Main: libc/include/setjmp.h: Implement setjmp/longjmp

COPYING

@@ -1,8 +1,12 @@
 MIT License
 
-Copyright (c) 2014-2019 Marco Paland
 Copyright (c) 2020-2022 Alex Kotov
 
+Copyright (c) 2011      Nicholas J. Kain
+Copyright (c) 2011-2015 Rich Felker
+Copyright (c) 2014-2019 Marco Paland
+Copyright (c) 2022      Alexander Monakov
+
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights

common/printf_orig.yml

@@ -1,3 +1,5 @@
+# The code was taken from Marco Paland's printf.
+
 # Copyright (c) 2014-2019 Marco Paland <info@paland.com>
 
 # TODO: add remaining tests from

libc/Makefile.am

@@ -12,3 +12,17 @@ libc_la_SOURCES = \
 	src/ctype.c \
 	src/stdlib.c \
 	src/string.c
+
+if ASM_I386
+libc_la_SOURCES += \
+	src/asm/i386/longjmp.S \
+	src/asm/i386/setjmp.S
+endif
+
+if ASM_X86_64
+libc_la_SOURCES += \
+	src/asm/x86_64/longjmp.S \
+	src/asm/x86_64/setjmp.S
+endif
+
+# TODO: implement setjmp/longjmp for riscv64

libc/include/setjmp.h

@@ -5,9 +5,19 @@
 extern "C" {
 #endif
 
-typedef int jmp_buf;
+// TODO: define in architecture-specific header
+typedef unsigned long __jmp_buf[sizeof(long) == 8 ? 8 : 6];
 
+typedef struct __jmp_buf_tag {
+    __jmp_buf __jb;
+    unsigned long __fl;
+    unsigned long __ss[128 / sizeof(long)];
+} jmp_buf[1];
+
+__attribute__((returns_twice))
 int setjmp(jmp_buf env);
+
+__attribute__((noreturn))
 void longjmp(jmp_buf env, int val);
 
 #ifdef __cplusplus

libc/src/asm/i386/longjmp.S

@@ -0,0 +1,24 @@
+/**
+ * The code was taken from musl libc.
+ *
+ * Copyright (c) 2011 Rich Felker
+ * Copyright (c) 2022 Alexander Monakov
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+.global longjmp
+.type longjmp, @function
+longjmp:
+    mov   4(%esp) , %edx
+    mov   8(%esp) , %eax
+    cmp     $1    , %eax
+    adc     $0    , %al
+    mov    (%edx) , %ebx
+    mov   4(%edx) , %esi
+    mov   8(%edx) , %edi
+    mov  12(%edx) , %ebp
+    mov  16(%edx) , %esp
+    jmp *20(%edx)

libc/src/asm/i386/setjmp.S

@@ -0,0 +1,24 @@
+/**
+ * The code was taken from musl libc.
+ *
+ * Copyright (c) 2011-2015 Rich Felker
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+.global setjmp
+.type setjmp, @function
+setjmp:
+    mov 4(%esp) ,    %eax
+    mov   %ebx  ,   (%eax)
+    mov   %esi  ,  4(%eax)
+    mov   %edi  ,  8(%eax)
+    mov   %ebp  , 12(%eax)
+    lea 4(%esp) ,    %ecx
+    mov   %ecx  , 16(%eax)
+    mov  (%esp) ,    %ecx
+    mov   %ecx  , 20(%eax)
+    xor   %eax  ,    %eax
+    ret

libc/src/asm/x86_64/longjmp.S

@@ -0,0 +1,26 @@
+/**
+ * The code was taken from musl libc.
+ *
+ * Copyright (c) 2011      Nicholas J. Kain
+ * Copyright (c) 2011-2012 Rich Felker
+ * Copyright (c) 2022      Alexander Monakov
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+.global longjmp
+.type longjmp, @function
+longjmp:
+    xor     %eax  , %eax
+    cmp     $1    , %esi /* CF = val ? 0 : 1 */
+    adc     %esi  , %eax /* eax = val + !val */
+    mov    (%rdi) , %rbx /* rdi is the jmp_buf, restore regs from it */
+    mov   8(%rdi) , %rbp
+    mov  16(%rdi) , %r12
+    mov  24(%rdi) , %r13
+    mov  32(%rdi) , %r14
+    mov  40(%rdi) , %r15
+    mov  48(%rdi) , %rsp
+    jmp *56(%rdi)        /* goto saved address without altering rsp */

libc/src/asm/x86_64/setjmp.S

@@ -0,0 +1,27 @@
+/**
+ * The code was taken from musl libc.
+ *
+ * Copyright (c) 2011      Nicholas J. Kain
+ * Copyright (c) 2011-2012 Rich Felker
+ * Copyright (c) 2022      Alexander Monakov
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+.global setjmp
+.type setjmp, @function
+setjmp:
+mov   %rbx  ,   (%rdi) /* rdi is jmp_buf, move registers onto it */
+mov   %rbp  ,  8(%rdi)
+mov   %r12  , 16(%rdi)
+mov   %r13  , 24(%rdi)
+mov   %r14  , 32(%rdi)
+mov   %r15  , 40(%rdi)
+lea 8(%rsp) ,    %rdx  /* this is our rsp WITHOUT current ret addr */
+mov   %rdx  , 48(%rdi)
+mov  (%rsp) ,    %rdx  /* save return addr ptr for new rip */
+mov   %rdx  , 56(%rdi)
+xor   %eax  ,    %eax  /* always return 0 */
+ret

src/printf.c

@@ -1,4 +1,6 @@
 /**
+ * The code was taken from Marco Paland's printf.
+ *
  * Copyright (c) 2014-2019 Marco Paland <info@paland.com>
  *
  * Tiny [v]fprintf, sfprintf and [v]snprintf implementation, optimized for speed

src/printf_fmt.c

@@ -1,4 +1,6 @@
 /**
+ * The code was taken from Marco Paland's printf.
+ *
  * Copyright (c) 2014-2019 Marco Paland <info@paland.com>
  */