auto merge of #5359 : luqmana/rust/inline-asm, r=pcwalton

Continuation of #5317. Actually use operands properly now, including any number of output operands.

Which means you can do things like call printf:
```Rust
fn main() {
    unsafe {
        do str::as_c_str(~"The answer is %d.\n") |c| {
            let a = 42;
            asm!("mov $0, %rdi\n\t\
                  mov $1, %rsi\n\t\
                  xorl %eax, %eax\n\t\
                  call _printf"
                 :
                 : "r"(c), "r"(a)
                 : "rdi", "rsi", "eax"
                 : "volatile","alignstack"
                 );
        }
    }
}
```

```
% rustc foo.rs
% ./foo
The answer is 42.
```

Or just add 2 numbers:
```Rust
fn add(a: int, b: int) -> int {
    let mut c = 0;
    unsafe {
        asm!("add $2, $0"
             : "=r"(c)
             : "0"(a), "r"(b)
             );
    }
    c
}

fn main() {
    io::println(fmt!("%d", add(1, 2)));
}
```

```
% rustc foo.rs
% ./foo
3
```

Multiple outputs!
```Rust
fn addsub(a: int, b: int) -> (int, int) {
    let mut c = 0;
    let mut d = 0;
    unsafe {
        asm!("add $4, $0\n\t\
              sub $4, $1"
             : "=r"(c), "=r"(d)
             : "0"(a), "1"(a), "r"(b)
             );
    }
    (c, d)
}

fn main() {
    io::println(fmt!("%?", addsub(5, 1)));
}
```
```
% rustc foo.rs
% ./foo
(6, 4)
```

This also classifies inline asm as RvalueStmtExpr instead of the somewhat arbitrary kind I made it initially. There are a few XXX's regarding what to do in the liveness and move passes.

Author: bors

src/librustc/middle/liveness.rs

@@ -1347,7 +1347,15 @@ pub impl Liveness {
             self.propagate_through_expr(e, succ)
           }
 
-          expr_inline_asm(*) |
+          expr_inline_asm(_, ins, outs, _, _, _) =>{
+            let succ = do ins.foldr(succ) |&(_, expr), succ| {
+                self.propagate_through_expr(expr, succ)
+            };
+            do outs.foldr(succ) |&(_, expr), succ| {
+                self.propagate_through_expr(expr, succ)
+            }
+          }
+
           expr_lit(*) => {
             succ
           }
@@ -1613,6 +1621,20 @@ fn check_expr(expr: @expr, &&self: @Liveness, vt: vt<@Liveness>) {
         visit::visit_expr(expr, self, vt);
       }
 
+      expr_inline_asm(_, ins, outs, _, _, _) => {
+        for ins.each |&(_, in)| {
+          (vt.visit_expr)(in, self, vt);
+        }
+
+        // Output operands must be lvalues
+        for outs.each |&(_, out)| {
+          self.check_lvalue(out, vt);
+          (vt.visit_expr)(out, self, vt);
+        }
+
+        visit::visit_expr(expr, self, vt);
+      }
+
       // no correctness conditions related to liveness
       expr_call(*) | expr_method_call(*) | expr_if(*) | expr_match(*) |
       expr_while(*) | expr_loop(*) | expr_index(*) | expr_field(*) |
@@ -1621,7 +1643,7 @@ fn check_expr(expr: @expr, &&self: @Liveness, vt: vt<@Liveness>) {
       expr_cast(*) | expr_unary(*) | expr_ret(*) | expr_break(*) |
       expr_again(*) | expr_lit(_) | expr_block(*) | expr_swap(*) |
       expr_mac(*) | expr_addr_of(*) | expr_struct(*) | expr_repeat(*) |
-      expr_paren(*) | expr_inline_asm(*) => {
+      expr_paren(*) => {
         visit::visit_expr(expr, self, vt);
       }
     }

src/librustc/middle/moves.rs

@@ -558,10 +558,10 @@ pub impl VisitContext {
                 self.use_expr(base, Read, visitor);
             }
 
