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-rw-r--r--include/clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h21
-rw-r--r--lib/StaticAnalyzer/Checkers/CStringChecker.cpp71
-rw-r--r--lib/StaticAnalyzer/Checkers/Checkers.td18
-rw-r--r--test/Analysis/bstring.c8
-rw-r--r--test/Analysis/string.c8
5 files changed, 106 insertions, 20 deletions
diff --git a/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h b/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h
index 0d8a80abd5..dca18926fb 100644
--- a/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h
+++ b/include/clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h
@@ -22,7 +22,13 @@ namespace ento {
class CheckerContext {
ExprEngine &Eng;
+ /// The current exploded(symbolic execution) graph node.
ExplodedNode *Pred;
+ /// The flag is true if the (state of the execution) has been modified
+ /// by the checker using this context. For example, a new transition has been
+ /// added or a bug report issued.
+ bool Changed;
+ /// The tagged location, which is used to generate all new nodes.
const ProgramPoint Location;
NodeBuilder &NB;
@@ -33,6 +39,7 @@ public:
const ProgramPoint &loc)
: Eng(eng),
Pred(pred),
+ Changed(false),
Location(loc),
NB(builder) {
assert(Pred->getState() &&
@@ -57,6 +64,10 @@ public:
ExplodedNode *getPredecessor() { return Pred; }
ProgramStateRef getState() const { return Pred->getState(); }
+ /// \brief Check if the checker changed the state of the execution; ex: added
+ /// a new transition or a bug report.
+ bool isDifferent() { return Changed; }
+
/// \brief Returns the number of times the current block has been visited
/// along the analyzed path.
unsigned getCurrentBlockCount() const {
@@ -146,6 +157,7 @@ public:
/// \brief Emit the diagnostics report.
void EmitReport(BugReport *R) {
+ Changed = true;
Eng.getBugReporter().EmitReport(R);
}
@@ -187,6 +199,7 @@ private:
if (State == Pred->getState() && !Tag && !MarkAsSink)
return Pred;
+ Changed = true;
ExplodedNode *node = NB.generateNode(Tag ? Location.withTag(Tag) : Location,
State,
P ? P : Pred, MarkAsSink);
@@ -194,6 +207,14 @@ private:
}
};
+/// \brief A helper class which wraps a boolean value set to false by default.
+struct DefaultBool {
+ bool Val;
+ DefaultBool() : Val(false) {}
+ operator bool() const { return Val; }
+ DefaultBool &operator=(bool b) { Val = b; return *this; }
+};
+
} // end GR namespace
} // end clang namespace
diff --git a/lib/StaticAnalyzer/Checkers/CStringChecker.cpp b/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
index 7518b96c63..748fc43a67 100644
--- a/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
+++ b/lib/StaticAnalyzer/Checkers/CStringChecker.cpp
@@ -32,12 +32,26 @@ class CStringChecker : public Checker< eval::Call,
check::DeadSymbols,
check::RegionChanges
> {
- mutable OwningPtr<BugType> BT_Null, BT_Bounds,
- BT_Overlap, BT_NotCString,
- BT_AdditionOverflow;
+ mutable OwningPtr<BugType> BT_Null,
+ BT_Bounds,
+ BT_Overlap,
+ BT_NotCString,
+ BT_AdditionOverflow;
+
mutable const char *CurrentFunctionDescription;
public:
+ /// The filter is used to filter out the diagnostics which are not enabled by
+ /// the user.
+ struct CStringChecksFilter {
+ DefaultBool CheckCStringNullArg;
+ DefaultBool CheckCStringOutOfBounds;
+ DefaultBool CheckCStringBufferOverlap;
+ DefaultBool CheckCStringNotNullTerm;
+ };
+
+ CStringChecksFilter Filter;
+
static void *getTag() { static int tag; return &tag; }
bool evalCall(const CallExpr *CE, CheckerContext &C) const;
@@ -215,12 +229,15 @@ ProgramStateRef CStringChecker::checkNonNull(CheckerContext &C,
llvm::tie(stateNull, stateNonNull) = assumeZero(C, state, l, S->getType());
if (stateNull && !stateNonNull) {
+ if (!Filter.CheckCStringNullArg)
+ return NULL;
+
ExplodedNode *N = C.generateSink(stateNull);
if (!N)
return NULL;
if (!BT_Null)
- BT_Null.reset(new BuiltinBug("API",
+ BT_Null.reset(new BuiltinBug("Unix API",
"Null pointer argument in call to byte string function"));
SmallString<80> buf;
@@ -342,6 +359,10 @@ ProgramStateRef CStringChecker::CheckBufferAccess(CheckerContext &C,
if (!state)
return NULL;
+ // If out-of-bounds checking is turned off, skip the rest.
+ if (!Filter.CheckCStringOutOfBounds)
+ return state;
+
// Get the access length and make sure it is known.
// FIXME: This assumes the caller has already checked that the access length
// is positive. And that it's unsigned.
