1 //===- DataStructure.h - Build data structure graphs -------------*- C++ -*--=//
3 // Implement the LLVM data structure analysis library.
5 //===----------------------------------------------------------------------===//
7 #ifndef LLVM_ANALYSIS_DATA_STRUCTURE_H
8 #define LLVM_ANALYSIS_DATA_STRUCTURE_H
10 #include "llvm/Pass.h"
13 // Hack around broken gdb! stack traces from system assert don't work, but do
17 do { if (!(x)) { std::cerr << "assertion failure!: " #x "\n"; \
18 int *P = 0; *P = 17; }} while (0)
22 class DSNode; // Each node in the graph
23 class DSGraph; // A graph for a function
24 class DSNodeIterator; // Data structure graph traversal iterator
25 class LocalDataStructures; // A collection of local graphs for a program
26 class BUDataStructures; // A collection of bu graphs for a program
27 class TDDataStructures; // A collection of td graphs for a program
29 //===----------------------------------------------------------------------===//
30 // DSNodeHandle - Implement a "handle" to a data structure node that takes care
31 // of all of the add/un'refing of the node to prevent the backpointers in the
32 // graph from getting out of date.
37 // Allow construction, destruction, and assignment...
38 DSNodeHandle(DSNode *n = 0) : N(0) { operator=(n); }
39 DSNodeHandle(const DSNodeHandle &H) : N(0) { operator=(H.N); }
40 ~DSNodeHandle() { operator=(0); }
41 DSNodeHandle &operator=(const DSNodeHandle &H) {operator=(H.N); return *this;}
43 // Assignment of DSNode*, implement all of the add/un'refing (defined later)
44 inline DSNodeHandle &operator=(DSNode *n);
46 // Allow automatic, implicit, conversion to DSNode*
47 operator DSNode*() { return N; }
48 operator const DSNode*() const { return N; }
49 operator bool() const { return N != 0; }
50 operator bool() { return N != 0; }
52 bool operator<(const DSNodeHandle &H) const { // Allow sorting
55 bool operator==(const DSNodeHandle &H) const { return N == H.N; }
56 bool operator!=(const DSNodeHandle &H) const { return N != H.N; }
57 bool operator==(const DSNode *Node) const { return N == Node; }
58 bool operator!=(const DSNode *Node) const { return N != Node; }
60 // Avoid having comparisons to null cause errors...
61 bool operator==(int X) const { return operator==((DSNode*)X); }
63 // Allow explicit conversion to DSNode...
64 DSNode *get() { return N; }
65 const DSNode *get() const { return N; }
67 // Allow this to be treated like a pointer...
68 DSNode *operator->() { return N; }
69 const DSNode *operator->() const { return N; }
73 //===----------------------------------------------------------------------===//
74 // DSNode - Data structure node class
76 // This class keeps track of a node's type, and the fields in the data
82 std::vector<DSNodeHandle> Links;
83 std::vector<DSNodeHandle*> Referrers;
85 // Globals - The list of global values that are merged into this node.
86 std::vector<GlobalValue*> Globals;
88 void operator=(const DSNode &); // DO NOT IMPLEMENT
91 ShadowNode = 0 << 0, // Nothing is known about this node...
92 ScalarNode = 1 << 0, // Scalar of the current function contains this value
93 AllocaNode = 1 << 1, // This node was allocated with alloca
94 NewNode = 1 << 2, // This node was allocated with malloc
95 GlobalNode = 1 << 3, // This node was allocated by a global var decl
96 SubElement = 1 << 4, // This node is a part of some other node
97 CastNode = 1 << 5, // This node is accessed in unsafe ways
98 Incomplete = 1 << 6, // This node may not be complete
101 // NodeType - A union of the above bits. "Shadow" nodes do not add any flags
102 // to the nodes in the data structure graph, so it is possible to have nodes
103 // with a value of 0 for their NodeType. Scalar and Alloca markers go away
104 // when function graphs are inlined.