+            expr_inline_asm(*) |
             expr_break(*) |
             expr_again(*) |
-            expr_lit(*)   |
-            expr_inline_asm(*) => {}
+            expr_lit(*) => {}
 
             expr_loop(ref blk, _) => {
                 self.consume_block(blk, visitor);

src/librustc/middle/trans/build.rs

@@ -873,6 +873,7 @@ pub fn add_comment(bcx: block, text: &str) {
 }
 
 pub fn InlineAsmCall(cx: block, asm: *c_char, cons: *c_char,
+                     inputs: &[ValueRef], output: TypeRef,
                      volatile: bool, alignstack: bool,
                      dia: AsmDialect) -> ValueRef {
     unsafe {
@@ -883,11 +884,17 @@ pub fn InlineAsmCall(cx: block, asm: *c_char, cons: *c_char,
         let alignstack = if alignstack { lib::llvm::True }
                          else          { lib::llvm::False };
 
-        let llfty = T_fn(~[], T_void());
+        let argtys = do inputs.map |v| {
+            debug!("Asm Input Type: %?", val_str(cx.ccx().tn, *v));
+            val_ty(*v)
+        };
+
+        debug!("Asm Output Type: %?", ty_str(cx.ccx().tn, output));
+        let llfty = T_fn(argtys, output);
         let v = llvm::LLVMInlineAsm(llfty, asm, cons, volatile,
                                     alignstack, dia as c_uint);
 
-        Call(cx, v, ~[])
+        Call(cx, v, inputs)
     }
 }
 

src/librustc/middle/trans/expr.rs

@@ -557,6 +557,109 @@ fn trans_rvalue_stmt_unadjusted(bcx: block, expr: @ast::expr) -> block {
         ast::expr_paren(a) => {
             return trans_rvalue_stmt_unadjusted(bcx, a);
         }
+        ast::expr_inline_asm(asm, ref ins, ref outs,
+                             clobs, volatile, alignstack) => {
+            let mut constraints = ~[];
+            let mut cleanups = ~[];
+            let mut aoutputs = ~[];
+
+            let outputs = do outs.map |&(c, out)| {
+                constraints.push(copy *c);
+
+                let aoutty = ty::arg {
+                    mode: ast::expl(ast::by_copy),
+                    ty: expr_ty(bcx, out)
+                };
+                aoutputs.push(unpack_result!(bcx, {
+                    callee::trans_arg_expr(bcx, aoutty, out, &mut cleanups,
+                                           None, callee::DontAutorefArg)
+                    }));
+
+                let e = match out.node {
+                    ast::expr_addr_of(_, e) => e,
+                    _ => fail!(~"Expression must be addr of")
+                };
+
+                let outty = ty::arg {
+                    mode: ast::expl(ast::by_copy),
+                    ty: expr_ty(bcx, e)
+                };
+
+                unpack_result!(bcx, {
+                    callee::trans_arg_expr(bcx, outty, e, &mut cleanups,
+                                           None, callee::DontAutorefArg)
+                })
+
+            };
+
+            for cleanups.each |c| {
+                revoke_clean(bcx, *c);
+            }
+            cleanups = ~[];
+
+            let inputs = do ins.map |&(c, in)| {
+                constraints.push(copy *c);
+
+                let inty = ty::arg {
+                    mode: ast::expl(ast::by_copy),
+                    ty: expr_ty(bcx, in)
+                };
+
+                unpack_result!(bcx, {
+                    callee::trans_arg_expr(bcx, inty, in, &mut cleanups,
+                                           None, callee::DontAutorefArg)
+                })
+
+            };
+
+            for cleanups.each |c| {
+                revoke_clean(bcx, *c);
+            }
+
+            let mut constraints = str::connect(constraints, ",");
+
+            // Add the clobbers
+            if *clobs != ~"" {
+                if constraints == ~"" {
+                    constraints += *clobs;
+                } else {
+                    constraints += ~"," + *clobs;
+                }
+            } else {
+                constraints += *clobs;
+            }
+
+            debug!("Asm Constraints: %?", constraints);
+
+            let output = if outputs.len() == 0 {
+                T_void()
+            } else if outputs.len() == 1 {
+                val_ty(outputs[0])
+            } else {
+                T_struct(outputs.map(|o| val_ty(*o)))
+            };
+
+            let r = do str::as_c_str(*asm) |a| {
+                do str::as_c_str(constraints) |c| {
+                    InlineAsmCall(bcx, a, c, inputs, output, volatile,
+                                  alignstack, lib::llvm::AD_ATT)
+                }
+            };
+
+            if outputs.len() == 1 {
+                let op = PointerCast(bcx, aoutputs[0],
+                                     T_ptr(val_ty(outputs[0])));
+                Store(bcx, r, op);
+            } else {
+                for aoutputs.eachi |i, o| {
+                    let v = ExtractValue(bcx, r, i);
+                    let op = PointerCast(bcx, *o, T_ptr(val_ty(outputs[i])));
+                    Store(bcx, v, op);
+                }
+            }
+
+            return bcx;
+        }
         _ => {
             bcx.tcx().sess.span_bug(
                 expr.span,
@@ -691,17 +794,6 @@ fn trans_rvalue_dps_unadjusted(bcx: block, expr: @ast::expr,
         ast::expr_assign_op(op, dst, src) => {
             return trans_assign_op(bcx, expr, op, dst, src);
         }
-        ast::expr_inline_asm(asm, cons, volatile, alignstack) => {
-            // XXX: cons doesn't actual contain ALL the stuff we should
-            // be passing since the constraints for in/outputs aren't included
-            do str::as_c_str(*asm) |a| {
-                do str::as_c_str(*cons) |c| {
-                    InlineAsmCall(bcx, a, c, volatile, alignstack,
-                                  lib::llvm::AD_ATT);
-                }
-            }
-            return bcx;
-        }
         _ => {
             bcx.tcx().sess.span_bug(
                 expr.span,

