Remove -print-callgraph-sccs and -print-cfg-sccs

[aeubanks]

Summary

These don't seem used and don't seem super useful, and aren't ported to the new PM.

-passes=print-callgraph is similar to -print-callgraph-sccs.
-print-cfg-sccs doesn't seem relevant, not sure why we'd want to look at SCCs in a CFG.

[asbirlea]

I think the call graph SCC pass can be very useful to understand SCCs and debug CGSCC passes if it were also ported to the NPM.
AFAICT, the CFGSCC pass is just a utility to see the output of the scc_iterator, which has some good use cases of its own (inliner, globalsaa, etc).
I would prefer having these ported to the NPM instead of discarding them.

[arsenm]

I did just run into this not working and would like to not drop it

llvm/docs/Passes.rst

 Yet to be written.
 
 ``-print-callgraph``: Print a call graph
 ----------------------------------------
 
 This pass, only available in ``opt``, prints the call graph to standard error
 in a human-readable form.
 
-``-print-callgraph-sccs``: Print SCCs of the Call Graph
--------------------------------------------------------
-
-This pass, only available in ``opt``, prints the SCCs of the call graph to
-standard error in a human-readable form.
-
-``-print-cfg-sccs``: Print SCCs of each function CFG
-----------------------------------------------------
-
-This pass, only available in ``opt``, printsthe SCCs of each function CFG to
-standard error in a human-readable fom.
-
 ``-print-dom-info``: Dominator Info Printer
 -------------------------------------------
 
 Dominator Info Printer.
 
 ``-print-externalfnconstants``: Print external fn callsites passed constants
 ----------------------------------------------------------------------------
 

llvm/test/Other/print-cfg-sccs.ll

-; RUN: opt -enable-new-pm=0 -print-cfg-sccs -disable-output < %s 2>&1 | FileCheck %s
-
-; CHECK: SCCs for Function test in PostOrder:
-; CHECK-NEXT: SCC #1 : %exit,
-; CHECK-NEXT: SCC #2 : %0,
-; CHECK-NEXT: SCC #3 : %3,
-; CHECK-NEXT: SCC #4 : %2, %1,
-; CHECK-NEXT: SCC #5 : %entry,
-define void @test(i1 %cond) {
-entry:
-  br i1 %cond, label %0, label %1
-
-0:
-  br label %exit
-
-1:
-  br label %2
-
-2:
-  br i1 %cond, label %1, label %3
-
-3:
-  br label %exit
-
-exit:
-  ret void
-}

llvm/tools/opt/CMakeLists.txt

set(LLVM_LINK_COMPONENTS
   )
 
 add_llvm_tool(opt
   AnalysisWrappers.cpp
   BreakpointPrinter.cpp
   GraphPrinters.cpp
   NewPMDriver.cpp
   PassPrinters.cpp
-  PrintSCC.cpp
   opt.cpp
 
   DEPENDS
   intrinsics_gen
   SUPPORT_PLUGINS
   )
 export_executable_symbols_for_plugins(opt)
 
 if(LLVM_BUILD_EXAMPLES)
     target_link_libraries(opt PRIVATE ExampleIRTransforms)
 endif(LLVM_BUILD_EXAMPLES)

