* Restructure code to let linker perform deadcode elimination step
Cobra, in its default configuration, will execute a template to generate
help, usage and version outputs. Text/template execution calls MethodByName
and MethodByName disables dead code elimination in the Go linker, therefore
all programs that make use of cobra will be linked with dead code
elimination disabled, even if they end up replacing the default usage, help
and version formatters with a custom function and no actual text/template
evaluations are ever made at runtime.
Dead code elimination in the linker helps reduce disk space and memory
utilization of programs. For example, for the simple example program used by
TestDeadcodeElimination 40% of the final executable size is dead code. For a
more realistic example, 12% of the size of Delve's executable is deadcode.
This PR changes Cobra so that, in its default configuration, it does not
automatically inhibit deadcode elimination by:
1. changing Cobra's default behavior to emit output for usage and help using
simple Go functions instead of template execution
2. quarantining all calls to template execution into SetUsageTemplate,
SetHelpTemplate and SetVersionTemplate so that the linker can statically
determine if they are reachable
Co-authored-by: Marc Khouzam <marc.khouzam@gmail.com>
* Improve site formatting
- Separate titles with blank lines
- Separate code blocks with blank lines
- Always use ``` blocks for examples
- Use console for console (bash syntax highlighting does work well with
example command output)
- Start console examples with $ (highlight command and output
differently and more friendly to other shells users)
* Unify indentation in example project structure
* Use single import line in the trivial examples
When we want to show a minimal example with single import it looks
cleaner and more minimal with a single line.
Currently, only one of the persistent pre-runs and post-runs is executed.
It is always the first one found in the parents chain, starting at this command.
Expected behavior is to execute all parents' persistent pre-runs and post-runs.
Dependent projects implemented various workarounds for this:
- manually building persistent hook chains (in every hook).
- applying some kind of monkey-patching on top of Cobra.
This change eliminates the necessity for such workarounds
by allowing to set a global variable EnableTraverseRunHooks.
Tickets:
- https://github.com/spf13/cobra/issues/216
- https://github.com/spf13/cobra/issues/252
Signed-off-by: Volodymyr Khoroz <volodymyr.khoroz@foundries.io>