src/librustc/middle/trans/type_use.rs

@@ -348,12 +348,22 @@ pub fn mark_for_expr(cx: Context, e: @expr) {
         }
         mark_for_method_call(cx, e.id, e.callee_id);
       }
+
+      expr_inline_asm(_, ref ins, ref outs, _, _, _) => {
+        for ins.each |&(_, in)| {
+          node_type_needs(cx, use_repr, in.id);
+        }
+        for outs.each |&(_, out)| {
+          node_type_needs(cx, use_repr, out.id);
+        }
+      }
+
       expr_paren(e) => mark_for_expr(cx, e),
 
       expr_match(*) | expr_block(_) | expr_if(*) | expr_while(*) |
       expr_break(_) | expr_again(_) | expr_unary(_, _) | expr_lit(_) |
       expr_mac(_) | expr_addr_of(_, _) | expr_ret(_) | expr_loop(_, _) |
-      expr_loop_body(_) | expr_do_body(_) | expr_inline_asm(*) => ()
+      expr_loop_body(_) | expr_do_body(_) => ()
     }
 }
 

src/librustc/middle/ty.rs

@@ -3102,7 +3102,6 @@ pub fn expr_kind(tcx: ctxt,
         ast::expr_block(*) |
         ast::expr_copy(*) |
         ast::expr_repeat(*) |
-        ast::expr_inline_asm(*) |
         ast::expr_lit(@codemap::spanned {node: lit_str(_), _}) |
         ast::expr_vstore(_, ast::expr_vstore_slice) |
         ast::expr_vstore(_, ast::expr_vstore_mut_slice) |
@@ -3145,6 +3144,7 @@ pub fn expr_kind(tcx: ctxt,
         ast::expr_loop(*) |
         ast::expr_assign(*) |
         ast::expr_swap(*) |
+        ast::expr_inline_asm(*) |
         ast::expr_assign_op(*) => {
             RvalueStmtExpr
         }

src/librustc/middle/typeck/check/mod.rs

@@ -2317,8 +2317,15 @@ pub fn check_expr_with_unifier(fcx: @mut FnCtxt,
         let region_lb = ty::re_scope(expr.id);
         instantiate_path(fcx, pth, tpt, expr.span, expr.id, region_lb);
       }
-      ast::expr_inline_asm(*) => {
+      ast::expr_inline_asm(_, ins, outs, _, _, _) => {
           fcx.require_unsafe(expr.span, ~"use of inline assembly");
+
+          for ins.each |&(_, in)| {
+              check_expr(fcx, in);
+          }
+          for outs.each |&(_, out)| {
+              check_expr(fcx, out);
+          }
           fcx.write_nil(id);
       }
       ast::expr_mac(_) => tcx.sess.bug(~"unexpanded macro"),

src/libsyntax/ast.rs

@@ -601,8 +601,10 @@ pub enum expr_ {
     expr_ret(Option<@expr>),
     expr_log(log_level, @expr, @expr),
 
