Teach CFGBuilder about null pointer constants in conditionals, and how they can be used to prune branches. Fixes false null pointer dereference warning in PR 8183.
llvm-svn: 126305
This commit is contained in:
parent
c49211c79a
commit
1a241d1619
|
@ -17,6 +17,7 @@
|
|||
#include "clang/AST/DeclCXX.h"
|
||||
#include "clang/AST/StmtVisitor.h"
|
||||
#include "clang/AST/PrettyPrinter.h"
|
||||
#include "clang/AST/CharUnits.h"
|
||||
#include "llvm/Support/GraphWriter.h"
|
||||
#include "llvm/Support/Allocator.h"
|
||||
#include "llvm/Support/Format.h"
|
||||
|
@ -413,9 +414,16 @@ private:
|
|||
|
||||
Expr::EvalResult Result;
|
||||
if (!S->isTypeDependent() && !S->isValueDependent() &&
|
||||
S->Evaluate(Result, *Context) && Result.Val.isInt())
|
||||
return Result.Val.getInt().getBoolValue();
|
||||
|
||||
S->Evaluate(Result, *Context)) {
|
||||
if (Result.Val.isInt())
|
||||
return Result.Val.getInt().getBoolValue();
|
||||
if (Result.Val.isLValue()) {
|
||||
Expr *e = Result.Val.getLValueBase();
|
||||
const CharUnits &c = Result.Val.getLValueOffset();
|
||||
if (!e && c.isZero())
|
||||
return false;
|
||||
}
|
||||
}
|
||||
return TryResult();
|
||||
}
|
||||
};
|
||||
|
|
|
@ -18,6 +18,14 @@ int test_pr8876() {
|
|||
return 0;
|
||||
}
|
||||
|
||||
// PR 8183 - Handle null pointer constants on the left-side of the '&&', and reason about
|
||||
// this when determining the reachability of the null pointer dereference on the right side.
|
||||
void pr8183(unsigned long long test)
|
||||
{
|
||||
(void)((((void*)0)) && (*((unsigned long long*)(((void*)0))) = ((unsigned long long)((test)) % (unsigned long long)((1000000000))))); // no-warning
|
||||
(*((unsigned long long*)(((void*)0))) = ((unsigned long long)((test)) % (unsigned long long)((1000000000)))); // expected-warning {{indirection of non-volatile null pointer will be deleted, not trap}} expected-note {{consider using __builtin_trap() or qualifying pointer with 'volatile'}}
|
||||
}
|
||||
|
||||
// PR1966
|
||||
_Complex double test1() {
|
||||
return __extension__ 1.0if;
|
||||
|
|
Loading…
Reference in New Issue