Including select builtin headers in system modules is a workaround for module cycles, primarily in Apple's Darwin module that includes all of its C standard library headers. The workaround is problematic because it doesn't include all of the builtin headers (inttypes.h is notably absent), and it also doesn't include C++ headers. The straightforward for for this is to make top level modules for all of the C standard library headers and unwind.h in C++, clang, and the OS.
However, doing so in clang before the OS modules are ready re-introduces the module cycles. Add a -fbuiltin-headers-in-system-modules option to control if the special builtin headers belong to system modules or builtin modules. Pass the option by default for Apple.
Reviewed By: ChuanqiXu, Bigcheese, benlangmuir
Differential Revision: https://reviews.llvm.org/D159483
We used to have a flag to enable module maps, and two more flags to enable
implicit module maps. This is all redundant; we don't need any flag for
enabling module maps in the abstract, and we don't usually have -fno- flags for
-cc1. We now have just a single flag, -fimplicit-module-maps, that enables
implicitly searching the file system for module map files and loading them.
The driver interface is unchanged for now. We should probably rename
-fmodule-maps to -fimplicit-module-maps at some point.
llvm-svn: 239789
This adds -nostdsysteminc to the %clang_cc1 expansion, which should
make it harder to accidentally write tests that depend on headers in
/usr/include. It also updates a few tests that use -isysroot <x> and a
darwin triple to omit the triple and use -isystem <x>/usr/include
instead, making them a little bit more general.
Incidentally, this fixes a test failure I'm seeing on darwin in
Modules/stddef.c, that happens because my system finds a stddef.h in
/usr/include.
llvm-svn: 219030
Fixed by moving ProcessWarningOptions from Frontend into Basic. All of
the dependencies for ProcessWarningOptions were already in Basic, so
this was a small change.
llvm-svn: 207549
This patch checks whether the diagnostic options that could lead to
errors (principally -Werror) are consistent between when a module was
built and when it is loaded. If there are new -Werror flags, then the
module is rebuilt. In order to canonicalize the options we do this
check at the level of the constructed DiagnosticsEngine, which contains
the final set of diag to diagnostic level mappings. Currently we only
rebuild with the new diagnostic options, but we intend to refine this in
the future to include the union of the new and old flags, since we know
the old ones did not cause errors. System modules are only rebuilt when
-Wsystem-headers is enabled.
One oddity is that unlike checking language options, we don’t perform
this diagnostic option checking when loading from a precompiled header.
The reason for this is that the compiler cannot rebuild the PCH, so
anything that requires it to be rebuilt effectively leaks into the build
system. And in this case, that would mean the build system
understanding the complex relationship between diagnostic options and
the underlying diagnostic mappings, which is unreasonable. Skipping the
check is safe, because these options do not affect the generated AST.
You simply won’t get new build errors due to changed -Werror options
automatically, which is also true for non-module cases.
llvm-svn: 207477
