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32 // graph from getting out of date.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 // Allow explicit conversion to DSNode...
61 DSNode *get() { return N; }
62 const DSNode *get() const { return N; }
64 // Allow this to be treated like a pointer...
65 DSNode *operator->() { return N; }
66 const DSNode *operator->() const { return N; }
70 //===----------------------------------------------------------------------===//
71 // DSNode - Data structure node class
73 // This class keeps track of a node's type, and the fields in the data
79 std::vector<DSNodeHandle> Links;
80 std::vector<DSNodeHandle*> Referrers;
82 // Globals - The list of global values that are merged into this node.
83 std::vector<GlobalValue*> Globals;
85 void operator=(const DSNode &); // DO NOT IMPLEMENT
88 ShadowNode = 0 << 0, // Nothing is known about this node...
89 ScalarNode = 1 << 0, // Scalar of the current function contains this value
90 AllocaNode = 1 << 1, // This node was allocated with alloca
91 NewNode = 1 << 2, // This node was allocated with malloc
92 GlobalNode = 1 << 3, // This node was allocated by a global var decl
93 SubElement = 1 << 4, // This node is a part of some other node
94 CastNode = 1 << 5, // This node is accessed in unsafe ways
95 Incomplete = 1 << 6, // This node may not be complete
98 // NodeType - A union of the above bits. "Shadow" nodes do not add any flags
99 // to the nodes in the data structure graph, so it is possible to have nodes
100 // with a value of 0 for their NodeType. Scalar and Alloca markers go away
101 // when function graphs are inlined.
103 unsigned char NodeType;
105 DSNode(enum NodeTy NT, const Type *T);
106 DSNode(const DSNode &);
110 dropAllReferences(); // Only needed to satisfy assertion checks...
112 assert(Referrers.empty() && "Referrers to dead node exist!");
115 // Iterator for graph interface...
116 typedef DSNodeIterator iterator;
117 inline iterator begin(); // Defined in DataStructureGraph.h
118 inline iterator end();
121 const Type *getType() const { return Ty; }
123 unsigned getNumLinks() const { return Links.size(); }
124 DSNode *getLink(unsigned i) {
125 assert(i < getNumLinks() && "Field links access out of range...");
128 const DSNode *getLink(unsigned i) const {
129 assert(i < getNumLinks() && "Field links access out of range...");
133 void setLink(unsigned i, DSNode *N) {
134 assert(i < getNumLinks() && "Field links access out of range...");
138 // addGlobal - Add an entry for a global value to the Globals list. This also
139 // marks the node with the 'G' flag if it does not already have it.
141 void addGlobal(GlobalValue *GV);
142 const std::vector<GlobalValue*> &getGlobals() const { return Globals; }
143 std::vector<GlobalValue*> &getGlobals() { return Globals; }
145 // addEdgeTo - Add an edge from the current node to the specified node. This
146 // can cause merging of nodes in the graph.
148 void addEdgeTo(unsigned LinkNo, DSNode *N);
149 void addEdgeTo(DSNode *N) {
150 assert(getNumLinks() == 1 && "Must specify a field number to add edge if "
151 " more than one field exists!");
155 // mergeWith - Merge this node into the specified node, moving all links to
156 // and from the argument node into the current node. The specified node may
157 // be a null pointer (in which case, nothing happens).
159 void mergeWith(DSNode *N);
161 // addReferrer - Keep the referrer set up to date...
162 void addReferrer(DSNodeHandle *H) { Referrers.push_back(H); }
163 void removeReferrer(DSNodeHandle *H);
164 const std::vector<DSNodeHandle*> &getReferrers() const { return Referrers; }
166 void print(std::ostream &O, const DSGraph *G) const;
169 std::string getCaption(const DSGraph *G) const;
171 void dropAllReferences() {
177 inline DSNodeHandle &DSNodeHandle::operator=(DSNode *n) {
178 if (N) N->removeReferrer(this);
180 if (N) N->addReferrer(this);
185 // DSGraph - The graph that represents a function.
189 std::vector<DSNode*> Nodes;
190 DSNodeHandle RetNode; // Node that gets returned...
191 std::map<Value*, DSNodeHandle> ValueMap;
193 // FunctionCalls - This vector maintains a single entry for each call
194 // instruction in the current graph. Each call entry contains DSNodeHandles
195 // that refer to the arguments that are passed into the function call. The
196 // first entry in the vector is the scalar that holds the return value for the
197 // call, the second is the function scalar being invoked, and the rest are
198 // pointer arguments to the function.
