Chore: cleaned up the exit code to cleanly interface with libc

We use weak linking to ensure we clean up at exit time correctly. If
libc is linked, then we call our cleanup function by registering an
atexit callback with the library. If libc is not linked, we have a weak
symbol that results in a noop. Similarly, if we call rt·exit while
linked with libc, this immediately calls libc's exit (which will call
our cleanup as we registered it). If we are not linked to libc, exit()
is given as a weak link to a noop function.

23 files changed, 215 insertions, 45 deletions

diff --git a/include/base.h b/include/base.h
index a7e9319..d532a85 100644
--- a/include/base.h
+++ b/include/base.h
@@ -3,8 +3,8 @@
 // ------------------------------------------------------------------------
 // standard library
 
+#include <rt.h>
 #include <sys.h>
-#include <arch/types.h>
 
 // TODO: remove dependency system headers
 #include <assert.h>
diff --git a/include/base/gz.h b/include/base/gz.h
index 3b3a830..ac241d3 100644
--- a/include/base/gz.h
+++ b/include/base/gz.h
@@ -25,5 +25,5 @@ int        gz·putbyte(gz·Stream *s, byte str);
 int        gz·putstring(gz·Stream *s, byte *str);
 int        gz·printf(gz·Stream *s, byte *fmt, ...);
 int        gz·flush(gz·Stream *s);
-int        gz·seek(gz·Stream *s, long off, enum SeekPos whence);
+int        gz·seek(gz·Stream *s, long off, int whence);
 long       gz·tell(gz·Stream *s);
diff --git a/include/base/io.h b/include/base/io.h
index 5e0f1e0..5d31282 100644
--- a/include/base/io.h
+++ b/include/base/io.h
@@ -1,12 +1,5 @@
 #pragma once
 
-enum SeekPos
-{
-    seek·cur = SEEK_CUR,
-    seek·set = SEEK_SET,
-    seek·end = SEEK_END
-};
-
 typedef struct io·Reader
 {
     int (*read)(void*, int sz, int n, void *buf);
@@ -22,7 +15,7 @@ extern io·Peeker sys·Peeker;
 
 typedef struct io·Seeker
 {
-    int        (*seek)(void *skr, long off, enum SeekPos whence);
+    int        (*seek)(void *skr, long off, int whence);
     long       (*tell)(void *skr);
 } io·Seeker;
 extern io·Seeker sys·Seeker;
@@ -93,10 +86,11 @@ int        io·putbyte(io·Stream *s, byte c);
 int        io·putstring(io·Stream *s, string str);
 int        io·write(io·Stream *s, int sz, int n, void *buf);
 int        io·flush(io·Stream *s);
-int        io·seek(io·Stream *s, long off, enum SeekPos whence);
+int        io·seek(io·Stream *s, long off, int whence);
 long       io·tell(io·Stream *s);
 
 /* buffered i/o */
+typedef struct io·Header io·Header;
 typedef struct io·Buffer io·Buffer;
 
 #define iota(x) (1 << (x))
@@ -116,21 +110,26 @@ enum
 };
 #undef iota
 
-struct io·Buffer
+struct io·Header
 {
-    int state, id, flag;
+    int state, fd, flag;
     struct{
-        int in;      /* negative number of bytes at end */
-        int out;     /* number of bytes at start */
-        int line;    /* number of bytes after last readline */
+        int in;    /* negative number of bytes at end */
+        int out;   /* number of bytes at start */
+        int ln;    /* number of bytes after last readline */
     } off;
     intptr pos, cap; /* position in file, capacity of buffer */
     uchar *b,*g,*e;  /* start, good bytes, end of byte pointers */
-    uchar bytes[];
+};
+
+struct io·Buffer
+{
+    io·Header;
+    uchar bytes[io·BufLen+io·BufUngets];
 };
 
 int     bio·init(io·Buffer *io, int fd, int mode);
-int     bio·initcap(io·Buffer *io, int fd, int mode, int cap);
+int     bio·initcap(io·Header *io, int fd, int mode, int cap, uchar *buf);
 
