discovery
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Published
20 hours ago •
rust-embedded
rust-embedded
the-led-and-delay-abstraction.md `set half_period` is broken.
https://github.com/rust-embedded/discovery/blob/b2b16247cdedef3fb6ce10b8132832b95ba4e91a/src/05-led-roulette/the-led-and-delay-abstractions.md#L207-L220
Doesn't work anymore on rustc 1.48.0 (7eac88abb 2020-11-16).
Full asm output (built with RUSTFLAGS="--emit asm" cargo build --target thumbv7em-none-eabi
.text
.syntax unified
.eabi_attribute 67, "2.09"
.eabi_attribute 6, 13
.eabi_attribute 7, 77
.eabi_attribute 8, 0
.eabi_attribute 9, 2
.eabi_attribute 34, 1
.eabi_attribute 17, 1
.eabi_attribute 20, 1
.eabi_attribute 21, 0
.eabi_attribute 23, 3
.eabi_attribute 24, 1
.eabi_attribute 25, 1
.eabi_attribute 38, 1
.eabi_attribute 14, 0
.file "33ne5uerfjn3u8oj"
.section .text.main,"ax",%progbits
.globl main
.p2align 1
.type main,%function
.code 16
.thumb_func
main:
.Lfunc_begin0:
.file 1 "/home/stefan/projects/discovery/src/05-led-roulette/src/main.rs"
.loc 1 7 0
.fnstart
.cfi_sections .debug_frame
.cfi_startproc
.save {r7, lr}
push {r7, lr}
.cfi_def_cfa_offset 8
.cfi_offset lr, -4
.cfi_offset r7, -8
.setfp r7, sp
mov r7, sp
.cfi_def_cfa_register r7
.Ltmp0:
.loc 1 7 1 prologue_end
bl _ZN12led_roulette18__cortex_m_rt_main17h0b2223cb0e38e500E
.inst.n 0xdefe
.Ltmp1:
.Lfunc_end0:
.size main, .Lfunc_end0-main
.cfi_endproc
.cantunwind
.fnend
.section .text._ZN12led_roulette18__cortex_m_rt_main17h0b2223cb0e38e500E,"ax",%progbits
.p2align 1
.type _ZN12led_roulette18__cortex_m_rt_main17h0b2223cb0e38e500E,%function
.code 16
.thumb_func
_ZN12led_roulette18__cortex_m_rt_main17h0b2223cb0e38e500E:
.Lfunc_begin1:
.loc 1 8 0
.fnstart
.cfi_startproc
.save {r7, lr}
push {r7, lr}
.cfi_def_cfa_offset 8
.cfi_offset lr, -4
.cfi_offset r7, -8
.setfp r7, sp
mov r7, sp
.cfi_def_cfa_register r7
.pad #72
sub sp, #72
add r0, sp, #40
.Ltmp2:
.loc 1 9 48 prologue_end
bl _ZN4aux54init17ha90da604cbc87758E
b .LBB1_1
.LBB1_1:
.loc 1 0 48 is_stmt 0
add r0, sp, #40
add r1, sp, #12
.loc 1 9 10
ldm.w r0, {r2, r3, r4, r12, lr}
stm.w r1, {r2, r3, r4, r12, lr}
.loc 1 9 21
ldr r0, [sp, #60]
ldr r1, [sp, #64]
str r1, [sp, #36]
str r0, [sp, #32]
mov.w r0, #500
.Ltmp3:
.loc 1 11 23 is_stmt 1
strh r0, [r7, #-2]
.Ltmp4:
.loc 1 13 5
b .LBB1_2
.LBB1_2:
.loc 1 14 9
movw r2, :lower16:.L__unnamed_1
movt r2, :upper16:.L__unnamed_1
add r0, sp, #32
movs r1, #0
bl _ZN73_$LT$f3..led..Leds$u20$as$u20$core..ops..index..IndexMut$LT$usize$GT$$GT$9index_mut17h381d5f4e0c621798E
str r0, [sp, #8]
b .LBB1_3
.LBB1_3:
ldr r0, [sp, #8]
bl _ZN2f33led3Led2on17hd271365517c0b11cE
b .LBB1_4
.LBB1_4:
.loc 1 0 9 is_stmt 0
add r0, sp, #12
mov.w r1, #500
.loc 1 15 9 is_stmt 1