@@ -395,6 +416,9 @@ ProgramStateRef CStringChecker::CheckOverlap(CheckerContext &C,
const Expr *Size,
const Expr *First,
const Expr *Second) const {
+ if (!Filter.CheckCStringBufferOverlap)
+ return state;
+
// Do a simple check for overlap: if the two arguments are from the same
// buffer, see if the end of the first is greater than the start of the second
// or vice versa.
@@ -525,6 +549,10 @@ ProgramStateRef CStringChecker::checkAdditionOverflow(CheckerContext &C,
ProgramStateRef state,
NonLoc left,
NonLoc right) const {
+ // If out-of-bounds checking is turned off, skip the rest.
+ if (!Filter.CheckCStringOutOfBounds)
+ return state;
+
// If a previous check has failed, propagate the failure.
if (!state)
return NULL;
@@ -664,9 +692,12 @@ SVal CStringChecker::getCStringLength(CheckerContext &C, ProgramStateRef &state,
// C string. In the context of locations, the only time we can issue such
// a warning is for labels.
if (loc::GotoLabel *Label = dyn_cast<loc::GotoLabel>(&Buf)) {
+ if (!Filter.CheckCStringNotNullTerm)
+ return UndefinedVal();
+
if (ExplodedNode *N = C.addTransition(state)) {
if (!BT_NotCString)
- BT_NotCString.reset(new BuiltinBug("API",
+ BT_NotCString.reset(new BuiltinBug("Unix API",
"Argument is not a null-terminated string."));
SmallString<120> buf;
@@ -683,8 +714,8 @@ SVal CStringChecker::getCStringLength(CheckerContext &C, ProgramStateRef &state,
report->addRange(Ex->getSourceRange());
C.EmitReport(report);
}
-
return UndefinedVal();
+
}
// If it's not a region and not a label, give up.
@@ -721,9 +752,12 @@ SVal CStringChecker::getCStringLength(CheckerContext &C, ProgramStateRef &state,
// Other regions (mostly non-data) can't have a reliable C string length.
// In this case, an error is emitted and UndefinedVal is returned.
// The caller should always be prepared to handle this case.
+ if (!Filter.CheckCStringNotNullTerm)
+ return UndefinedVal();
+
if (ExplodedNode *N = C.addTransition(state)) {
if (!BT_NotCString)
- BT_NotCString.reset(new BuiltinBug("API",
+ BT_NotCString.reset(new BuiltinBug("Unix API",
"Argument is not a null-terminated string."));
SmallString<120> buf;
@@ -1715,6 +1749,16 @@ bool CStringChecker::evalCall(const CallExpr *CE, CheckerContext &C) const {
// Check and evaluate the call.
(this->*evalFunction)(C, CE);
+
+ // If the evaluate call resulted in no change, chain to the next eval call
+ // handler.
+ // Note, the custom CString evaluation calls assume that basic safety
+ // properties are held. However, if the user chooses to turn off some of these
+ // checks, we ignore the issues and leave the call evaluation to a generic
+ // handler.
+ if (!C.isDifferent())
+ return false;
+
return true;
}
@@ -1850,6 +1894,15 @@ void CStringChecker::checkDeadSymbols(SymbolReaper &SR,
C.addTransition(state);
}
-void ento::registerCStringChecker(CheckerManager &mgr) {
- mgr.registerChecker<CStringChecker>();
+#define REGISTER_CHECKER(name) \
+void ento::register##name(CheckerManager &mgr) {\
+ static CStringChecker *TheChecker = 0; \
+ if (TheChecker == 0) \
+ TheChecker = mgr.registerChecker<CStringChecker>(); \
+ TheChecker->Filter.Check##name = true; \
}
+
+REGISTER_CHECKER(CStringNullArg)
+REGISTER_CHECKER(CStringOutOfBounds)
+REGISTER_CHECKER(CStringBufferOverlap)
+REGISTER_CHECKER(CStringNotNullTerm)
diff --git a/lib/StaticAnalyzer/Checkers/Checkers.td b/lib/StaticAnalyzer/Checkers/Checkers.td
index d08739e2a3..24a79485c8 100644
--- a/lib/StaticAnalyzer/Checkers/Checkers.td
+++ b/lib/StaticAnalyzer/Checkers/Checkers.td
@@ -302,8 +302,20 @@ def StreamChecker : Checker<"Stream">,
let ParentPackage = CString in {
-def CStringChecker : Checker<"Generic">,
- HelpText<"Check calls to functions in <string.h>">,
+def CStringNullArg : Checker<"NullArg">,
+ HelpText<"Check for null pointers being passed as arguments to C string functions">,
+ DescFile<"CStringChecker.cpp">;
+
+def CStringOutOfBounds : Checker<"OutOfBounds">,
+ HelpText<"Check for out-of-bounds access in string functions">,
+ DescFile<"CStringChecker.cpp">;
+
+def CStringBufferOverlap : Checker<"BufferOverlap">,
+ HelpText<"Checks for overlap in two buffer arguments">,
