From 62771839061aaa7dd518d40969bee609d7d2bda8 Mon Sep 17 00:00:00 2001
From: Emil Fresk <emil.fresk@gmail.com>
Date: Sun, 13 Dec 2020 14:52:16 +0100
Subject: [PATCH] Now handling SysTick as well

---
 examples/test_new_monotonic.rs    |  2 +-
 macros/src/codegen.rs             |  4 +++-
 macros/src/codegen/module.rs      | 17 ++++++++++++++--
 macros/src/codegen/pre_init.rs    | 32 +++++++++++++++++++++----------
 macros/src/codegen/timer_queue.rs | 12 ++++++++++--
 macros/src/codegen/util.rs        | 11 ++++++++++-
 6 files changed, 61 insertions(+), 17 deletions(-)

diff --git a/examples/test_new_monotonic.rs b/examples/test_new_monotonic.rs
index 3323c09b3b..67883465b6 100644
--- a/examples/test_new_monotonic.rs
+++ b/examples/test_new_monotonic.rs
@@ -8,7 +8,7 @@ use rtic::app;
 
 #[app(device = lm3s6965, dispatchers = [UART])]
 mod app {
-    #[monotonic(binds = SomeISR1)]
+    #[monotonic(binds = SysTick)]
     type MyMono1 = hal::Mono1;
 
     #[monotonic(binds = SomeISR2, default = true)]
diff --git a/macros/src/codegen.rs b/macros/src/codegen.rs
index 1219e14f97..bb8aa4e751 100644
--- a/macros/src/codegen.rs
+++ b/macros/src/codegen.rs
@@ -114,11 +114,13 @@ pub fn app(app: &App, analysis: &Analysis, extra: &Extra) -> TokenStream2 {
         })
         .collect();
 
+    let rt_err = util::rt_err_ident();
+
     quote!(
         /// Implementation details
         pub mod #name {
             /// Always include the device crate which contains the vector table
-            use #device as you_must_enable_the_rt_feature_for_the_pac_in_your_cargo_toml;
+            use #device as #rt_err;
 
             #(#monotonic_imports)*
 
diff --git a/macros/src/codegen/module.rs b/macros/src/codegen/module.rs
index 2b6042c8c8..bf77c4d9fb 100644
--- a/macros/src/codegen/module.rs
+++ b/macros/src/codegen/module.rs
@@ -246,6 +246,19 @@ pub fn codegen(
                 items.push(quote!(pub use #m::spawn_at;));
             }
 
+            let (unmask, pend) = if &*m_isr.to_string() == "SysTick" {
+                (
+                    quote!(core::mem::transmute::<_, cortex_m::peripheral::SYST>(()).disable_interrupt()),
+                    quote!(cortex_m::peripheral::SCB::set_pendst()),
+                )
+            } else {
+                let rt_err = util::rt_err_ident();
+                (
+                    quote!(rtic::export::NVIC::unmask(#app_path::#rt_err::#enum_::#m_isr)),
+                    quote!(rtic::pend(#app_path::#rt_err::#enum_::#m_isr)),
+                )
+            };
+
             items.push(quote!(
             pub mod #m {
                 #(#cfgs)*
@@ -287,8 +300,8 @@ pub fn codegen(
 
                             rtic::export::interrupt::free(|_| #app_path::#tq.enqueue_unchecked(
                                     nr,
-                                    || rtic::export::NVIC::unmask(#app_path::you_must_enable_the_rt_feature_for_the_pac_in_your_cargo_toml::#enum_::#m_isr),
-                                    || rtic::pend(#app_path::you_must_enable_the_rt_feature_for_the_pac_in_your_cargo_toml::#enum_::#m_isr),
+                                    || #unmask,
+                                    || #pend,
                             ));
 
                             Ok(())
diff --git a/macros/src/codegen/pre_init.rs b/macros/src/codegen/pre_init.rs
index 26ba558c8f..e7b1b03bc6 100644
--- a/macros/src/codegen/pre_init.rs
+++ b/macros/src/codegen/pre_init.rs
@@ -8,6 +8,8 @@ use crate::{analyze::Analysis, check::Extra, codegen::util};
 pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream2> {
     let mut stmts = vec![];
 
+    let rt_err = util::rt_err_ident();
+
     // Disable interrupts -- `init` must run with interrupts disabled
     stmts.push(quote!(rtic::export::interrupt::disable();));
 
@@ -47,14 +49,14 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
         let interrupt = util::interrupt_ident();
         stmts.push(quote!(
             core.NVIC.set_priority(
-                you_must_enable_the_rt_feature_for_the_pac_in_your_cargo_toml::#interrupt::#name,
+                #rt_err::#interrupt::#name,
                 rtic::export::logical2hw(#priority, #nvic_prio_bits),
             );
         ));
 
         // NOTE unmask the interrupt *after* setting its priority: changing the priority of a pended
         // interrupt is implementation defined
-        stmts.push(quote!(rtic::export::NVIC::unmask(you_must_enable_the_rt_feature_for_the_pac_in_your_cargo_toml::#interrupt::#name);));
+        stmts.push(quote!(rtic::export::NVIC::unmask(#rt_err::#interrupt::#name);));
     }
 
