From be92041a592f65f38cee8475b61d35e7fcee3694 Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <jorge@japaric.io>
Date: Sat, 29 Jun 2019 09:11:42 +0200
Subject: [PATCH] WIP

---
 build.rs                             |  5 +++-
 macros/src/codegen.rs                |  2 ++
 macros/src/codegen/dispatchers.rs    |  7 ++++-
 macros/src/codegen/hardware_tasks.rs |  8 +++++-
 macros/src/codegen/idle.rs           | 13 ++++------
 macros/src/codegen/init.rs           |  4 ++-
 macros/src/codegen/locals.rs         |  5 +++-
 macros/src/codegen/resources.rs      | 17 +++++++-----
 macros/src/codegen/schedule.rs       |  4 +++
 macros/src/codegen/software_tasks.rs | 24 ++++++++++++++---
 macros/src/codegen/spawn.rs          |  4 +++
 macros/src/codegen/timer_queue.rs    |  6 ++++-
 macros/src/codegen/util.rs           | 39 ++++++++++++++++++++++++++++
 13 files changed, 115 insertions(+), 23 deletions(-)

diff --git a/build.rs b/build.rs
index 2419b4eb84..14c3d248ac 100644
--- a/build.rs
+++ b/build.rs
@@ -7,7 +7,10 @@ fn main() {
         println!("cargo:rustc-cfg=armv6m")
     }
 
-    if target.starts_with("thumbv7m") | target.starts_with("thumbv7em") {
+    if target.starts_with("thumbv7m")
+        | target.starts_with("thumbv7em")
+        | target.starts_with("thumbv8m")
+    {
         println!("cargo:rustc-cfg=armv7m")
     }
 
diff --git a/macros/src/codegen.rs b/macros/src/codegen.rs
index 8a5483237b..8ac06d5343 100644
--- a/macros/src/codegen.rs
+++ b/macros/src/codegen.rs
@@ -68,8 +68,10 @@ pub fn app(app: &App, analysis: &Analysis, extra: &Extra) -> TokenStream2 {
 
         let cfg_core = util::cfg_core(core, app.args.cores);
         let main = util::suffixed("main", core);
+        let section = util::link_section("text", core);
         mains.push(quote!(
             #[no_mangle]
+            #section
             #cfg_core
             unsafe extern "C" fn #main() -> ! {
                 #(#assertion_stmts)*
diff --git a/macros/src/codegen/dispatchers.rs b/macros/src/codegen/dispatchers.rs
index 988e3c84c9..9a9cb102f9 100644
--- a/macros/src/codegen/dispatchers.rs
+++ b/macros/src/codegen/dispatchers.rs
@@ -46,13 +46,14 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
 
                 let n = util::capacity_typenum(channel.capacity, true);
                 let rq = util::rq_ident(receiver, level, sender);
-                let (rq_attr, rq_ty, rq_expr) = if sender == receiver {
+                let (rq_attr, rq_ty, rq_expr, section) = if sender == receiver {
                     (
                         cfg_sender.clone(),
                         quote!(rtfm::export::SCRQ<#t, #n>),
                         quote!(rtfm::export::Queue(unsafe {
                             rtfm::export::iQueue::u8_sc()
                         })),
+                        util::link_section("bss", sender),
                     )
                 } else {
                     let shared = if cfg!(feature = "heterogeneous") {
@@ -65,6 +66,7 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
                         shared,
                         quote!(rtfm::export::MCRQ<#t, #n>),
                         quote!(rtfm::export::Queue(rtfm::export::iQueue::u8())),
+                        None,
                     )
                 };
 
@@ -77,6 +79,7 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
                 items.push(quote!(
                     #[doc = #doc]
                     #rq_attr
+                    #section
                     static mut #rq: #rq_ty = #rq_expr;
                 ));
 
