[clang] [llvm] [llvm][clang] Sandbox filesystem reads (PR #165350)

[Jan Svoboda via llvm-commits]

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@@ -110,9 +105,6 @@ class LLVM_ABI AsmPrinter : public MachineFunctionPass {
   /// generating (such as the current section etc).
   std::unique_ptr<MCStreamer> OutStreamer;
 
-  /// The VFS to resolve asm include directives.
-  IntrusiveRefCntPtr<vfs::FileSystem> VFS;
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jansvoboda11 wrote:

Not a strictly necessary change, I think this might be a leftover from my attempt to make `AsmPrinter` sandbox-clean, which didn't pan out (very hard to propagate VFS from all clients).

The `VFS` was being set in `AsmPrinter::doInitialization()`, which the clients **always** call. I made the `VFS` local to `AsmPrinter::emitInlineAsm()` so that the sandbox is turned off only when necessary.

I can probably revert this and just turn off the sandbox in `AsmPrinter::doInitialization()` to minimize the diff, if you'd prefer.

https://github.com/llvm/llvm-project/pull/165350