Thanks. Is there any solution could help to find which file need to be modified? It would be very useful in some very large project. I used to try stm32h7+Hal driver+lvgl library, LTO did a 20%+ size reduction.ESP_igrr wrote: ↑Fri Nov 18, 2022 10:31 pmHi Stat_headcrabed,
The problem with enabling LTO support in esp-idf is not architecture-specific. It has to do with the fact that IDF uses -ffunction-sections in combination with linker script rules to place certain functions or whole object files into specific memory regions.
With LTO enabled, functions may end up in intermediate object files generated by the LTO process. This prevents the linker script rules from working.
The "solution" to this would be to selectively disable LTO for object files affected by linker script rules. However we don't yet have a mechanism to do this automatically or to make sure that LTO is correctly disabled for all the object files which have related linker script rules.
I'm sorry, I couldn't parse this sentence. Could you explain what you mean in a bit more detail?Stat_headcrabed wrote: Is there any solution could help to find which file need to be modified?
Sorry for my bad English. You said "selectively disable LTO for object files affected by linker script rules" would solve this problem, how could I find those affected files?
Code: Select all
*libesp_hw_support.a:esp_memory_utils.*(.rodata .rodata.* .sdata2 .sdata2.* .srodata .srodata.*)Code: Select all
*libriscv.a:vectors.*(.literal .literal.* .text .text.*)
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*(EXCLUDE_FILE(*libesp_ringbuf.a *libfreertos.a *libgcov.a *librtc.a *libapp_trace.a:app_trace.* *libapp_trace.a:app_trace_util.* *libapp_trace.a:port_uart.* *libesp_event.a:default_event_loop.* *libesp_event.a:esp_event.* *libesp_hw_support.a:cpu.* *libesp_hw_support.a:esp_memory_utils.* *libesp_hw_support.a:rtc_clk.* *libesp_hw_support.a:rtc_init.* *libesp_hw_support.a:rtc_pm.* *libesp_hw_support.a:rtc_sleep.* *libesp_hw_support.a:rtc_time.* *libesp_hw_support.a:systimer.* *libesp_rom.a:esp_rom_regi2c.* *libesp_rom.a:esp_rom_spiflash.* *libesp_rom.a:esp_rom_systimer.* *libesp_system.a:esp_err.* *libesp_system.a:esp_system.* *libesp_system.a:ubsan.* *libgcc.a:_divsf3.* *libgcc.a:lib2funcs.* *libgcc.a:save-restore.* *libhal.a:cache_hal.* *libhal.a:i2c_hal_iram.* *libhal.a:ledc_hal_iram.* *libhal.a:mmu_hal.* *libhal.a:spi_flash_encrypt_hal_iram.* *libhal.a:spi_flash_hal_gpspi.* *libhal.a:spi_flash_hal_iram.* *libhal.a:spi_hal_iram.* *libhal.a:spi_slave_hal_iram.* *libhal.a:systimer_hal.* *libhal.a:wdt_hal_iram.* *libheap.a:multi_heap.* *libheap.a:tlsf.* *liblog.a:log.* *liblog.a:log_freertos.* *libnewlib.a:abort.* *libnewlib.a:assert.* *libnewlib.a:heap.* *libnewlib.a:stdatomic.* *libriscv.a:interrupt.* *libriscv.a:vectors.* *libsoc.a:lldesc.* *libspi_flash.a:flash_brownout_hook.* *libspi_flash.a:memspi_host_driver.* *libspi_flash.a:spi_flash_chip_boya.* *libspi_flash.a:spi_flash_chip_gd.* *libspi_flash.a:spi_flash_chip_generic.* *libspi_flash.a:spi_flash_chip_issi.* *libspi_flash.a:spi_flash_chip_mxic.* *libspi_flash.a:spi_flash_chip_th.