@@ -162,12 +165,14 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
                 receiver, level
             );
             let cfg_receiver = util::cfg_core(receiver, app.args.cores);
+            let section = util::link_section("text", receiver);
             let interrupt = util::suffixed(&interrupts[&level].to_string(), receiver);
             items.push(quote!(
                 #[allow(non_snake_case)]
                 #[doc = #doc]
                 #[no_mangle]
                 #cfg_receiver
+                #section
                 unsafe fn #interrupt() {
                     /// The priority of this interrupt handler
                     const PRIORITY: u8 = #level;
diff --git a/macros/src/codegen/hardware_tasks.rs b/macros/src/codegen/hardware_tasks.rs
index a7af510a86..cf92e07867 100644
--- a/macros/src/codegen/hardware_tasks.rs
+++ b/macros/src/codegen/hardware_tasks.rs
@@ -56,9 +56,11 @@ pub fn codegen(
         };
         let priority = task.args.priority;
 
+        let section = util::link_section("text", core);
         const_app.push(quote!(
             #[allow(non_snake_case)]
             #[no_mangle]
+            #section
             #cfg_core
             unsafe fn #symbol() {
                 const PRIORITY: u8 = #priority;
@@ -101,7 +103,8 @@ pub fn codegen(
         // `${task}Locals`
         let mut locals_pat = None;
         if !task.locals.is_empty() {
-            let (struct_, pat) = locals::codegen(Context::HardwareTask(name), &task.locals, app);
+            let (struct_, pat) =
+                locals::codegen(Context::HardwareTask(name), &task.locals, core, app);
 
             root.push(struct_);
             locals_pat = Some(pat);
@@ -110,9 +113,12 @@ pub fn codegen(
         let attrs = &task.attrs;
         let context = &task.context;
         let stmts = &task.stmts;
+        let section = util::link_section("text", core);
+        // XXX shouldn't this have a cfg_core?
         user_tasks.push(quote!(
             #(#attrs)*
             #[allow(non_snake_case)]
+            #section
             fn #name(#(#locals_pat,)* #context: #name::Context) {
                 use rtfm::Mutex as _;
 
diff --git a/macros/src/codegen/idle.rs b/macros/src/codegen/idle.rs
index 7af01c9132..d6560761c0 100644
--- a/macros/src/codegen/idle.rs
+++ b/macros/src/codegen/idle.rs
@@ -44,7 +44,7 @@ pub fn codegen(
 
         let name = &idle.name;
         if !idle.locals.is_empty() {
-            let (locals, pat) = locals::codegen(Context::Idle(core), &idle.locals, app);
+            let (locals, pat) = locals::codegen(Context::Idle(core), &idle.locals, core, app);
 
             locals_new = Some(quote!(#name::Locals::new()));
             locals_pat = Some(pat);
@@ -57,10 +57,12 @@ pub fn codegen(
         let attrs = &idle.attrs;
         let context = &idle.context;
         let stmts = &idle.stmts;
+        let section = util::link_section("text", core);
         let user_idle = Some(quote!(
-            #cfg_core
             #(#attrs)*
             #[allow(non_snake_case)]
+            #cfg_core
+            #section
             fn #name(#(#locals_pat,)* #context: #name::Context) -> ! {
                 use rtfm::Mutex as _;
 
@@ -73,12 +75,7 @@ pub fn codegen(
             #name::Context::new(&rtfm::export::Priority::new(0))
         ));
 
-        (
-            const_app,
-            root_idle,
-            user_idle,
-            call_idle,
-        )
+        (const_app, root_idle, user_idle, call_idle)
     } else {
         (
             None,
diff --git a/macros/src/codegen/init.rs b/macros/src/codegen/init.rs
index 271be94ca1..878c633eaf 100644
--- a/macros/src/codegen/init.rs
+++ b/macros/src/codegen/init.rs
@@ -72,7 +72,7 @@ pub fn codegen(
         let mut locals_pat = None;
         let mut locals_new = None;
         if !init.locals.is_empty() {
-            let (struct_, pat) = locals::codegen(Context::Init(core), &init.locals, app);
+            let (struct_, pat) = locals::codegen(Context::Init(core), &init.locals, core, app);
 
