1//===- RegionPrinter.cpp - Print regions tree pass ------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8// Print out the region tree of a function using dotty/graphviz.
9//===----------------------------------------------------------------------===//
10
11#include "llvm/Analysis/RegionPrinter.h"
12#include "llvm/Analysis/DOTGraphTraitsPass.h"
13#include "llvm/Analysis/RegionInfo.h"
14#include "llvm/Analysis/RegionIterator.h"
15#include "llvm/InitializePasses.h"
16#include "llvm/Support/CommandLine.h"
17#include "llvm/Support/raw_ostream.h"
18#ifndef NDEBUG
19#include "llvm/IR/LegacyPassManager.h"
20#endif
21
22using namespace llvm;
23
24//===----------------------------------------------------------------------===//
25/// onlySimpleRegion - Show only the simple regions in the RegionViewer.
26static cl::opt<bool>
27onlySimpleRegions("only-simple-regions",
28 cl::desc("Show only simple regions in the graphviz viewer"),
29 cl::Hidden,
30 cl::init(Val: false));
31
32namespace llvm {
33
34std::string DOTGraphTraits<RegionNode *>::getNodeLabel(RegionNode *Node,
35 RegionNode *Graph) {
36 if (!Node->isSubRegion()) {
37 BasicBlock *BB = Node->getNodeAs<BasicBlock>();
38
39 if (isSimple())
40 return DOTGraphTraits<DOTFuncInfo *>::getSimpleNodeLabel(Node: BB, nullptr);
41 else
42 return DOTGraphTraits<DOTFuncInfo *>::getCompleteNodeLabel(Node: BB, nullptr);
43 }
44
45 return "Not implemented";
46}
47
48template <>
49struct DOTGraphTraits<RegionInfo *> : public DOTGraphTraits<RegionNode *> {
50
51 DOTGraphTraits (bool isSimple = false)
52 : DOTGraphTraits<RegionNode*>(isSimple) {}
53
54 static std::string getGraphName(const RegionInfo *) { return "Region Graph"; }
55
56 std::string getNodeLabel(RegionNode *Node, RegionInfo *G) {
57 return DOTGraphTraits<RegionNode *>::getNodeLabel(
58 Node, Graph: reinterpret_cast<RegionNode *>(G->getTopLevelRegion()));
59 }
60
61 std::string getEdgeAttributes(RegionNode *srcNode,
62 GraphTraits<RegionInfo *>::ChildIteratorType CI,
63 RegionInfo *G) {
64 RegionNode *destNode = *CI;
65
66 if (srcNode->isSubRegion() || destNode->isSubRegion())
67 return "";
68
69 // In case of a backedge, do not use it to define the layout of the nodes.
70 BasicBlock *srcBB = srcNode->getNodeAs<BasicBlock>();
71 BasicBlock *destBB = destNode->getNodeAs<BasicBlock>();
72
73 Region *R = G->getRegionFor(BB: destBB);
74
75 while (R && R->getParent())
76 if (R->getParent()->getEntry() == destBB)
77 R = R->getParent();
78 else
79 break;
80
81 if (R && R->getEntry() == destBB && R->contains(BB: srcBB))
82 return "constraint=false";
83
84 return "";
85 }
86
87 // Print the cluster of the subregions. This groups the single basic blocks
88 // and adds a different background color for each group.
89 static void printRegionCluster(const Region &R, GraphWriter<RegionInfo *> &GW,
90 unsigned depth = 0) {
91 raw_ostream &O = GW.getOStream();
92 O.indent(NumSpaces: 2 * depth) << "subgraph cluster_" << static_cast<const void*>(&R)
93 << " {\n";
94 O.indent(NumSpaces: 2 * (depth + 1)) << "label = \"\";\n";
95
96 if (!onlySimpleRegions || R.isSimple()) {
97 O.indent(NumSpaces: 2 * (depth + 1)) << "style = filled;\n";
98 O.indent(NumSpaces: 2 * (depth + 1)) << "color = "
99 << ((R.getDepth() * 2 % 12) + 1) << "\n";
100
101 } else {
102 O.indent(NumSpaces: 2 * (depth + 1)) << "style = solid;\n";
103 O.indent(NumSpaces: 2 * (depth + 1)) << "color = "
104 << ((R.getDepth() * 2 % 12) + 2) << "\n";
105 }
106
107 for (const auto &RI : R)
108 printRegionCluster(R: *RI, GW, depth: depth + 1);
109
110 const RegionInfo &RI = *static_cast<const RegionInfo*>(R.getRegionInfo());
111
112 for (auto *BB : R.blocks())
113 if (RI.getRegionFor(BB) == &R)
114 O.indent(NumSpaces: 2 * (depth + 1)) << "Node"
115 << static_cast<const void*>(RI.getTopLevelRegion()->getBBNode(BB))
116 << ";\n";
117
118 O.indent(NumSpaces: 2 * depth) << "}\n";
119 }
120
121 static void addCustomGraphFeatures(const RegionInfo *G,
122 GraphWriter<RegionInfo *> &GW) {
