[PATCH] D95799: [analyzer] Symbolicate float values with integral casting
Denys Petrov via Phabricator via cfe-commits
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Mon Feb 1 10:07:36 PST 2021
ASDenysPetrov created this revision.
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ASDenysPetrov added a project: clang.
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Create nonloc::SymbolVal with SymbolCast expression from //integral// type to //float// type.
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D95799
Files:
clang/lib/StaticAnalyzer/Core/SValBuilder.cpp
clang/lib/StaticAnalyzer/Core/Store.cpp
clang/test/Analysis/svalbuilder-float-cast.c
Index: clang/test/Analysis/svalbuilder-float-cast.c
===================================================================
--- clang/test/Analysis/svalbuilder-float-cast.c
+++ clang/test/Analysis/svalbuilder-float-cast.c
@@ -4,17 +4,23 @@
void SymbolCast_of_float_type_aux(int *p) {
*p += 0;
- // FIXME: Ideally, all unknown values should be symbolicated.
- clang_analyzer_denote(*p, "$x"); // expected-warning{{Not a symbol}}
+ clang_analyzer_denote(*p, "$x");
*p += 1;
- // This should NOT be (float)$x + 1. Symbol $x was never casted to float.
- // FIXME: Ideally, this should be $x + 1.
- clang_analyzer_express(*p); // expected-warning{{Not a symbol}}
+ // expected-warning at +3{{(float)$x + 1}}
+ // expected-warning at +2{{(double)$x + 1}}
+ // expected-warning at +1{{(long double)$x + 1}}
+ clang_analyzer_express(*p);
}
void SymbolCast_of_float_type() {
- extern float x;
+ extern float x1;
+ extern double x2;
+ extern long double x3;
+
void (*f)() = SymbolCast_of_float_type_aux;
- f(&x);
+
+ f(&x1);
+ f(&x2);
+ f(&x3);
}
Index: clang/lib/StaticAnalyzer/Core/Store.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Core/Store.cpp
+++ clang/lib/StaticAnalyzer/Core/Store.cpp
@@ -409,14 +409,8 @@
// The dispatchCast() call below would convert the int into a float.
// What we want, however, is a bit-by-bit reinterpretation of the int
- // as a float, which usually yields nothing garbage. For now skip casts
- // from ints to floats.
+ // as a float, which usually yields nothing garbage.
// TODO: What other combinations of types are affected?
- if (castTy->isFloatingType()) {
- SymbolRef Sym = V.getAsSymbol();
- if (Sym && !Sym->getType()->isFloatingType())
- return UnknownVal();
- }
// When retrieving symbolic pointer and expecting a non-void pointer,
// wrap them into element regions of the expected type if necessary.
Index: clang/lib/StaticAnalyzer/Core/SValBuilder.cpp
===================================================================
--- clang/lib/StaticAnalyzer/Core/SValBuilder.cpp
+++ clang/lib/StaticAnalyzer/Core/SValBuilder.cpp
@@ -501,8 +501,9 @@
if (getContext().getTypeSize(castTy) >= getContext().getTypeSize(originalTy))
return evalCast(val, castTy, originalTy);
+ // Let evalCast handle non symbolic expressions.
SymbolRef se = val.getAsSymbol();
- if (!se) // Let evalCast handle non symbolic expressions.
+ if (!se || se->getType()->isFloatingType())
return evalCast(val, castTy, originalTy);
// Find the maximum value of the target type.
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