Merge #19

bors[bot] · japaric · bors[bot] · commit 7861c4a884c9 · 2018-09-14T20:08:03.000Z
19: move code to the 2018 edition r=japaric a=japaric most code changes are minor the annoying part of using the 2018 edition right now is that there is no easy way to create new 2018 project (Cargo still defaults to 2015 projects; see rust-lang/cargo#5980) and there's no visible documentation on how to move a new project to the 2018 edition (see rust-lang/edition-guide#102) so I have included the required changes in the preface -- I hope people won't miss that part. r? @rust-embedded/resources (anyone) closes #1 Co-authored-by: Jorge Aparicio <jorge@japaric.io>
diff --git a/ci/exceptions/app/Cargo.toml b/ci/exceptions/app/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
+authors = ["Jorge Aparicio <jorge@japaric.io>"]
+edition = "2018"
 name = "app"
 version = "0.1.0"
-authors = ["Jorge Aparicio <jorge@japaric.io>"]
 
 [dependencies]
 rt = { path = "../rt" }
diff --git a/ci/exceptions/app/src/main.rs b/ci/exceptions/app/src/main.rs
@@ -2,11 +2,10 @@
 #![no_main]
 #![no_std]
 
-#[macro_use]
-extern crate rt;
-
 use core::intrinsics;
 
+use rt::entry;
+
 entry!(main);
 
 fn main() -> ! {
diff --git a/ci/exceptions/app2/src/main.rs b/ci/exceptions/app2/src/main.rs
@@ -2,11 +2,10 @@
 #![no_main]
 #![no_std]
 
-#[macro_use]
-extern crate rt;
-
 use core::intrinsics;
 
+use rt::entry;
+
 entry!(main);
 
 fn main() -> ! {
diff --git a/ci/exceptions/rt/src/lib.rs b/ci/exceptions/rt/src/lib.rs
@@ -1,4 +1,3 @@
-#![feature(panic_handler)]
 #![no_std]
 
 use core::panic::PanicInfo;
@@ -37,7 +36,7 @@ pub unsafe extern "C" fn Reset() -> ! {
 pub static RESET_VECTOR: unsafe extern "C" fn() -> ! = Reset;
 
 #[panic_handler]
-fn panic(_panic: &PanicInfo) -> ! {
+fn panic(_panic: &PanicInfo<'_>) -> ! {
     loop {}
 }
 
diff --git a/ci/main/app/Cargo.toml b/ci/main/app/Cargo.toml
@@ -1,4 +1,5 @@
 [package]
+edition = "2018"
 name = "app"
 version = "0.1.0"
 authors = ["Jorge Aparicio <jorge@japaric.io>"]
diff --git a/ci/main/app2/src/main.rs b/ci/main/app2/src/main.rs
@@ -1,8 +1,7 @@
 #![no_std]
 #![no_main]
 
-#[macro_use]
-extern crate rt;
+use rt::entry;
 
 entry!(main);
 
diff --git a/ci/main/app3/src/main.rs b/ci/main/app3/src/main.rs
@@ -1,8 +1,7 @@
 #![no_std]
 #![no_main]
 
-#[macro_use]
-extern crate rt;
+use rt::entry;
 
 entry!(main);
 
diff --git a/ci/main/app4/Cargo.toml b/ci/main/app4/Cargo.toml
@@ -1,7 +1,8 @@
 [package]
+authors = ["Jorge Aparicio <jorge@japaric.io>"]
+edition = "2018"
 name = "app"
 version = "0.1.0"
-authors = ["Jorge Aparicio <jorge@japaric.io>"]
 
 [dependencies]
 rt = { path = "../rt2" }
diff --git a/ci/main/app4/src/main.rs b/ci/main/app4/src/main.rs
@@ -2,11 +2,10 @@
 #![no_main]
 #![no_std]
 
-#[macro_use]
-extern crate rt;
-
 use core::ptr;
 
+use rt::entry;
+
 entry!(main);
 
 static mut DATA: i32 = 1;
diff --git a/ci/main/rt/Cargo.toml b/ci/main/rt/Cargo.toml
@@ -1,5 +1,6 @@
 [package]
-name = "rt"
+edition = "2018"
+name = "rt" # <-
 version = "0.1.0"
 authors = ["Jorge Aparicio <jorge@japaric.io>"]
 
diff --git a/ci/main/rt/src/lib.rs b/ci/main/rt/src/lib.rs
@@ -1,4 +1,3 @@
-#![feature(panic_handler)]
 #![no_std]
 
 use core::panic::PanicInfo;
@@ -19,7 +18,7 @@ pub unsafe extern "C" fn Reset() -> ! {
 pub static RESET_VECTOR: unsafe extern "C" fn() -> ! = Reset;
 
 #[panic_handler]
-fn panic(_panic: &PanicInfo) -> ! {
+fn panic(_panic: &PanicInfo<'_>) -> ! {
     loop {}
 }
 
diff --git a/ci/main/rt2/src/lib.rs b/ci/main/rt2/src/lib.rs
@@ -1,4 +1,3 @@
-#![feature(panic_handler)]
 #![no_std]
 
 use core::panic::PanicInfo;
@@ -37,7 +36,7 @@ pub unsafe extern "C" fn Reset() -> ! {
 pub static RESET_VECTOR: unsafe extern "C" fn() -> ! = Reset;
 