 /* basic os helpers */
 /* XXX: find a better location for this */
diff --git a/include/rt.h b/include/rt.h
index 43357cd..ce92af0 100644
--- a/include/rt.h
+++ b/include/rt.h
@@ -12,4 +12,5 @@ extern struct rt·Context
 
 extern char **rt·environ;
 
+int  rt·atexit(void (*func)(void *), void *arg);
 void noreturn rt·exit(int code);
diff --git a/include/sys.h b/include/sys.h
index 0c703a8..e983f2a 100644
--- a/include/sys.h
+++ b/include/sys.h
@@ -2,6 +2,7 @@
 
 /* types declarations */
 #include <arch/types.h>
+#include <arch/constants.h>
 
 #include <os/types.h>
 #include <os/constants.h>
@@ -14,6 +15,7 @@
 #define sys·ORead    0x0u
 #define sys·OWrite   0x1u
 #define sys·ORdwr    0x2u
+#define sys·OExec    sys·OPath
 
 /* seek */
 #define sys·SeekSet  0u
diff --git a/include/u.h b/include/u.h
index d415d82..fe251ac 100644
--- a/include/u.h
+++ b/include/u.h
@@ -112,6 +112,7 @@ typedef __builtin_va_list va_list;
 #define noreturn _Noreturn

 #define hidden __attribute__((__visibility__("hidden")))

 #define weakalias(old, new) extern __typeof(old) new __attribute__((weak, alias(#old)))

+#define weaklink __attribute__((weak))

 

 /* offsets */

 #define offsetof(t, d) __builtin_offsetof(t, d)

diff --git a/src/base/bufio/internal.h b/src/base/bufio/internal.h
index a1a006a..a59e787 100644
--- a/src/base/bufio/internal.h
+++ b/src/base/bufio/internal.h
@@ -1,2 +1,4 @@
 #include <u.h>
 #include <base.h>
+
+#define header(io) ((io·Header*)(io))
diff --git a/src/base/fmt/test.c b/src/base/fmt/test.c
index 73f5e7c..3f7f070 100644
--- a/src/base/fmt/test.c
+++ b/src/base/fmt/test.c
@@ -15,9 +15,18 @@ Xfmt(fmt·State *io)
     return fmt·write(io, "(real=%g,imag=%g)", c.r, c.i);
 }
 
+static void
+saygoodbye(void *arg)
+{
+    intptr n;
+    sys·write(1, 9, "goodbye\n", &n);
+}
+
 int
 main(int argc, char *argv[])
 {
+    rt·atexit(saygoodbye, nil);
+
     fmt·print("basic tests\n");
     fmt·print("\tx: %x\n", 0x87654321);
     fmt·print("\tu: %u\n", 0x87654321);
diff --git a/src/base/gz/seek.c b/src/base/gz/seek.c
index 328886d..8230a79 100644
--- a/src/base/gz/seek.c
+++ b/src/base/gz/seek.c
@@ -1,7 +1,7 @@
 #include "internal.h"
 
 int
-gz·seek(gz·Stream *s, long off, enum SeekPos whence)
+gz·seek(gz·Stream *s, long off, int whence)
 {
     return gzseek(s, off, whence);
 }
diff --git a/src/base/io/interface.c b/src/base/io/interface.c
index bc9d5ff..80469bf 100644
--- a/src/base/io/interface.c
+++ b/src/base/io/interface.c
@@ -44,7 +44,7 @@ int
 
 static
 int
-·seek(void *skr, long off, enum SeekPos whence)
+·seek(void *skr, long off, int whence)
 {
     return io·seek((io·Stream *)skr, off, whence);
 }
diff --git a/src/base/io/seek.c b/src/base/io/seek.c
index d0e7488..1be4ee7 100644
--- a/src/base/io/seek.c
+++ b/src/base/io/seek.c
@@ -1,7 +1,7 @@
 #include "internal.h"
 
