what is the use of "-frontend" argument to swift?

Atul_Sowani · December 5, 2017, 9:49am

Hi,

What is the purpose of "-frontend -c" arguments of swift? I tried "swift
--help" but that does not mention it. Also I couldn't find it easily in any
swift documents. Can somebody kindly let me know the purpose of these
arguments?

Thanks,
Atul.

krilnon · December 5, 2017, 10:23pm

Looks like it's an alias for -emit-object:

github.com

apple/swift/blob/main/include/swift/Option/Options.td#L576


      
          def emit_module_path_EQ : Joined<["-"], "emit-module-path=">,
            Flags<[FrontendOption, NoInteractiveOption, ArgumentIsPath,
                   SupplementaryOutput, CacheInvariant]>,
            Alias<emit_module_path>;
          
          def emit_module_summary :
            Flag<["-"], "emit-module-summary">,
            Flags<[NoInteractiveOption, SupplementaryOutput]>,
            HelpText<"Output module summary file">;
          def emit_module_summary_path :
            Separate<["-"], "emit-module-summary-path">,
            Flags<[FrontendOption, NoInteractiveOption, ArgumentIsPath,
                   SupplementaryOutput, CacheInvariant]>,
            MetaVarName<"<path>">, HelpText<"Output module summary file to <path>">;
          
          def emit_module_interface :
            Flag<["-"], "emit-module-interface">,
            Flags<[NoInteractiveOption, SupplementaryOutput]>,
            HelpText<"Output module interface file">;
          def emit_module_interface_path :
            Separate<["-"], "emit-module-interface-path">,

...which will give an object file as output rather than the default, an executable.

-Kyle

···

On Dec 5, 2017, at 1:49 AM, Atul Sowani via swift-users <swift-users@swift.org> wrote:

Hi,

What is the purpose of "-frontend -c" arguments of swift? I tried "swift --help" but that does not mention it. Also I couldn't find it easily in any swift documents. Can somebody kindly let me know the purpose of these arguments?

Thanks,
Atul.
_______________________________________________
swift-users mailing list
swift-users@swift.org
https://lists.swift.org/mailman/listinfo/swift-users

jrose · December 5, 2017, 10:46pm

-c is an alias for -emit-object. -frontend is "magically start talking to Swift's implementation details" and you shouldn't use it. More info in docs/Driver.md <https://github.com/apple/swift/blob/master/docs/Driver.md>\.

Jordan

···

On Dec 5, 2017, at 14:23, Kyle Murray via swift-users <swift-users@swift.org> wrote:

Looks like it's an alias for -emit-object:

https://github.com/apple/swift/blob/master/include/swift/Option/Options.td#L576

...which will give an object file as output rather than the default, an executable.

-Kyle

On Dec 5, 2017, at 1:49 AM, Atul Sowani via swift-users <swift-users@swift.org <mailto:swift-users@swift.org>> wrote:

Hi,

What is the purpose of "-frontend -c" arguments of swift? I tried "swift --help" but that does not mention it. Also I couldn't find it easily in any swift documents. Can somebody kindly let me know the purpose of these arguments?

Thanks,
Atul.
_______________________________________________
swift-users mailing list
swift-users@swift.org <mailto:swift-users@swift.org>
https://lists.swift.org/mailman/listinfo/swift-users

_______________________________________________
swift-users mailing list
swift-users@swift.org
https://lists.swift.org/mailman/listinfo/swift-users

Atul_Sowani · December 6, 2017, 6:09am

Thanks Kyle and Jordan! That's the information I was looking for. Anyway I
am not using these options explicitly, but found that they are invoked
while Swift test suite is run. A few test cases are failing for me on
ppc64le and while analyzing it I came across these options. Thanks for the
info!

Best regards,
Atul.

···

On Wed, Dec 6, 2017 at 4:16 AM, Jordan Rose <jordan_rose@apple.com> wrote:

-c is an alias for -emit-object. -frontend is "magically start talking to
Swift's implementation details" and you shouldn't use it. More info in
docs/Driver.md <https://github.com/apple/swift/blob/master/docs/Driver.md>
.

