Re: [Qemu-devel] [PATCH] Makefile: simpler/faster "make help"

["Daniel P. Berrange" <berrange@redhat.com>]

On Wed, Nov 08, 2017 at 12:20:52AM -0300, Philippe Mathieu-Daudé wrote:
> Using obscure black magic introduced in eaa2ddbb767 :)
> 
> In an out-of-tree directory, running "../configure && make help" will generate
> some required files (.mak), then clone some submodules, compile at least
> the capstone submodule, generate QMP and Trace files, and finally display
> the help.
> 
> On an outdated computer (Sun Blade workstation), running "make help" took
> more than 5h :) With this patch it took roughly 37min.

Wow, that's some seriously slow hardware :-)

> 
> Suggested-by: Daniel P. Berrange <berrange@redhat.com>
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
> 
> before:
> 
> $ make help
>   GEN     config-host.h
>   CC      cs.o
>   CC      utils.o
>   CC      SStream.o
>   CC      MCInstrDesc.o
>   CC      MCRegisterInfo.o
>   CC      arch/ARM/ARMDisassembler.o
>   CC      arch/ARM/ARMInstPrinter.o
>   CC      arch/ARM/ARMMapping.o
>   CC      arch/ARM/ARMModule.o
>   CC      arch/AArch64/AArch64BaseInfo.o
>   CC      arch/AArch64/AArch64Disassembler.o
>   CC      arch/AArch64/AArch64InstPrinter.o
>   CC      arch/AArch64/AArch64Mapping.o
>   CC      arch/AArch64/AArch64Module.o
>   CC      arch/Mips/MipsDisassembler.o
>   CC      arch/Mips/MipsInstPrinter.o
>   CC      arch/Mips/MipsMapping.o
>   CC      arch/Mips/MipsModule.o
>   CC      arch/PowerPC/PPCDisassembler.o
>   CC      arch/PowerPC/PPCInstPrinter.o
>   CC      arch/PowerPC/PPCMapping.o
>   CC      arch/PowerPC/PPCModule.o
>   CC      arch/Sparc/SparcDisassembler.o
>   CC      arch/Sparc/SparcInstPrinter.o
>   CC      arch/Sparc/SparcMapping.o
>   CC      arch/Sparc/SparcModule.o
>   CC      arch/SystemZ/SystemZDisassembler.o
>   CC      arch/SystemZ/SystemZInstPrinter.o
>   CC      arch/SystemZ/SystemZMapping.o
>   CC      arch/SystemZ/SystemZModule.o
>   CC      arch/SystemZ/SystemZMCTargetDesc.o
>   CC      arch/X86/X86DisassemblerDecoder.o
>   CC      arch/X86/X86Disassembler.o
>   CC      arch/X86/X86IntelInstPrinter.o
>   CC      arch/X86/X86ATTInstPrinter.o
>   CC      arch/X86/X86Mapping.o
>   CC      arch/X86/X86Module.o
>   CC      arch/XCore/XCoreDisassembler.o
>   CC      arch/XCore/XCoreInstPrinter.o
>   CC      arch/XCore/XCoreMapping.o
>   CC      arch/XCore/XCoreModule.o
>   CC      MCInst.o
>   AR      libcapstone.a
> ar: creating capstone/libcapstone.a
>   GEN     trace/generated-tcg-tracers.h
>   GEN     trace/generated-helpers-wrappers.h
>   GEN     trace/generated-helpers.h
>   GEN     trace/generated-helpers.c
>   GEN     module_block.h
> make[1]: 'capstone/libcapstone.a' is up to date.
> Generic targets:
>   all             - Build all
>   dir/file.o      - Build specified target only
>   install         - Install QEMU, documentation and tools
>   ctags/TAGS      - Generate tags file for editors
>   cscope          - Generate cscope index
> [...]
> 
> after:
> 
> $ make help
> Generic targets:
>   all             - Build all
>   dir/file.o      - Build specified target only
>   install         - Install QEMU, documentation and tools
>   ctags/TAGS      - Generate tags file for editors
>   cscope          - Generate cscope index
> [...]
> 
>  Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/Makefile b/Makefile
> index 0496c5057a..7850ca5928 100644
> --- a/Makefile
> +++ b/Makefile
> @@ -6,7 +6,7 @@ BUILD_DIR=$(CURDIR)
>  # Before including a proper config-host.mak, assume we are in the source tree
>  SRC_PATH=.
>  
> -UNCHECKED_GOALS := %clean TAGS cscope ctags docker docker-%
> +UNCHECKED_GOALS := %clean TAGS cscope ctags docker docker-% help
>  
>  # All following code might depend on configuration variables
>  ifneq ($(wildcard config-host.mak),)

Reviewed-by: Daniel P. Berrange <berrange@redhat.com>


Regards,
Daniel
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