 int
-io·seek(io·Stream *s, long off, enum SeekPos origin)
+io·seek(io·Stream *s, long off, int whence)
 {
-    return fseek(s, off, origin);
+    return fseek(s, off, whence);
 }
diff --git a/src/rules.mk b/src/rules.mk
index 8e8594c..368479c 100644
--- a/src/rules.mk
+++ b/src/rules.mk
@@ -8,10 +8,10 @@ include $(DIR)/rules.mk
 DIR := $(d)/base
 include $(DIR)/rules.mk
 
-# DIR := $(d)/libmath
-# include $(DIR)/rules.mk
+DIR := $(d)/libmath
+include $(DIR)/rules.mk
 
-# DIR := $(d)/libbio
-# include $(DIR)/rules.mk
+DIR := $(d)/libbio
+include $(DIR)/rules.mk
 
 include share/pop.mk
diff --git a/sys/linux/amd64/arch/constants.h b/sys/linux/amd64/arch/constants.h
new file mode 100644
index 0000000..1949bdf
--- /dev/null
+++ b/sys/linux/amd64/arch/constants.h
@@ -0,0 +1,23 @@
+#pragma once
+
+#define  sys·OCreate     0100
+#define  sys·OUnique     0200
+#define  sys·ONoTTY      0400
+#define  sys·OTrunc      01000
+#define  sys·OAppend     02000
+#define  sys·ONoBlock    04000
+#define  sys·ODsync      010000
+#define  sys·OSync       04010000
+#define  sys·ORsync      04010000
+#define  sys·ODirectory  0200000
+#define  sys·ONoFollow   0400000
+#define  sys·OCloseExec  02000000
+
+#define  sys·OAsync      020000
+#define  sys·ODirect     040000
+#define  sys·OLargeFile  0
+#define  sys·ONoATime    01000000
+#define  sys·OPath       010000000
+#define  sys·OTempFile   020200000
+
+#define SYS·HAVE_FCNTL
diff --git a/sys/linux/arm/arch/constants.h b/sys/linux/arm/arch/constants.h
new file mode 100644
index 0000000..149c2eb
--- /dev/null
+++ b/sys/linux/arm/arch/constants.h
@@ -0,0 +1,20 @@
+#pragma once
+
+#define  sys·OCreate     0100
+#define  sys·OUnique     0200
+#define  sys·ONoTTY      0400
+#define  sys·OTrunc      01000
+#define  sys·OAppend     02000
+#define  sys·ONoBlock    04000
+#define  sys·ODsync      010000
+#define  sys·OSync       04010000
+#define  sys·ORsync      04010000
+#define  sys·ODirectory  040000
+#define  sys·ONoFollow   0100000
+#define  sys·OCloseExec  02000000
+#define  sys·OAsync      020000
+#define  sys·ODirect     0200000
+#define  sys·OLargeFile  0400000
+#define  sys·ONoATime    01000000
+#define  sys·OPath       010000000
+#define  sys·OTempFile   020040000
diff --git a/sys/linux/arm64/arch/constants.h b/sys/linux/arm64/arch/constants.h
new file mode 100644
index 0000000..f3f42e5
--- /dev/null
+++ b/sys/linux/arm64/arch/constants.h
@@ -0,0 +1,22 @@
+#pragma once
+
+#define  sys·OCreate     0100
+#define  sys·OUnique     0200
+#define  sys·ONoTTY      0400
+#define  sys·OTrunc      01000
+#define  sys·OAppend     02000
+#define  sys·ONoBlock    04000
+#define  sys·ODsync      010000
+#define  sys·OSync       04010000
+#define  sys·ORsync      04010000
+#define  sys·ODirectory  040000
+#define  sys·ONoFollow   0100000
+#define  sys·OCloseExec  02000000
+#define  sys·OAsync      020000
+#define  sys·ODirect     0200000
+#define  sys·OLargeFile  0400000
+#define  sys·ONoATime    01000000
+#define  sys·OPath       010000000
+#define  sys·OTempFile   020040000
+
+#define SYS·HAVE_FCNTL
diff --git a/sys/linux/i386/arch/constants.h b/sys/linux/i386/arch/constants.h
new file mode 100644
index 0000000..ff6aa0c
--- /dev/null
+++ b/sys/linux/i386/arch/constants.h
@@ -0,0 +1,20 @@
+#pragma once
+
+#define  sys·OCreate     0100
+#define  sys·OUnique     0200
+#define  sys·ONoTTY      0400
+#define  sys·OTrunc      01000
+#define  sys·OAppend     02000
+#define  sys·ONoBlock    04000
+#define  sys·ODsync      010000
+#define  sys·OSync       04010000
+#define  sys·ORsync      04010000
+#define  sys·ODirectory  0200000
+#define  sys·ONoFollow   0400000
+#define  sys·OCloseExec  02000000
+#define  sys·OAsync      020000
+#define  sys·ODirect     040000
+#define  sys·OLargeFile  0100000
+#define  sys·ONoATime    01000000
+#define  sys·OPath       010000000
+#define  sys·OTempfile   020200000
diff --git a/sys/linux/port/os/constants.h b/sys/linux/port/os/constants.h
index 8fb913f..ffe8610 100644
--- a/sys/linux/port/os/constants.h
+++ b/sys/linux/port/os/constants.h
@@ -1,18 +1,5 @@
 #pragma once
 