* *libspi_flash.a:spi_flash_chip_winbond.*) .literal EXCLUDE_FILE(*libesp_ringbuf.a *libfreertos.a *libgcov.a *librtc.a *libapp_trace.a:app_trace.* *libapp_trace.a:app_trace_util.* *libapp_trace.a:port_uart.* *libesp_event.a:default_event_loop.* *libesp_event.a:esp_event.* *libesp_hw_support.a:cpu.* *libesp_hw_support.a:esp_memory_utils.* *libesp_hw_support.a:rtc_clk.* *libesp_hw_support.a:rtc_init.* *libesp_hw_support.a:rtc_pm.* *libesp_hw_support.a:rtc_sleep.* *libesp_hw_support.a:rtc_time.* *libesp_hw_support.a:systimer.* *libesp_rom.a:esp_rom_regi2c.* *libesp_rom.a:esp_rom_spiflash.* *libesp_rom.a:esp_rom_systimer.* *libesp_system.a:esp_err.* *libesp_system.a:esp_system.* *libesp_system.a:ubsan.* *libgcc.a:_divsf3.* *libgcc.a:lib2funcs.* *libgcc.a:save-restore.* *libhal.a:cache_hal.* *libhal.a:i2c_hal_iram.* *libhal.a:ledc_hal_iram.* *libhal.a:mmu_hal.* *libhal.a:spi_flash_encrypt_hal_iram.* *libhal.a:spi_flash_hal_gpspi.* *libhal.a:spi_flash_hal_iram.* *libhal.a:spi_hal_iram.* *libhal.a:spi_slave_hal_iram.* *libhal.a:systimer_hal.* *libhal.a:wdt_hal_iram.* *libheap.a:multi_heap.* *libheap.a:tlsf.* *liblog.a:log.* *liblog.a:log_freertos.* *libnewlib.a:abort.* *libnewlib.a:assert.* *libnewlib.a:heap.* *libnewlib.a:stdatomic.* *libriscv.a:interrupt.* *libriscv.a:vectors.* *libsoc.a:lldesc.* *libspi_flash.a:flash_brownout_hook.* *libspi_flash.a:memspi_host_driver.* *libspi_flash.a:spi_flash_chip_boya.* *libspi_flash.a:spi_flash_chip_gd.* *libspi_flash.a:spi_flash_chip_generic.* *libspi_flash.a:spi_flash_chip_issi.* *libspi_flash.a:spi_flash_chip_mxic.* *libspi_flash.a:spi_flash_chip_th.* *libspi_flash.a:spi_flash_chip_winbond.*) .literal.* EXCLUDE_FILE(*libesp_ringbuf.a *libfreertos.a *libgcov.a *librtc.a *libapp_trace.a:app_trace.* *libapp_trace.a:app_trace_util.* *libapp_trace.a:port_uart.* *libesp_event.a:default_event_loop.* *libesp_event.a:esp_event.* *libesp_hw_support.a:cpu.* *libesp_hw_support.a:esp_memory_utils.* *libesp_hw_support.a:rtc_clk.* *libesp_hw_support.a:rtc_init.* *libesp_hw_support.a:rtc_pm.* *libesp_hw_support.a:rtc_sleep.* *libesp_hw_support.a:rtc_time.* *libesp_hw_support.a:systimer.* *libesp_rom.a:esp_rom_regi2c.* *libesp_rom.a:esp_rom_spiflash.* *libesp_rom.a:esp_rom_systimer.* *libesp_system.a:esp_err.* *libesp_system.a:esp_system.* *libesp_system.a:ubsan.* *libgcc.a:_divsf3.* *libgcc.a:lib2funcs.* *libgcc.a:save-restore.* *libhal.a:cache_hal.* *libhal.a:i2c_hal_iram.* *libhal.a:ledc_hal_iram.* *libhal.a:mmu_hal.* *libhal.a:spi_flash_encrypt_hal_iram.* *libhal.a:spi_flash_hal_gpspi.* *libhal.a:spi_flash_hal_iram.* *libhal.a:spi_hal_iram.* *libhal.a:spi_slave_hal_iram.* *libhal.a:systimer_hal.* *libhal.a:wdt_hal_iram.* *libheap.a:multi_heap.* *libheap.a:tlsf.* *liblog.a:log.* *liblog.a:log_freertos.* *libnewlib.a:abort.* *libnewlib.a:assert.* *libnewlib.a:heap.* *libnewlib.a:stdatomic.* *libriscv.a:interrupt.* *libriscv.a:vectors.* *libsoc.a:lldesc.* *libspi_flash.a:flash_brownout_hook.* *libspi_flash.a:memspi_host_driver.* *libspi_flash.a:spi_flash_chip_boya.* *libspi_flash.a:spi_flash_chip_gd.* *libspi_flash.a:spi_flash_chip_generic.* *libspi_flash.a:spi_flash_chip_issi.