working setjmp()/longjmp()

3 files changed, 68 insertions, 13 deletions

diff --git a/src/nonstd/x86-64.s b/src/nonstd/x86-64.s
index 60aba7a1..f78a09fb 100644
--- a/src/nonstd/x86-64.s
+++ b/src/nonstd/x86-64.s
@@ -10,6 +10,60 @@ __syscall:
 	syscall
 	ret
 
+.global __setjmp
+__setjmp:
+	/* setjmp() in C sets env[0] to 0 */
+	mov %rbx, 0x08(%rdi)
+	mov %rcx, 0x10(%rdi)
+	mov %rdx, 0x18(%rdi)
+	mov %rsp, 0x20(%rdi)
+	mov %rbp, 0x28(%rdi)
+	mov %rsi, 0x30(%rdi)
+	mov %rdi, 0x38(%rdi)
+	mov %r8,  0x40(%rdi)
+	mov %r9,  0x48(%rdi)
+	mov %r10, 0x50(%rdi)
+	mov %r11, 0x58(%rdi)
+	mov %r12, 0x60(%rdi)
+	mov %r13, 0x68(%rdi)
+	mov %r14, 0x70(%rdi)
+	mov %r15, 0x78(%rdi)
+	mov 0x00(%rbp), %rax
+	mov %rax, 0x80(%rdi)
+	mov 0x08(%rbp), %rax
+	mov %rax, 0x88(%rdi)
+	mov 0x00(%rsp), %rax
+	mov %rax, 0x90(%rdi)
+	xor %rax, %rax
+	ret
+
+.global __longjmp
+__longjmp:
+	mov %rdi, %rax
+	mov 0x08(%rax), %rbx
+	mov 0x18(%rax), %rdx
+	mov 0x20(%rax), %rsp
+	mov 0x28(%rax), %rbp
+	mov 0x30(%rax), %rsi
+	mov 0x38(%rax), %rdi
+	mov 0x40(%rax), %r8
+	mov 0x48(%rax), %r9
+	mov 0x50(%rax), %r10
+	mov 0x58(%rax), %r11
+	mov 0x60(%rax), %r12
+	mov 0x68(%rax), %r13
+	mov 0x70(%rax), %r14
+	mov 0x78(%rax), %r15
+	mov 0x80(%rax), %rcx
+	mov %rcx, 0x00(%rbp)
+	mov 0x88(%rax), %rcx
+	mov %rcx, 0x08(%rbp)
+	mov 0x90(%rax), %rcx
+	mov %rcx, 0x00(%rsp)
+	mov 0x10(%rax), %rcx
+	mov 0x00(%rax), %rax
+	ret
+
 /* FIXME: this seems to be unpossible to put in a shared library */
 /* FIXME: it may be worthwhile to separate this into crt1.s */
 .global _start
diff --git a/src/setjmp/longjmp.c b/src/setjmp/longjmp.c
index c8ed34af..57819ddb 100644
--- a/src/setjmp/longjmp.c
+++ b/src/setjmp/longjmp.c
@@ -4,13 +4,14 @@
 
 _Noreturn void longjmp(jmp_buf env, int val)
 {
-	(void)env;
-	if (val == 0) {
-		val = 1;
+	extern _Noreturn void __longjmp(jmp_buf);
+
+	/* use val if nonzero, otherwise 1 */
+	env[0] = val ? val : 1;
+	
+	for (;;) {
+		__longjmp(env);
 	}
-	/* Set env.return_register to val */
-	/* Load all registers from env */
-	for (;;); /* silence _Noreturn function returns warning */
 }
 
 /***
diff --git a/src/setjmp/setjmp.c b/src/setjmp/setjmp.c
index a297dd6f..a098997e 100644
--- a/src/setjmp/setjmp.c
+++ b/src/setjmp/setjmp.c
@@ -1,16 +1,13 @@
 #include <setjmp.h>
+#include "string.h"
 
 /** save program state **/
 
 int setjmp(jmp_buf env)
 {
-	(void)env;
-	/* extern int setjmp(jmp_buf); */
-	/*
-	RETURN(0, the environment has been saved by THIS())
-	RETURN(NONZERO, the environment has been restored by FUNCTION(longjmp))
-	*/
-	return 0; /* setjmp(env); */
+	extern int __setjmp(jmp_buf);
+	memset(env, 0, sizeof(jmp_buf));
+	return __setjmp(env);
 }
 
 /***
@@ -19,6 +16,9 @@ in the TYPEDEF(jmp_buf) ARGUMENT(env).
 ***/
 
 /*
+RETURN(0, the environment has been saved by THIS())
+RETURN(NONZERO, the environment has been restored by FUNCTION(longjmp))
+
 CONSTRAINT: entire controlling expression of a selection or iteration statement
 CONSTRAINT: one operand of a relational or equality operator which is the entire controlling expression of a selction or iteration statement
 CONSTRAINT: the operand of a unary ! as the entire controlling expression of a selection or iteration statement