[Lldb-commits] [lldb] [lldb] Fix the DWARF index cache when index is partial. (PR #118390)

[Pavel Labath via lldb-commits]

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+// REQUIRES: lld
+
+// Test if we build a mixed binary where one .o file has a .debug_names and
+// another doesn't have one, that we save a full or partial index cache.
+// Previous versions of LLDB would have ManualDWARFIndex.cpp that would save out
+// an index cache to the same file regardless of wether the index cache was a
+// full DWARF manual index, or just the CUs and TUs that were missing from any
+// .debug_names tables. If the user had a .debug_names table and debugged once
+// with index caching enabled, then debugged again but set the setting to ignore
+// .debug_names ('settings set plugin.symbol-file.dwarf.ignore-file-indexes 1')
+// this could cause LLDB to load the index cache from the previous run which
+// was incomplete and it only contained the manually indexed DWARF from the run
+// where we used .debug_names, but it would now load it as if it were the
+// complete DWARF index.
+
+// Test that if we don't have .debug_names, that we save a full DWARF index.
+// RUN: %clang -target x86_64-pc-linux -gsplit-dwarf -gdwarf-5 -DMAIN=1 -c %s -o %t.main.o
+// RUN: %clang -target x86_64-pc-linux -gsplit-dwarf -gdwarf-5 -DMAIN=0 -c %s -o %t.foo.o
+// RUN: ld.lld %t.main.o %t.foo.o -o %t.nonames
+// RUN: llvm-dwp %t.main.dwo %t.foo.dwo -o %t.nonames.dwp
+// RUN: rm %t.main.dwo %t.foo.dwo
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labath wrote:

Are these steps necessary. We should be able to build/save the index from dwo files alone, right?

https://github.com/llvm/llvm-project/pull/118390