Ted Kremenek | 61f3e05 | 2008-04-03 04:42:52 +0000 | [diff] [blame^] | 1 | // BugReporter.cpp - Generate PathDiagnostics for Bugs ------------*- C++ -*--// |
| 2 | // |
| 3 | // The LLVM Compiler Infrastructure |
| 4 | // |
| 5 | // This file is distributed under the University of Illinois Open Source |
| 6 | // License. See LICENSE.TXT for details. |
| 7 | // |
| 8 | //===----------------------------------------------------------------------===// |
| 9 | // |
| 10 | // This file defines BugReporter, a utility class for generating |
| 11 | // PathDiagnostics for analyses based on GRSimpleVals. |
| 12 | // |
| 13 | //===----------------------------------------------------------------------===// |
| 14 | |
| 15 | #include "clang/Analysis/PathSensitive/BugReporter.h" |
| 16 | #include "clang/Basic/SourceManager.h" |
| 17 | #include "clang/Basic/SourceLocation.h" |
| 18 | #include "clang/AST/ASTContext.h" |
| 19 | #include "clang/AST/CFG.h" |
| 20 | #include "clang/AST/Expr.h" |
| 21 | #include "clang/Analysis/ProgramPoint.h" |
| 22 | #include "clang/Analysis/PathDiagnostic.h" |
| 23 | #include <sstream> |
| 24 | |
| 25 | using namespace clang; |
| 26 | |
| 27 | BugReporter::~BugReporter() {} |
| 28 | |
| 29 | static inline Stmt* GetStmt(const ProgramPoint& P) { |
| 30 | if (const PostStmt* PS = dyn_cast<PostStmt>(&P)) { |
| 31 | return PS->getStmt(); |
| 32 | } |
| 33 | else if (const BlockEdge* BE = dyn_cast<BlockEdge>(&P)) { |
| 34 | return BE->getSrc()->getTerminator(); |
| 35 | } |
| 36 | else if (const BlockEntrance* BE = dyn_cast<BlockEntrance>(&P)) { |
| 37 | return BE->getFirstStmt(); |
| 38 | } |
| 39 | |
| 40 | assert (false && "Unsupported ProgramPoint."); |
| 41 | return NULL; |
| 42 | } |
| 43 | |
| 44 | |
| 45 | PathDiagnosticPiece* |
| 46 | BugDescription::getEndPath(ASTContext& Ctx, |
| 47 | ExplodedNode<ValueState> *N) const { |
| 48 | |
| 49 | Stmt* S = GetStmt(N->getLocation()); |
| 50 | |
| 51 | if (!S) |
| 52 | return NULL; |
| 53 | |
| 54 | FullSourceLoc L(S->getLocStart(), Ctx.getSourceManager()); |
| 55 | PathDiagnosticPiece* P = new PathDiagnosticPiece(L, getDescription()); |
| 56 | |
| 57 | if (Expr* E = dyn_cast<Expr>(S)) |
| 58 | P->addRange(E->getSourceRange()); |
| 59 | |
| 60 | return P; |
| 61 | } |
| 62 | |
| 63 | void BugReporter::GeneratePathDiagnostic(PathDiagnostic& PD, ASTContext& Ctx, |
| 64 | const BugDescription& B, |
| 65 | ExplodedGraph<GRExprEngine>& G, |
| 66 | ExplodedNode<ValueState>* N) { |
| 67 | |
| 68 | PD.push_back(B.getEndPath(Ctx, N)); |
| 69 | |
| 70 | SourceManager& SMgr = Ctx.getSourceManager(); |
| 71 | |
| 72 | |
| 73 | llvm::OwningPtr<ExplodedGraph<GRExprEngine> > GTrim(G.Trim(&N, &N+1)); |
| 74 | |
| 75 | while (!N->pred_empty()) { |
| 76 | |
| 77 | ExplodedNode<ValueState>* LastNode = N; |
| 78 | N = *(N->pred_begin()); |
| 79 | |
| 80 | ProgramPoint P = N->getLocation(); |
| 81 | |
| 82 | if (const BlockEdge* BE = dyn_cast<BlockEdge>(&P)) { |
| 83 | |
| 84 | CFGBlock* Src = BE->getSrc(); |
| 85 | CFGBlock* Dst = BE->getDst(); |
| 86 | |
| 87 | Stmt* T = Src->getTerminator(); |
| 88 | |
| 89 | if (!T) |
| 90 | continue; |
| 91 | |
| 92 | FullSourceLoc L(T->getLocStart(), SMgr); |
| 93 | |
| 94 | switch (T->getStmtClass()) { |
| 95 | default: |
| 96 | break; |
| 97 | |
| 98 | case Stmt::GotoStmtClass: |
| 99 | case Stmt::IndirectGotoStmtClass: { |
| 100 | |
| 101 | Stmt* S = GetStmt(LastNode->getLocation()); |
| 102 | |
| 103 | if (!S) |
| 104 | continue; |
| 105 | |
| 106 | std::ostringstream os; |
| 107 | |
| 108 | os << "Control jumps to line " |
| 109 | << SMgr.getLogicalLineNumber(S->getLocStart()) << ".\n"; |
| 110 | |
| 111 | PD.push_front(new PathDiagnosticPiece(L, os.str())); |
| 112 | break; |
| 113 | } |
| 114 | |
| 115 | case Stmt::SwitchStmtClass: { |
| 116 | |
| 117 | // Figure out what case arm we took. |
| 118 | |
| 119 | Stmt* S = Dst->getLabel(); |
| 120 | |
| 121 | if (!S) |
| 122 | continue; |
| 123 | |
