Identified with misc-include-cleaner.
This adds support for generating Chrome-tracing .json profile traces in the LLD COFF driver. Also add the necessary time scopes, so that the profile trace shows in great detail which tasks are executed. As an example, this is what we see when linking a Unreal Engine executable: 
Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup Differential Revision: https://reviews.llvm.org/D121332
accumulated preprocessed size: before: 1065515095 after: 1065629059 Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup Differential Revision: https://reviews.llvm.org/D120195
to reflect the new license. We understand that people may be surprised that we're moving the header entirely to discuss the new license. We checked this carefully with the Foundation's lawyer and we believe this is the correct approach. Essentially, all code in the project is now made available by the LLVM project under our new license, so you will see that the license headers include that license only. Some of our contributors have contributed code under our old license, and accordingly, we have retained a copy of our old license notice in the top-level files in each project and repository. llvm-svn: 351636
Naively computing the hash after the PDB data has been generated is in practice as fast as other approaches I tried. I also tried online-computing the hash as parts of the PDB were written out (https://reviews.llvm.org/D51887; that's also where all the measuring data is) and computing the hash in parallel (https://reviews.llvm.org/D51957). This approach here is simplest, without being slower. Differential Revision: https://reviews.llvm.org/D51956 llvm-svn: 342333
When investigating bugs in PDB generation, the first step is often to do the same link with link.exe and then compare PDBs. But comparing PDBs is hard because two completely different byte sequences can both be correct, so it hampers the investigation when you also have to spend time figuring out not just which bytes are different, but also if the difference is meaningful. This patch fixes a couple of cases related to string table emission, hash table emission, and the order in which we emit strings that makes more of our bytes the same as the bytes generated by MS PDBs. Differential Revision: https://reviews.llvm.org/D44810 llvm-svn: 328348
This is still failing on a different bot this time due to some issue related to hashing absolute paths. Reverting until I can figure it out. llvm-svn: 328014
The issue causing this to fail in certain configurations should be fixed. It was due to the fact that DIA apparently expects there to be a null string at ID 1 in the string table. I'm not sure why this is important but it seems to make a difference, so set it. llvm-svn: 328002
This is causing a test failure on a certain bot, so I'm removing this temporarily until we can figure out the source of the error. llvm-svn: 327903