 #[panic_handler]
-fn panic(_panic: &PanicInfo) -> ! {
+fn panic(_panic: &PanicInfo<'_>) -> ! {
     loop {}
 }
 
diff --git a/ci/memory-layout/src/main.rs b/ci/memory-layout/src/main.rs
@@ -1,4 +1,3 @@
-#![feature(panic_handler)]
 #![no_main]
 #![no_std]
 
@@ -19,6 +18,6 @@ pub unsafe extern "C" fn Reset() -> ! {
 pub static RESET_VECTOR: unsafe extern "C" fn() -> ! = Reset;
 
 #[panic_handler]
-fn panic(_panic: &PanicInfo) -> ! {
+fn panic(_panic: &PanicInfo<'_>) -> ! {
     loop {}
 }
diff --git a/ci/script.sh b/ci/script.sh
@@ -23,6 +23,8 @@ main() {
     diff app.o.nm \
          <(cargo nm -- target/thumbv7m-none-eabi/debug/deps/app-*.o | grep '[0-9]* [^n] ')
 
+    edition_check
+
     popd
 
     # # memory-layout
@@ -38,6 +40,8 @@ main() {
 
     qemu_check target/thumbv7m-none-eabi/debug/app
 
+    edition_check
+
     popd
 
     # # main
@@ -47,20 +51,25 @@ main() {
     pushd app
     diff app.objdump \
          <(cargo objdump --bin app -- -d -no-show-raw-insn)
+    # disabled because of rust-lang/rust#53964
+    # edition_check
     popd
 
     # check that it builds
     pushd app2
     cargo build
+    edition_check
     popd
 
     pushd app3
     cargo build
+    edition_check
     popd
 
     pushd app4
     cargo build
     qemu_check target/thumbv7m-none-eabi/debug/app
+    edition_check
     popd
 
     popd
@@ -72,16 +81,23 @@ main() {
     pushd app
     diff app.vector_table.objdump \
          <(cargo objdump --bin app --release -- -s -j .vector_table)
+    edition_check
     popd
 
     # check that it builds
     pushd app2
     cargo build
+    edition_check
     popd
 
     popd
 }
 
+# checks that 2018 idioms are being used
+edition_check() {
+    RUSTFLAGS="-D rust_2018_compatibility -D rust_2018_idioms" cargo check
+}
+
 # checks that QEMU doesn't crash and that it produces no error messages
 qemu_check() {
     qemu-system-arm \
diff --git a/ci/smallest-no-std/Cargo.toml b/ci/smallest-no-std/Cargo.toml
@@ -1,6 +1,7 @@
 [package]
-authors = ["Jorge Aparicio <jorge@japaric.io>"]
+edition = "2018"
 name = "app"
+authors = ["Jorge Aparicio <jorge@japaric.io>"]
 version = "0.1.0"
 
 [dependencies]
diff --git a/ci/smallest-no-std/src/main.rs b/ci/smallest-no-std/src/main.rs
@@ -1,10 +1,9 @@
-#![feature(panic_handler)]
 #![no_main]
 #![no_std]
 
 use core::panic::PanicInfo;
 
 #[panic_handler]
-fn panic(_panic: &PanicInfo) -> ! {
+fn panic(_panic: &PanicInfo<'_>) -> ! {
     loop {}
 }
diff --git a/src/exceptions.md b/src/exceptions.md
@@ -43,11 +43,11 @@ The first thing we'll do is create an array of vectors (pointers to exception ha
 `rt` crate's code:
 
 ``` console
-$ sed -n 57,92p ../rt/src/lib.rs
+$ sed -n 56,91p ../rt/src/lib.rs
 ```
 
 ``` rust
-{{#include ../ci/exceptions/rt/src/lib.rs:57:92}}
+{{#include ../ci/exceptions/rt/src/lib.rs:56:91}}
 ```
 
 Some of the entries in the vector table are *reserved*; the ARM documentation states that they
@@ -63,7 +63,7 @@ $ tail -n4 ../rt/src/lib.rs
 ```
 
 ``` rust
-{{#include ../ci/exceptions/rt/src/lib.rs:94:97}}
+{{#include ../ci/exceptions/rt/src/lib.rs:93:97}}
 ```
 
 ## Linker script side
@@ -105,24 +105,31 @@ handler for the respective exception.
 That's it! The `rt` crate now has support for exception handlers. We can test it out with following
 application:
 
+> **NOTE**: Turns out it's hard to generate an exception in QEMU. On real
+> hardware a read to an invalid memory address (i.e. outside of the Flash and
+> RAM regions) would be enough but QEMU happily accepts the operation and
+> returns zero. A trap instruction works on both QEMU and hardware but
+> unfortunately it's not available on stable so you'll have to temporarily
+> switch to nightly to run this and the next example.
+
 ``` rust
 {{#include ../ci/exceptions/app/src/main.rs}}
 ```
 