| 124 | std::ostringstream os; |
| 125 | |
| 126 | switch (S->getStmtClass()) { |
| 127 | default: |
| 128 | continue; |
| 129 | |
| 130 | case Stmt::DefaultStmtClass: { |
| 131 | |
| 132 | os << "Control jumps to the 'default' case at line " |
| 133 | << SMgr.getLogicalLineNumber(S->getLocStart()) << ".\n"; |
| 134 | |
| 135 | break; |
| 136 | } |
| 137 | |
| 138 | case Stmt::CaseStmtClass: { |
| 139 | |
| 140 | os << "Control jumps to 'case "; |
| 141 | |
| 142 | Expr* CondE = cast<SwitchStmt>(T)->getCond(); |
| 143 | unsigned bits = Ctx.getTypeSize(CondE->getType()); |
| 144 | |
| 145 | llvm::APSInt V1(bits, false); |
| 146 | |
| 147 | CaseStmt* Case = cast<CaseStmt>(S); |
| 148 | |
| 149 | if (!Case->getLHS()->isIntegerConstantExpr(V1, Ctx, 0, true)) { |
| 150 | assert (false && |
| 151 | "Case condition must evaluate to an integer constant."); |
| 152 | continue; |
| 153 | } |
| 154 | |
| 155 | os << V1.toString(); |
| 156 | |
| 157 | // Get the RHS of the case, if it exists. |
| 158 | |
| 159 | if (Expr* E = Case->getRHS()) { |
| 160 | |
| 161 | llvm::APSInt V2(bits, false); |
| 162 | |
| 163 | if (!E->isIntegerConstantExpr(V2, Ctx, 0, true)) { |
| 164 | assert (false && |
| 165 | "Case condition (RHS) must evaluate to an integer constant."); |
| 166 | continue; |
| 167 | } |
| 168 | |
| 169 | os << " .. " << V2.toString(); |
| 170 | } |
| 171 | |
| 172 | os << ":' at line " |
| 173 | << SMgr.getLogicalLineNumber(S->getLocStart()) << ".\n"; |
| 174 | |
| 175 | break; |
| 176 | |
| 177 | } |
| 178 | } |
| 179 | |
| 180 | PD.push_front(new PathDiagnosticPiece(L, os.str())); |
| 181 | break; |
| 182 | } |
| 183 | |
| 184 | |
| 185 | case Stmt::DoStmtClass: |
| 186 | case Stmt::WhileStmtClass: |
| 187 | case Stmt::ForStmtClass: |
| 188 | case Stmt::IfStmtClass: { |
| 189 | |
| 190 | if (*(Src->succ_begin()+1) == Dst) |
| 191 | PD.push_front(new PathDiagnosticPiece(L, "Taking false branch.")); |
| 192 | else |
| 193 | PD.push_front(new PathDiagnosticPiece(L, "Taking true branch.")); |
| 194 | |
| 195 | break; |
| 196 | } |
| 197 | } |
| 198 | } |
| 199 | } |
| 200 | } |
| 201 | |
| 202 | bool BugReporter::IsCached(ExplodedNode<ValueState>* N) { |
| 203 | |
| 204 | // HACK: Cache the location of the error. Don't emit the same |
| 205 | // warning for the same error type that occurs at the same program |
| 206 | // location but along a different path. |
| 207 | |
| 208 | void* p = N->getLocation().getRawData(); |
| 209 | |
| 210 | if (CachedErrors.count(p)) |
| 211 | return true; |
| 212 | |
| 213 | CachedErrors.insert(p); |
| 214 | |
| 215 | return false; |
| 216 | } |
| 217 | |
| 218 | void BugReporter::EmitPathWarning(Diagnostic& Diag, |
| 219 | PathDiagnosticClient* PDC, |
| 220 | ASTContext& Ctx, |
| 221 | const BugDescription& B, |
| 222 | ExplodedGraph<GRExprEngine>& G, |
| 223 | ExplodedNode<ValueState>* N) { |
| 224 | |
| 225 | if (!PDC) { |
| 226 | EmitWarning(Diag, Ctx, B, N); |
| 227 | return; |
| 228 | } |
| 229 | |
| 230 | if (IsCached(N)) |
| 231 | return; |
| 232 | |
| 233 | PathDiagnostic D; |
| 234 | GeneratePathDiagnostic(D, Ctx, B, G, N); |
| 235 | PDC->HandlePathDiagnostic(D); |
| 236 | } |
| 237 | |
| 238 | |
| 239 | void BugReporter::EmitWarning(Diagnostic& Diag, ASTContext& Ctx, |
| 240 | const BugDescription& B, |
| 241 | ExplodedNode<ValueState>* N) { |
| 242 | if (IsCached(N)) |
| 243 | return; |
| 244 | |
| 245 | std::ostringstream os; |
| 246 | os << "[CHECKER] " << B.getName(); |
| 247 | |
| 248 | unsigned ErrorDiag = Diag.getCustomDiagID(Diagnostic::Warning, |
| 249 | os.str().c_str()); |
| 250 | |
| 251 | // FIXME: Add support for multiple ranges. |
| 252 | |
| 253 | Stmt* S = GetStmt(N->getLocation()); |
| 254 | |
| 255 | if (!S) |
| 256 | return; |
| 257 | |
| 258 | SourceRange R = S->getSourceRange(); |
| 259 | |
| 260 | Diag.Report(FullSourceLoc(S->getLocStart(), Ctx.getSourceManager()), |
| 261 | ErrorDiag, NULL, 0, &R, 1); |
| 262 | } |