106 unsigned char NodeType;
108 DSNode(enum NodeTy NT, const Type *T);
109 DSNode(const DSNode &);
113 dropAllReferences(); // Only needed to satisfy assertion checks...
115 assert(Referrers.empty() && "Referrers to dead node exist!");
118 // Iterator for graph interface...
119 typedef DSNodeIterator iterator;
120 inline iterator begin(); // Defined in DataStructureGraph.h
121 inline iterator end();
124 const Type *getType() const { return Ty; }
126 unsigned getNumLinks() const { return Links.size(); }
127 DSNode *getLink(unsigned i) {
128 assert(i < getNumLinks() && "Field links access out of range...");
131 const DSNode *getLink(unsigned i) const {
132 assert(i < getNumLinks() && "Field links access out of range...");
136 void setLink(unsigned i, DSNode *N) {
137 assert(i < getNumLinks() && "Field links access out of range...");
141 // addGlobal - Add an entry for a global value to the Globals list. This also
142 // marks the node with the 'G' flag if it does not already have it.
144 void addGlobal(GlobalValue *GV);
145 const std::vector<GlobalValue*> &getGlobals() const { return Globals; }
146 std::vector<GlobalValue*> &getGlobals() { return Globals; }
148 // addEdgeTo - Add an edge from the current node to the specified node. This
149 // can cause merging of nodes in the graph.
151 void addEdgeTo(unsigned LinkNo, DSNode *N);
152 void addEdgeTo(DSNode *N) {
153 assert(getNumLinks() == 1 && "Must specify a field number to add edge if "
154 " more than one field exists!");
158 // mergeWith - Merge this node into the specified node, moving all links to
159 // and from the argument node into the current node. The specified node may
160 // be a null pointer (in which case, nothing happens).
162 void mergeWith(DSNode *N);
164 // addReferrer - Keep the referrer set up to date...
165 void addReferrer(DSNodeHandle *H) { Referrers.push_back(H); }
166 void removeReferrer(DSNodeHandle *H);
167 const std::vector<DSNodeHandle*> &getReferrers() const { return Referrers; }
169 void print(std::ostream &O, const DSGraph *G) const;
172 std::string getCaption(const DSGraph *G) const;
174 void dropAllReferences() {
180 inline DSNodeHandle &DSNodeHandle::operator=(DSNode *n) {
181 if (N) N->removeReferrer(this);
183 if (N) N->addReferrer(this);
188 // DSGraph - The graph that represents a function.
192 std::vector<DSNode*> Nodes;
193 DSNodeHandle RetNode; // Node that gets returned...
194 std::map<Value*, DSNodeHandle> ValueMap;
196 // FunctionCalls - This vector maintains a single entry for each call
197 // instruction in the current graph. Each call entry contains DSNodeHandles
198 // that refer to the arguments that are passed into the function call. The
199 // first entry in the vector is the scalar that holds the return value for the
200 // call, the second is the function scalar being invoked, and the rest are
201 // pointer arguments to the function.
203 std::vector<std::vector<DSNodeHandle> > FunctionCalls;
205 // OrigFunctionCalls - This vector retains a copy of the original function
206 // calls of the current graph. This is needed to support top-down inlining
207 // after bottom-up inlining is complete, since the latter deletes call nodes.
209 std::vector<std::vector<DSNodeHandle> > OrigFunctionCalls;
211 // PendingCallers - This vector records all unresolved callers of the
212 // current function, i.e., ones whose graphs have not been inlined into
213 // the current graph. As long as there are unresolved callers, the nodes
214 // for formal arguments in the current graph cannot be eliminated, and
215 // nodes in the graph reachable from the formal argument nodes or
216 // global variable nodes must be considered incomplete.
