Rule in question: c:S836 SonarQube warning: The result of the right shift is undefined due to shifting by '8', which is greater or equal to the width of type 'uint16_t' SonarQube Server: 9.2.4 SonarScanner 4.6.2.2472 TI Code Composer 9.0.1 Relevant code snippets: #include <stdint.h> typedef e…

Hello @mikeschlag , So, this is what I expected… We currently consider that a char is 8-bits (and it’s not something that can be easily changed). Since uint16_t is a typedef to unsigned int, and since sizeof(int) (and therefore sizeof(unsigned int) is 1, we also believe that uint16_t is 8 bits. We …

[image] Mike Schlagenhauf: uint32/16/8 types are TI-defined in their <stdint.h> header file Hello @mikeschlag , Could you tell us how those types are defined there? We don’t support very well architectures where CHAR_BIT is not 8 (which might be the case, according to what you said), so for …

On this TI architecture (TMS320C2000 series), 8-bit values are in-memory stored in 16-bit spaces, and accessed as such, regardless of their typing. In TI’s stdint.h file, they define as follows: typedef signed char int8_t; typedef unsigned char uint8_t; typedef int in…

Thank you for that information. Can you also tell us what are the values of sizeof(int) and sizeof(short) on this platform?

I will ask a dev to run that and let me know, and I will update this here when I have that info. Additionally, we have now tried the last case I mentioned above, and it’s still showing the same warning. Of note, this line of code does not generate the warning, as a native-typed uint16_t: grp_head…

Hi Mike, Could you then also ask him what is sizeof(SCI_GROUP_ID_t)? Thanks,

I feel like I should point out, the size of 1 here is expected because of the 16-bit minimum size of this processor. sizeof(char) comes out as 1 as well.

Okay, thanks for the information, we’ll proceed as such!

S836 False Positive with right shift on TI Code Composer

Rules and Languages Report False-positive / False-negative...

mikeschlag (Mike Schlagenhauf) July 1, 2022, 3:35pm 8

For this architecture, all three sizeof checks came back with a value of 1.

Need support for Texas Instruments C28x microcontrollers

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S836 False Positive with right shift on TI Code Composer

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