* *libspi_flash.a:spi_flash_chip_mxic.* *libspi_flash.a:spi_flash_chip_th.* *libspi_flash.a:spi_flash_chip_winbond.*) .text EXCLUDE_FILE(*libesp_ringbuf.a *libfreertos.a *libgcov.a *librtc.a *libapp_trace.a:app_trace.* *libapp_trace.a:app_trace_util.* *libapp_trace.a:port_uart.* *libesp_event.a:default_event_loop.* *libesp_event.a:esp_event.* *libesp_hw_support.a:cpu.* *libesp_hw_support.a:esp_memory_utils.* *libesp_hw_support.a:rtc_clk.* *libesp_hw_support.a:rtc_init.* *libesp_hw_support.a:rtc_pm.* *libesp_hw_support.a:rtc_sleep.* *libesp_hw_support.a:rtc_time.* *libesp_hw_support.a:systimer.* *libesp_rom.a:esp_rom_regi2c.* *libesp_rom.a:esp_rom_spiflash.* *libesp_rom.a:esp_rom_systimer.* *libesp_system.a:esp_err.* *libesp_system.a:esp_system.* *libesp_system.a:ubsan.* *libgcc.a:_divsf3.* *libgcc.a:lib2funcs.* *libgcc.a:save-restore.* *libhal.a:cache_hal.* *libhal.a:i2c_hal_iram.* *libhal.a:ledc_hal_iram.* *libhal.a:mmu_hal.* *libhal.a:spi_flash_encrypt_hal_iram.* *libhal.a:spi_flash_hal_gpspi.* *libhal.a:spi_flash_hal_iram.* *libhal.a:spi_hal_iram.* *libhal.a:spi_slave_hal_iram.* *libhal.a:systimer_hal.* *libhal.a:wdt_hal_iram.* *libheap.a:multi_heap.* *libheap.a:tlsf.* *liblog.a:log.* *liblog.a:log_freertos.* *libnewlib.a:abort.* *libnewlib.a:assert.* *libnewlib.a:heap.* *libnewlib.a:stdatomic.* *libriscv.a:interrupt.* *libriscv.a:vectors.* *libsoc.a:lldesc.* *libspi_flash.a:flash_brownout_hook.* *libspi_flash.a:memspi_host_driver.* *libspi_flash.a:spi_flash_chip_boya.* *libspi_flash.a:spi_flash_chip_gd.* *libspi_flash.a:spi_flash_chip_generic.* *libspi_flash.a:spi_flash_chip_issi.* *libspi_flash.a:spi_flash_chip_mxic.* *libspi_flash.a:spi_flash_chip_th.* *libspi_flash.a:spi_flash_chip_winbond.*) .text.*)
Thanks, I'll try this.ESP_igrr wrote: ↑Fri Nov 25, 2022 3:48 pmUnfortunately I don't yet know of a way to reliably find all the files which are affected by linker script rules.
After you have built an app, you can take a look at the generated linker script, it should be located in build/esp-idf/esp_system/ld/sections.ld.
This file contains numerous lines which look like this:This means that there is a static library libesp_hw_support.a and an object file esp_memory_utils.c.obj inside it. In most cases this can be used to find the file "esp_memory_utils.c" in "esp_hw_support" component and add a rule in CMake to disable LTO when compiling that file.Code: Select all
*libesp_hw_support.a:esp_memory_utils.*(.rodata .rodata.* .sdata2 .sdata2.* .srodata .srodata.*)
Here's another one:What might not be clear here, is vectors.* object file produced from a .c or from a .S file? We might be able to use a glob expression and check which file is actually present in the repository.Code: Select all
*libriscv.a:vectors.*(.literal .literal.* .text .text.*)
Some rules are more tricky. This one, for instance:We probably need to disable LTO for all these files in order for the rule to work correctly.Code: Select all