             locals_new = Some(quote!(#name::Locals::new()));
             locals_pat = Some(pat);
@@ -82,10 +82,12 @@ pub fn codegen(
         let context = &init.context;
         let attrs = &init.attrs;
         let stmts = &init.stmts;
+        let section = util::link_section("text", core);
         let user_init = Some(quote!(
             #(#attrs)*
             #cfg_core
             #[allow(non_snake_case)]
+            #section
             fn #name(#(#locals_pat,)* #context: #name::Context) #ret {
                 #(#stmts)*
             }
diff --git a/macros/src/codegen/locals.rs b/macros/src/codegen/locals.rs
index 9663563730..799ef7a0ad 100644
--- a/macros/src/codegen/locals.rs
+++ b/macros/src/codegen/locals.rs
@@ -2,7 +2,7 @@ use proc_macro2::TokenStream as TokenStream2;
 use quote::quote;
 use rtfm_syntax::{
     ast::{App, Local},
-    Context, Map,
+    Context, Core, Map,
 };
 
 use crate::codegen::util;
@@ -10,6 +10,7 @@ use crate::codegen::util;
 pub fn codegen(
     ctxt: Context,
     locals: &Map<Local>,
+    core: Core,
     app: &App,
 ) -> (
     // locals
@@ -41,6 +42,7 @@ pub fn codegen(
         let cfgs = &local.cfgs;
         has_cfgs |= !cfgs.is_empty();
 
+        let section = util::link_section("data", core);
         let expr = &local.expr;
         let ty = &local.ty;
         fields.push(quote!(
@@ -49,6 +51,7 @@ pub fn codegen(
         ));
         items.push(quote!(
             #(#cfgs)*
+            #section
             static mut #name: #ty = #expr
         ));
         values.push(quote!(
diff --git a/macros/src/codegen/resources.rs b/macros/src/codegen/resources.rs
index 2425681ba5..1161a7a53e 100644
--- a/macros/src/codegen/resources.rs
+++ b/macros/src/codegen/resources.rs
@@ -26,20 +26,24 @@ pub fn codegen(
         let ty = &res.ty;
 
         {
-            let loc_attr = match loc {
+            let (loc_attr, section) = match loc {
                 Location::Owned {
                     core,
                     cross_initialized: false,
-                } => util::cfg_core(*core, app.args.cores),
+                } => (
+                    util::cfg_core(*core, app.args.cores),
+                    util::link_section("data", *core),
+                ),
 
                 // shared `static`s and cross-initialized resources need to be in `.shared` memory
-                _ => {
+                _ => (
                     if cfg!(feature = "heterogeneous") {
                         Some(quote!(#[rtfm::export::shared]))
                     } else {
                         None
-                    }
-                }
+                    },
+                    None,
+                ),
             };
 
             let (ty, expr) = if let Some(expr) = expr {
@@ -53,9 +57,10 @@ pub fn codegen(
 
             let attrs = &res.attrs;
             const_app.push(quote!(
-                #loc_attr
                 #(#attrs)*
                 #(#cfgs)*
+                #loc_attr
+                #section
                 static mut #name: #ty = #expr;
             ));
         }
diff --git a/macros/src/codegen/schedule.rs b/macros/src/codegen/schedule.rs
index 57f01a2c79..8cf6098501 100644
--- a/macros/src/codegen/schedule.rs
+++ b/macros/src/codegen/schedule.rs
@@ -35,8 +35,10 @@ pub fn codegen(app: &App, extra: &Extra) -> Vec<TokenStream2> {
 
                 let body = schedule_body::codegen(scheduler, &name, app);
 
+                let section = util::link_section("text", sender);
                 methods.push(quote!(
                     #(#cfgs)*
+                    #section
                     fn #name(&self, instant: #instant #(,#args)*) -> Result<(), #ty> {
                         #body
                     }
@@ -50,9 +52,11 @@ pub fn codegen(app: &App, extra: &Extra) -> Vec<TokenStream2> {
 
                     let body = schedule_body::codegen(scheduler, &name, app);
 