-/* open */
-#define sys·OCreate     0x40u
-#define sys·ONoTTY      0x100u
-#define sys·OTrunc      0x200u
-#define sys·OAppend     0x400u
-#define sys·ONoBlock    0x800u
-#define sys·OSync       0x1000u
-#define sys·OAsync      0x2000u
-#define sys·OLargeFile  0x8000u
-#define sys·ODirectory  0x10000u
-#define sys·ONoFollow   0x20000u
-#define sys·OTmpFile    0x410000u
-
 /* device modes */
 #define sys·ModeFile   0170000
 #define sys·ModeDir    0040000
diff --git a/sys/linux/riscv64/arch/constants.h b/sys/linux/riscv64/arch/constants.h
new file mode 100644
index 0000000..ff6aa0c
--- /dev/null
+++ b/sys/linux/riscv64/arch/constants.h
@@ -0,0 +1,20 @@
+#pragma once
+
+#define  sys·OCreate     0100
+#define  sys·OUnique     0200
+#define  sys·ONoTTY      0400
+#define  sys·OTrunc      01000
+#define  sys·OAppend     02000
+#define  sys·ONoBlock    04000
+#define  sys·ODsync      010000
+#define  sys·OSync       04010000
+#define  sys·ORsync      04010000
+#define  sys·ODirectory  0200000
+#define  sys·ONoFollow   0400000
+#define  sys·OCloseExec  02000000
+#define  sys·OAsync      020000
+#define  sys·ODirect     040000
+#define  sys·OLargeFile  0100000
+#define  sys·ONoATime    01000000
+#define  sys·OPath       010000000
+#define  sys·OTempfile   020200000
diff --git a/sys/rt/atexit.c b/sys/rt/atexit.c
new file mode 100644
index 0000000..208cc6e
--- /dev/null
+++ b/sys/rt/atexit.c
@@ -0,0 +1,49 @@
+#include <u.h>
+#include <rt.h>
+
+#define COUNT 32
+
+static struct cleaner
+{
+    struct cleaner *next;
+    void (*clean[COUNT])(void *);
+    void *arg[COUNT];
+} arena, *head;
+static int slot;
+
+void weaklink exit(int code){};
+
+void
+rt·clean(void)
+{
+    void (*clean)(void *), *arg;
+    /*LOCK*/
+    for(; head; head=head->next, slot=COUNT) {
+        while(slot-- > 0){
+            arg   = head->arg[slot];
+            clean = head->clean[slot];
+            /* UNLOCK */
+            clean(arg);
+            /* LOCK */
+        }
+    }
+}
+
+int
+rt·atexit(void (*clean)(void *), void *arg)
+{
+    /* LOCK */
+    if(!head)
+        head = &arena;
+
+    /* we need malloc... */
+    if(slot==COUNT)
+        return -1;
+
+    head->arg[slot]   = arg;
+    head->clean[slot] = clean;
+    slot++;
+
+    /* UNLOCK */
+    return 0;
+}
diff --git a/sys/rt/boot.c b/sys/rt/boot.c
index 320a596..8c6616d 100644
--- a/sys/rt/boot.c
+++ b/sys/rt/boot.c
@@ -3,7 +3,10 @@
 #include <elf.h>
 
