Use llvm-objcpy to strip the producers section when not running wasm-opt #12075
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sbc100
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Aug 31, 2020
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Thanks @sbc100 , yes, looks like |
kripken
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Aug 31, 2020
…12077) Relative to / followup to #12075. This does the same for debug info, it gets us back to the same output as before (even stripping it in unoptimized builds if -g is not present) by using llvm-objcopy when wasm-opt isn't being run anyhow. Together these PRs make our work on WebAssembly/binaryen#3043 have less noticeable effect that could surprise users. Note that wasm-ld has --strip-debug which we could use, but it will strip both the Names section and DWARF sections, and we may want just the Names section, so we can't just use that.
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As part of WebAssembly/binaryen#3043 we stopped
stripping the producers section in unoptimized builds in #11996
However there is a way to still strip it with very little overhead, using llvm-objcpy.
This PR makes us strip it using wasm-opt normally if we are running wasm-opt
anyhow, but if we are not (as we hope to get to soon in some builds) then it uses
llvm-objcpy. This does a little more work after link but it's pretty trivial and does
not rewrite code or anything like that.
This does add some complexity, but it is complexity we'll need anyhow for
not running wasm-opt when it isn't needed.
Fixes #12071