+                    let section = util::link_section("text", sender);
                     items.push(quote!(
                         #cfg_sender
                         #(#cfgs)*
+                        #section
                         unsafe fn #schedule(
                             priority: &rtfm::export::Priority,
                             instant: #instant
diff --git a/macros/src/codegen/software_tasks.rs b/macros/src/codegen/software_tasks.rs
index 383a5d82d0..2960faf965 100644
--- a/macros/src/codegen/software_tasks.rs
+++ b/macros/src/codegen/software_tasks.rs
@@ -43,13 +43,21 @@ pub fn codegen(
                 let cfg_sender = util::cfg_core(sender, app.args.cores);
                 let fq = util::fq_ident(name, sender);
 
-                let (loc, fq_ty, fq_expr) = if receiver == sender {
+                let (loc, fq_ty, fq_expr, bss, mk_uninit): (
+                    _,
+                    _,
+                    _,
+                    _,
+                    Box<dyn Fn() -> Option<_>>,
+                ) = if receiver == sender {
                     (
                         cfg_sender.clone(),
                         quote!(rtfm::export::SCFQ<#cap_ty>),
                         quote!(rtfm::export::Queue(unsafe {
                             rtfm::export::iQueue::u8_sc()
                         })),
+                        util::link_section("bss", sender),
+                        Box::new(|| util::link_section_uninit(Some(sender))),
                     )
                 } else {
                     let shared = if cfg!(feature = "heterogeneous") {
@@ -62,6 +70,8 @@ pub fn codegen(
                         shared,
                         quote!(rtfm::export::MCFQ<#cap_ty>),
                         quote!(rtfm::export::Queue(rtfm::export::iQueue::u8())),
+                        None,
+                        Box::new(|| util::link_section_uninit(None)),
                     )
                 };
                 let loc = &loc;
@@ -70,6 +80,7 @@ pub fn codegen(
                     /// Queue version of a free-list that keeps track of empty slots in
                     /// the following buffers
                     #loc
+                    #bss
                     static mut #fq: #fq_ty = #fq_expr;
                 ));
 
@@ -102,8 +113,10 @@ pub fn codegen(
                     let m = extra.monotonic();
                     let instants = util::instants_ident(name, sender);
 
+                    let uninit = mk_uninit();
                     const_app.push(quote!(
                         #loc
+                        #uninit
                         /// Buffer that holds the instants associated to the inputs of a task
                         static mut #instants:
                             [core::mem::MaybeUninit<<#m as rtfm::Monotonic>::Instant>; #cap_lit] =
@@ -111,9 +124,11 @@ pub fn codegen(
                     ));
                 }
 
+                let uninit = mk_uninit();
                 let inputs = util::inputs_ident(name, sender);
                 const_app.push(quote!(
                     #loc
+                    #uninit
                     /// Buffer that holds the inputs of a task
                     static mut #inputs: [core::mem::MaybeUninit<#input_ty>; #cap_lit] =
                         [#(#elems,)*];
@@ -140,13 +155,15 @@ pub fn codegen(
         // `${task}Locals`
         let mut locals_pat = None;
         if !task.locals.is_empty() {
-            let (struct_, pat) = locals::codegen(Context::SoftwareTask(name), &task.locals, app);
+            let (struct_, pat) =
+                locals::codegen(Context::SoftwareTask(name), &task.locals, receiver, app);
 
             locals_pat = Some(pat);
             root.push(struct_);
         }
 
         let cfg_receiver = util::cfg_core(receiver, app.args.cores);
+        let section = util::link_section("text", receiver);
         let context = &task.context;
         let attrs = &task.attrs;
         let cfgs = &task.cfgs;
@@ -154,8 +171,9 @@ pub fn codegen(
         user_tasks.push(quote!(
             #(#attrs)*
             #(#cfgs)*
-            #cfg_receiver
             #[allow(non_snake_case)]
+            #cfg_receiver
+            #section
             fn #name(#(#locals_pat,)* #context: #name::Context #(,#inputs)*) {
                 use rtfm::Mutex as _;
 
diff --git a/macros/src/codegen/spawn.rs b/macros/src/codegen/spawn.rs
index 1539e27722..c63c410b5d 100644
--- a/macros/src/codegen/spawn.rs
+++ b/macros/src/codegen/spawn.rs
@@ -42,8 +42,10 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
                     None
                 };
 
