From c08dd88b999dc0852b1b9cce748c42b072ad30fb Mon Sep 17 00:00:00 2001
From: "henthe-5@student.ltu.se" <henthe-5@student.ltu.se>
Date: Tue, 19 Feb 2019 13:01:24 +0100
Subject: [PATCH] bare0_3 fix and bare0_5
---
examples/bare0.rs | 37 ++++++++++++++++++++++++++++---------
1 file changed, 28 insertions(+), 9 deletions(-)
diff --git a/examples/bare0.rs b/examples/bare0.rs
index 2f36a34..d7f0c54 100644
--- a/examples/bare0.rs
+++ b/examples/bare0.rs
@@ -28,18 +28,37 @@ static mut Y: u32 = 0;
#[entry]
fn main() -> ! {
// local mutabale variable (changed in safe code)
- let mut x = unsafe { X };
+ let mut x = read_x();
loop {
- x.wrapping_add(1); // <- place breakpoint here (3)
- unsafe {
- X.wrapping_add(1);
- Y = X;
- assert!(x == X && X == Y +1 );
- }
+ x = x.wrapping_add(1); // <- place breakpoint here (3)
+ write_x(read_x().wrapping_add(1));
+ write_y(read_x());
+ assert!(x == read_x() && read_x() == read_y() );
}
}
+fn read_x() -> u32 {
+ return unsafe { X };
+}
+
+fn read_y() -> u32 {
+ return unsafe { Y };
+}
+
+fn write_x(x: u32) {
+ unsafe {
+ X = x;
+ }
+}
+
+fn write_y(y: u32) {
+ unsafe {
+ Y = y
+ }
+
+}
+
// 0. Compile/build the example in debug (dev) mode.
//
// > cargo build --example bare0
@@ -75,10 +94,10 @@ fn main() -> ! {
//
// Change (both) += opertions to use wrapping_add
// load and run the progam, what happens
-// ** x value stays at u32 max 4294967295**
+// ** x value wraps around u32 max 4294967295 and get value 0**
//
// Now continue exectution, what happens
-// ** X,Y and x = 4294967295 **
+// ** X,Y and x is incremented and wraps around max **
//
// Commit your answers (bare0_3)
//
--
GitLab