200 std::vector<std::vector<DSNodeHandle> > FunctionCalls;
202 // OrigFunctionCalls - This vector retains a copy of the original function
203 // calls of the current graph. This is needed to support top-down inlining
204 // after bottom-up inlining is complete, since the latter deletes call nodes.
206 std::vector<std::vector<DSNodeHandle> > OrigFunctionCalls;
208 // PendingCallers - This vector records all unresolved callers of the
209 // current function, i.e., ones whose graphs have not been inlined into
210 // the current graph. As long as there are unresolved callers, the nodes
211 // for formal arguments in the current graph cannot be eliminated, and
212 // nodes in the graph reachable from the formal argument nodes or
213 // global variable nodes must be considered incomplete.
214 std::vector<Function*> PendingCallers;
217 // Define the interface only accessable to DataStructure
218 friend class LocalDataStructures;
219 friend class BUDataStructures;
220 friend class TDDataStructures;
221 DSGraph(Function &F); // Compute the local DSGraph
222 DSGraph(const DSGraph &DSG); // Copy ctor
225 // clone all the call nodes and save the copies in OrigFunctionCalls
226 void saveOrigFunctionCalls() {
227 assert(OrigFunctionCalls.size() == 0 && "Do this only once!");
228 OrigFunctionCalls = FunctionCalls;
231 // get the saved copies of the original function call nodes
232 std::vector<std::vector<DSNodeHandle> > &getOrigFunctionCalls() {
233 return OrigFunctionCalls;
236 void operator=(const DSGraph &); // DO NOT IMPLEMENT
239 Function &getFunction() const { return Func; }
241 // getValueMap - Get a map that describes what the nodes the scalars in this
242 // function point to...
244 std::map<Value*, DSNodeHandle> &getValueMap() { return ValueMap; }
245 const std::map<Value*, DSNodeHandle> &getValueMap() const { return ValueMap;}
247 std::vector<std::vector<DSNodeHandle> > &getFunctionCalls() {
248 return FunctionCalls;
251 const DSNode *getRetNode() const { return RetNode; }
253 unsigned getGraphSize() const {
257 void print(std::ostream &O) const;
260 // maskNodeTypes - Apply a mask to all of the node types in the graph. This
261 // is useful for clearing out markers like Scalar or Incomplete.
263 void maskNodeTypes(unsigned char Mask);
264 void maskIncompleteMarkers() { maskNodeTypes(~DSNode::Incomplete); }
266 // markIncompleteNodes - Traverse the graph, identifying nodes that may be
267 // modified by other functions that have not been resolved yet. This marks
268 // nodes that are reachable through three sources of "unknownness":
269 // Global Variables, Function Calls, and Incoming Arguments
271 // For any node that may have unknown components (because something outside
272 // the scope of current analysis may have modified it), the 'Incomplete' flag
273 // is added to the NodeType.
275 void markIncompleteNodes();
277 // removeDeadNodes - After the graph has been constructed, this method removes
278 // all unreachable nodes that are created because they got merged with other
279 // nodes in the graph.
281 void removeDeadNodes();
283 // AddCaller - add a known caller node into the graph and mark it pending.
284 // getCallers - get a vector of the functions that call this one
285 // getCallersPending - get a matching vector of bools indicating if each
286 // caller's DSGraph has been resolved into this one.
288 void addCaller(Function& caller) {
289 PendingCallers.push_back(&caller);
291 std::vector<Function*>& getPendingCallers() {
292 return PendingCallers;
295 // cloneInto - Clone the specified DSGraph into the current graph, returning
296 // the Return node of the graph. The translated ValueMap for the old function
297 // is filled into the OldValMap member. If StripLocals is set to true, Scalar
298 // and Alloca markers are removed from the graph, as the graph is being cloned
299 // into a calling function's graph.
301 DSNode *cloneInto(const DSGraph &G, std::map<Value*, DSNodeHandle> &OldValMap,
302 std::map<const DSNode*, DSNode*>& OldNodeMap,
303 bool StripLocals = true);
305 bool isNodeDead(DSNode *N);
310 // LocalDataStructures - The analysis that computes the local data structure
311 // graphs for all of the functions in the program.
