[TargetParser] Fix flaky installs of generated headers (#137853)

The `llvm-headers` target wasn't depending on the generated TargetParser
headers, so they'd be flakily installed or not installed depending on
which order the build steps ran in. Add an explicit dependency to fix
this, and switch to a single `target_parser_gen` target to mirror the
pattern used by `intrinsics_gen` (which also fixes a few other missing
dependencies). Switch `llvm-headers` to use `add_dependencies` instead
of `DEPENDS` for the tablegen dependencies as well, since `DEPENDS` is
only intended for creating a file-level dependency on the output of an
`add_custom_command` in the same CMakeLists.txt (see `DEPENDS` under
https://cmake.org/cmake/help/latest/command/add_custom_target.html).

Author: smeenai

clang/lib/AST/CMakeLists.txt

@@ -145,5 +145,5 @@ add_clang_library(clangAST
   ClangDriverOptions
   intrinsics_gen
   # These generated headers are included transitively.
-  AArch64TargetParserTableGen
+  target_parser_gen
   )

clang/lib/Basic/CMakeLists.txt

@@ -134,8 +134,7 @@ add_clang_library(clangBasic
   omp_gen
   ClangDriverOptions
   # These generated headers are included transitively.
-  ARMTargetParserTableGen
-  AArch64TargetParserTableGen
+  target_parser_gen
   )
 
 target_link_libraries(clangBasic

clang/lib/CodeGen/CMakeLists.txt

@@ -162,8 +162,7 @@ add_clang_library(clangCodeGen
   intrinsics_gen
   ClangDriverOptions
   # These generated headers are included transitively.
-  ARMTargetParserTableGen
-  AArch64TargetParserTableGen
+  target_parser_gen
 
   LINK_LIBS
   clangAST

clang/lib/Driver/CMakeLists.txt

@@ -94,8 +94,7 @@ add_clang_library(clangDriver
   DEPENDS
   ClangDriverOptions
   # These generated headers are included transitively.
-  ARMTargetParserTableGen
-  AArch64TargetParserTableGen
+  target_parser_gen
 
   LINK_LIBS
   clangBasic

clang/tools/driver/CMakeLists.txt

@@ -48,8 +48,7 @@ add_clang_tool(clang
   DEPENDS
   intrinsics_gen
   # These generated headers are included transitively.
-  ARMTargetParserTableGen
-  AArch64TargetParserTableGen
+  target_parser_gen
   ${support_plugins}
   ${CLANG_BOLT_DEPS}
   GENERATE_DRIVER

llvm/CMakeLists.txt

@@ -1415,7 +1415,8 @@ if (NOT LLVM_INSTALL_TOOLCHAIN_ONLY)
 
   # Installing the headers needs to depend on generating any public
   # tablegen'd headers.
-  add_custom_target(llvm-headers DEPENDS intrinsics_gen omp_gen)
+  add_custom_target(llvm-headers)
+  add_dependencies(llvm-headers intrinsics_gen omp_gen target_parser_gen)
   set_target_properties(llvm-headers PROPERTIES FOLDER "LLVM/Resources")
 
   if (NOT LLVM_ENABLE_IDE)

llvm/cmake/modules/LLVMConfig.cmake.in

@@ -162,14 +162,8 @@ endif()
 if(NOT TARGET acc_gen)
   add_custom_target(acc_gen)
 endif()
-if(NOT TARGET ARMTargetParserTableGen)
-  add_custom_target(ARMTargetParserTableGen)
-endif()
-if(NOT TARGET AArch64TargetParserTableGen)
-  add_custom_target(AArch64TargetParserTableGen)
-endif()
-if(NOT TARGET RISCVTargetParserTableGen)
-  add_custom_target(RISCVTargetParserTableGen)
+if(NOT TARGET target_parser_gen)
+  add_custom_target(target_parser_gen)
 endif()
 
 set_property(GLOBAL PROPERTY LLVM_TARGETS_CONFIGURED On)

llvm/include/llvm/TargetParser/CMakeLists.txt

@@ -1,12 +1,11 @@
 set(LLVM_TARGET_DEFINITIONS ${PROJECT_SOURCE_DIR}/lib/Target/ARM/ARM.td)
 tablegen(LLVM ARMTargetParserDef.inc -gen-arm-target-def -I ${PROJECT_SOURCE_DIR}/lib/Target/ARM/)
-add_public_tablegen_target(ARMTargetParserTableGen)
 
 set(LLVM_TARGET_DEFINITIONS ${PROJECT_SOURCE_DIR}/lib/Target/AArch64/AArch64.td)
 tablegen(LLVM AArch64TargetParserDef.inc -gen-arm-target-def -I ${PROJECT_SOURCE_DIR}/lib/Target/AArch64/)
-add_public_tablegen_target(AArch64TargetParserTableGen)
 
 set(LLVM_TARGET_DEFINITIONS ${PROJECT_SOURCE_DIR}/lib/Target/RISCV/RISCV.td)
 tablegen(LLVM RISCVTargetParserDef.inc -gen-riscv-target-def -I ${PROJECT_SOURCE_DIR}/lib/Target/RISCV/)
-add_public_tablegen_target(RISCVTargetParserTableGen)
 
+# This covers all of the tablegen calls above.
+add_public_tablegen_target(target_parser_gen)

llvm/lib/TargetParser/CMakeLists.txt

@@ -39,7 +39,5 @@ add_llvm_component_library(LLVMTargetParser
   Support
 
   DEPENDS
-  ARMTargetParserTableGen
-  AArch64TargetParserTableGen
-  RISCVTargetParserTableGen
+  target_parser_gen
   )