[lldb] [llvm] [Support][lldb] Port xz (lzma) decompression from LLDB into LLVM (PR #220092)

[Janet Yang via llvm-commits]

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@@ -59,12 +59,25 @@ mark_as_advanced(LLDB_LIBXML2_VERSION)
 add_optional_dependency(LLDB_ENABLE_SWIG "Enable SWIG to generate LLDB bindings" SWIG VERSION 4)
 add_optional_dependency(LLDB_ENABLE_LIBEDIT "Enable editline support in LLDB" LibEdit)
 add_optional_dependency(LLDB_ENABLE_CURSES "Enable curses support in LLDB" CursesAndPanel)
-add_optional_dependency(LLDB_ENABLE_LZMA "Enable LZMA compression support in LLDB" LibLZMA)
 add_optional_dependency(LLDB_ENABLE_LUA "Enable Lua scripting support in LLDB" LuaAndSwig)
 add_optional_dependency(LLDB_ENABLE_PYTHON "Enable Python scripting support in LLDB" PythonAndSwig)
 add_optional_dependency(LLDB_ENABLE_LIBXML2 "Enable Libxml 2 support in LLDB" LibXml2 VERSION ${LLDB_LIBXML2_VERSION})
 add_optional_dependency(LLDB_ENABLE_TREESITTER "Enable Tree-sitter syntax highlighting" TreeSitter)
 
+# liblzma comes from LLVM, and a standalone build cannot change how LLVM was
+# built, so LLDB_ENABLE_LZMA can only be reported here.
+if(LLDB_BUILT_STANDALONE AND DEFINED LLDB_ENABLE_LZMA)
+  string(TOUPPER "${LLDB_ENABLE_LZMA}" lldb_enable_lzma)
+  if(NOT lldb_enable_lzma STREQUAL "AUTO")
+    message(DEPRECATION
+      "LLDB_ENABLE_LZMA is deprecated and has no effect in a standalone build. "
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qxy11 wrote:

Sounds good, updated to error if the LLVM value has a mismatch.

https://github.com/llvm/llvm-project/pull/220092