bl _ZN97_$LT$stm32f30x_hal..delay..Delay$u20$as$u20$embedded_hal..blocking..delay..DelayMs$LT$u16$GT$$GT$8delay_ms17h5400aa5c3c87f438E
b .LBB1_5
.LBB1_5:
.loc 1 17 9
movw r2, :lower16:.L__unnamed_2
movt r2, :upper16:.L__unnamed_2
add r0, sp, #32
movs r1, #0
bl _ZN73_$LT$f3..led..Leds$u20$as$u20$core..ops..index..IndexMut$LT$usize$GT$$GT$9index_mut17h381d5f4e0c621798E
str r0, [sp, #4]
b .LBB1_6
.LBB1_6:
ldr r0, [sp, #4]
bl _ZN2f33led3Led3off17hef007257bef9f451E
b .LBB1_7
.LBB1_7:
.loc 1 0 9 is_stmt 0
add r0, sp, #12
mov.w r1, #500
.loc 1 18 9 is_stmt 1
bl _ZN97_$LT$stm32f30x_hal..delay..Delay$u20$as$u20$embedded_hal..blocking..delay..DelayMs$LT$u16$GT$$GT$8delay_ms17h5400aa5c3c87f438E
b .LBB1_8
.LBB1_8:
.loc 1 13 5
b .LBB1_2
.Ltmp5:
.Lfunc_end1:
.size _ZN12led_roulette18__cortex_m_rt_main17h0b2223cb0e38e500E, .Lfunc_end1-_ZN12led_roulette18__cortex_m_rt_main17h0b2223cb0e38e500E
.cfi_endproc
.cantunwind
.fnend
.type .L__unnamed_3,%object
.section .rodata..L__unnamed_3,"a",%progbits
.L__unnamed_3:
.ascii "src/05-led-roulette/src/main.rs"
.size .L__unnamed_3, 31
.type .L__unnamed_1,%object
.section .rodata..L__unnamed_1,"a",%progbits
.p2align 2
.L__unnamed_1:
.long .L__unnamed_3
.asciz "\037\000\000\000\016\000\000\000\t\000\000"
.size .L__unnamed_1, 16
.type .L__unnamed_2,%object
.section .rodata..L__unnamed_2,"a",%progbits
.p2align 2
.L__unnamed_2:
.long .L__unnamed_3
.asciz "\037\000\000\000\021\000\000\000\t\000\000"
.size .L__unnamed_2, 16
.section .debug_abbrev,"",%progbits
.byte 1
.byte 17
.byte 1
.byte 37
.byte 14
.byte 19
.byte 5
.byte 3
.byte 14
.byte 16
.byte 23
.byte 27
.byte 14
.ascii "\264B"
.byte 25
.byte 17
.byte 1
.byte 85
.byte 23
.byte 0
.byte 0
.byte 2
.byte 57
.byte 1
.byte 3
.byte 14
.byte 0
.byte 0
.byte 3
.byte 46
.byte 0
.byte 17
.byte 1
.byte 18
.byte 6
.byte 64
.byte 24
.byte 110
.byte 14
.byte 3
.byte 14
.byte 58
.byte 11
.byte 59
.byte 11
.byte 63
.byte 25
.byte 0
.byte 0
.byte 4
.byte 46
.byte 1
.byte 17
.byte 1
.byte 18
.byte 6
.byte 64
.byte 24
.byte 110
.byte 14
.byte 3
.byte 14
.byte 58
.byte 11
.byte 59
.byte 11
.ascii "\207\001"
.byte 25
.byte 0
.byte 0
.byte 5
.byte 11
.byte 1
.byte 17
.byte 1
.byte 18
.byte 6
.byte 0
.byte 0
.byte 6
.byte 52
.byte 0
.byte 2
.byte 24
.byte 3
.byte 14
.byte 58
.byte 11
.byte 59
.byte 11
.byte 73
.byte 19
.byte 0
.byte 0
.byte 7
.byte 19
.byte 1
.byte 3
.byte 14
.byte 11
.byte 11
.ascii "\210\001"
.byte 15
.byte 0
.byte 0
.byte 8
.byte 13
.byte 0
.byte 3
.byte 14
.byte 73
.byte 19
.ascii "\210\001"
.byte 15
.byte 56
.byte 11
.byte 0
.byte 0
.byte 9
.byte 47
.byte 0
.byte 73
.byte 19
.byte 3
.byte 14
.byte 0
.byte 0
.byte 10
.byte 19
.byte 0
.byte 3
.byte 14
.byte 11
.byte 11
.ascii "\210\001"
.byte 15
.byte 0
.byte 0
.byte 11
.byte 36
.byte 0
.byte 3
.byte 14
.byte 62
.byte 11
.byte 11
.byte 11
.byte 0
.byte 0
.byte 12
