Repatch (from linux) of OSX IRAF

1 files changed, 35 insertions, 0 deletions

diff --git a/unix/as.vax/zsvjmp.s b/unix/as.vax/zsvjmp.s
new file mode 100644
index 00000000..f4664dac
--- /dev/null
+++ b/unix/as.vax/zsvjmp.s
@@ -0,0 +1,35 @@
+# ZSVJMP, ZDOJMP -- Set up a jump (non-local goto) by saving the processor
+# registers in the buffer jmpbuf.  A subsequent call to ZDOJMP restores
+# the registers, effecting a call in the context of the procedure which
+# originally called ZSVJMP, but with the new status code.  These are Fortran
+# callable procedures.
+
+        .globl  _zsvjmp_
+
+        # The following has nothing to do with ZSVJMP, and is included here
+        # only because this assembler module is loaded with every process.
+        # This code sets the value of the symbol MEM (the Mem common) to zero,
+        # setting the origin for IRAF pointers to zero rather than some
+        # arbitrary value, and ensuring that the MEM common is aligned for
+        # all datatypes as well as page aligned.  A further advantage is that
+        # references to NULL pointers will cause a memory violation.
+
+        .globl  _mem_
+        .set    _mem_,  0
+
+        .set    JMPBUF, 4
+        .set    STATUS, 8
+
+        # The strategy here is to build on the services provided by the C
+        # setjmp/longjmp.  Note that we cannot do this by writing a C function
+        # which calls setjmp, because the procedure which calls setjmp cannot
+        # return before the longjmp is executed (we want to return to the caller        # of the routine containing the setjmp call, not the routine itself).
+
+        .align  1
+_zsvjmp_:                               # CALL ZSVJMP (JMPBUF, STATUS)
+        .word   0x0
+        movl    STATUS(ap),*JMPBUF(ap)  # jmp_buf[0] = addr of status variable
+        clrl    *STATUS(ap)             # return zero status
+        addl2   $4, JMPBUF(ap)          # skip first cell of jmp_buf
+        movl    $1, (ap)                # SETJMP (JMP_BUF)
+        jmp     _setjmp+2               # let setjmp do the rest.