 ``` console
 (lldb) b DefaultExceptionHandler
-Breakpoint 1: where = app`DefaultExceptionHandler at lib.rs:96, address = 0x000000ec
+Breakpoint 1: where = app`DefaultExceptionHandler at lib.rs:95, address = 0x000000ec
 
 (lldb) continue
 Process 1 resuming
 Process 1 stopped
 * thread #1, stop reason = breakpoint 1.1
-    frame #0: 0x000000ec app`DefaultExceptionHandler at lib.rs:96
-   93
-   94   #[no_mangle]
-   95   pub extern "C" fn DefaultExceptionHandler() {
--> 96       loop {}
-   97   }
+    frame #0: 0x000000ec app`DefaultExceptionHandler at lib.rs:95
+   92
+   93   #[no_mangle]
+   94   pub extern "C" fn DefaultExceptionHandler() {
+-> 95       loop {}
+   96   }
 ```
 
 And for completeness, here's the disassembly of the optimized version of the program:
@@ -220,12 +227,12 @@ You can test it in QEMU
 Process 1 resuming
 Process 1 stopped
 * thread #1, stop reason = breakpoint 1.1
-    frame #0: 0x00000044 app`HardFault at main.rs:19
-   16   #[no_mangle]
-   17   pub extern "C" fn HardFault() -> ! {
-   18       // do something interesting here
--> 19       loop {}
-   20   }
+    frame #0: 0x00000044 app`HardFault at main.rs:18
+   15   #[no_mangle]
+   16   pub extern "C" fn HardFault() -> ! {
+   17       // do something interesting here
+-> 18       loop {}
+   19   }
 ```
 
 The program now executes the user defined `HardFault` function instead of the
@@ -234,6 +241,8 @@ The program now executes the user defined `HardFault` function instead of the
 Like our first attempt at a `main` interface, this first implementation has the problem of having no
 type safety. It's also easy to mistype the name of the exception, but that doesn't produce an error
 or warning. Instead the user defined handler is simply ignored. Those problems can be fixed using a
-macro like the [`exception!`] macro defined in `cortex-m-rt`.
+macro like the [`exception!`] macro defined in `cortex-m-rt` v0.5.x or the
+[`exception`] attribute in `cortex-m-rt` v0.6.x.
 
-[`exception!`]: https://github.com/japaric/cortex-m-rt/blob/v0.5.1/src/lib.rs#L79
+[`exception!`]: https://github.com/japaric/cortex-m-rt/blob/v0.5.1/src/lib.rs#L792
+[`exception`]: https://github.com/rust-embedded/cortex-m-rt/blob/v0.6.3/macros/src/lib.rs#L254
diff --git a/src/main.md b/src/main.md
@@ -15,21 +15,21 @@ And then rename it to `rt` which stands for "runtime".
 ``` console
 $ sed -i s/app/rt/ Cargo.toml
 
-$ head -n2 Cargo.toml
+$ head -n4 Cargo.toml
 ```
 
 ``` toml
-{{#include ../ci/main/rt/Cargo.toml:1:2}}
+{{#include ../ci/main/rt/Cargo.toml:1:4}}
 ```
 
 The first change is to have the reset handler call an external `main` function:
 
 ``` console
-$ head -n14 src/lib.rs
+$ head -n13 src/lib.rs
 ```
 
 ``` rust
-{{#include ../ci/main/rt/src/lib.rs:1:14}}
+{{#include ../ci/main/rt/src/lib.rs:1:13}}
 ```
 
 We also drop the `#![no_main]` attribute has it has no effect on library crates.
@@ -63,7 +63,7 @@ The `rt` will take care of giving the program the right memory layout.
 ``` console
 $ cd ..
 
-$ cargo new --bin app
+$ cargo new --edition 2018 --bin app
 
 $ cd app
 
@@ -104,7 +104,7 @@ $ tail -n12 ../rt/src/lib.rs
 ```
 
 ``` rust
-{{#include ../ci/main/rt/src/lib.rs:26:37}}
+{{#include ../ci/main/rt/src/lib.rs:25:37}}
 ```
 
 Then the application writers can invoke it like this:
@@ -215,7 +215,7 @@ $ head -n32 ../rt/src/lib.rs
 ```
 
 ``` rust
-{{#include ../ci/main/rt2/src/lib.rs:1:32}}
+{{#include ../ci/main/rt2/src/lib.rs:1:31}}
 ```
 
 Now end users can directly and indirectly make use of `static` variables without running into
diff --git a/src/memory-layout.md b/src/memory-layout.md
diff --git a/src/preface.md b/src/preface.md
diff --git a/src/smallest-no-std.md b/src/smallest-no-std.md

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,5 @@`
`1`	`1`	`[package]`
	`2`	`+edition = "2018"`
`2`	`3`	`name = "app"`
`3`	`4`	`version = "0.1.0"`
`4`	`5`	`authors = ["Jorge Aparicio <jorge@japaric.io>"]`