Reapply [2] [VFS] Add 'overlay-relative' field to YAML files
This reapplies r261552 and r263748. Fixed testcase to reapply.
The VFS overlay mapping between virtual paths and real paths is done through
the 'external-contents' entries in YAML files, which contains hardcoded paths
to the real files.
When a module compilation crashes, headers are dumped into <name>.cache/vfs
directory and are mapped via the <name>.cache/vfs/vfs.yaml. The script
generated for reproduction uses -ivfsoverlay pointing to file to gather the
mapping between virtual paths and files inside <name>.cache/vfs. Currently, we
are only capable of reproducing such crashes in the same machine as they
happen, because of the hardcoded paths in 'external-contents'.
To be able to reproduce a crash in another machine, this patch introduces a new
option in the VFS yaml file called 'overlay-relative'. When it's equal to
'true' it means that the provided path to the YAML file through the
-ivfsoverlay option should also be used to prefix the final path for every
'external-contents'.
Example, given the invocation snippet "... -ivfsoverlay
<name>.cache/vfs/vfs.yaml" and the following entry in the yaml file:
"overlay-relative": "true",
"roots": [
...
"type": "directory",
"name": "/usr/include",
"contents": [
{
"type": "file",
"name": "stdio.h",
"external-contents": "/usr/include/stdio.h"
},
...
Here, a file manager request for virtual "/usr/include/stdio.h", that will map
into real path "/<absolute_path_to>/<name>.cache/vfs/usr/include/stdio.h.
This is a useful feature for debugging module crashes in machines other than
the one where the error happened.
Differential Revision: http://reviews.llvm.org/D17457
rdar://problem/24499339
llvm-svn: 263893
diff --git a/clang/lib/Frontend/ModuleDependencyCollector.cpp b/clang/lib/Frontend/ModuleDependencyCollector.cpp
index 8da10098..1f187b1 100644
--- a/clang/lib/Frontend/ModuleDependencyCollector.cpp
+++ b/clang/lib/Frontend/ModuleDependencyCollector.cpp
@@ -50,6 +50,10 @@
SmallString<256> Dest = getDest();
llvm::sys::path::append(Dest, "vfs.yaml");
+ // Default to use relative overlay directories in the VFS yaml file. This
+ // allows crash reproducer scripts to work across machines.
+ VFSWriter.setOverlayDir(getDest());
+
std::error_code EC;
llvm::raw_fd_ostream OS(Dest, EC, llvm::sys::fs::F_Text);
if (EC) {