) inline static rc_t ptr_rev(void* ptr)
+{
+	if (!ptr) _fail_invptr();
+	return (rc_t)(((uint8_t*)ptr) - sizeof(struct rc));
+}
+
+_rc_attr((nonnull)) inline static void rc_checkptr(const rc_t rc)
+{
+	if (rc->check != RC_CHK) _fail_invptr();
+}
+
+ _rc_attr((malloc, alloc_size(1), returns_nonnull)) void* restrict rc_malloc(size_t sz)
+{
+	register rc_t rc = malloc(sz + sizeof(struct rc));
+
+	if (!rc) _fail_malloc(sz);
+
+	rc->check = RC_CHK;
+	rc->refs = 1;
+
+	return (void*) rc->ptr;	
+}
+
+ _rc_attr((nonnull)) void rc_free(void* ptr)
+{
+	register rc_t rc = ptr_rev(ptr);
+	rc_checkptr(rc);
+	if (!--rc->refs) free(rc);
+}
+
+_rc_attr((pure, nonnull, returns_nonnull)) void* _rc_attr((may_alias)) rc_clone(void* ptr)
+{
+	register rc_t rc = ptr_rev(ptr);
+	rc_checkptr(rc);
+	++rc->refs;
+	return ptr;
+}