TMS570LC4357: Migration to Clang - Issue with Conditional Assembly Directives

Fernando Aguado

Part Number: TMS570LC4357

Hi, we are working with the TMS570LC4357 MCU with a project migrated to TI Clang v3.0.0.STS. I am trying to use conditional assembly and saw this in the TI Safety Library which we are also using:

However, after testing (by clobbering the instructions to induce an error) it seems that the expression $$isdefed is returning 0. _VFP_SUPPORT_ is defined in the project's predefined symbols as the instructions had stated. Then I found this in the Clang migration guide:

However, when attempting to use .ifdef, the following happens:

over 2 years ago

0 Fernando Aguado over 2 years ago

Prodigy 40 points

To add to this, I have noticed this as well:

0 QJ Wang over 2 years ago in reply to Fernando Aguado

TI__Guru**** 198746 points

Please replace _VFP_SUPPORT_ with __TI_VFP_SUPPORT__

https://software-dl.ti.com/codegen/docs/tiarmclang/compiler_tools_user_guide/latex/TI_Arm_Clang_Compiler_Tools_User_Guide.pdf

0 Fernando Aguado over 2 years ago in reply to QJ Wang

Prodigy 40 points

It worked with $$defined(__TI_VFP_SUPPORT__), but I'm confused, why is the guide you sent me saying that macro should be replaced with __ARM_FP_ (which doesn't work by the way).

Also, how do I use conditional assembly with my own predefined macros?

0 QJ Wang over 2 years ago in reply to Fernando Aguado

TI__Guru**** 198746 points

Hi Fermando,

For safety application, TI ARMCL is strongly recommended for Hercules devices.

0 Fernando Aguado over 2 years ago in reply to QJ Wang

Prodigy 40 points

So there is no way to do this with Clang? And any info about the documentation being wrong?

0 QJ Wang over 2 years ago in reply to Fernando Aguado

TI__Guru**** 198746 points

#if defined(__ARM_FP) can be used in C/C++ code.

.if __TI_VFP_SUPPORT__ is used in assembly code

Some macro symbols are shared by armcl and tiarmclang.

0 QJ Wang over 2 years ago in reply to QJ Wang

TI__Guru**** 198746 points

https://software-dl.ti.com/codegen/docs/tiarmclang/compiler_tools_user_guide/migration_guide/index.html

0 Fernando Aguado over 2 years ago in reply to QJ Wang

Prodigy 40 points

Thanks for the link. I understand now, .asm files are being silently passed onto the legacy assembler via the flag -xti-asm which explains the warnings for unused arguments. .asm files must be translated to GNU syntax and the file extension changed to .s or .S (depending on whether the file needs preprocessing).

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TMS570LC4357: Migration to Clang - Issue with Conditional Assembly Directives