Auto merge of #1077 - RalfJung:unwind_to_block, r=RalfJung

bors · bors · commit 3bf51f591f7f · 2019-11-27T08:13:59.000Z
adjust for goto_block refactoring The Miri side of rust-lang/rust#66646
diff --git a/rust-version b/rust-version
@@ -1 +1 @@
-bd816fd76f4f7a040ca7ac8ca5bc556d761f96fa
+809e180a76ce97340bf4354ff357bc59e3ca40b2
diff --git a/src/eval.rs b/src/eval.rs
@@ -201,16 +201,18 @@ pub fn eval_main<'tcx>(tcx: TyCtxt<'tcx>, main_id: DefId, config: MiriConfig) ->
     // Process the result.
     match res {
         Ok(return_code) => {
-            let leaks = ecx.memory.leak_report();
             // Disable the leak test on some platforms where we do not
             // correctly implement TLS destructors.
             let target_os = ecx.tcx.tcx.sess.target.target.target_os.to_lowercase();
             let ignore_leaks = target_os == "windows" || target_os == "macos";
-            if !ignore_leaks && leaks != 0 {
-                tcx.sess.err("the evaluated program leaked memory");
-                // Ignore the provided return code - let the reported error
-                // determine the return code.
-                return None;
+            if !ignore_leaks {
+                let leaks = ecx.memory.leak_report();
+                if leaks != 0 {
+                    tcx.sess.err("the evaluated program leaked memory");
+                    // Ignore the provided return code - let the reported error
+                    // determine the return code.
+                    return None;
+                }
             }
             return Some(return_code)
         }
diff --git a/src/machine.rs b/src/machine.rs
@@ -186,22 +186,21 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for Evaluator<'tcx> {
         ecx: &mut InterpCx<'mir, 'tcx, Self>,
         instance: ty::Instance<'tcx>,
         args: &[OpTy<'tcx, Tag>],
-        dest: Option<PlaceTy<'tcx, Tag>>,
-        ret: Option<mir::BasicBlock>,
+        ret: Option<(PlaceTy<'tcx, Tag>, mir::BasicBlock)>,
         unwind: Option<mir::BasicBlock>,
     ) -> InterpResult<'tcx, Option<&'mir mir::Body<'tcx>>> {
-        ecx.find_fn(instance, args, dest, ret, unwind)
+        ecx.find_fn(instance, args, ret, unwind)
     }
 
     #[inline(always)]
     fn call_extra_fn(
         ecx: &mut InterpCx<'mir, 'tcx, Self>,
         fn_val: Dlsym,
         args: &[OpTy<'tcx, Tag>],
-        dest: Option<PlaceTy<'tcx, Tag>>,
-        ret: Option<mir::BasicBlock>,
+        ret: Option<(PlaceTy<'tcx, Tag>, mir::BasicBlock)>,
+        _unwind: Option<mir::BasicBlock>,
     ) -> InterpResult<'tcx> {
-        ecx.call_dlsym(fn_val, args, dest, ret)
+        ecx.call_dlsym(fn_val, args, ret)
     }
 
     #[inline(always)]
@@ -210,11 +209,10 @@ impl<'mir, 'tcx> Machine<'mir, 'tcx> for Evaluator<'tcx> {
         span: Span,
         instance: ty::Instance<'tcx>,
         args: &[OpTy<'tcx, Tag>],
-        dest: Option<PlaceTy<'tcx, Tag>>,
-        ret: Option<mir::BasicBlock>,
+        ret: Option<(PlaceTy<'tcx, Tag>, mir::BasicBlock)>,
         unwind: Option<mir::BasicBlock>,
     ) -> InterpResult<'tcx> {
-        ecx.call_intrinsic(span, instance, args, dest, ret, unwind)
+        ecx.call_intrinsic(span, instance, args, ret, unwind)
     }
 
     #[inline(always)]
diff --git a/src/shims/dlsym.rs b/src/shims/dlsym.rs
@@ -27,15 +27,12 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         &mut self,
         dlsym: Dlsym,
         args: &[OpTy<'tcx, Tag>],
-        dest: Option<PlaceTy<'tcx, Tag>>,
-        ret: Option<mir::BasicBlock>,
+        ret: Option<(PlaceTy<'tcx, Tag>, mir::BasicBlock)>,
     ) -> InterpResult<'tcx> {
         use self::Dlsym::*;
 
         let this = self.eval_context_mut();
-
-        let dest = dest.expect("we don't support any diverging dlsym");
-        let ret = ret.expect("dest is `Some` but ret is `None`");
+        let (dest, ret) = ret.expect("we don't support any diverging dlsym");
 
         match dlsym {
             GetEntropy => {
@@ -46,8 +43,8 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
             }
         }
 