 /* tell linker to go find */
+int atexit(void (*)(void));
 int __libc_start_main(int (*main)(int,char **,char **), int argc, char **argv);
+
+void rt·clean(void);
 void rt·guardstack(void);
 
 #define NAUX 38
@@ -30,6 +33,7 @@ rt·boot(int (*main)(), int argc, char **argv, void (*init)(), void (*fini)(), v
 	rt·init(env, argv[0]);
 
 	/* ring libc, anyone home? */
+    atexit(rt·clean);
 	__libc_start_main(main, argc, argv);
 
 	/* no? ok we continue on if there is no libc linked */
diff --git a/sys/rt/dummy.c b/sys/rt/dummy.c
index f123d16..0cef224 100644
--- a/sys/rt/dummy.c
+++ b/sys/rt/dummy.c
@@ -4,3 +4,6 @@
 /* provide a dummy implementation if libc is not linked */
 static int noop(int (*main)(), int argc, char **argv) { return 0; }
 weakalias(noop, __libc_start_main);
+
+static int noop2(void (*func)(void)) { return 0; }
+weakalias(noop, atexit);
diff --git a/sys/rt/exit.c b/sys/rt/exit.c
index e6027b7..386a1bf 100644
--- a/sys/rt/exit.c
+++ b/sys/rt/exit.c
@@ -2,10 +2,13 @@
 #include <rt.h>
 #include <syscall.h>
 
-/* XXX:
- * if we are here, we are in charge, call exit syscalls
- * think of better way to encapsulate these syscalls?
- */
+/* tell linker to go find */
+void noreturn exit(int code);
+
+/* if did not call rt·atexit, then don't pull it in */
+static void noop(void){}
+weakalias(noop, rt·clean);
+
 static noreturn void
 rt·shutdown(int code)
 {
@@ -14,14 +17,18 @@ rt·shutdown(int code)
     if(rt·context.exit)
         rt·context.exit();
 
+    /* XXX: better way to encapsulate these calls? */
 	_syscall1(·ExitGroup, code);
     for(;;)
 		_syscall1(·Exit, code);
 }
-weakalias(rt·shutdown, exit);
 
 noreturn void
 rt·exit(int code)
 {
-	rt·shutdown(code);
+    /* ring libc, anyone home? */
+	exit(code);
+    /* if we are here, we are in charge, shut it down */
+    rt·clean();
+    rt·shutdown(code);
 }
diff --git a/sys/rules.mk b/sys/rules.mk
index 4bba9aa..1cbe50e 100644
--- a/sys/rules.mk
+++ b/sys/rules.mk
@@ -20,6 +20,7 @@ RT1_OBJ := $(patsubst $(SYS_DIR)/rt/%, $(OBJ_DIR)/rt/%, $(RT1_OBJ))
 RT3_SRC := \
 	$(SYS_DIR)/rt/stack.c\
 	$(SYS_DIR)/rt/dummy.c\
+	$(SYS_DIR)/rt/atexit.c\
 	$(SYS_DIR)/rt/exit.c
 
 RT3_OBJ := $(filter %.o, $(RT3_SRC:.c=.o))