     // Set exception priorities
@@ -83,14 +85,24 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
         // Compile time assert that this priority is supported by the device
         stmts.push(quote!(let _ = [(); ((1 << #nvic_prio_bits) - #priority as usize)];));
 
-        // NOTE this also checks that the interrupt exists in the `Interrupt` enumeration
-        let interrupt = util::interrupt_ident();
-        stmts.push(quote!(
-            core.NVIC.set_priority(
-                you_must_enable_the_rt_feature_for_the_pac_in_your_cargo_toml::#interrupt::#name,
-                rtic::export::logical2hw(#priority, #nvic_prio_bits),
-            );
-        ));
+
+        if &*name.to_string() == "SysTick" {
+            stmts.push(quote!(
+                core.SCB.set_priority(
+                    rtic::export::SystemHandler::SysTick,
+                    rtic::export::logical2hw(#priority, #nvic_prio_bits),
+                );
+            ));
+        } else {
+            // NOTE this also checks that the interrupt exists in the `Interrupt` enumeration
+            let interrupt = util::interrupt_ident();
+            stmts.push(quote!(
+                core.NVIC.set_priority(
+                    #rt_err::#interrupt::#name,
+                    rtic::export::logical2hw(#priority, #nvic_prio_bits),
+                );
+            ));
+        }
 
         // NOTE we do not unmask the interrupt as this is part of the monotonic to keep track of
     }
diff --git a/macros/src/codegen/timer_queue.rs b/macros/src/codegen/timer_queue.rs
index dc29835577..ef0fda37df 100644
--- a/macros/src/codegen/timer_queue.rs
+++ b/macros/src/codegen/timer_queue.rs
@@ -68,6 +68,9 @@ pub fn codegen(app: &App, analysis: &Analysis, _extra: &Extra) -> Vec<TokenStrea
         // Timer queue handler
         {
             let enum_ = util::interrupt_ident();
+            let app_name = &app.name;
+            let app_path = quote! {crate::#app_name};
+            let rt_err = util::rt_err_ident();
 
             let arms = app
                 .software_tasks
@@ -83,7 +86,7 @@ pub fn codegen(app: &App, analysis: &Analysis, _extra: &Extra) -> Vec<TokenStrea
 
                     let pend = {
                         quote!(
-                            rtic::pend(you_must_enable_the_rt_feature_for_the_pac_in_your_cargo_toml::#enum_::#interrupt);
+                            rtic::pend(#rt_err::#enum_::#interrupt);
                         )
                     };
 
@@ -99,6 +102,11 @@ pub fn codegen(app: &App, analysis: &Analysis, _extra: &Extra) -> Vec<TokenStrea
                 .collect::<Vec<_>>();
 
             let bound_interrupt = &monotonic.args.binds;
+            let enable_isr = if &*bound_interrupt.to_string() == "SysTick" {
+                quote!(core::mem::transmute::<_, cortex_m::peripheral::SYST>(()).enable_interrupt())
+            } else {
+                quote!(rtic::export::NVIC::mask(#rt_err::#enum_::#bound_interrupt))
+            };
 
             items.push(quote!(
                 #[no_mangle]
@@ -106,7 +114,7 @@ pub fn codegen(app: &App, analysis: &Analysis, _extra: &Extra) -> Vec<TokenStrea
                     use rtic::Mutex as _;
 
                     while let Some((task, index)) = rtic::export::interrupt::free(|_| #tq.dequeue(
-                                || rtic::export::NVIC::unmask(you_must_enable_the_rt_feature_for_the_pac_in_your_cargo_toml::#enum_::#bound_interrupt),
+                                || #enable_isr,
                             ))
                     {
                         match task {
diff --git a/macros/src/codegen/util.rs b/macros/src/codegen/util.rs
index a201dfe5c4..287ba408b8 100644
--- a/macros/src/codegen/util.rs
+++ b/macros/src/codegen/util.rs
@@ -217,7 +217,7 @@ pub fn rq_ident(priority: u8) -> Ident {
 
 /// Generates an identifier for the `enum` of `schedule`-able tasks
 pub fn schedule_t_ident() -> Ident {
-    Ident::new(&"SCHED_T".to_string(), Span::call_site())
+    Ident::new(&"SCHED_T", Span::call_site())
 }
 
 /// Generates an identifier for the `enum` of `spawn`-able tasks
@@ -228,6 +228,7 @@ pub fn spawn_t_ident(priority: u8) -> Ident {
     Ident::new(&format!("P{}_T", priority), Span::call_site())
 }
 
+/// Suffixed identifier
 pub fn suffixed(name: &str) -> Ident {
     let span = Span::call_site();
     Ident::new(name, span)
@@ -237,3 +238,11 @@ pub fn suffixed(name: &str) -> Ident {
 pub fn tq_ident(name: &str) -> Ident {
     Ident::new(&format!("TQ_{}", name), Span::call_site())
 }
+
+/// The name to get better RT flag errors
+pub fn rt_err_ident() -> Ident {
+    Ident::new(
+        &"you_must_enable_the_rt_feature_for_the_pac_in_your_cargo_toml",
+        Span::call_site(),
+    )
+}