*(EXCLUDE_FILE(*libesp_ringbuf.a *libfreertos.a *libgcov.a *librtc.a *libapp_trace.a:app_trace.* *libapp_trace.a:app_trace_util.* *libapp_trace.a:port_uart.* *libesp_event.a:default_event_loop.* *libesp_event.a:esp_event.* *libesp_hw_support.a:cpu.* *libesp_hw_support.a:esp_memory_utils.* *libesp_hw_support.a:rtc_clk.* *libesp_hw_support.a:rtc_init.* *libesp_hw_support.a:rtc_pm.* *libesp_hw_support.a:rtc_sleep.* *libesp_hw_support.a:rtc_time.* *libesp_hw_support.a:systimer.* *libesp_rom.a:esp_rom_regi2c.* *libesp_rom.a:esp_rom_spiflash.* *libesp_rom.a:esp_rom_systimer.* *libesp_system.a:esp_err.* *libesp_system.a:esp_system.* *libesp_system.a:ubsan.* *libgcc.a:_divsf3.* *libgcc.a:lib2funcs.* *libgcc.a:save-restore.* *libhal.a:cache_hal.* *libhal.a:i2c_hal_iram.* *libhal.a:ledc_hal_iram.* *libhal.a:mmu_hal.* *libhal.a:spi_flash_encrypt_hal_iram.* *libhal.a:spi_flash_hal_gpspi.* *libhal.a:spi_flash_hal_iram.* *libhal.a:spi_hal_iram.* *libhal.a:spi_slave_hal_iram.* *libhal.a:systimer_hal.* *libhal.a:wdt_hal_iram.* *libheap.a:multi_heap.* *libheap.a:tlsf.* *liblog.a:log.* *liblog.a:log_freertos.* *libnewlib.a:abort.* *libnewlib.a:assert.* *libnewlib.a:heap.* *libnewlib.a:stdatomic.* *libriscv.a:interrupt.* *libriscv.a:vectors.* *libsoc.a:lldesc.* *libspi_flash.a:flash_brownout_hook.* *libspi_flash.a:memspi_host_driver.* *libspi_flash.a:spi_flash_chip_boya.* *libspi_flash.a:spi_flash_chip_gd.* *libspi_flash.a:spi_flash_chip_generic.* *libspi_flash.a:spi_flash_chip_issi.* *libspi_flash.a:spi_flash_chip_mxic.* *libspi_flash.a:spi_flash_chip_th.* *libspi_flash.a:spi_flash_chip_winbond.*) .literal EXCLUDE_FILE(*libesp_ringbuf.a *libfreertos.a *libgcov.a *librtc.a *libapp_trace.a:app_trace.* *libapp_trace.a:app_trace_util.* *libapp_trace.a:port_uart.* *libesp_event.a:default_event_loop.* *libesp_event.a:esp_event.* *libesp_hw_support.a:cpu.* *libesp_hw_support.a:esp_memory_utils.* *libesp_hw_support.a:rtc_clk.* *libesp_hw_support.a:rtc_init.* *libesp_hw_support.a:rtc_pm.* *libesp_hw_support.a:rtc_sleep.* *libesp_hw_support.a:rtc_time.* *libesp_hw_support.a:systimer.* *libesp_rom.a:esp_rom_regi2c.* *libesp_rom.a:esp_rom_spiflash.* *libesp_rom.a:esp_rom_systimer.* *libesp_system.a:esp_err.* *libesp_system.a:esp_system.* *libesp_system.a:ubsan.* *libgcc.a:_divsf3.* *libgcc.a:lib2funcs.* *libgcc.a:save-restore.* *libhal.a:cache_hal.* *libhal.a:i2c_hal_iram.* *libhal.a:ledc_hal_iram.* *libhal.a:mmu_hal.* *libhal.a:spi_flash_encrypt_hal_iram.* *libhal.a:spi_flash_hal_gpspi.* *libhal.a:spi_flash_hal_iram.* *libhal.a:spi_hal_iram.* *libhal.a:spi_slave_hal_iram.* *libhal.a:systimer_hal.* *libhal.a:wdt_hal_iram.* *libheap.a:multi_heap.* *libheap.a:tlsf.* *liblog.a:log.* *liblog.a:log_freertos.* *libnewlib.a:abort.* *libnewlib.a:assert.* *libnewlib.a:heap.* *libnewlib.a:stdatomic.* *libriscv.a:interrupt.* *libriscv.a:vectors.* *libsoc.a:lldesc.* *libspi_flash.a:flash_brownout_hook.* *libspi_flash.a:memspi_host_driver.* *libspi_flash.a:spi_flash_chip_boya.* *libspi_flash.a:spi_flash_chip_gd.* *libspi_flash.a:spi_flash_chip_generic.* *libspi_flash.a:spi_flash_chip_issi.* *libspi_flash.a:spi_flash_chip_mxic.* *libspi_flash.a:spi_flash_chip_th.* *libspi_flash.a:spi_flash_chip_winbond.*) .literal.* EXCLUDE_FILE(*libesp_ringbuf.a *libfreertos.a *libgcov.a *librtc.a *libapp_trace.a:app_trace.