217 std::vector<Function*> PendingCallers;
220 // Define the interface only accessable to DataStructure
221 friend class LocalDataStructures;
222 friend class BUDataStructures;
223 friend class TDDataStructures;
224 DSGraph(Function &F); // Compute the local DSGraph
225 DSGraph(const DSGraph &DSG); // Copy ctor
228 // clone all the call nodes and save the copies in OrigFunctionCalls
229 void saveOrigFunctionCalls() {
230 assert(OrigFunctionCalls.size() == 0 && "Do this only once!");
231 OrigFunctionCalls = FunctionCalls;
234 // get the saved copies of the original function call nodes
235 std::vector<std::vector<DSNodeHandle> > &getOrigFunctionCalls() {
236 return OrigFunctionCalls;
239 void operator=(const DSGraph &); // DO NOT IMPLEMENT
242 Function &getFunction() const { return Func; }
244 // getValueMap - Get a map that describes what the nodes the scalars in this
245 // function point to...
247 std::map<Value*, DSNodeHandle> &getValueMap() { return ValueMap; }
248 const std::map<Value*, DSNodeHandle> &getValueMap() const { return ValueMap;}
250 std::vector<std::vector<DSNodeHandle> > &getFunctionCalls() {
251 return FunctionCalls;
254 const DSNode *getRetNode() const { return RetNode; }
256 unsigned getGraphSize() const {
260 void print(std::ostream &O) const;
263 // maskNodeTypes - Apply a mask to all of the node types in the graph. This
264 // is useful for clearing out markers like Scalar or Incomplete.
266 void maskNodeTypes(unsigned char Mask);
267 void maskIncompleteMarkers() { maskNodeTypes(~DSNode::Incomplete); }
269 // markIncompleteNodes - Traverse the graph, identifying nodes that may be
270 // modified by other functions that have not been resolved yet. This marks
271 // nodes that are reachable through three sources of "unknownness":
272 // Global Variables, Function Calls, and Incoming Arguments
274 // For any node that may have unknown components (because something outside
275 // the scope of current analysis may have modified it), the 'Incomplete' flag
276 // is added to the NodeType.
278 void markIncompleteNodes();
280 // removeTriviallyDeadNodes - After the graph has been constructed, this
281 // method removes all unreachable nodes that are created because they got
282 // merged with other nodes in the graph.
284 void removeTriviallyDeadNodes();
286 // removeDeadNodes - Use a more powerful reachability analysis to eliminate
287 // subgraphs that are unreachable. This often occurs because the data
288 // structure doesn't "escape" into it's caller, and thus should be eliminated
289 // from the caller's graph entirely. This is only appropriate to use when
292 void removeDeadNodes();
295 // AddCaller - add a known caller node into the graph and mark it pending.
296 // getCallers - get a vector of the functions that call this one
297 // getCallersPending - get a matching vector of bools indicating if each
298 // caller's DSGraph has been resolved into this one.
300 void addCaller(Function& caller) {
301 PendingCallers.push_back(&caller);
303 std::vector<Function*>& getPendingCallers() {
304 return PendingCallers;
307 // cloneInto - Clone the specified DSGraph into the current graph, returning
308 // the Return node of the graph. The translated ValueMap for the old function
309 // is filled into the OldValMap member. If StripLocals is set to true, Scalar
310 // and Alloca markers are removed from the graph, as the graph is being cloned
311 // into a calling function's graph.
313 DSNode *cloneInto(const DSGraph &G, std::map<Value*, DSNodeHandle> &OldValMap,
314 std::map<const DSNode*, DSNode*>& OldNodeMap,
315 bool StripLocals = true);
317 bool isNodeDead(DSNode *N);
322 // LocalDataStructures - The analysis that computes the local data structure
323 // graphs for all of the functions in the program.
325 // FIXME: This should be a Function pass that can be USED by a Pass, and would
326 // be automatically preserved. Until we can do that, this is a Pass.