123 raw_ostream &O = GW.getOStream();
124 O << "\tcolorscheme = \"paired12\"\n";
125 printRegionCluster(R: *G->getTopLevelRegion(), GW, depth: 4);
126 }
127};
128} // end namespace llvm
129
130namespace {
131
132struct RegionInfoPassGraphTraits {
133 static RegionInfo *getGraph(RegionInfoPass *RIP) {
134 return &RIP->getRegionInfo();
135 }
136};
137
138struct RegionPrinter
139 : public DOTGraphTraitsPrinterWrapperPass<
140 RegionInfoPass, false, RegionInfo *, RegionInfoPassGraphTraits> {
141 static char ID;
142 RegionPrinter()
143 : DOTGraphTraitsPrinterWrapperPass<RegionInfoPass, false, RegionInfo *,
144 RegionInfoPassGraphTraits>("reg", ID) {
145 }
146};
147char RegionPrinter::ID = 0;
148
149struct RegionOnlyPrinter
150 : public DOTGraphTraitsPrinterWrapperPass<
151 RegionInfoPass, true, RegionInfo *, RegionInfoPassGraphTraits> {
152 static char ID;
153 RegionOnlyPrinter()
154 : DOTGraphTraitsPrinterWrapperPass<RegionInfoPass, true, RegionInfo *,
155 RegionInfoPassGraphTraits>("reg", ID) {
156 }
157};
158char RegionOnlyPrinter::ID = 0;
159
160struct RegionViewer
161 : public DOTGraphTraitsViewerWrapperPass<
162 RegionInfoPass, false, RegionInfo *, RegionInfoPassGraphTraits> {
163 static char ID;
164 RegionViewer()
165 : DOTGraphTraitsViewerWrapperPass<RegionInfoPass, false, RegionInfo *,
166 RegionInfoPassGraphTraits>("reg", ID) {}
167};
168char RegionViewer::ID = 0;
169
170struct RegionOnlyViewer
171 : public DOTGraphTraitsViewerWrapperPass<RegionInfoPass, true, RegionInfo *,
172 RegionInfoPassGraphTraits> {
173 static char ID;
174 RegionOnlyViewer()
175 : DOTGraphTraitsViewerWrapperPass<RegionInfoPass, true, RegionInfo *,
176 RegionInfoPassGraphTraits>("regonly",
177 ID) {}
178};
179char RegionOnlyViewer::ID = 0;
180
181} //end anonymous namespace
182
183INITIALIZE_PASS(RegionPrinter, "dot-regions",
184 "Print regions of function to 'dot' file", true, true)
185
186INITIALIZE_PASS(
187 RegionOnlyPrinter, "dot-regions-only",
188 "Print regions of function to 'dot' file (with no function bodies)", true,
189 true)
190
191INITIALIZE_PASS(RegionViewer, "view-regions", "View regions of function",
192 true, true)
193
194INITIALIZE_PASS(RegionOnlyViewer, "view-regions-only",
195 "View regions of function (with no function bodies)",
196 true, true)
197
198FunctionPass *llvm::createRegionPrinterPass() { return new RegionPrinter(); }
199
200FunctionPass *llvm::createRegionOnlyPrinterPass() {
201 return new RegionOnlyPrinter();
202}
203
204FunctionPass* llvm::createRegionViewerPass() {
205 return new RegionViewer();
206}
207
208FunctionPass* llvm::createRegionOnlyViewerPass() {
209 return new RegionOnlyViewer();
210}
211
212#ifndef NDEBUG
213static void viewRegionInfo(RegionInfo *RI, bool ShortNames) {
214 assert(RI && "Argument must be non-null");
215
216 llvm::Function *F = RI->getTopLevelRegion()->getEntry()->getParent();
217 std::string GraphName = DOTGraphTraits<RegionInfo *>::getGraphName(RI);
218
219 llvm::ViewGraph(RI, "reg", ShortNames,
220 Twine(GraphName) + " for '" + F->getName() + "' function");
221}
222
223static void invokeFunctionPass(const Function *F, FunctionPass *ViewerPass) {
224 assert(F && "Argument must be non-null");
225 assert(!F->isDeclaration() && "Function must have an implementation");
226
227 // The viewer and analysis passes do not modify anything, so we can safely
228 // remove the const qualifier
229 auto NonConstF = const_cast<Function *>(F);
230
231 llvm::legacy::FunctionPassManager FPM(NonConstF->getParent());
232 FPM.add(ViewerPass);
233 FPM.doInitialization();
234 FPM.run(*NonConstF);
235 FPM.doFinalization();
236}
237
238void llvm::viewRegion(RegionInfo *RI) { viewRegionInfo(RI, false); }
239
240void llvm::viewRegion(const Function *F) {
241 invokeFunctionPass(F, createRegionViewerPass());
242}
243
244void llvm::viewRegionOnly(RegionInfo *RI) { viewRegionInfo(RI, true); }
245
246void llvm::viewRegionOnly(const Function *F) {
247 invokeFunctionPass(F, createRegionOnlyViewerPass());
248}
249#endif
250