Jordan

On Dec 5, 2017, at 14:23, Kyle Murray via swift-users < > swift-users@swift.org> wrote:

Looks like it's an alias for -emit-object:

https://github.com/apple/swift/blob/master/include/
swift/Option/Options.td#L576

...which will give an object file as output rather than the default, an
executable.

-Kyle

On Dec 5, 2017, at 1:49 AM, Atul Sowani via swift-users < > swift-users@swift.org> wrote:

Hi,

What is the purpose of "-frontend -c" arguments of swift? I tried "swift
--help" but that does not mention it. Also I couldn't find it easily in any
swift documents. Can somebody kindly let me know the purpose of these
arguments?

Thanks,
Atul.
_______________________________________________
swift-users mailing list
swift-users@swift.org
https://lists.swift.org/mailman/listinfo/swift-users

_______________________________________________
swift-users mailing list
swift-users@swift.org
https://lists.swift.org/mailman/listinfo/swift-users

Frank_Swarbrick · December 6, 2017, 8:29am

If you compile with the -v option you’ll see how -frontend is used, (below, with some comments by me):

frank@DESKTOP-6Q7P3OK:~/src/swift$ swiftc -v -module-name CTest CTest.swift ../c/CTest.o

Swift version 4.0.2 (swift-4.0.2-RELEASE)

Target: x86_64-unknown-linux-gnu

Compile:

/home/frank/swift-4.0.2-RELEASE-ubuntu16.04/usr/bin/swift -frontend -c -primary-file CTest.swift -target x86_64-unknown-linux-gnu -disable-objc-interop -color-diagnostics -module-name CTest -o /tmp/CTest-f4b853.o

Extract “autolink data”:

/home/frank/swift-4.0.2-RELEASE-ubuntu16.04/usr/bin/swift-autolink-extract /tmp/CTest-f4b853.o ../c/CTest.o -o /tmp/CTest-8bd3ee.autolink

Link:

/usr/bin/clang++ -fuse-ld=gold -target x86_64-unknown-linux-gnu -Xlinker -rpath -Xlinker /home/frank/swift-4.0.2-RELEASE-ubuntu16.04/usr/lib/swift/linux /home/frank/swift-4.0.2-RELEASE-ubuntu16.04/usr/lib/swift/linux/x86_64/swift_begin.o /tmp/CTest-f4b853.o ../c/CTest.o -L /home/frank/swift-4.0.2-RELEASE-ubuntu16.04/usr/lib/swift/linux -lswiftCore --target=x86_64-unknown-linux-gnu @/tmp/CTest-8bd3ee.autolink /home/frank/swift-4.0.2-RELEASE-ubuntu16.04/usr/lib/swift/linux/x86_64/swift_end.o -o CTest

···

From: swift-users-bounces@swift.org [mailto:swift-users-bounces@swift.org] On Behalf Of Atul Sowani via swift-users
Sent: Tuesday, December 5, 2017 11:10 PM
To: swift-users@swift.org
Subject: Re: [swift-users] what is the use of "-frontend" argument to swift?

Thanks Kyle and Jordan! That's the information I was looking for. Anyway I am not using these options explicitly, but found that they are invoked while Swift test suite is run. A few test cases are failing for me on ppc64le and while analyzing it I came across these options. Thanks for the info!

Best regards,

Atul.

On Wed, Dec 6, 2017 at 4:16 AM, Jordan Rose <jordan_rose@apple.com <mailto:jordan_rose@apple.com> > wrote:

-c is an alias for -emit-object. -frontend is "magically start talking to Swift's implementation details" and you shouldn't use it. More info in docs/Driver.md <https://github.com/apple/swift/blob/master/docs/Driver.md> .

