[Scons-users] adding text to compile line

[Bill Deegan]

Jeremy,

Any chance you could contribute that to the
https://github.com/SCons/scons-contrib repo?

Pretty interesting.
-Bill

On Sun, Jan 21, 2024 at 1:40 PM Jeremy Elson <jelson at gmail.com> wrote:

> This is a lot more than what OP asked for, but I'll describe the custom
> output code I wrote for one of my Scons-based build systems.(It's not
> open-source, so I can't link to the full code.)
>
> My goal was to replace all the raw command-line output with something like:
>
> Compiling src/app/foo.c
> Compiling src/app/bar.c
> Linking build/libs/libfoo.a
> Linking build/output/foo.elf
> Signing build/output/foo.elf
>
> In this case, "Compiling" and "Linking" are standard scons rules;
> "Signing" is a custom builder. The trick is that for some of the outputs,
> such as Compiling, should show the name of the source. Others, such as
> Linking, show the name of the target.
>
> First, I defined a class called SpinnerPrinter that looks sort of like
> this:
>
> class SpinnerPrinter:
> SPINNER = '<<spinner>>'
> SOURCE = 'src'
> TARGET = 'trg'
>
> def spin_source(s):
> return SpinnerPrinter.SPINNER + SpinnerPrinter.SOURCE + s
>
> def spin_target(s):
> return SpinnerPrinter.SPINNER + SpinnerPrinter.TARGET + s
>
> Then, in my function that sets up the scons build env, I have code that
> looks like the examples below. I call spin_source to indicate the build
> output should use the source filenames, and spin_target to show it should
> be target. The COMSTRs all end up being configuration strings for the
> custom output function.
>
> if not build_options.verbose:
> env['PRINT_CMD_LINE_FUNC'] = SpinnerPrinter().spinner_print
> # Overrides to standard builders
> env['CCCOMSTR'] = SpinnerPrinter.spin_source("Compiling")
> env['ASPPCOMSTR'] = SpinnerPrinter.spin_source("Assembling")
> env['LINKCOMSTR'] = SpinnerPrinter.spin_target("Linking")
> env['ARCOMSTR'] = SpinnerPrinter.spin_target("Creating library")
>
> # locally defined builders
> env['PROTOBUFCOMSTR'] = SpinnerPrinter.spin_source("Creating protobuf")
> env['SIGNCOMSTR'] = SpinnerPrinter.spin_source("Signing")
>
> The SpinnerPrinter class has a function spinner_print that uses the
> config string to generate the output based on the config
> string generated by spin_source and spin_target:
>
> def spinner_print(self, s, target, source, env):
> # Regular (non-spinner-aware) strings just get emitted as
> # usual
> if not s.startswith(self.SPINNER):
> sys.stdout.write(s + "\n")
> return
>
> # take off the marker
> s = s[len(self.SPINNER):]
>
> # figure out if we are supposed to print the source or target
> which = s[0:3]
>
> # Generate the prefix (the part printed before the filename).
> print_prefix = s[3:]
> # Find out what filename to print as part of the output. We'd
> # rather print the name of the source, but steps such as
> # library creation have a zillion sources and one target, so
> # we'll print the target instead for those.
> if which == SpinnerPrinter.SOURCE:
> file_to_print = source[0]
> else:
> file_to_print = target[0]
> fn_to_print = os.path.realpath(str(file_to_print))
>
> # Combine the directive we were given (e.g. "Compiling")
> # with the filename
> sys.stdout.write(f"{print_prefix} {fn_to_print}\n"
>
> This can be made much fancier; I've elided various details. For example,
> the real spinner senses if stdout is a tty. If it is a tty, it uses ANSI
> escape sequences so the output lines overwrite themselves, and it prints
> only the part of the filename that fits on a single terminal line (after
> sensing its width). So when our team builds from the command-line, a normal
> build does not use any terminal space at all! When running from a script,
> the "Compiling" and "Linking" lines all appear as separate lines. And
> without the --verbose option, the entire custom output block is skipped and
> full command-lines get printed (the default scons behavior).
>
> Hopefully this helps someone! We've been very happy with how it works (and
> with scons in general).
>
> -Jeremy
>
> On Sun, Jan 21, 2024 at 1:07 PM Bill Deegan <bill at baddogconsulting.com>
> wrote:
>
>> Dagg,
>>
>> What Mats said.. with more detail.
>>
>> So if your compiling c++, the relevant variables are
>> CXXCOM, CXXCOMSTR
>> SHCXXCOM, SHCXXCOMSTR
>>
>> The *STR variables are what is output to the screen, the non *STR are
>> what's used to build the command line and execute.
>> replace CXX with CC for C compiles..
>> You can see the complete list of such variables in the manpage:
>> https://scons.org/doc/production/HTML/scons-man.html
>>
>> Hope this helps~!
>> -=Bill
>>
>> On Sun, Jan 21, 2024 at 11:07 AM Mats Wichmann <mats at wichmann.us> wrote:
>>
>>> On January 21, 2024 5:40:14 AM MST, daggs via Scons-users <
>>> scons-users at scons.org> wrote:
>>> >Greetings,
>>> >
>>> >I want to add a prefix the compile line scons is displaying, is it
>>> possible?
>>> >
>>> >Thanks,
>>> >
>>> >Dagg
>>> >_______________________________________________
>>> >Scons-users mailing list
>>> >Scons-users at scons.org
>>> >https://pairlist4.pair.net/mailman/listinfo/scons-users
>>>
>>> yes.
>>>
>>> sorry not at a place I can answer more fully, but can modify the
>>> relevant COMSTR (command string), or supply your own $PRINT_CMD_LINE_FUNC
>>> --
>>> Sent from my Android device with K-9 Mail. Please excuse my brevity.
>>> _______________________________________________
>>> Scons-users mailing list
>>> Scons-users at scons.org
>>> https://pairlist4.pair.net/mailman/listinfo/scons-users
>>>
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