tools: fix toolchain extend inc paths

[0xc0170]

inc paths might be a list or might not be (just single string). If they don't, we are ending up with non valid include paths (one letter include paths).
This as result would not compile.

As inc_dirs might be just D:/SomePath, extend this would lead to producing [D, :, S..........] thus we were not able to compile with tools/build.py for instance. This is an example I was seeing
[DEBUG] INC DIRS: ['C', ':', '\\', 'C', 'o', 'd', 'e', '\\', 'm', 'b', 'e', 'd', '-', 'o', 's', '\\', 'B', 'U', 'I', 'L', 'D', '\\', 'm', 'b', 'e', 'd', '\\', '.', 't', 'e', 'm', 'p', '\\', 'T', 'A', 'R', 'G', 'E', 'T', '_', 'N', 'U', 'C', 'L', 'E', 'O', '_', 'F', '4', '1', '1', 'R', 'E', '\\', 'T', 'O', 'O', 'L', 'C', 'H', 'A', 'I', 'N', '_', 'I', 'A', 'R']

@jeromecoutant This should fix the issue you were seeing today with IAR

@theotherjimmy please review, we handle inc dirs in scan resources similarly, might be better to always consider this as a list, or hack like this. You can take this patch and just push to my branch.

[0xc0170]

Without this patch, we would get

[DEBUG] Return: 3
Traceback (most recent call last):
  File "tools/build.py", line 212, in <module>
    build_profile=profile)
  File "mbed-os\tools\build_api.py", line 1014, in build_mbed_libs
    objects = toolchain.compile_sources(resources, tmp_path)
  File "mbed-os\tools\toolchains\__init__.py", line 908, in compile_sources
    return self.compile_seq(queue, objects)
  File "mbed-os\tools\toolchains\__init__.py", line 922, in compile_seq
    res['command']
  File "mbed-os\tools\toolchains\__init__.py", line 1064, in compile_output
    raise ToolException(_stderr)
ToolException

@bridadan This looks similar to what we seen with CI in the last 2 days, this might fix it ! However I wonder why this problem has not been seen earlier.

[jeromecoutant]

Verified
Thx

[theotherjimmy]

A more current pythonic way to do this is:

if isinstance(inc_dirs, list):

Please use that form.

[0xc0170]

will update

[theotherjimmy]

Thanks!

[theotherjimmy]

Meant to request changes. :(

[theotherjimmy]

I think that the confusion came from the fact that the argument is plural, implying an unordered set of include directories.

[0xc0170]

Fixed, rebased

[theotherjimmy]

Awesome. Thanks!

[0xc0170]

/morph test

[0xc0170]

/morph export-build

[mbed-bot]

Result: SUCCESS

Your command has finished executing! Here's what you wrote!

/morph export-build

Output

mbed Build Number: 86

All exports and builds passed!

[mbed-bot]

Result: FAILURE

Your command has finished executing! Here's what you wrote!

/morph test

Output

mbed Build Number: 794

Test failed!

[studavekar]

/morph test

[mbed-bot]

Result: SUCCESS

Your command has finished executing! Here's what you wrote!

/morph test

Output

mbed Build Number: 795

All builds and test passed!