f19e85
project: added a 'rationale' section to the README document.
Authored and Committed by 
midipix
8 years ago
README
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@@ -15,6 +15,31 @@ between packages, and is most noticeable in builds that invoke libtool a large
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number of times, and which are characterized by the short compilation time of
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individual translation units.
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# why reimplement libtool?
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Midipix targets use the PE binary format and so require import library
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integration on the one hand, yet follow ELF naming conventions
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(i.e. libfoo.so.x.y.z) on the other. In consequence, midipix shared
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libraries are not fully supported by existing libtool implementations.
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As an interim solution used for the porting of gcc, a libtool script
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generated by ltmain.sh was hand-edited so that it would correctly produce
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the host's shared libraries as part of the toolchain build process.
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Bypassing the libtool script generated by a package's ltmain.sh requires
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overriding the `LIBTOOL` variable as part of invoking `make(1)`. In that
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sense, and unless midipix support is added to every single ltmain.sh in
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every single package that uses autotools, it does not truly matter whether
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the surrogate libtool that one chooses be a script, a program written in C,
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or something else.
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At the time of this writing, an average libtool script consists of about
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`10K lines of code` with `several hundred case-esac statements` and a similar
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number of `if-then blocks`. In view of the length of the generated script,
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and in light of its challenging logic and overall complexity, a rewrite of
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the tool in C seemed to be the right choice not only with respect to quality,
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readability, and anticipated performance, but also in terms of development
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effort, ease of customization, and long-term maintenance.
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# Requirements for building slibtool
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- a C toolchain, consisting of...
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