+                let section = util::link_section("text", sender);
                 methods.push(quote!(
                     #(#cfgs)*
+                    #section
                     fn #name(&self #(,#args)*) -> Result<(), #ty> {
                         #let_instant
                         #body
@@ -66,9 +68,11 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
 
                     let body = spawn_body::codegen(spawner, &name, app, analysis, extra);
 
+                    let section = util::link_section("text", sender);
                     items.push(quote!(
                         #cfg_sender
                         #(#cfgs)*
+                        #section
                         unsafe fn #spawn(
                             priority: &rtfm::export::Priority
                             #instant
diff --git a/macros/src/codegen/timer_queue.rs b/macros/src/codegen/timer_queue.rs
index d306ed5b12..3af7e432aa 100644
--- a/macros/src/codegen/timer_queue.rs
+++ b/macros/src/codegen/timer_queue.rs
@@ -48,9 +48,11 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
             let n = util::capacity_typenum(timer_queue.capacity, false);
             let tq_ty = quote!(rtfm::export::TimerQueue<#m, #t, #n>);
 
+            let section = util::link_section("bss", sender);
             items.push(quote!(
                 #cfg_sender
                 #[doc = #doc]
+                #section
                 static mut #tq: #tq_ty = rtfm::export::TimerQueue(
                     rtfm::export::BinaryHeap(
                         rtfm::export::iBinaryHeap::new()
@@ -117,9 +119,11 @@ pub fn codegen(app: &App, analysis: &Analysis, extra: &Extra) -> Vec<TokenStream
 
             let priority = timer_queue.priority;
             let sys_tick = util::suffixed("SysTick", sender);
+            let section = util::link_section("text", sender);
             items.push(quote!(
-                #cfg_sender
                 #[no_mangle]
+                #cfg_sender
+                #section
                 unsafe fn #sys_tick() {
                     use rtfm::Mutex as _;
 
diff --git a/macros/src/codegen/util.rs b/macros/src/codegen/util.rs
index cd01264dde..f5f96deaa4 100644
--- a/macros/src/codegen/util.rs
+++ b/macros/src/codegen/util.rs
@@ -1,3 +1,5 @@
+use core::sync::atomic::{AtomicUsize, Ordering};
+
 use proc_macro2::{Span, TokenStream as TokenStream2};
 use quote::quote;
 use rtfm_syntax::{ast::App, Context, Core};
@@ -133,6 +135,43 @@ pub fn late_resources_ident(init: &Ident) -> Ident {
     )
 }
 
+fn link_section_index() -> usize {
+    static INDEX: AtomicUsize = AtomicUsize::new(0);
+
+    INDEX.fetch_add(1, Ordering::Relaxed)
+}
+
+pub fn link_section(section: &str, core: Core) -> Option<TokenStream2> {
+    if cfg!(feature = "homogeneous") {
+        let section = format!(".{}_{}.rtfm{}", section, core, link_section_index());
+        Some(quote!(#[link_section = #section]))
+    } else {
+        None
+    }
+}
+
+// NOTE `None` means in shared memory
+pub fn link_section_uninit(core: Option<Core>) -> Option<TokenStream2> {
+    let section = if let Some(core) = core {
+        let index = link_section_index();
+
+        if cfg!(feature = "homogeneous") {
+            format!(".uninit_{}.rtfm{}", core, index)
+        } else {
+            format!(".uninit.rtfm{}", index)
+        }
+    } else {
+        if cfg!(feature = "heterogeneous") {
+            // `#[shared]` attribute sets the linker section
+            return None;
+        }
+
+        format!(".uninit.rtfm{}", link_section_index())
+    };
+
+    Some(quote!(#[link_section = #section]))
+}
+
 /// Generates a pre-reexport identifier for the "locals" struct
 pub fn locals_ident(ctxt: Context, app: &App) -> Ident {
     let mut s = match ctxt {