Commit Graph

3 Commits

Author SHA1 Message Date
Benson Chu 7bd92f5911 [AST] Pick last tentative definition as the acting definition
Clang currently picks the second tentative definition when
VarDecl::getActingDefinition is called.

This can lead to attributes being dropped if they are attached to
tentative definitions that appear after the second one. This is
because VarDecl::getActingDefinition loops through VarDecl::redecls
assuming that the last tentative definition is the last element in the
iterator. However, it is the second element that would be the last
tentative definition.

This changeset modifies getActingDefinition to iterate through the
declaration chain in reverse, so that it can immediately return when
it encounters a tentative definition.

Originally the unit test for this changeset did not have a -triple
flag for the clang invocation, leading to this test being broken on
MacOS, since Mach-O does not support the section attribute.

Differential Revision: https://reviews.llvm.org/D99732
2021-08-26 16:49:54 -05:00
Benson Chu 1b19f90a23 Revert "[AST] Pick last tentative definition as the acting definition"
This reverts commit 9a5f388850.

The written test breaks some builds on Mach-O.
2021-08-24 11:41:50 -05:00
Benson Chu 9a5f388850 [AST] Pick last tentative definition as the acting definition
Clang currently picks the second tentative definition when
VarDecl::getActingDefinition is called.

This can lead to attributes being dropped if they are attached to
tentative definitions that appear after the second one. This is
because VarDecl::getActingDefinition loops through VarDecl::redecls
assuming that the last tentative definition is the last element in the
iterator. However, it is the second element that would be the last
tentative definition.

This changeset modifies getActingDefinition to iterate through the
declaration chain in reverse, so that it can immediately return when
it encounters a tentative definition.

Differential Revision: https://reviews.llvm.org/D99732
2021-08-24 08:51:50 -05:00