In `SourceManager::getFileID()`, Clang performs binary search over its
buffer of `SLocEntries`. For modules, this binary search fully
deserializes the entire `SLocEntry` block for each visited entry. For
some entries, that includes decompressing the associated buffer (e.g.
the predefines buffer, macro expansion buffers, contents of volatile
files), which shows up in profiles of the dependency scanner.
This patch moves the binary search over loaded entries into `ASTReader`,
which can perform cheaper partial deserialization during the binary
search, reducing the wall time of dependency scans by ~3%. This also
reduces the number of retired instructions by ~1.4% on regular
(implicit) modules compilation.
Note that this patch drops the optimizations based on the last lookup ID
(pruning the search space and performing linear search before resorting
to the full binary search). Instead, it reduces the search space by
asking `ASTReader::GlobalSLocOffsetMap` for the containing `ModuleFile`
and only does binary search over entries of single module file.
and we fall back to textual inclusion, don't require the module as a whole to
be marked available; it's OK if some other file in the same module is missing,
just as it would be if the header were explicitly marked textual.
llvm-svn: 266113
This flag causes all files that were read by the compilation to be embedded
into a produced module file. This is useful for distributed build systems that
use an include scanning system to determine which files are "needed" by a
compilation, and only provide those files to remote compilation workers. Since
using a module can require any file that is part of that module (or anything it
transitively includes), files that are not found by an include scanner can be
required in a regular build using explicit modules. With this flag, only files
that are actually referenced by transitively-#included files are required to be
present on the build machine.
llvm-svn: 253950
It is flaky due to inability to remove files with open handles. We
could paper over it with rm -f, but then the file would still be
present.
This is more evidence to me that we should roll our own 'rm'
implementation in LLVM.
llvm-svn: 245083
file in the .pcm files. This allows a smaller set of files to be sent to a
remote build worker when building with explicit modules (for instance, module
map files need not be sent along with the corresponding precompiled modules).
This doesn't actually make the embedded files visible to header search, so
it's not useful as a packaging format for public header files.
llvm-svn: 245028