.byte 15
.byte 0
.byte 73
.byte 19
.byte 3
.byte 14
.byte 51
.byte 6
.byte 0
.byte 0
.byte 13
.byte 1
.byte 1
.byte 73
.byte 19
.byte 0
.byte 0
.byte 14
.byte 33
.byte 0
.byte 73
.byte 19
.byte 34
.byte 13
.byte 55
.byte 11
.byte 0
.byte 0
.byte 15
.byte 36
.byte 0
.byte 3
.byte 14
.byte 11
.byte 11
.byte 62
.byte 11
.byte 0
.byte 0
.byte 0
.section .debug_info,"",%progbits
.Lcu_begin0:
.long .Ldebug_info_end0-.Ldebug_info_start0
.Ldebug_info_start0:
.short 4
.long .debug_abbrev
.byte 4
.byte 1
.long .Linfo_string0
.short 28
.long .Linfo_string1
.long .Lline_table_start0
.long .Linfo_string2
.long 0
.long .Ldebug_ranges0
.byte 2
.long .Linfo_string3
.byte 3
.long .Lfunc_begin0
.long .Lfunc_end0-.Lfunc_begin0
.byte 1
.byte 87
.long .Linfo_string4
.long .Linfo_string5
.byte 1
.byte 7
.byte 4
.long .Lfunc_begin1
.long .Lfunc_end1-.Lfunc_begin1
.byte 1
.byte 87
.long .Linfo_string6
.long .Linfo_string7
.byte 1
.byte 8
.byte 5
.long .Ltmp3
.long .Ltmp5-.Ltmp3
.byte 6
.byte 2
.byte 125
.byte 12
.long .Linfo_string8
.byte 1
.byte 9
.long 159
.byte 6
.byte 2
.byte 125
.byte 32
.long .Linfo_string36
.byte 1
.byte 9
.long 520
.byte 5
.long .Ltmp4
.long .Ltmp5-.Ltmp4
.byte 6
.byte 2
.byte 145
.byte 126
.long .Linfo_string53
.byte 1
.byte 11
.long 580
.byte 0
.byte 0
.byte 0
.byte 0
.byte 2
.long .Linfo_string9
.byte 2
.long .Linfo_string8
.byte 7
.long .Linfo_string35
.byte 20
.byte 4
.byte 8
.long .Linfo_string10
.long 195
.byte 4
.byte 0
.byte 8
.long .Linfo_string24
.long 406
.byte 1
.byte 0
.byte 0
.byte 0
.byte 2
.long .Linfo_string11
.byte 7
.long .Linfo_string23
.byte 20
.byte 4
.byte 8
.long .Linfo_string12
.long 275
.byte 4
.byte 0
.byte 8
.long .Linfo_string17
.long 275
.byte 4
.byte 4
.byte 8
.long .Linfo_string18
.long 275
.byte 4
.byte 8
.byte 8
.long .Linfo_string19
.long 389
.byte 1
.byte 16
.byte 8
.long .Linfo_string21
.long 389
.byte 1
.byte 17
.byte 8
.long .Linfo_string22
.long 275
.byte 4
.byte 12
.byte 0
.byte 0
.byte 2
.long .Linfo_string13
.byte 7
.long .Linfo_string16
.byte 4
.byte 4
.byte 8
.long .Linfo_string14
.long 382
.byte 4
.byte 0
.byte 0
.byte 0
.byte 2
.long .Linfo_string40
.byte 2
.long .Linfo_string41
.byte 7
.long .Linfo_string49
.byte 1
.byte 1
.byte 8
.long .Linfo_string42
.long 389
.byte 1
.byte 0
.byte 8
.long .Linfo_string43
.long 454
.byte 1
.byte 0
.byte 9
.long 345
.long .Linfo_string46
.byte 0
.byte 0
.byte 7
.long .Linfo_string47
.byte 0
.byte 1
.byte 8
.long .Linfo_string43
.long 471
.byte 1
.byte 0
.byte 9
.long 373
.long .Linfo_string46
.byte 0
.byte 10
.long .Linfo_string44
.byte 0
.byte 1
.byte 0
.byte 0
.byte 11
.long .Linfo_string15
.byte 7
.byte 4
.byte 11
.long .Linfo_string20
.byte 7
.byte 1
.byte 2
.long .Linfo_string25
.byte 2
.long .Linfo_string26
.byte 7
.long .Linfo_string34