313 // FIXME: This should be a Function pass that can be USED by a Pass, and would
314 // be automatically preserved. Until we can do that, this is a Pass.
316 class LocalDataStructures : public Pass {
317 // DSInfo, one graph for each function
318 std::map<Function*, DSGraph*> DSInfo;
320 static AnalysisID ID; // DataStructure Analysis ID
322 LocalDataStructures(AnalysisID id) { assert(id == ID); }
323 ~LocalDataStructures() { releaseMemory(); }
325 virtual const char *getPassName() const {
326 return "Local Data Structure Analysis";
329 virtual bool run(Module &M);
331 // getDSGraph - Return the data structure graph for the specified function.
332 DSGraph &getDSGraph(Function &F) const {
333 std::map<Function*, DSGraph*>::const_iterator I = DSInfo.find(&F);
334 assert(I != DSInfo.end() && "Function not in module!");
338 // print - Print out the analysis results...
339 void print(std::ostream &O, Module *M) const;
341 // If the pass pipeline is done with this pass, we can release our memory...
342 virtual void releaseMemory();
344 // getAnalysisUsage - This obviously provides a data structure graph.
345 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
346 AU.setPreservesAll();
352 // BUDataStructures - The analysis that computes the interprocedurally closed
353 // data structure graphs for all of the functions in the program. This pass
354 // only performs a "Bottom Up" propogation (hence the name).
356 class BUDataStructures : public Pass {
357 // DSInfo, one graph for each function
358 std::map<Function*, DSGraph*> DSInfo;
360 static AnalysisID ID; // BUDataStructure Analysis ID
362 BUDataStructures(AnalysisID id) { assert(id == ID); }
363 ~BUDataStructures() { releaseMemory(); }
365 virtual const char *getPassName() const {
366 return "Bottom-Up Data Structure Analysis Closure";
369 virtual bool run(Module &M);
371 // getDSGraph - Return the data structure graph for the specified function.
372 DSGraph &getDSGraph(Function &F) const {
373 std::map<Function*, DSGraph*>::const_iterator I = DSInfo.find(&F);
374 assert(I != DSInfo.end() && "Function not in module!");
378 // print - Print out the analysis results...
379 void print(std::ostream &O, Module *M) const;
381 // If the pass pipeline is done with this pass, we can release our memory...
382 virtual void releaseMemory();
384 // getAnalysisUsage - This obviously provides a data structure graph.
385 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
386 AU.setPreservesAll();
388 AU.addRequired(LocalDataStructures::ID);
391 DSGraph &calculateGraph(Function &F);
395 // TDDataStructures - Analysis that computes new data structure graphs
396 // for each function using the closed graphs for the callers computed
397 // by the bottom-up pass.
399 class TDDataStructures : public Pass {
400 // DSInfo, one graph for each function
401 std::map<Function*, DSGraph*> DSInfo;
403 static AnalysisID ID; // TDDataStructure Analysis ID
405 TDDataStructures(AnalysisID id) { assert(id == ID); }
406 ~TDDataStructures() { releaseMemory(); }
408 virtual const char *getPassName() const {
409 return "Top-down Data Structure Analysis Closure";
412 virtual bool run(Module &M);
414 // getDSGraph - Return the data structure graph for the specified function.
415 DSGraph &getDSGraph(Function &F) const {
416 std::map<Function*, DSGraph*>::const_iterator I = DSInfo.find(&F);
417 assert(I != DSInfo.end() && "Function not in module!");
421 // print - Print out the analysis results...
422 void print(std::ostream &O, Module *M) const;
424 // If the pass pipeline is done with this pass, we can release our memory...
425 virtual void releaseMemory();
427 // getAnalysisUsage - This obviously provides a data structure graph.
428 virtual void getAnalysisUsage(AnalysisUsage &AU) const {
429 AU.setPreservesAll();
431 AU.addRequired(BUDataStructures::ID);
434 DSGraph &calculateGraph(Function &F);
435 void pushGraphIntoCallee(DSGraph &callerGraph, DSGraph &calleeGraph,
436 std::map<Value*, DSNodeHandle> &OldValMap,
437 std::map<const DSNode*, DSNode*> &OldNodeMap);