[flang][tco] Remove unneeded dependencies

[awarzynski]

Summary

tco does not generate machine code, so it does not require (machine)
code-gen related dependencies.

[mehdi_amini]

Thanks for the cleanup!

[schweitz]

flang/tools/tco/tco.cpp

139

Is this not needed for specifying target triples other than the host?

[mehdi_amini]

I believe Triple is entirely implemented in libSupport.

[awarzynski]

@schweitz ${LLVM_TARGETS_TO_BUILD} and InitializeAllTargets(); are for initializing LLVM backends (i.e. backends that generate machine code). IIUC, this is irrelevant in tco (it's not meant to generate machine code). Also, I've tested tco before and after this change and I see no difference in behavior.

[schweitz]

In D118112#3270237, @awarzynski wrote:

@schweitz ${LLVM_TARGETS_TO_BUILD} and InitializeAllTargets(); are for initializing LLVM backends (i.e. backends that generate machine code). IIUC, this is irrelevant in tco (it's not meant to generate machine code). Also, I've tested tco before and after this change and I see no difference in behavior.

Thanks for checking, Andrzej.

flang/tools/tco/CMakeLists.txt

-set(LLVM_LINK_COMPONENTS
-  ${LLVM_TARGETS_TO_BUILD}
-)
-
 add_flang_tool(tco tco.cpp)
 llvm_update_compile_flags(tco)
 get_property(dialect_libs GLOBAL PROPERTY MLIR_DIALECT_LIBS)
 target_link_libraries(tco PRIVATE
   FIRCodeGen
   FIRDialect
   FIRSupport
   FIRTransforms

flang/tools/tco/tco.cpp

compileFIR(const mlir::PassPipelineCLParser &passPipeline) {
   return mlir::failure();
 }
 
 int main(int argc, char **argv) {
   [[maybe_unused]] InitLLVM y(argc, argv);
   fir::support::registerMLIRPassesForFortranTools();
   fir::registerOptCodeGenPasses();
   fir::registerOptTransformPasses();
-  InitializeAllTargets();
-  mlir::registerAsmPrinterCLOptions();
   mlir::registerMLIRContextCLOptions();
   mlir::registerPassManagerCLOptions();
   mlir::PassPipelineCLParser passPipe("", "Compiler passes to run");
   cl::ParseCommandLineOptions(argc, argv, "Tilikum Crossing Optimizer\n");
   return mlir::failed(compileFIR(passPipe));
 }