-        this.goto_block(Some(ret))?;
         this.dump_place(*dest);
+        this.go_to_block(ret);
         Ok(())
     }
 }
diff --git a/src/shims/foreign_items.rs b/src/shims/foreign_items.rs
@@ -114,8 +114,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         &mut self,
         def_id: DefId,
         args: &[OpTy<'tcx, Tag>],
-        dest: Option<PlaceTy<'tcx, Tag>>,
-        ret: Option<mir::BasicBlock>,
+        ret: Option<(PlaceTy<'tcx, Tag>, mir::BasicBlock)>,
         _unwind: Option<mir::BasicBlock>
     ) -> InterpResult<'tcx, Option<&'mir mir::Body<'tcx>>> {
         let this = self.eval_context_mut();
@@ -129,7 +128,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         let tcx = &{ this.tcx.tcx };
 
         // First: functions that diverge.
-        match link_name {
+        let (dest, ret) = match link_name {
             // Note that this matches calls to the *foreign* item `__rust_start_panic* -
             // that is, calls to `extern "Rust" { fn __rust_start_panic(...) }`.
             // We forward this to the underlying *implementation* in the panic runtime crate.
@@ -154,15 +153,15 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                 return Err(InterpError::Exit(code).into());
             }
             _ => {
-                if dest.is_none() {
+                if let Some(p) = ret {
+                    p
+                } else {
                     throw_unsup_format!("can't call (diverging) foreign function: {}", link_name);
                 }
             }
-        }
+        };
 
-        // Next: functions that assume a ret and dest.
-        let dest = dest.expect("we already checked for a dest");
-        let ret = ret.expect("dest is `Some` but ret is `None`");
+        // Next: functions that return.
         match link_name {
             "malloc" => {
                 let size = this.read_scalar(args[0])?.to_machine_usize(this)?;
@@ -928,8 +927,8 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
             _ => throw_unsup_format!("can't call foreign function: {}", link_name),
         }
 
-        this.goto_block(Some(ret))?;
         this.dump_place(*dest);
+        this.go_to_block(ret);
         Ok(None)
     }
 
diff --git a/src/shims/intrinsics.rs b/src/shims/intrinsics.rs
@@ -16,12 +16,11 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         span: Span,
         instance: ty::Instance<'tcx>,
         args: &[OpTy<'tcx, Tag>],
-        dest: Option<PlaceTy<'tcx, Tag>>,
-        _ret: Option<mir::BasicBlock>,
+        ret: Option<(PlaceTy<'tcx, Tag>, mir::BasicBlock)>,
         unwind: Option<mir::BasicBlock>
     ) -> InterpResult<'tcx> {
         let this = self.eval_context_mut();
-        if this.emulate_intrinsic(span, instance, args, dest)? {
+        if this.emulate_intrinsic(span, instance, args, ret)? {
             return Ok(());
         }
         let tcx = &{this.tcx.tcx};
@@ -32,23 +31,21 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         // that might still hang around!
         let intrinsic_name = &*tcx.item_name(instance.def_id()).as_str();
 
-        // Handle diverging intrinsics
-        match intrinsic_name {
+        // Handle diverging intrinsics.
+        let (dest, ret) = match intrinsic_name {
             "abort" => {
                 // FIXME: Add a better way of indicating 'abnormal' termination,
                 // since this is not really an 'unsupported' behavior
                 throw_unsup_format!("the evaluated program aborted!");
             }
             "miri_start_panic" => return this.handle_miri_start_panic(args, unwind),
-            _ => {}
-        }
-
-        // Handle non-diverging intrinsics
-        // The intrinsic itself cannot diverge (otherwise, we would have handled it above),
-        // so if we got here without a return place that's UB (can happen e.g., for transmute returning `!`).
-        let dest = match dest {
-            Some(dest) => dest,
-            None => throw_ub!(Unreachable)
+            _ => {
+                if let Some(p) = ret {
+                    p
+                } else {
+                    throw_unsup_format!("unimplemented (diverging) intrinsic: {}", intrinsic_name);
+                }
+            }
         };
 
         match intrinsic_name {
@@ -581,6 +578,8 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
             name => throw_unsup_format!("unimplemented intrinsic: {}", name),
         }
 