-    /* asm, clobbers + constraints, volatile, align stack */
-    expr_inline_asm(@~str, @~str, bool, bool),
+    expr_inline_asm(@~str,              // asm
+                    ~[(@~str, @expr)],  // inputs
+                    ~[(@~str, @expr)],  // outputs
+                    @~str, bool, bool), // clobbers, volatile, align stack
 
     expr_mac(mac),
 

src/libsyntax/ext/asm.rs

@@ -75,6 +75,13 @@ pub fn expand_asm(cx: @ext_ctxt, sp: span, tts: &[ast::token_tree])
                     let out = p.parse_expr();
                     p.expect(&token::RPAREN);
 
+                    let out = @ast::expr {
+                        id: cx.next_id(),
+                        callee_id: cx.next_id(),
+                        span: out.span,
+                        node: ast::expr_addr_of(ast::m_mutbl, out)
+                    };
+
                     outputs.push((constraint, out));
                 }
             }
@@ -156,7 +163,8 @@ pub fn expand_asm(cx: @ext_ctxt, sp: span, tts: &[ast::token_tree])
     MRExpr(@ast::expr {
         id: cx.next_id(),
         callee_id: cx.next_id(),
-        node: ast::expr_inline_asm(@asm, @cons, volatile, alignstack),
+        node: ast::expr_inline_asm(@asm, inputs, outputs,
+                                   @cons, volatile, alignstack),
         span: sp
     })
 }

src/libsyntax/fold.rs

@@ -560,7 +560,14 @@ pub fn noop_fold_expr(e: &expr_, fld: @ast_fold) -> expr_ {
                 fld.fold_expr(e)
             )
         }
-        expr_inline_asm(*) => copy *e,
+        expr_inline_asm(asm, ins, outs, c, v, a) => {
+            expr_inline_asm(
+                asm,
+                ins.map(|&(c, in)| (c, fld.fold_expr(in))),
+                outs.map(|&(c, out)| (c, fld.fold_expr(out))),
+                c, v, a
+            )
+        }
         expr_mac(ref mac) => expr_mac(fold_mac((*mac))),
         expr_struct(path, ref fields, maybe_expr) => {
             expr_struct(

src/libsyntax/print/pprust.rs

@@ -1403,15 +1403,31 @@ pub fn print_expr(s: @ps, &&expr: @ast::expr) {
           }
         }
       }
-      ast::expr_inline_asm(a, c, v, _) => {
+      ast::expr_inline_asm(a, in, out, c, v, _) => {
         if v {
             word(s.s, ~"__volatile__ asm!");
         } else {
             word(s.s, ~"asm!");
         }
         popen(s);
         print_string(s, *a);
-        word_space(s, ~",");
+        word_space(s, ~":");
+        for out.each |&(co, o)| {
+            print_string(s, *co);
+            popen(s);
+            print_expr(s, o);
+            pclose(s);
+            word_space(s, ~",");
+        }
+        word_space(s, ~":");
+        for in.each |&(co, o)| {
+            print_string(s, *co);
+            popen(s);
+            print_expr(s, o);
+            pclose(s);
+            word_space(s, ~",");
+        }
+        word_space(s, ~":");
         print_string(s, *c);
         pclose(s);
       }

src/libsyntax/visit.rs

@@ -562,7 +562,14 @@ pub fn visit_expr<E>(ex: @expr, e: E, v: vt<E>) {
         }
         expr_mac(ref mac) => visit_mac((*mac), e, v),
         expr_paren(x) => (v.visit_expr)(x, e, v),
-        expr_inline_asm(*) => (),
+        expr_inline_asm(_, ins, outs, _, _, _) => {
+            for ins.each |&(_, in)| {
+                (v.visit_expr)(in, e, v);
+            }
+            for outs.each |&(_, out)| {
+                (v.visit_expr)(out, e, v);
+            }
+        }
     }
     (v.visit_expr_post)(ex, e, v);
 }