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stream: make the variadic interface methods final - #60
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InputStream.readf(...), OutputStream.printf(fmt, ...), writef(...) and
writefln(...) are D-style variadic interface methods. For a class that
implements the interface at a non-zero offset (Stream), LDC has to emit
this-adjusting thunks for them and can only forward the variadic
arguments with a `musttail` call. LLVM's PowerPC backend cannot honour
`musttail` there, so compiling the library aborts on ppc64/ppc64le:
LLVM ERROR: failed to perform tail call elimination on a call site
marked musttail
All four are thin forwarders to the non-variadic virtual methods
(vreadf, vprintf, writefx). Make them `final` in the interfaces with
those bodies and drop the identical copies from Stream: final interface
methods are dispatched statically, so no thunk is generated. The API is
unchanged and the methods remain callable through interface references;
customisation still happens by overriding vreadf/vprintf/writefx.
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InputStream.readf(...), OutputStream.printf(fmt, ...), writef(...) and
writefln(...) are D-style variadic interface methods. For a class that
implements the interface at a non-zero offset (Stream), LDC has to emit
this-adjusting thunks for them and can only forward the variadic
arguments with a
musttailcall. LLVM's PowerPC backend cannot honourmusttailthere, so compiling the library aborts on ppc64/ppc64le:All four are thin forwarders to the non-variadic virtual methods
(vreadf, vprintf, writefx). Make them
finalin the interfaces withthose bodies and drop the identical copies from Stream: final interface
methods are dispatched statically, so no thunk is generated. The API is
unchanged and the methods remain callable through interface references;
customisation still happens by overriding vreadf/vprintf/writefx.