Commit Graph

12 Commits

Author SHA1 Message Date
Richard Smith 7ae1b4a0ce Implement P1766R1: diagnose giving non-C-compatible classes a typedef name for linkage purposes.
Summary:
Due to a recent (but retroactive) C++ rule change, only sufficiently
C-compatible classes are permitted to be given a typedef name for
linkage purposes. Add an enabled-by-default warning for these cases, and
rephrase our existing error for the case where we encounter the typedef
name for linkage after we've already computed and used a wrong linkage
in terms of the new rule.

Reviewers: rjmccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D74103
2020-02-07 11:47:37 -08:00
David Blaikie a953f2825b Update Clang tests to handle explicitly typed load changes in LLVM.
llvm-svn: 230795
2015-02-27 21:19:58 +00:00
Rafael Espindola e5df59ff78 Emit DeferredDeclsToEmit in a DFS order.
Currently we emit DeferredDeclsToEmit in reverse order. This patch changes that.

The advantages of the change are that

* The output order is a bit closer to the source order. The change to
test/CodeGenCXX/pod-member-memcpys.cpp is a good example.

* If we decide to deffer more, it will not cause as large changes in the
estcases as it would without this patch.

llvm-svn: 226751
2015-01-22 00:24:57 +00:00
John McCall a900d1cf4a Actually test that the local static variable from my
test in r200380 gets linkonce_odr linkage.

llvm-svn: 200437
2014-01-30 01:12:47 +00:00
John McCall 8a4e2e41de Short-circuit a couple of queries (and avoid corrupting
the linkage cache) when type-checking static local
variables.

There's a very deep problem here where the linkage of
a declaration can suddenly massively change as soon as
it's given a typedef name; these fixes, while optimizations
in their own right, are really just targeted workarounds.

rdar://15928125

llvm-svn: 200380
2014-01-29 08:33:09 +00:00
Rafael Espindola 1a7902c767 Add a testcase for a recent regression.
Thanks to Bill Wendling for the original testcase.

llvm-svn: 180586
2013-04-26 00:29:11 +00:00
Eli Friedman 839192fd29 Change linkage computation so it doesn't depend on FunctionDecl::isExternC or VarDecl::isExternC, and instead queries what it actually cares about: whether the given declaration is inside an extern "C" context. Fundamentally, figuring out whether a function/variable uses C linkage requires knowing the linkage, and the logic in FunctionDecl::isExternC and VarDecl::isExternC was getting it wrong. Given that, fix FunctionDecl::isExternC and VarDecl::isExternC to use much simpler implementations that depend on the fixed linkage computation.
Fixes a regression to test/SemaCXX/linkage.cpp caused by a new warning exposing the fact that the internal state was wrong.

llvm-svn: 148207
2012-01-15 01:23:58 +00:00
Eli Friedman c09e0557a5 Progress towards making isUsed() reflect whether a declaration is odr-used; don't set isUsed for local variables which are referenced in unevaluated contexts. Make other code use isReferenced() (which basically indicates that a declaration isn't dead) where appropriate.
I was forced to change test/SemaCXX/linkage.cpp because we aren't actually modeling extern "C" in the AST the way that testcase expects; we were not printing a warning only because we skipped the relevant check.  Someone who actually understands the semantics here should fix that.

llvm-svn: 148158
2012-01-13 23:41:25 +00:00
Chandler Carruth 4322a2864e Fix the rest of PR9316 along with some other bugs spotted by inspection.
I tried to add test cases for these, but I can't because variables
aren't warned on the way functions are and the codegen layer appears to
use different logic for determining that 'a' and 'g' in the test case
should receive C mangling. I've included the test so that if we ever
switch the codegen layer to use these functions, we won't regress due to
latent bugs.

llvm-svn: 126453
2011-02-25 00:05:02 +00:00
Chandler Carruth 9682a2fd3a Likely fix for PR9316 and other unknown bugs: don't use the anonynmous
namespace blanket rule for variables and functions declared 'extern
"C"'.

llvm-svn: 126400
2011-02-24 19:03:39 +00:00
John McCall f768aa7613 Move the check that gives functions with unique-external types unique-external
linkage into Decl.cpp.  Disable this logic for extern "C" functions, because
the operative rule there is weaker.  Fixes rdar://problem/8898466

llvm-svn: 125268
2011-02-10 06:50:24 +00:00
John McCall 53c72e71cc Test case accidentally left out of my last commit.
llvm-svn: 125119
2011-02-08 22:28:39 +00:00