328 class LocalDataStructures : public Pass {
329 // DSInfo, one graph for each function
330 std::map<Function*, DSGraph*> DSInfo;
332 static AnalysisID ID; // DataStructure Analysis ID
334 LocalDataStructures(AnalysisID id) { assert(id == ID); }
335 ~LocalDataStructures() { releaseMemory(); }
337 virtual const char *getPassName() const {
338 return "Local Data Structure Analysis";
341 virtual bool run(Module &M);
343 // getDSGraph - Return the data structure graph for the specified function.
344 DSGraph &getDSGraph(Function &F) const {
345 std::map<Function*, DSGraph*>::const_iterator I = DSInfo.find(&F);
346 assert(I != DSInfo.end() && "Function not in module!");
350 // print - Print out the analysis results...
351 void print(std::ostream &O, Module *M) const;
353 // If the pass pipeline is done with this pass, we can release our memory...
354 virtual void releaseMemory();
356 // getAnalysisUsage - This obviously provides a data structure graph.
357 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
358 AU.setPreservesAll();
364 // BUDataStructures - The analysis that computes the interprocedurally closed
365 // data structure graphs for all of the functions in the program. This pass
366 // only performs a "Bottom Up" propogation (hence the name).
368 class BUDataStructures : public Pass {
369 // DSInfo, one graph for each function
370 std::map<Function*, DSGraph*> DSInfo;
372 static AnalysisID ID; // BUDataStructure Analysis ID
374 BUDataStructures(AnalysisID id) { assert(id == ID); }
375 ~BUDataStructures() { releaseMemory(); }
377 virtual const char *getPassName() const {
378 return "Bottom-Up Data Structure Analysis Closure";
381 virtual bool run(Module &M);
383 // getDSGraph - Return the data structure graph for the specified function.
384 DSGraph &getDSGraph(Function &F) const {
385 std::map<Function*, DSGraph*>::const_iterator I = DSInfo.find(&F);
386 assert(I != DSInfo.end() && "Function not in module!");
390 // print - Print out the analysis results...
391 void print(std::ostream &O, Module *M) const;
393 // If the pass pipeline is done with this pass, we can release our memory...
394 virtual void releaseMemory();
396 // getAnalysisUsage - This obviously provides a data structure graph.
397 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
398 AU.setPreservesAll();
400 AU.addRequired(LocalDataStructures::ID);
403 DSGraph &calculateGraph(Function &F);
407 // TDDataStructures - Analysis that computes new data structure graphs
408 // for each function using the closed graphs for the callers computed
409 // by the bottom-up pass.
411 class TDDataStructures : public Pass {
412 // DSInfo, one graph for each function
413 std::map<Function*, DSGraph*> DSInfo;
415 static AnalysisID ID; // TDDataStructure Analysis ID
417 TDDataStructures(AnalysisID id) { assert(id == ID); }
418 ~TDDataStructures() { releaseMemory(); }
420 virtual const char *getPassName() const {
421 return "Top-down Data Structure Analysis Closure";
424 virtual bool run(Module &M);
426 // getDSGraph - Return the data structure graph for the specified function.
427 DSGraph &getDSGraph(Function &F) const {
428 std::map<Function*, DSGraph*>::const_iterator I = DSInfo.find(&F);
429 assert(I != DSInfo.end() && "Function not in module!");
433 // print - Print out the analysis results...
434 void print(std::ostream &O, Module *M) const;
436 // If the pass pipeline is done with this pass, we can release our memory...
437 virtual void releaseMemory();
439 // getAnalysisUsage - This obviously provides a data structure graph.
440 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
441 AU.setPreservesAll();
443 AU.addRequired(BUDataStructures::ID);
446 DSGraph &calculateGraph(Function &F);
447 void pushGraphIntoCallee(DSGraph &callerGraph, DSGraph &calleeGraph,
448 std::map<Value*, DSNodeHandle> &OldValMap,
449 std::map<const DSNode*, DSNode*> &OldNodeMap);