Get size of integers using libc

Author: pvdrz

src/shims/foreign_items.rs

@@ -522,6 +522,12 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                     } else {
                         let tp = this.force_ptr(this.read_scalar(args[1])?.not_undef()?)?;
 
+                        let long = this.resolve_path(&["libc", "c_long"])?.ty(*tcx);
+                        let time_t = this.resolve_path(&["libc", "time_t"])?.ty(*tcx);
+
+                        let tv_sec_size = this.layout_of(time_t)?.size;
+                        let tv_nsec_size = this.layout_of(long)?.size;
+
                         let allocation = this.memory_mut().get_mut(tp.alloc_id)?;
 
                         let mut sign = 1;
@@ -533,13 +539,11 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                                 e.duration()
                             });
 
-                        let tv_sec_size = Size::from_bits(64);
-                        let tv_nsec_size = Size::from_bits(64);
-
                         allocation.write_scalar(
                             tcx,
                             tp,
-                            Scalar::from_int(sign * (duration.as_secs() as i64), tv_sec_size).into(),
+                            Scalar::from_int(sign * (duration.as_secs() as i64), tv_sec_size)
+                                .into(),
                             tv_sec_size,
                         )?;
 
@@ -555,16 +559,16 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                 }
             }
 
-                "strlen" => {
-                    let ptr = this.read_scalar(args[0])?.not_undef()?;
-                    let n = this.memory().read_c_str(ptr)?.len();
-                    this.write_scalar(Scalar::from_uint(n as u64, dest.layout.size), dest)?;
-                }
+            "strlen" => {
+                let ptr = this.read_scalar(args[0])?.not_undef()?;
+                let n = this.memory().read_c_str(ptr)?.len();
+                this.write_scalar(Scalar::from_uint(n as u64, dest.layout.size), dest)?;
+            }
 
-                // math functions
-                "cbrtf" | "coshf" | "sinhf" | "tanf" => {
-                    // FIXME: Using host floats.
-                    let f = f32::from_bits(this.read_scalar(args[0])?.to_u32()?);
+            // math functions
+            "cbrtf" | "coshf" | "sinhf" | "tanf" => {
+                // FIXME: Using host floats.
+                let f = f32::from_bits(this.read_scalar(args[0])?.to_u32()?);
                 let f = match link_name {
                     "cbrtf" => f.cbrt(),
                     "coshf" => f.cosh(),
@@ -1068,6 +1072,42 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
             Size::from_bits(32),
         ))
     }
+    //
+    // fn path_to_res(tcx: &TyCtxt<'tcx>, path: &[&str]) -> Option<(def::Res)> {
+    //     let crates = tcx.crates();
+    //     let krate = crates
+    //         .iter()
+    //         .find(|&&krate| cx.tcx.crate_name(krate).as_str() == path[0]);
+    //     if let Some(krate) = krate {
+    //         let krate = DefId {
+    //             krate: *krate,
+    //             index: CRATE_DEF_INDEX,
+    //         };
+    //         let mut items = cx.tcx.item_children(krate);
+    //         let mut path_it = path.iter().skip(1).peekable();
+    //
+    //         loop {
+    //             let segment = match path_it.next() {
+    //                 Some(segment) => segment,
+    //                 None => return None,
+    //             };
+    //
+    //             let result = SmallVec::<[_; 8]>::new();
+    //             for item in mem::replace(&mut items, cx.tcx.arena.alloc_slice(&result)).iter() {
+    //                 if item.ident.name.as_str() == *segment {
+    //                     if path_it.peek().is_none() {
+    //                         return Some(item.res);
+    //                     }
+    //
+    //                     items = cx.tcx.item_children(item.res.def_id());
+    //                     break;
+    //                 }
+    //             }
+    //         }
+    //     } else {
+    //         None
+    //     }
+    // }
 }
 
 // Shims the linux 'getrandom()' syscall.