* *libapp_trace.a:app_trace_util.* *libapp_trace.a:port_uart.* *libesp_event.a:default_event_loop.* *libesp_event.a:esp_event.* *libesp_hw_support.a:cpu.* *libesp_hw_support.a:esp_memory_utils.* *libesp_hw_support.a:rtc_clk.* *libesp_hw_support.a:rtc_init.* *libesp_hw_support.a:rtc_pm.* *libesp_hw_support.a:rtc_sleep.* *libesp_hw_support.a:rtc_time.* *libesp_hw_support.a:systimer.* *libesp_rom.a:esp_rom_regi2c.* *libesp_rom.a:esp_rom_spiflash.* *libesp_rom.a:esp_rom_systimer.* *libesp_system.a:esp_err.* *libesp_system.a:esp_system.* *libesp_system.a:ubsan.* *libgcc.a:_divsf3.* *libgcc.a:lib2funcs.* *libgcc.a:save-restore.* *libhal.a:cache_hal.* *libhal.a:i2c_hal_iram.* *libhal.a:ledc_hal_iram.* *libhal.a:mmu_hal.* *libhal.a:spi_flash_encrypt_hal_iram.* *libhal.a:spi_flash_hal_gpspi.* *libhal.a:spi_flash_hal_iram.* *libhal.a:spi_hal_iram.* *libhal.a:spi_slave_hal_iram.* *libhal.a:systimer_hal.* *libhal.a:wdt_hal_iram.* *libheap.a:multi_heap.* *libheap.a:tlsf.* *liblog.a:log.* *liblog.a:log_freertos.* *libnewlib.a:abort.* *libnewlib.a:assert.* *libnewlib.a:heap.* *libnewlib.a:stdatomic.* *libriscv.a:interrupt.* *libriscv.a:vectors.* *libsoc.a:lldesc.* *libspi_flash.a:flash_brownout_hook.* *libspi_flash.a:memspi_host_driver.* *libspi_flash.a:spi_flash_chip_boya.* *libspi_flash.a:spi_flash_chip_gd.* *libspi_flash.a:spi_flash_chip_generic.* *libspi_flash.a:spi_flash_chip_issi.* *libspi_flash.a:spi_flash_chip_mxic.* *libspi_flash.a:spi_flash_chip_th.* *libspi_flash.a:spi_flash_chip_winbond.*) .text EXCLUDE_FILE(*libesp_ringbuf.a *libfreertos.a *libgcov.a *librtc.a *libapp_trace.a:app_trace.* *libapp_trace.a:app_trace_util.* *libapp_trace.a:port_uart.* *libesp_event.a:default_event_loop.* *libesp_event.a:esp_event.* *libesp_hw_support.a:cpu.* *libesp_hw_support.a:esp_memory_utils.* *libesp_hw_support.a:rtc_clk.* *libesp_hw_support.a:rtc_init.* *libesp_hw_support.a:rtc_pm.* *libesp_hw_support.a:rtc_sleep.* *libesp_hw_support.a:rtc_time.* *libesp_hw_support.a:systimer.* *libesp_rom.a:esp_rom_regi2c.* *libesp_rom.a:esp_rom_spiflash.* *libesp_rom.a:esp_rom_systimer.* *libesp_system.a:esp_err.* *libesp_system.a:esp_system.* *libesp_system.a:ubsan.* *libgcc.a:_divsf3.* *libgcc.a:lib2funcs.* *libgcc.a:save-restore.* *libhal.a:cache_hal.* *libhal.a:i2c_hal_iram.* *libhal.a:ledc_hal_iram.* *libhal.a:mmu_hal.* *libhal.a:spi_flash_encrypt_hal_iram.* *libhal.a:spi_flash_hal_gpspi.* *libhal.a:spi_flash_hal_iram.* *libhal.a:spi_hal_iram.* *libhal.a:spi_slave_hal_iram.* *libhal.a:systimer_hal.* *libhal.a:wdt_hal_iram.* *libheap.a:multi_heap.* *libheap.a:tlsf.* *liblog.a:log.* *liblog.a:log_freertos.* *libnewlib.a:abort.* *libnewlib.a:assert.* *libnewlib.a:heap.* *libnewlib.a:stdatomic.* *libriscv.a:interrupt.* *libriscv.a:vectors.* *libsoc.a:lldesc.* *libspi_flash.a:flash_brownout_hook.* *libspi_flash.a:memspi_host_driver.* *libspi_flash.a:spi_flash_chip_boya.* *libspi_flash.a:spi_flash_chip_gd.* *libspi_flash.a:spi_flash_chip_generic.* *libspi_flash.a:spi_flash_chip_issi.* *libspi_flash.a:spi_flash_chip_mxic.* *libspi_flash.a:spi_flash_chip_th.* *libspi_flash.a:spi_flash_chip_winbond.*) .text.*)