From edcece33caeb0453c105efad799a94239c128dff Mon Sep 17 00:00:00 2001 From: Ayke van Laethem Date: Wed, 3 Nov 2021 01:24:25 +0100 Subject: transform: refactor interrupt lowering Instead of doing everything in the interrupt lowering pass, generate some more code in gen-device to declare interrupt handler functions and do some work in the compiler so that interrupt lowering becomes a lot simpler. This has several benefits: - Overall code is smaller, in particular the interrupt lowering pass. - The code should be a bit less "magical" and instead a bit easier to read. In particular, instead of having a magic runtime.callInterruptHandler (that is fully written by the interrupt lowering pass), the runtime calls a generated function like device/sifive.InterruptHandler where this switch already exists in code. - Debug information is improved. This can be helpful during actual debugging but is also useful for other uses of DWARF debug information. For an example on debug information improvement, this is what a backtrace might look like before this commit: Breakpoint 1, 0x00000b46 in UART0_IRQHandler () (gdb) bt #0 0x00000b46 in UART0_IRQHandler () #1 [..etc] Notice that the debugger doesn't see the source code location where it has stopped. After this commit, breaking at the same line might look like this: Breakpoint 1, (*machine.UART).handleInterrupt (arg1=..., uart=) at /home/ayke/src/github.com/tinygo-org/tinygo/src/machine/machine_nrf.go:200 200 uart.Receive(byte(nrf.UART0.RXD.Get())) (gdb) bt #0 (*machine.UART).handleInterrupt (arg1=..., uart=) at /home/ayke/src/github.com/tinygo-org/tinygo/src/machine/machine_nrf.go:200 #1 UART0_IRQHandler () at /home/ayke/src/github.com/tinygo-org/tinygo/src/device/nrf/nrf51.go:176 #2 [..etc] By now, the debugger sees an actual source location for UART0_IRQHandler (in the generated file) and an inlined function. --- tools/gen-device-avr/gen-device-avr.go | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'tools/gen-device-avr') diff --git a/tools/gen-device-avr/gen-device-avr.go b/tools/gen-device-avr/gen-device-avr.go index 9b9c627ae..c553ec30d 100755 --- a/tools/gen-device-avr/gen-device-avr.go +++ b/tools/gen-device-avr/gen-device-avr.go @@ -288,7 +288,6 @@ func writeGo(outdir string, device *Device) error { package {{.pkgName}} import ( - "runtime/interrupt" "runtime/volatile" "unsafe" ) @@ -306,11 +305,18 @@ const ({{range .interrupts}} IRQ_max = {{.interruptMax}} // Highest interrupt number on this device. ) -// Map interrupt numbers to function names. -// These aren't real calls, they're removed by the compiler. -var ({{range .interrupts}} - _ = interrupt.Register(IRQ_{{.Name}}, "__vector_{{.Name}}"){{end}} -) +// Pseudo function call that is replaced by the compiler with the actual +// functions registered through interrupt.New. +//go:linkname callHandlers runtime/interrupt.callHandlers +func callHandlers(num int) + +{{- range .interrupts}} +//export __vector_{{.Name}} +//go:interrupt +func interrupt{{.Name}}() { + callHandlers(IRQ_{{.Name}}) +} +{{- end}} // Peripherals. var ({{range .peripherals}} -- cgit v1.2.3