We have a new policy in place making links to private resources
something we try to avoid in source and test files. Normally, we'd
organically switch to the new policy rather than make a sweeping change
across a project. However, Clang is in a somewhat special circumstance
currently: recently, I've had several new contributors run into rdar
links around test code which their patch was changing the behavior of.
This turns out to be a surprisingly bad experience, especially for
newer folks, for a handful of reasons: not understanding what the link
is and feeling intimidated by it, wondering whether their changes are
actually breaking something important to a downstream in some way,
having to hunt down strangers not involved with the patch to impose on
them for help, accidental pressure from asking for potentially private
IP to be made public, etc. Because folks run into these links entirely
by chance (through fixing bugs or working on new features), there's not
really a set of problematic links to focus on -- all of the links have
basically the same potential for causing these problems. As a result,
this is an omnibus patch to remove all such links.
This was not a mechanical change; it was done by manually searching for
rdar, radar, radr, and other variants to find all the various
problematic links. From there, I tried to retain or reword the
surrounding comments so that we would lose as little context as
possible. However, because most links were just a plain link with no
supporting context, the majority of the changes are simple removals.
Differential Review: https://reviews.llvm.org/D158071
Consider the following statements:
long x = 1;
short y = 1;
With the following AST:
|-VarDecl 0x55d289973730 <x.c:1:1, col:10> col:6 x 'long' cinit
| `-ImplicitCastExpr 0x55d289973800 <col:10> 'long' <IntegralCast>
| `-IntegerLiteral 0x55d2899737e0 <col:10> 'int' 1
`-VarDecl 0x55d289973830 <line:2:1, col:11> col:7 y 'short' cinit
`-ImplicitCastExpr 0x55d2899738b8 <col:11> 'short' <IntegralCast>
`-IntegerLiteral 0x55d289973898 <col:11> 'int' 1
Sign or Zero extend or truncate based on the source signedness and
destination width.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D156466
A variable with `weak` attribute signifies that it can be replaced with
a "strong" symbol link time. Therefore it must not emitted with
"weak_odr" linkage, as that allows the backend to use its value in
optimizations.
The frontend already considers weak const variables as
non-constant (note_constexpr_var_init_weak diagnostic) so this change
makes frontend and backend consistent.
This commit reverses the
f49573d1 weak globals that are const should get weak_odr linkage.
commit from 2009-08-05 which introduced this behavior. Unfortunately
that commit doesn't provide any details on why the change was made.
This was discussed in
https://discourse.llvm.org/t/weak-attribute-semantics-on-const-variables/62311
Differential Revision: https://reviews.llvm.org/D126324
For a default visibility external linkage definition, dso_local is set for ELF
-fno-pic/-fpie and COFF and Mach-O. Since default clang -cc1 for ELF is similar
to -fpic ("PIC Level" is not set), this nuance causes unneeded binary format differences.
To make emitted IR similar, ELF -cc1 -fpic will default to -fno-semantic-interposition,
which sets dso_local for default visibility external linkage definitions.
To make this flip smooth and enable future (dso_local as definition default),
this patch replaces (function) `define ` with `define{{.*}} `,
(variable/constant/alias) `= ` with `={{.*}} `, or inserts appropriate `{{.*}} `.
Summary:
Clang -fpic defaults to -fno-semantic-interposition (GCC -fpic defaults
to -fsemantic-interposition).
Users need to specify -fsemantic-interposition to get semantic
interposition behavior.
Semantic interposition is currently a best-effort feature. There may
still be some cases where it is not handled well.
Reviewers: peter.smith, rnk, serge-sans-paille, sfertile, jfb, jdoerfert
Subscribers: dschuff, jyknight, dylanmckay, nemanjai, jvesely, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, sabuasal, niosHD, jrtc27, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, arphaman, PkmX, jocewei, jsji, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D73865
ConvertType on InitListExprs as they are being converted. This is
needed for a forthcoming patch, and improves the IR generated anyway
(see additional type names in testcases).
This patch also converts a bunch of std::vector's in CGObjCMac to use
C arrays. There are a ton more that should be converted as well.
llvm-svn: 133413
- This is designed to make it obvious that %clang_cc1 is a "test variable"
which is substituted. It is '%clang_cc1' instead of '%clang -cc1' because it
can be useful to redefine what gets run as 'clang -cc1' (for example, to set
a default target).
llvm-svn: 91446