+        this.dump_place(*dest);
+        this.go_to_block(ret);
         Ok(())
     }
 }
diff --git a/src/shims/mod.rs b/src/shims/mod.rs
@@ -16,25 +16,24 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         &mut self,
         instance: ty::Instance<'tcx>,
         args: &[OpTy<'tcx, Tag>],
-        dest: Option<PlaceTy<'tcx, Tag>>,
-        ret: Option<mir::BasicBlock>,
+        ret: Option<(PlaceTy<'tcx, Tag>, mir::BasicBlock)>,
         unwind: Option<mir::BasicBlock>
     ) -> InterpResult<'tcx, Option<&'mir mir::Body<'tcx>>> {
         let this = self.eval_context_mut();
         trace!(
             "eval_fn_call: {:#?}, {:?}",
             instance,
-            dest.map(|place| *place)
+            ret.map(|p| *p.0)
         );
 
         // There are some more lang items we want to hook that CTFE does not hook (yet).
         if this.tcx.lang_items().align_offset_fn() == Some(instance.def.def_id()) {
-            let dest = dest.unwrap();
+            let (dest, ret) = ret.unwrap();
             let n = this
                 .align_offset(args[0], args[1])?
                 .unwrap_or_else(|| this.truncate(u128::max_value(), dest.layout));
             this.write_scalar(Scalar::from_uint(n, dest.layout.size), dest)?;
-            this.goto_block(ret)?;
+            this.go_to_block(ret);
             return Ok(None);
         }
 
@@ -46,7 +45,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
             // to run extra MIR), and Ok(Some(body)) if we found MIR to run for the
             // foreign function
             // Any needed call to `goto_block` will be performed by `emulate_foreign_item`.
-            return this.emulate_foreign_item(instance.def_id(), args, dest, ret, unwind);
+            return this.emulate_foreign_item(instance.def_id(), args, ret, unwind);
         }
 
         // Otherwise, load the MIR.
diff --git a/src/shims/panic.rs b/src/shims/panic.rs
@@ -53,10 +53,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         this.machine.panic_payload = Some(scalar);
 
         // Jump to the unwind block to begin unwinding.
-        // We don't use `goto_block` as that is just meant for normal returns.
-        let next_frame = this.frame_mut();
-        next_frame.block = unwind;
-        next_frame.stmt = 0;
+        this.unwind_to_block(unwind);
         return Ok(())
     }
 

Original file line number	Diff line number	Diff line change
`@@ -1 +1 @@`
`1`		`-bd816fd76f4f7a040ca7ac8ca5bc556d761f96fa`
	`1`	`+809e180a76ce97340bf4354ff357bc59e3ca40b2`
Original file line number	Diff line number	Diff line change
`@@ -27,15 +27,12 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx`
`27`	`27`	`&mut self,`
`28`	`28`	`dlsym: Dlsym,`
`29`	`29`	`args: &[OpTy<'tcx, Tag>],`
`30`		`- dest: Option<PlaceTy<'tcx, Tag>>,`
`31`		`- ret: Option<mir::BasicBlock>,`
	`30`	`+ ret: Option<(PlaceTy<'tcx, Tag>, mir::BasicBlock)>,`
`32`	`31`	`) -> InterpResult<'tcx> {`
`33`	`32`	`use self::Dlsym::*;`
`34`	`33`
`35`	`34`	`let this = self.eval_context_mut();`
`36`		`-`
`37`		`- let dest = dest.expect("we don't support any diverging dlsym");`
`38`		- let ret = ret.expect("dest is `Some` but ret is `None`");
	`35`	`+ let (dest, ret) = ret.expect("we don't support any diverging dlsym");`
`39`	`36`
`40`	`37`	`match dlsym {`
`41`	`38`	`GetEntropy => {`
`@@ -46,8 +43,8 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx`
`46`	`43`	`}`
`47`	`44`	`}`
`48`	`45`
`49`		`- this.goto_block(Some(ret))?;`
`50`	`46`	`this.dump_place(*dest);`
	`47`	`+ this.go_to_block(ret);`
`51`	`48`	`Ok(())`
`52`	`49`	`}`
`53`	`50`	`}`