The approach in D30000 assumes that the '/' returned by path::begin()
is the first element for absolute paths, but that's not true on
Windows.
Also, on Windows backslashes in include lines often end up escaped
so that there are two of them. Having backslashes in include lines
is undefined behavior in most cases and implementation-defined
behavior in C++20, but since clang treats it as normal repeated
path separators, the diagnostic should too.
Unbreaks -Wnonportable-include-path for absolute paths on Windows,
and unbreaks it on non-Windows in the case of absolute paths with
repeated directory separators.
This affects e.g. the `#include __FILE__` technique if the file
passed to clang has the wrong case for the drive letter. Before:
C:\src\llvm-project>bin\clang-cl.exe c:\src\llvm-project\test.cc
c:\\src\\llvm-project\\test.cc(4,10): warning: non-portable path to file
'"c\\srccllvm-projectctest.cc.'; specified path differs in case from
file name on disk [-Wnonportable-include-path]
^
Now:
C:\src\llvm-project> out\gn\bin\clang-cl c:\src\llvm-project\test.cc
c:\\src\\llvm-project\\test.cc(4,10): warning: non-portable path to file
'"C:\\src\\llvm-project\\test.cc"'; specified path differs in case from
file name on disk [-Wnonportable-include-path]
^
Differential Revision: https://reviews.llvm.org/D79223
The %T lit expansion expands to a common directory shared between all the tests in the same directory, which is unexpected and unintuitive, and more importantly, it's been a source of subtle race conditions and flaky tests. In https://reviews.llvm.org/D35396, it was agreed that it would be best to simply ban %T and only keep %t, which is unique to each test. When a test needs a temporary directory, it can just create one using mkdir %t.
This patch removes %T in clang.
Differential Revision: https://reviews.llvm.org/D36437
llvm-svn: 310950
Differential Revision: http://reviews.llvm.org/D19843
Corresponding LLVM change: http://reviews.llvm.org/D19842
Re-commit after addressing issues with of generating too many warnings for Windows and asan test failures.
Patch by Eric Niebler
llvm-svn: 272562
Nico Weber