.byte 0
.byte 1
.byte 8
.long .Linfo_string27
.long 437
.byte 1
.byte 0
.byte 0
.byte 0
.byte 0
.byte 2
.long .Linfo_string28
.byte 2
.long .Linfo_string29
.byte 7
.long .Linfo_string33
.byte 0
.byte 1
.byte 9
.long 490
.long .Linfo_string32
.byte 0
.byte 7
.long .Linfo_string48
.byte 0
.byte 1
.byte 9
.long 345
.long .Linfo_string32
.byte 0
.byte 7
.long .Linfo_string45
.byte 0
.byte 1
.byte 9
.long 373
.long .Linfo_string32
.byte 0
.byte 0
.byte 0
.byte 12
.long 503
.long .Linfo_string31
.long 0
.byte 11
.long .Linfo_string30
.byte 7
.byte 0
.byte 2
.long .Linfo_string37
.byte 2
.long .Linfo_string38
.byte 7
.long .Linfo_string52
.byte 8
.byte 1
.byte 8
.long .Linfo_string36
.long 560
.byte 1
.byte 0
.byte 0
.byte 7
.long .Linfo_string50
.byte 1
.byte 1
.byte 8
.long .Linfo_string39
.long 305
.byte 1
.byte 0
.byte 0
.byte 0
.byte 0
.byte 13
.long 539
.byte 14
.long 573
.byte 0
.byte 8
.byte 0
.byte 15
.long .Linfo_string51
.byte 8
.byte 7
.byte 11
.long .Linfo_string54
.byte 7
.byte 2
.byte 0
.Ldebug_info_end0:
.section .text.main,"ax",%progbits
.Lsec_end0:
.section .text._ZN12led_roulette18__cortex_m_rt_main17h0b2223cb0e38e500E,"ax",%progbits
.Lsec_end1:
.section .debug_aranges,"",%progbits
.long 36
.short 2
.long .Lcu_begin0
.byte 4
.byte 0
.zero 4,255
.long .Lfunc_begin0
.long .Lsec_end0-.Lfunc_begin0
.long .Lfunc_begin1
.long .Lsec_end1-.Lfunc_begin1
.long 0
.long 0
.section .debug_ranges,"",%progbits
.Ldebug_ranges0:
.long .Lfunc_begin0
.long .Lfunc_end0
.long .Lfunc_begin1
.long .Lfunc_end1
.long 0
.long 0
.section .debug_str,"MS",%progbits,1
.Linfo_string0:
.asciz "clang LLVM (rustc version 1.48.0 (7eac88abb 2020-11-16))"
.Linfo_string1:
.asciz "src/05-led-roulette/src/main.rs"
.Linfo_string2:
.asciz "/home/stefan/projects/discovery"
.Linfo_string3:
.asciz "led_roulette"
.Linfo_string4:
.asciz "main"
.Linfo_string5:
.asciz "__cortex_m_rt_main_trampoline"
.Linfo_string6:
.asciz "_ZN12led_roulette18__cortex_m_rt_main17h0b2223cb0e38e500E"
.Linfo_string7:
.asciz "__cortex_m_rt_main"
.Linfo_string8:
.asciz "delay"
.Linfo_string9:
.asciz "stm32f30x_hal"
.Linfo_string10:
.asciz "clocks"
.Linfo_string11:
.asciz "rcc"
.Linfo_string12:
.asciz "hclk"
.Linfo_string13:
.asciz "time"
.Linfo_string14:
.asciz "__0"
.Linfo_string15:
.asciz "u32"
.Linfo_string16:
.asciz "Hertz"
.Linfo_string17:
.asciz "pclk1"
.Linfo_string18:
.asciz "pclk2"
.Linfo_string19:
.asciz "ppre1"
.Linfo_string20:
.asciz "u8"
.Linfo_string21:
.asciz "ppre2"
.Linfo_string22:
.asciz "sysclk"
.Linfo_string23:
.asciz "Clocks"
.Linfo_string24:
.asciz "syst"
.Linfo_string25:
.asciz "cortex_m"
.Linfo_string26:
.asciz "peripheral"
.Linfo_string27:
.asciz "_marker"
.Linfo_string28:
.asciz "core"
.Linfo_string29:
.asciz "marker"
.Linfo_string30:
.asciz "()"
.Linfo_string31:
.asciz "*const ()"
.Linfo_string32:
.asciz "T"
.Linfo_string33:
.asciz "PhantomData<*const ()>"
.Linfo_string34:
.asciz "SYST"
.Linfo_string35:
.asciz "Delay"
.Linfo_string36:
.asciz "leds"
.Linfo_string37:
.asciz "f3"
.Linfo_string38:
.asciz "led"
.Linfo_string39:
.asciz "pex"
.Linfo_string40:
.asciz "gpio"
.Linfo_string41:
.asciz "gpioe"
.Linfo_string42:
.asciz "i"
.Linfo_string43:
.asciz "_mode"
.Linfo_string44:
.asciz "PushPull"
.Linfo_string45:
.asciz "PhantomData<stm32f30x_hal::gpio::PushPull>"
.Linfo_string46:
.asciz "MODE"
.Linfo_string47:
.asciz "Output<stm32f30x_hal::gpio::PushPull>"
.Linfo_string48:
.asciz "PhantomData<stm32f30x_hal::gpio::Output<stm32f30x_hal::gpio::PushPull>>"
.Linfo_string49:
.asciz "PEx<stm32f30x_hal::gpio::Output<stm32f30x_hal::gpio::PushPull>>"
.Linfo_string50:
.asciz "Led"
.Linfo_string51:
.asciz "__ARRAY_SIZE_TYPE__"
.Linfo_string52:
.asciz "Leds"
.Linfo_string53:
.asciz "half_period"
.Linfo_string54:
.asciz "u16"
.section .debug_pubnames,"",%progbits
.long .LpubNames_end0-.LpubNames_begin0
.LpubNames_begin0:
.short 2
.long .Lcu_begin0
.long 588
.long 396
.asciz "cortex_m"
.long 43
.asciz "__cortex_m_rt_main_trampoline"
.long 432
.asciz "marker"
.long 38
.asciz "led_roulette"
.long 64
.asciz "__cortex_m_rt_main"
.long 427
.asciz "core"
.long 401
.asciz "peripheral"
.long 149
.asciz "stm32f30x_hal"
.long 270
.asciz "time"
.long 154
.asciz "delay"
.long 295
.asciz "gpio"
.long 300
.asciz "gpioe"
.long 515
.asciz "led"
.long 190
.asciz "rcc"
.long 510
.asciz "f3"
.long 0
.LpubNames_end0:
.section .debug_pubtypes,"",%progbits
.long .LpubTypes_end0-.LpubTypes_begin0
.LpubTypes_begin0:
.short 2
.long .Lcu_begin0
.long 588
.long 490
.asciz "*const ()"
.long 580
.asciz "u16"
.long 520
.asciz "Leds"
.long 437
.asciz "PhantomData<*const ()>"
.long 275
.asciz "Hertz"
.long 159
.asciz "Delay"
.long 389
.asciz "u8"
.long 503
.asciz "()"
.long 406
.asciz "SYST"
.long 539
.asciz "Led"
.long 345
.asciz "Output<stm32f30x_hal::gpio::PushPull>"
.long 305
.asciz "PEx<stm32f30x_hal::gpio::Output<stm32f30x_hal::gpio::PushPull>>"
.long 382
.asciz "u32"
.long 471
.asciz "PhantomData<stm32f30x_hal::gpio::PushPull>"
.long 454
.asciz "PhantomData<stm32f30x_hal::gpio::Output<stm32f30x_hal::gpio::PushPull>>"
.long 373
.asciz "PushPull"
.long 195
.asciz "Clocks"
.long 0
.LpubTypes_end0:
.section ".note.GNU-stack","",%progbits
.eabi_attribute 30, 5
.section .debug_line,"",%progbits
.Lline_table_start0:
I think the relevant part of this output is section .LBB1_4 where we see that the constant 500 gets moved into r1 before calling the delay function instead of loading the variable from the stack.
Explanation is given in issue #236 , although this does not resolve it. Maybe simply remove this gdb example from the book?