Jordan

On Dec 5, 2017, at 14:23, Kyle Murray via swift-users <swift-users@swift.org <mailto:swift-users@swift.org> > wrote:

Looks like it's an alias for -emit-object:

github.com

apple/swift/blob/main/include/swift/Option/Options.td#L576


      
          def import_cf_types : Flag<["-"], "import-cf-types">,
            Flags<[FrontendOption, HelpHidden]>,
            HelpText<"Recognize and import CF types as class types">;
          
          
def solver_memory_threshold : Separate<["-"], "solver-memory-threshold">,
            Flags<[FrontendOption, HelpHidden, DoesNotAffectIncrementalBuild]>,
            HelpText<"Set the upper bound for memory consumption, in bytes, by the constraint solver">;
          
          
def solver_shrink_unsolved_threshold : Separate<["-"], "solver-shrink-unsolved-threshold">,
          Flags<[FrontendOption, HelpHidden, DoesNotAffectIncrementalBuild]>,
          HelpText<"Set The upper bound to number of sub-expressions unsolved before termination of the shrink phrase">;
          
          
def value_recursion_threshold : Separate<["-"], "value-recursion-threshold">,
            Flags<[FrontendOption, HelpHidden, DoesNotAffectIncrementalBuild]>,
            HelpText<"Set the maximum depth for direct recursion in value types">;
          
          
def disable_swift_bridge_attr : Flag<["-"], "disable-swift-bridge-attr">,
            Flags<[FrontendOption, HelpHidden]>,
            HelpText<"Disable using the swift bridge attribute">;
          
          
def enable_bridging_pch : Flag<["-"], "enable-bridging-pch">,

...which will give an object file as output rather than the default, an executable.

-Kyle

On Dec 5, 2017, at 1:49 AM, Atul Sowani via swift-users <swift-users@swift.org <mailto:swift-users@swift.org> > wrote:

Hi,

What is the purpose of "-frontend -c" arguments of swift? I tried "swift --help" but that does not mention it. Also I couldn't find it easily in any swift documents. Can somebody kindly let me know the purpose of these arguments?

Thanks,

Atul.

_______________________________________________
swift-users mailing list
swift-users@swift.org <mailto:swift-users@swift.org>
https://lists.swift.org/mailman/listinfo/swift-users

jrose · December 6, 2017, 6:53pm

Ah, got it. Sorry for being brusque—the question coming in on swift-users rather than swift-dev threw me off. If you need help with tests feel free to ask! (…but probably on swift-dev)

Jordan

···

On Dec 5, 2017, at 22:09, Atul Sowani via swift-users <swift-users@swift.org> wrote:

Thanks Kyle and Jordan! That's the information I was looking for. Anyway I am not using these options explicitly, but found that they are invoked while Swift test suite is run. A few test cases are failing for me on ppc64le and while analyzing it I came across these options. Thanks for the info!

Best regards,
Atul.

On Wed, Dec 6, 2017 at 4:16 AM, Jordan Rose <jordan_rose@apple.com <mailto:jordan_rose@apple.com>> wrote:
-c is an alias for -emit-object. -frontend is "magically start talking to Swift's implementation details" and you shouldn't use it. More info in docs/Driver.md <https://github.com/apple/swift/blob/master/docs/Driver.md>\.

Jordan

On Dec 5, 2017, at 14:23, Kyle Murray via swift-users <swift-users@swift.org <mailto:swift-users@swift.org>> wrote:

Looks like it's an alias for -emit-object:

https://github.com/apple/swift/blob/master/include/swift/Option/Options.td#L576

...which will give an object file as output rather than the default, an executable.

-Kyle

On Dec 5, 2017, at 1:49 AM, Atul Sowani via swift-users <swift-users@swift.org <mailto:swift-users@swift.org>> wrote:

Hi,

What is the purpose of "-frontend -c" arguments of swift? I tried "swift --help" but that does not mention it. Also I couldn't find it easily in any swift documents. Can somebody kindly let me know the purpose of these arguments?

Thanks,
Atul.
_______________________________________________
swift-users mailing list
swift-users@swift.org <mailto:swift-users@swift.org>
https://lists.swift.org/mailman/listinfo/swift-users

_______________________________________________
swift-users mailing list
swift-users@swift.org <mailto:swift-users@swift.org>
https://lists.swift.org/mailman/listinfo/swift-users

_______________________________________________
swift-users mailing list
swift-users@swift.org
https://lists.swift.org/mailman/listinfo/swift-users