Introduce NewPM DOT printers for DomTree

[DaniilSuchkov]

Summary

This patch adds a couple of NewPM function passes (dot-dom and dot-dom-only) that dump DomTree into .dot files.

[DaniilSuchkov]

Fixed formatting.

[aeubanks]

could you fix the lint checks and also add a test (a simple one is fine)

llvm/include/llvm/Analysis/DOTGraphTraitsPass.h

186

probably better to make this not have a default argument

[DaniilSuchkov]

Fixed lint checks, added a couple of tests and addressed a comment.

[aeubanks]

llvm/test/Analysis/Dominators/print-dot-dom.ll

1

ideally the files would go in a temp directory (%t) rather than the cwd, but I think the cwd is in the build directory so this is probably fine

[DaniilSuchkov]

llvm/test/Analysis/Dominators/print-dot-dom.ll

1

but I think the cwd is in the build directory

Yeah, that's correct. There are other tests that do the same thing, like the test from https://reviews.llvm.org/D90638, and it seems to work fine.

llvm/include/llvm/Analysis/DOTGraphTraitsPass.h

void getAnalysisUsage(AnalysisUsage &AU) const override {
     AU.setPreservesAll();
     AU.addRequired<AnalysisT>();
   }
 
 private:
   std::string Name;
 };
 
+template <typename GraphT>
+void WriteDOTGraphToFile(Function &F, GraphT &&Graph,
+                         std::string FileNamePrefix, bool IsSimple) {
+  std::string Filename = FileNamePrefix + "." + F.getName().str() + ".dot";
+  std::error_code EC;
+
+  errs() << "Writing '" << Filename << "'...";
+
+  raw_fd_ostream File(Filename, EC, sys::fs::OF_TextWithCRLF);
+  std::string GraphName = DOTGraphTraits<GraphT>::getGraphName(Graph);
+  std::string Title = GraphName + " for '" + F.getName().str() + "' function";
+
+  if (!EC)
+    WriteGraph(File, Graph, IsSimple, Title);
+  else
+    errs() << "  error opening file for writing!";
+  errs() << "\n";
+}
+
 } // end namespace llvm
 
 #endif

llvm/include/llvm/Analysis/DomPrinter.h

 //===-- DomPrinter.h - Dom printer external interface ------------*- C++ -*-===//
 //
 // 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 defines external functions that can be called to explicitly
 // instantiate the dominance tree printer.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_ANALYSIS_DOMPRINTER_H
 #define LLVM_ANALYSIS_DOMPRINTER_H
 
+#include "llvm/IR/PassManager.h"
+
+namespace llvm {
+class DomTreePrinterPass : public PassInfoMixin<DomTreePrinterPass> {
+public:
+  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
+};
+
+class DomTreeOnlyPrinterPass : public PassInfoMixin<DomTreeOnlyPrinterPass> {
+public:
+  PreservedAnalyses run(Function &F, FunctionAnalysisManager &AM);
+};
+} // namespace llvm
+
 namespace llvm {
   class FunctionPass;
   FunctionPass *createDomPrinterPass();
   FunctionPass *createDomOnlyPrinterPass();
   FunctionPass *createDomViewerPass();
   FunctionPass *createDomOnlyViewerPass();
   FunctionPass *createPostDomPrinterPass();
   FunctionPass *createPostDomOnlyPrinterPass();
   FunctionPass *createPostDomViewerPass();
   FunctionPass *createPostDomOnlyViewerPass();
 } // End llvm namespace
 
 #endif

llvm/lib/Analysis/DomPrinter.cpp

struct DOTGraphTraits<PostDominatorTree*>
   }
 
   std::string getNodeLabel(DomTreeNode *Node, PostDominatorTree *G ) {
     return DOTGraphTraits<DomTreeNode*>::getNodeLabel(Node, G->getRootNode());
   }
 };
 }
 
+PreservedAnalyses DomTreePrinterPass::run(Function &F,
+                                          FunctionAnalysisManager &AM) {
+  WriteDOTGraphToFile(F, &AM.getResult<DominatorTreeAnalysis>(F), "dom", false);
+  return PreservedAnalyses::all();
+}
+
+PreservedAnalyses DomTreeOnlyPrinterPass::run(Function &F,
+                                              FunctionAnalysisManager &AM) {
+  WriteDOTGraphToFile(F, &AM.getResult<DominatorTreeAnalysis>(F), "domonly",
+                      true);
+  return PreservedAnalyses::all();
+}
+
 void DominatorTree::viewGraph(const Twine &Name, const Twine &Title) {
 #ifndef NDEBUG
   ViewGraph(this, Name, false, Title);
 #else
   errs() << "DomTree dump not available, build with DEBUG\n";
 #endif  // NDEBUG
 }
 

llvm/lib/Passes/PassBuilder.cpp

 #include "llvm/Analysis/CostModel.h"
 #include "llvm/Analysis/CycleAnalysis.h"
 #include "llvm/Analysis/DDG.h"
 #include "llvm/Analysis/DDGPrinter.h"
 #include "llvm/Analysis/Delinearization.h"
 #include "llvm/Analysis/DemandedBits.h"
 #include "llvm/Analysis/DependenceAnalysis.h"
 #include "llvm/Analysis/DivergenceAnalysis.h"
+#include "llvm/Analysis/DomPrinter.h"
 #include "llvm/Analysis/DominanceFrontier.h"
 #include "llvm/Analysis/FunctionPropertiesAnalysis.h"
 #include "llvm/Analysis/GlobalsModRef.h"
 #include "llvm/Analysis/IRSimilarityIdentifier.h"
 #include "llvm/Analysis/IVUsers.h"
 #include "llvm/Analysis/InlineAdvisor.h"
 #include "llvm/Analysis/InlineSizeEstimatorAnalysis.h"
 #include "llvm/Analysis/InstCount.h"