llvm/tools/opt/PrintSCC.cpp

-//===- PrintSCC.cpp - Enumerate SCCs in some key graphs -------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-// This file provides passes to print out SCCs in a CFG or a CallGraph.
-// Normally, you would not use these passes; instead, you would use the
-// scc_iterator directly to enumerate SCCs and process them in some way.  These
-// passes serve three purposes:
-//
-// (1) As a reference for how to use the scc_iterator.
-// (2) To print out the SCCs for a CFG or a CallGraph:
-//       analyze -print-cfg-sccs            to print the SCCs in each CFG of a module.
-//       analyze -print-cfg-sccs -stats     to print the #SCCs and the maximum SCC size.
-//       analyze -print-cfg-sccs -debug > /dev/null to watch the algorithm in action.
-//
-//     and similarly:
-//       analyze -print-callgraph-sccs [-stats] [-debug] to print SCCs in the CallGraph
-//
-// (3) To test the scc_iterator.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/ADT/SCCIterator.h"
-#include "llvm/Analysis/CallGraph.h"
-#include "llvm/IR/CFG.h"
-#include "llvm/IR/Module.h"
-#include "llvm/Pass.h"
-#include "llvm/Support/raw_ostream.h"
-using namespace llvm;
-
-namespace {
-  struct CFGSCC : public FunctionPass {
-    static char ID;  // Pass identification, replacement for typeid
-    CFGSCC() : FunctionPass(ID) {}
-    bool runOnFunction(Function& func) override;
-
-    void print(raw_ostream &O, const Module* = nullptr) const override { }
-
-    void getAnalysisUsage(AnalysisUsage &AU) const override {
-      AU.setPreservesAll();
-    }
-  };
-
-  struct CallGraphSCC : public ModulePass {
-    static char ID;  // Pass identification, replacement for typeid
-    CallGraphSCC() : ModulePass(ID) {}
-
-    // run - Print out SCCs in the call graph for the specified module.
-    bool runOnModule(Module &M) override;
-
-    void print(raw_ostream &O, const Module* = nullptr) const override { }
-
-    // getAnalysisUsage - This pass requires the CallGraph.
-    void getAnalysisUsage(AnalysisUsage &AU) const override {
-      AU.setPreservesAll();
-      AU.addRequired<CallGraphWrapperPass>();
-    }
-  };
-}
-
-char CFGSCC::ID = 0;
-static RegisterPass<CFGSCC>
-Y("print-cfg-sccs", "Print SCCs of each function CFG");
-
-char CallGraphSCC::ID = 0;
-static RegisterPass<CallGraphSCC>
-Z("print-callgraph-sccs", "Print SCCs of the Call Graph");
-
-bool CFGSCC::runOnFunction(Function &F) {
-  unsigned sccNum = 0;
-  errs() << "SCCs for Function " << F.getName() << " in PostOrder:";
-  for (scc_iterator<Function*> SCCI = scc_begin(&F); !SCCI.isAtEnd(); ++SCCI) {
-    const std::vector<BasicBlock *> &nextSCC = *SCCI;
-    errs() << "\nSCC #" << ++sccNum << " : ";
-    for (BasicBlock *BB : nextSCC) {
-      BB->printAsOperand(errs(), false);
-      errs() << ", ";
-    }
-    if (nextSCC.size() == 1 && SCCI.hasCycle())
-      errs() << " (Has self-loop).";
-  }
-  errs() << "\n";
-
-  return true;
-}
-
-
-// run - Print out SCCs in the call graph for the specified module.
-bool CallGraphSCC::runOnModule(Module &M) {
-  CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
-  unsigned sccNum = 0;
-  errs() << "SCCs for the program in PostOrder:";
-  for (scc_iterator<CallGraph*> SCCI = scc_begin(&CG); !SCCI.isAtEnd();
-       ++SCCI) {
-    const std::vector<CallGraphNode*> &nextSCC = *SCCI;
-    errs() << "\nSCC #" << ++sccNum << " : ";
-    for (std::vector<CallGraphNode*>::const_iterator I = nextSCC.begin(),
-           E = nextSCC.end(); I != E; ++I)
-      errs() << ((*I)->getFunction() ? (*I)->getFunction()->getName()
-                                     : "external node") << ", ";
-    if (nextSCC.size() == 1 && SCCI.hasCycle())
-      errs() << " (Has self-loop).";
-  }
-  errs() << "\n";
-
-  return true;
-}

llvm/utils/gn/secondary/llvm/tools/opt/BUILD.gn

deps = [
     "//llvm/lib/Transforms/Vectorize",
   ]
   sources = [
     "AnalysisWrappers.cpp",
     "BreakpointPrinter.cpp",
     "GraphPrinters.cpp",
     "NewPMDriver.cpp",
     "PassPrinters.cpp",
-    "PrintSCC.cpp",
     "opt.cpp",
   ]
 
   # Support plugins.
   # FIXME: Disable dead stripping once other binaries are dead-stripped.
   if (host_os != "mac" && host_os != "win") {
     # Corresponds to export_executable_symbols() in cmake.
     ldflags = [ "-rdynamic" ]
   }
 }