µVISION: Options for xxx - C/C++ - Warnings settings are inconsistent

Information in this knowledgebase article applies to:

• Keil MDK v. 5.20 and older
• Keil µVision IDE v. 5.20.0.0 and older
• ARM Compiler 5 (Armcc) v. 5.06u2 (build 183) and older
• ARM Compiler 6 (Armclang) v. 6.4 and older
• Keil MDK Middleware v. 7.1.0 and older
• CMSIS-Pack v. 4.5.0 and older
• Compiler Pack v. 1.1.0 and older

QUESTION

In µVision I selected Pedantic in Options for Target - C/C++(AC6) - Warnings for the entire target, as shown in the following screenshot.

Then I click on the individual source code file name in the Project window and select "All Warnings" in Options for File - C/C++(AC6) - Warnings, instead of Pedantic, as shown in the following screenshot. But from the compilation output of my project, I can see that the source code file still inherits the warnings from the Options for Target waarings setting.

However, as long as I modified something in Options for File for an individual file, with a star mark shown up on the file icon as shown in the following screenshot, this deviation of the warnings setting for individual files will take effect. That means "All Warnings" will be selected to compiler this file instead of "Pedantic" inherited from Options for Target. Many additional warnings are generated in the compilation output. Is it a bug or feature of µVision?

CAUSE

This is actually a bug in MDK v5.20 and all older MDK v5.x versions. By default this warnings setting should inherit and depend on options on parent µVision group levels, where "unspecified" instead of "All Warnings" should be selected by default for this warnings setting.

RESOLUTION

By updating MDK-ARM to a version newer than v5.20 can resolve this issue.

MORE INFORMATION

• Refer to Arm C/C++ (AC6) Compiler in the µVision User's Guide.

Last Reviewed: Wednesday, February 24, 2021