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Mark all extern functions as nounwind - #28358

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bors merged 3 commits into
rust-lang:masterfrom
dotdash:nounwind
Sep 14, 2015
Merged

Mark all extern functions as nounwind#28358
bors merged 3 commits into
rust-lang:masterfrom
dotdash:nounwind

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@dotdash

@dotdashdotdash commented Sep 11, 2015

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This allows to skip the codegen for all the unneeded landing pads, reducing code size across the board by about 2-5%, depending on the crate. Compile times seem to be pretty unaffected though :-/

@rust-highfive

rust-highfive commented Sep 11, 2015

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r? @huonw

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@alexcrichton

alexcrichton commented Sep 11, 2015

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Thanks @dotdash! I'm excited to see how this plays out. Some thoughts of mine:

  • This adds #[nounwind], but doesn't end up adding it anywhere, did you mean to attach this to the allocation functions? If not, perhaps this could be left out for now?
  • Could this have some codegen tests? E.g. testing for the nounwind attribute emission, external functions are nounwind by default, and calling a nounwind function with cleanup in scope doesn't use invoke but instead uses call.

@bors

bors commented Sep 11, 2015

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☔ The latest upstream changes (presumably #28306) made this pull request unmergeable. Please resolve the merge conflicts.

@huonwhuonw assigned alexcrichton and unassigned huonwSep 12, 2015
@dotdash
dotdashforce-pushed the nounwind branch 2 times, most recently from 494e66b to be96d9fCompareSeptember 12, 2015 17:48
@dotdash

dotdash commented Sep 12, 2015

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Added codegen tests for the attributes, but not for the call (as discussed on IRC) because we never use invoke an external functions anyway. Also removed the check for nounwind in invoke() because that's for rust functions only, and they don't get marked nounwind yet.

@alexcrichton

alexcrichton commented Sep 13, 2015

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Looks good to me, thanks! Can you also mark the RaiseException function in both places as being able to unwind as well? Other than that r=me

@dotdash

dotdash commented Sep 13, 2015

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@bors r=alexcrichton bd6da30

@bors

bors commented Sep 14, 2015

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⌛ Testing commit bd6da30 with merge 21ba40d...

@bors

bors commented Sep 14, 2015

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💔 Test failed - auto-win-msvc-64-opt

@dotdash

dotdash commented Sep 14, 2015

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@bors retry

I'm confused about this error...

@bors

bors commented Sep 14, 2015

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⌛ Testing commit bd6da30 with merge dcf66cb...

@bors

bors commented Sep 14, 2015

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💔 Test failed - auto-win-msvc-64-opt

@dotdash
Mark all extern functions as nounwind
3ef75d5
Unwinding across an FFI boundary is undefined behaviour, so we can mark
all external function as nounwind. The obvious exception are those
functions that actually perform the unwinding.
@dotdash

dotdash commented Sep 14, 2015

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@bors r=alexcrichton 3ef75d5

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bors commented Sep 14, 2015

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⌛ Testing commit 3ef75d5 with merge 2d4ae52...

bors added a commit that referenced this pull request Sep 14, 2015
@bors
Auto merge of#28358- dotdash:nounwind, r=alexcrichton
2d4ae52
This allows to skip the codegen for all the unneeded landing pads, reducing code size across the board by about 2-5%, depending on the crate. Compile times seem to be pretty unaffected though :-/
@bors

bors commented Sep 14, 2015

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💔 Test failed - auto-win-msvc-64-opt

@dotdash

dotdash commented Sep 14, 2015

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@bors retry

At least it hit a known intermittent failure this time...

@bors

bors commented Sep 14, 2015

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⚡ Previous build results for auto-win-msvc-32-opt are reusable. Rebuilding only auto-linux-32-nopt-t, auto-linux-32-opt, auto-linux-64-nopt-t, auto-linux-64-opt, auto-linux-64-x-android-t, auto-mac-32-opt, auto-mac-64-nopt-t, auto-mac-64-opt, auto-win-gnu-32-nopt-t, auto-win-gnu-32-opt, auto-win-gnu-64-nopt-t, auto-win-gnu-64-opt, auto-win-msvc-64-opt...

@bors

bors commented Sep 14, 2015

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☀️ Test successful - auto-linux-32-nopt-t, auto-linux-32-opt, auto-linux-64-nopt-t, auto-linux-64-opt, auto-linux-64-x-android-t, auto-mac-32-opt, auto-mac-64-nopt-t, auto-mac-64-opt, auto-win-gnu-32-nopt-t, auto-win-gnu-32-opt, auto-win-gnu-64-nopt-t, auto-win-gnu-64-opt, auto-win-msvc-32-opt, auto-win-msvc-64-opt

@bors
bors merged commit 3ef75d5 into rust-lang:masterSep 14, 2015
@borsbors mentioned this pull request Sep 14, 2015
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@dotdash
dotdash deleted the nounwind branch January 15, 2016 08:40
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