include Clang builtin headers even with -nostdinc
Some projects use -nostdinc, but need to access some intrinsics files when building specific files.
The new -ibuiltininc flag lets them use this flag when compiling these files to ensure they can
find Clang's builtin headers.
The use of -nobuiltininc after the -ibuiltininc flag does not add the builtin header
search path to the list of header search paths.
Differential Revision: https://reviews.llvm.org/D73500
Before e97b5f5cf3 ([clang][Darwin] Refactor header search path logic
into the driver), both --sysroot and -isysroot worked to specify where
to look for system and C++ headers on Darwin. However, that change
caused clang to start ignoring --sysroot.
This fixes the regression, and adds tests.
(I also note that on all other platforms, clang seems to almost
completely ignore -isysroot, but that's another issue...)
Differential Revision: https://reviews.llvm.org/D62268
llvm-svn: 361429
Summary:
This commit moves the logic for determining system, resource and C++
header search paths from CC1 to the driver. This refactor has already
been made for several platforms, but Darwin had been left behind.
This refactor tries to implement the previous search path logic with
perfect accuracy. In particular, the order of all include paths inside
CC1 and all paths that were skipped because nonexistent are conserved
after the refactor. This change was also tested against a code base
of significant size and revealed no problems.
Reviewers: jfb, arphaman
Subscribers: nemanjai, javed.absar, kbarton, christof, jkorous, dexonsmith, jsji, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D61963
llvm-svn: 361278
Alex Lorenz