llvm/lib/Passes/PassRegistry.def

 FUNCTION_PASS("coro-cleanup", CoroCleanupPass())
 FUNCTION_PASS("correlated-propagation", CorrelatedValuePropagationPass())
 FUNCTION_PASS("dce", DCEPass())
 FUNCTION_PASS("dfa-jump-threading", DFAJumpThreadingPass())
 FUNCTION_PASS("div-rem-pairs", DivRemPairsPass())
 FUNCTION_PASS("dse", DSEPass())
 FUNCTION_PASS("dot-cfg", CFGPrinterPass())
 FUNCTION_PASS("dot-cfg-only", CFGOnlyPrinterPass())
+FUNCTION_PASS("dot-dom", DomTreePrinterPass())
+FUNCTION_PASS("dot-dom-only", DomTreeOnlyPrinterPass())
 FUNCTION_PASS("fix-irreducible", FixIrreduciblePass())
 FUNCTION_PASS("flattencfg", FlattenCFGPass())
 FUNCTION_PASS("make-guards-explicit", MakeGuardsExplicitPass())
 FUNCTION_PASS("gvn-hoist", GVNHoistPass())
 FUNCTION_PASS("gvn-sink", GVNSinkPass())
 FUNCTION_PASS("helloworld", HelloWorldPass())
 FUNCTION_PASS("infer-address-spaces", InferAddressSpacesPass())
 FUNCTION_PASS("instcombine", InstCombinePass())

llvm/test/Analysis/Dominators/print-dot-dom.ll

+; RUN: opt %s -passes=dot-dom -disable-output
+; RUN: FileCheck %s -input-file=dom.test1.dot -check-prefix=TEST1
+; RUN: FileCheck %s -input-file=dom.test2.dot -check-prefix=TEST2
+
+define void @test1() {
+; TEST1: digraph "Dominator tree for 'test1' function"
+; TEST1-NEXT: label="Dominator tree for 'test1' function"
+; TEST1:      Node0x[[EntryID:.*]] [shape=record,label="{entry:
+; TEST1-NEXT: Node0x[[EntryID]] -> Node0x[[A_ID:.*]];
+; TEST1-NEXT: Node0x[[EntryID]] -> Node0x[[C_ID:.*]];
+; TEST1-NEXT: Node0x[[EntryID]] -> Node0x[[B_ID:.*]];
+; TEST1-NEXT: Node0x[[A_ID]] [shape=record,label="{a:
+; TEST1-NEXT: Node0x[[C_ID]] [shape=record,label="{c:
+; TEST1-NEXT: Node0x[[C_ID]] -> Node0x[[D_ID:.*]];
+; TEST1-NEXT: Node0x[[C_ID]] -> Node0x[[E_ID:.*]];
+; TEST1-NEXT: Node0x[[D_ID]] [shape=record,label="{d:
+; TEST1-NEXT: Node0x[[E_ID]] [shape=record,label="{e:
+; TEST1-NEXT: Node0x[[B_ID]] [shape=record,label="{b:
+
+entry:
+  br i1 undef, label %a, label %b
+
+a:
+  br label %c
+
+b:
+  br label %c
+
+c:
+  br i1 undef, label %d, label %e
+
+d:
+  ret void
+
+e:
+  ret void
+}
+
+define void @test2() {
+; TEST2: digraph "Dominator tree for 'test2' function"
+; TEST2-NEXT: label="Dominator tree for 'test2' function"
+; TEST2: Node0x[[EntryID:.*]] [shape=record,label="{entry:
+; TEST2-NEXT: Node0x[[EntryID]] -> Node0x[[A_ID:.*]];
+; TEST2-NEXT: Node0x[[A_ID]] [shape=record,label="{a:
+; TEST2-NEXT: Node0x[[A_ID]] -> Node0x[[B_ID:.*]];
+; TEST2-NEXT: Node0x[[B_ID]] [shape=record,label="{b:
+; TEST2-NEXT: Node0x[[B_ID]] -> Node0x[[C_ID:.*]];
+; TEST2-NEXT: Node0x[[C_ID]] [shape=record,label="{c:
+; TEST2-NEXT: Node0x[[C_ID]] -> Node0x[[D_ID:.*]];
+; TEST2-NEXT: Node0x[[C_ID]] -> Node0x[[E_ID:.*]];
+; TEST2-NEXT: Node0x[[D_ID]] [shape=record,label="{d:
+; TEST2-NEXT: Node0x[[E_ID]] [shape=record,label="{e:
+
+entry:
+  br label %a
+
+a:
+  br label %b
+
+b:
+  br i1 undef, label %a, label %c
+
+c:
+  br i1 undef, label %d, label %e
+
+d:
+  br i1 undef, label %a, label %e
+
+e:
+  ret void
+}