+ DescFile<"CStringChecker.cpp">;
+
+def CStringNotNullTerm : Checker<"NotNullTerminated">,
+ HelpText<"Check for arguments which are not null-terminating strings">,
DescFile<"CStringChecker.cpp">;
def CStringSyntaxChecker : Checker<"BadSizeArg">,
@@ -408,7 +420,7 @@ def ObjCContainersASTChecker : Checker<"PointerSizedValues">,
DescFile<"ObjCContainersASTChecker.cpp">;
def ObjCContainersChecker : Checker<"OutOfBounds">,
- HelpText<"Checks for index out of bounds when using 'CFArray' API">,
+ HelpText<"Checks for index out-of-bounds when using 'CFArray' API">,
DescFile<"ObjCContainersChecker.cpp">;
}
diff --git a/test/Analysis/bstring.c b/test/Analysis/bstring.c
index 8cdbb18b35..f847a220f9 100644
--- a/test/Analysis/bstring.c
+++ b/test/Analysis/bstring.c
@@ -1,7 +1,7 @@
-// RUN: %clang_cc1 -analyze -analyzer-checker=core,experimental.unix.cstring.Generic -analyzer-store=region -Wno-null-dereference -verify %s
-// RUN: %clang_cc1 -analyze -DUSE_BUILTINS -analyzer-checker=core,experimental.unix.cstring.Generic -analyzer-store=region -Wno-null-dereference -verify %s
-// RUN: %clang_cc1 -analyze -DVARIANT -analyzer-checker=core,experimental.unix.cstring.Generic -analyzer-store=region -Wno-null-dereference -verify %s
-// RUN: %clang_cc1 -analyze -DUSE_BUILTINS -DVARIANT -analyzer-checker=core,experimental.unix.cstring.Generic -analyzer-store=region -Wno-null-dereference -verify %s
+// RUN: %clang_cc1 -analyze -analyzer-checker=core,experimental.unix.cstring -analyzer-store=region -Wno-null-dereference -verify %s
+// RUN: %clang_cc1 -analyze -DUSE_BUILTINS -analyzer-checker=core,experimental.unix.cstring -analyzer-store=region -Wno-null-dereference -verify %s
+// RUN: %clang_cc1 -analyze -DVARIANT -analyzer-checker=core,experimental.unix.cstring -analyzer-store=region -Wno-null-dereference -verify %s
+// RUN: %clang_cc1 -analyze -DUSE_BUILTINS -DVARIANT -analyzer-checker=core,experimental.unix.cstring.NullArg,experimental.unix.cstring.OutOfBounds,experimental.unix.cstring.BufferOverlap,experimental.unix.cstring.NotNullTerminated -analyzer-store=region -Wno-null-dereference -verify %s
//===----------------------------------------------------------------------===
// Declarations
diff --git a/test/Analysis/string.c b/test/Analysis/string.c
index 9b0dea3d6c..43da6d70fc 100644
--- a/test/Analysis/string.c
+++ b/test/Analysis/string.c
@@ -1,7 +1,7 @@
-// RUN: %clang_cc1 -analyze -analyzer-checker=core,experimental.unix.cstring.Generic,experimental.deadcode.UnreachableCode -analyzer-store=region -Wno-null-dereference -verify %s
-// RUN: %clang_cc1 -analyze -DUSE_BUILTINS -analyzer-checker=core,experimental.unix.cstring.Generic,experimental.deadcode.UnreachableCode -analyzer-store=region -Wno-null-dereference -verify %s
-// RUN: %clang_cc1 -analyze -DVARIANT -analyzer-checker=core,experimental.unix.cstring.Generic,experimental.deadcode.UnreachableCode -analyzer-store=region -Wno-null-dereference -verify %s
-// RUN: %clang_cc1 -analyze -DUSE_BUILTINS -DVARIANT -analyzer-checker=experimental.security.taint,core,experimental.unix.cstring.Generic,experimental.deadcode.UnreachableCode -analyzer-store=region -Wno-null-dereference -verify %s
+// RUN: %clang_cc1 -analyze -analyzer-checker=core,experimental.unix.cstring,experimental.deadcode.UnreachableCode -analyzer-store=region -Wno-null-dereference -verify %s
+// RUN: %clang_cc1 -analyze -DUSE_BUILTINS -analyzer-checker=core,experimental.unix.cstring,experimental.deadcode.UnreachableCode -analyzer-store=region -Wno-null-dereference -verify %s
+// RUN: %clang_cc1 -analyze -DVARIANT -analyzer-checker=core,experimental.unix.cstring,experimental.deadcode.UnreachableCode -analyzer-store=region -Wno-null-dereference -verify %s
+// RUN: %clang_cc1 -analyze -DUSE_BUILTINS -DVARIANT -analyzer-checker=experimental.security.taint,core,experimental.unix.cstring,experimental.deadcode.UnreachableCode -analyzer-store=region -Wno-null-dereference -verify %s
//===----------------------------------------------------------------------===
// Declarations
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2025-08-03 05:20:40 +0000