Preprocessor: Suppress -Wnonportable-include-path for header maps

If a file search involves a header map, suppress
-Wnonportable-include-path.  It's firing lots of false positives for
framework authors internally, and it's not trivial to fix.

Consider a framework called "Foo" with a main (installed) framework header
"Foo/Foo.h".  It's atypical for "Foo.h" to actually live inside a
directory called "Foo" in the source repository.  Instead, the
build system generates a header map while building the framework.
If Foo.h lives at the top-level of the source repository (common), and
the git repo is called ssh://some.url/foo.git, then the header map will
have something like:

    Foo/Foo.h -> /Users/myname/code/foo/Foo.h

where "/Users/myname/code/foo" is the clone of ssh://some.url/foo.git.

After #import <Foo/Foo.h>, the current implementation of
-Wnonportable-include-path will falsely assume that Foo.h was found in a
nonportable way, because of the name of the git clone (.../foo/Foo.h).
However, that directory name was not involved in the header search at
all.

This commit adds an extra parameter to Preprocessor::LookupFile and
HeaderSearch::LookupFile to track if the search used a header map,
making it easy to suppress the warning.  Longer term, once we find a way
to avoid the false positive, we should turn the warning back on.

rdar://problem/28863903

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@301592 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 1 insertions, 1 deletions

diff --git a/include/clang/Lex/Preprocessor.h b/include/clang/Lex/Preprocessor.h
index 3efe914daa..f48cab6837 100644
--- a/include/clang/Lex/Preprocessor.h
+++ b/include/clang/Lex/Preprocessor.h
@@ -1686,7 +1686,7 @@ public:
                               SmallVectorImpl<char> *SearchPath,
                               SmallVectorImpl<char> *RelativePath,
                               ModuleMap::KnownHeader *SuggestedModule,
-                              bool SkipCache = false);
+                              bool *IsMapped, bool SkipCache = false);
 
   /// \brief Get the DirectoryLookup structure used to find the current
   /// FileEntry, if CurLexer is non-null and if applicable.