martong updated this revision to Diff 293168.
martong marked an inline comment as done.
martong added a comment.
- Avoid same pattern when checking whether the assumption is infeasible
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D88019/new/
https://reviews.llvm.org/D88019
Files:
clang/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp
clang/test/Analysis/equality_tracking.c
Index: clang/test/Analysis/equality_tracking.c
===================================================================
--- clang/test/Analysis/equality_tracking.c
+++ clang/test/Analysis/equality_tracking.c
@@ -185,3 +185,37 @@
}
}
}
+
+void avoidInfeasibleConstraintforGT(int a, int b) {
+ int c = b - a;
+ if (c <= 0)
+ return;
+ // c > 0
+ // b - a > 0
+ // b > a
+ if (a != b) {
+ clang_analyzer_warnIfReached(); // expected-warning{{REACHABLE}}
+ return;
+ }
+ clang_analyzer_warnIfReached(); // no warning
+ // a == b
+ if (c < 0)
+ ;
+}
+
+void avoidInfeasibleConstraintforLT(int a, int b) {
+ int c = b - a;
+ if (c >= 0)
+ return;
+ // c < 0
+ // b - a < 0
+ // b < a
+ if (a != b) {
+ clang_analyzer_warnIfReached(); // expected-warning{{REACHABLE}}
+ return;
+ }
+ clang_analyzer_warnIfReached(); // no warning
+ // a == b
+ if (c < 0)
+ ;
+}
Index: clang/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp
+++ clang/lib/StaticAnalyzer/Core/RangeConstraintManager.cpp
@@ -1347,27 +1347,35 @@
// Equality tracking implementation
//===------------------------------------------------------------------===//
- ProgramStateRef trackEQ(ProgramStateRef State, SymbolRef Sym,
- const llvm::APSInt &Int,
+ ProgramStateRef trackEQ(RangeSet NewConstraint, ProgramStateRef State,
+ SymbolRef Sym, const llvm::APSInt &Int,
const llvm::APSInt &Adjustment) {
- if (auto Equality = EqualityInfo::extract(Sym, Int, Adjustment)) {
- // Extract function assumes that we gave it Sym + Adjustment != Int,
- // so the result should be opposite.
- Equality->invert();
- return track(State, *Equality);
- }
-
- return State;
+ return track<true>(NewConstraint, State, Sym, Int, Adjustment);
}
- ProgramStateRef trackNE(ProgramStateRef State, SymbolRef Sym,
- const llvm::APSInt &Int,
+ ProgramStateRef trackNE(RangeSet NewConstraint, ProgramStateRef State,
+ SymbolRef Sym, const llvm::APSInt &Int,
const llvm::APSInt &Adjustment) {
+ return track<false>(NewConstraint, State, Sym, Int, Adjustment);
+ }
+
+ template <bool EQ>
+ ProgramStateRef track(RangeSet NewConstraint, ProgramStateRef State,
+ SymbolRef Sym, const llvm::APSInt &Int,
+ const llvm::APSInt &Adjustment) {
+ if (NewConstraint.isEmpty())
+ // This is an infeasible assumption.
+ return nullptr;
+
+ ProgramStateRef NewState = setConstraint(State, Sym, NewConstraint);
if (auto Equality = EqualityInfo::extract(Sym, Int, Adjustment)) {
- return track(State, *Equality);
+ // If the original assumption is not Sym + Adjustment !=/</> Int,
+ // we should invert IsEquality flag.
+ Equality->IsEquality = Equality->IsEquality != EQ;
+ return track(NewState, *Equality);
}
- return State;
+ return NewState;
}
ProgramStateRef track(ProgramStateRef State, EqualityInfo ToTrack) {
@@ -2042,12 +2050,7 @@
RangeSet New = getRange(St, Sym).Delete(getBasicVals(), F, Point);
- if (New.isEmpty())
- // this is infeasible assumption
- return nullptr;
-
- ProgramStateRef NewState = setConstraint(St, Sym, New);
- return trackNE(NewState, Sym, Int, Adjustment);
+ return trackNE(New, St, Sym, Int, Adjustment);
}
ProgramStateRef
@@ -2063,12 +2066,7 @@
llvm::APSInt AdjInt = AdjustmentType.convert(Int) - Adjustment;
RangeSet New = getRange(St, Sym).Intersect(getBasicVals(), F, AdjInt, AdjInt);
- if (New.isEmpty())
- // this is infeasible assumption
- return nullptr;
-
- ProgramStateRef NewState = setConstraint(St, Sym, New);
- return trackEQ(NewState, Sym, Int, Adjustment);
+ return trackEQ(New, St, Sym, Int, Adjustment);
}
RangeSet RangeConstraintManager::getSymLTRange(ProgramStateRef St,
@@ -2104,7 +2102,7 @@
const llvm::APSInt &Int,
const llvm::APSInt &Adjustment) {
RangeSet New = getSymLTRange(St, Sym, Int, Adjustment);
- return New.isEmpty() ? nullptr : setConstraint(St, Sym, New);
+ return trackNE(New, St, Sym, Int, Adjustment);
}
RangeSet RangeConstraintManager::getSymGTRange(ProgramStateRef St,
@@ -2140,7 +2138,7 @@
const llvm::APSInt &Int,
const llvm::APSInt &Adjustment) {
RangeSet New = getSymGTRange(St, Sym, Int, Adjustment);
- return New.isEmpty() ? nullptr : setConstraint(St, Sym, New);
+ return trackNE(New, St, Sym, Int, Adjustment);
}
RangeSet RangeConstraintManager::getSymGERange(ProgramStateRef St,
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