[llvm] [RFC][TableGen] Restructure TableGen Source (PR #80847)

[Nico Weber via llvm-commits]

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@@ -1,26 +1,25 @@
-add_subdirectory(GlobalISel)
+# Basic utilities which is the strict minimum needed to build
+# llvm-min-tblgen.
+add_subdirectory(Basic)
+# Common utilities are all of the reusable components and helper
+# code needed by the backends.
+add_subdirectory(Common)
 
-add_llvm_library(LLVMTableGenCommon STATIC OBJECT EXCLUDE_FROM_ALL
+set(LLVM_LINK_COMPONENTS Support)
+
+# llvm-min-tablegen only contains a subset of backends necessary to
+# build llvm/include. It must not depend on TableGenCommon, as
+# TableGenCommon depends on this already to generate things such as
+# ValueType definitions.
+add_tablegen(llvm-min-tblgen LLVM_HEADERS
+  TableGen.cpp
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nico wrote:

Keep this source list alphabetized?

https://github.com/llvm/llvm-project/pull/80847