[all-commits] [llvm/llvm-project] 356a4b: [clang][clang-scan-deps] Aggregate the full depend...

[Michael Spencer via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 356a4b433bf7224666fd7152a8ad2560fb286ef4
      https://github.com/llvm/llvm-project/commit/356a4b433bf7224666fd7152a8ad2560fb286ef4
  Author: Michael Spencer <michael_spencer at apple.com>
  Date:   2020-01-23 (Thu, 23 Jan 2020)

  Changed paths:
    M clang/include/clang/Tooling/DependencyScanning/DependencyScanningTool.h
    M clang/include/clang/Tooling/DependencyScanning/ModuleDepCollector.h
    M clang/lib/Tooling/DependencyScanning/DependencyScanningTool.cpp
    M clang/lib/Tooling/DependencyScanning/DependencyScanningWorker.cpp
    M clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp
    M clang/test/ClangScanDeps/Inputs/modules_cdb.json
    M clang/test/ClangScanDeps/modules-full.cpp
    M clang/tools/clang-scan-deps/ClangScanDeps.cpp

  Log Message:
  -----------
  [clang][clang-scan-deps] Aggregate the full dependency information.

Differential Revision: https://reviews.llvm.org/D70268

This is a recommit of f978ea498309 with a fix for the PowerPC failure.

The issue was that:
* `CompilerInstance::ExecuteAction` calls
  `getTarget().adjust(getLangOpts());`.
* `PPCTargetInfo::adjust` changes `LangOptions::HasAltivec`.
* This happens after the first few calls to `getModuleHash`.

There’s even a FIXME saying:
```
  // FIXME: We shouldn't need to do this, the target should be immutable once
  // created. This complexity should be lifted elsewhere.
```

This only showed up on PowerPC because it's one of the few targets that
almost always changes a hashed langopt.

I looked into addressing the fixme, but that would be a much larger
change, and it's not the only thing that happens in `ExecuteAction` that
can change the module context hash. Instead I changed the code to not
call `getModuleHash` until after it has been modified in `ExecuteAction`.