How to compile littlevgl v7.11.0 with c++14 on iar 8.32.2


when compiling littlevgl v7.11.0 with c++14 on iar 8.32.2, reporting errors about LV_COLOR_MAKE(r, g, b); which is “expected an expression”

What MCU/Processor/Board and compiler are you using?


What LVGL version are you using?


What do you want to achieve?

compile littlevgl with c++14 on iar 8.32.2

What have you tried so far?

when compiling static inline lv_color_t lv_color_make(uint8_t r, uint8_t g, uint8_t b) and lv_color_t ct = LV_COLOR_TRANSP; compiler complaining about “expected an expression”

Code to reproduce

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Screenshot and/or video

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Hi John,
Welcome to the wonderful world of LVGL!
This is more an FYI than a fix to your issue. I use LVGL with IAR Workbench 8.50.9 targeting an iMXRT1064 with no issues. However, I compile LVGL as a C library in a separate project. When I switch to C++ I get a whole slew of other errors (838 in total) along the lines of
Error[Pe144]: a value of type "void *" cannot be used to initialize an entity of type "lv_.... so my guess is you have “fixed” those in some way before arriving at the issue with lv_color_make.
Also, in my application I use a mixed project (C & C++) with no problem i.e. I have the compiler set to Auto (extension-based)

LVGL headers should be able to be included by C++ code without issues, but the source files themselves need to be compiled as C code.

hi jupeos, embeddedt,thank you all, thanks for your comments.

To avoid compiling the macro #define LV_COLOR_MAKE(r8, g8, b8) LV_CONCAT(LV_COLOR_MAKE, LV_COLOR_DEPTH)(r8, g8, b8) ,

so changing static inline lv_color_t lv_color_make(uint8_t r, uint8_t g, uint8_t b) into an usual function call which is lv_color_t lv_color_make(uint8_t r, uint8_t g, uint8_t b),

then the compiler of c++14 on iar 8.32.2 compiled lvgl_v7.11.0 without errors.

For some reason I suppose the c++14 compiler somehow doesn’t handle the LV_COLOR_MAKE marco as expected.