first attempt at real FFI support.

in a .6 file, an export line

	//ffi T localfib remotefib remote.so

means the dynamic linker should initialize
localfib, always a pointer, to the address of
remotefib, either text (T) or data (D) after
loading remote.so.

the C compiler will generate an export section
when given the pragmas

	#pragma package fib
	#pragma ffi T localfib remotefib remote.so

needing #pragma package is a bit of a kludge
and hopefully could go away later.

this is just the 6 tool chain support.
other architectures will happen once 6 settles down.

code using this to do FFI is in a later CL.

R=r
DELTA=161  (141 added, 14 deleted, 6 changed)
OCL=33783
CL=33795

1 files changed, 13 insertions, 0 deletions

diff --git a/src/cmd/6c/swt.c b/src/cmd/6c/swt.c
index b3f31b04d..9b2381ae9 100644
--- a/src/cmd/6c/swt.c
+++ b/src/cmd/6c/swt.c
@@ -232,6 +232,19 @@ outcode(void)
 	Binit(&b, f, OWRITE);
 
 	Bprint(&b, "%s\n", thestring);
+	if(nffi > 0) {
+		int i;
+
+		if(package == nil) {
+			yyerror("#pragma ffi without #pragma package");
+			package = "_ffi_";
+		}
+		Bprint(&b, "\n$$  // ffi\n", thestring);
+		Bprint(&b, "package %s\n", package);
+		for(i=0; i<nffi; i++)
+			Bprint(&b, "//ffi %c %s %s %s\n", ffi[i].type, ffi[i].local, ffi[i].remote, ffi[i].path);
+		Bprint(&b, "$$\n\n$$\n\n");
+	}
 	Bprint(&b, "!\n");
 
 	outhist(&b);