A rule to link with -force_load for direct deps#358
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jerrymarino merged 3 commits intomasterfrom Nov 24, 2021
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ld has different behavior when loading members of a static library VS objects as far as visibility. Under `-dynamic` - linked _swift object files_ can have public visibility - symbols from _swift static libraries_ are omitted unless used, and not visible otherwise By using `-force_load`, we can load static libraries in the attributes of an application's direct depenencies. These args need go at the _front_ of the linker invocation otherwise these arguments don't work with lds logic. Why not put it into `rules_apple`? Ideally it could be, and perhaps consider a PR to there .The underlying java rule, `AppleBinary.linkMultiArchBinary` places `extraLinkopts` at the end of the linker invocation. At the time of writing these args need to go into the current rule context where `AppleBinary.linkMultiArchBinary` is called. One use case of this is that iOS developers want to load above mentioned symbols from applications. Another alternate could be to create an aspect, that actually generates a different application and linker invocation instead of force loading symbols. This could be more complicated from an integration perspective so it isn't used. Another case is present in dynamic frameworks in rules_apple ( bazelbuild/rules_apple#332 )
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thiagohmcruz
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congt
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rules/app.bzl
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| application_kwargs["families"] = application_kwargs.pop("families", ["iphone", "ipad"]) | ||
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| import_middleman(name = name + ".import_middleman", deps = library.deps, tags = ["manual"]) | ||
| force_load_direct_deps(name = name + ".__internal__.force_load_direct_deps", deps = library.deps, tags = ["manual"]) |
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Should we only force load swift_library?
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Nope we need to force load c++/objc too
Plus misc cleanups
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ld has different behavior when loading members of a static library VS objects
as far as visibility. Under
-dynamicBy using
-force_load, we can load static libraries in the attributes of anapplication's direct depenencies. These args need go at the front of the
linker invocation otherwise these arguments don't work with lds logic.
Why not put it into
rules_apple? Ideally it could be, and perhaps consider aPR to there .The underlying java rule,
AppleBinary.linkMultiArchBinaryplaces
extraLinkoptsat the end of the linker invocation. At the time ofwriting these args need to go into the current rule context where
AppleBinary.linkMultiArchBinaryis called.One use case of this is that iOS developers want to load above mentioned
symbols from applications. Another alternate could be to create an aspect, that
actually generates a different application and linker invocation instead of
force loading symbols. This could be more complicated from an integration
perspective so it isn't used. Another case is present in dynamic frameworks in
rules_apple ( bazelbuild/rules_apple#332 )