comex updated this revision to Diff 220771.
comex added a comment.
Herald added subscribers: llvm-commits, dexonsmith.
Herald added a project: LLVM.
Here's a new version of the patch that uses iterator ranges instead of
`ArrayRef`, to avoid adding new uses of `CallExpr::getArgs()` in case it has to
be removed in the future due to the strict aliasing issue.
To support this, the following additional changes are included:
- Fix `CastIterator`'s use of `iterator_adaptor_base` so that `operator[]`
isn't broken.
- Add an `operator[]` implementation to `iterator_range`.
- Improve the existing `llvm::drop_begin` helper to assert that it doesn't go
out of bounds. (The implementation would be a lot less ugly if we could use
C++17 features; oh well.)
Repository:
rG LLVM Github Monorepo
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D67647/new/
https://reviews.llvm.org/D67647
Files:
clang/include/clang/AST/Stmt.h
clang/lib/Analysis/Consumed.cpp
llvm/include/llvm/ADT/iterator_range.h
Index: llvm/include/llvm/ADT/iterator_range.h
===================================================================
--- llvm/include/llvm/ADT/iterator_range.h
+++ llvm/include/llvm/ADT/iterator_range.h
@@ -20,9 +20,17 @@
#include <iterator>
#include <utility>
+#include <cassert>
namespace llvm {
+template <typename T>
+constexpr bool is_random_iterator() {
+ return std::is_same<
+ typename std::iterator_traits<T>::iterator_category,
+ std::random_access_iterator_tag>::value;
+}
+
/// A range adaptor for a pair of iterators.
///
/// This just wraps two iterators into a range-compatible interface. Nothing
@@ -44,6 +52,15 @@
IteratorT begin() const { return begin_iterator; }
IteratorT end() const { return end_iterator; }
+
+ template <typename _IteratorT = IteratorT>
+ decltype(std::declval<_IteratorT>()[0]) operator[](
+ typename std::iterator_traits<_IteratorT>::difference_type N) const {
+ static_assert(is_random_iterator<IteratorT>(),
+ "Must be a random access iterator to use []");
+ assert(N < end_iterator - begin_iterator && "Index out of range!");
+ return begin_iterator[N];
+ }
};
/// Convenience function for iterating over sub-ranges.
@@ -58,11 +75,31 @@
return iterator_range<T>(std::move(p.first), std::move(p.second));
}
+/// Non-random-iterator version
template <typename T>
-iterator_range<decltype(adl_begin(std::declval<T>()))> drop_begin(T &&t,
- int n) {
- return make_range(std::next(adl_begin(t), n), adl_end(t));
+auto drop_begin(T &&t, int n) ->
+ typename std::enable_if<!is_random_iterator<decltype(adl_begin(t))>(),
+ iterator_range<decltype(adl_begin(t))>>::type {
+ auto begin = adl_begin(t);
+ auto end = adl_end(t);
+ for (int i = 0; i < n; i++) {
+ assert(begin != end);
+ ++begin;
+ }
+ return make_range(begin, end);
}
+
+/// Optimized version for random iterators
+template <typename T>
+auto drop_begin(T &&t, int n) ->
+ typename std::enable_if<is_random_iterator<decltype(adl_begin(t))>(),
+ iterator_range<decltype(adl_begin(t))>>::type {
+ auto begin = adl_begin(t);
+ auto end = adl_end(t);
+ assert(end - begin >= n && "Dropping more elements than exist!");
+ return make_range(std::next(begin, n), end);
+}
+
}
#endif
Index: clang/lib/Analysis/Consumed.cpp
===================================================================
--- clang/lib/Analysis/Consumed.cpp
+++ clang/lib/Analysis/Consumed.cpp
@@ -494,8 +494,10 @@
void checkCallability(const PropagationInfo &PInfo,
const FunctionDecl *FunDecl,
SourceLocation BlameLoc);
- bool handleCall(const CallExpr *Call, const Expr *ObjArg,
- const FunctionDecl *FunD);
+
+ using ArgRange = llvm::iterator_range<CallExpr::const_arg_iterator>;
+ bool handleCall(const Expr *Call, const Expr *ObjArg,
+ ArgRange args, const FunctionDecl *FunD);
void VisitBinaryOperator(const BinaryOperator *BinOp);
void VisitCallExpr(const CallExpr *Call);
@@ -608,22 +610,21 @@
// Factors out common behavior for function, method, and operator calls.
// Check parameters and set parameter state if necessary.
// Returns true if the state of ObjArg is set, or false otherwise.
-bool ConsumedStmtVisitor::handleCall(const CallExpr *Call, const Expr *ObjArg,
+bool ConsumedStmtVisitor::handleCall(const Expr *Call,
+ const Expr *ObjArg,
+ ArgRange Args,
const FunctionDecl *FunD) {
- unsigned Offset = 0;
- if (isa<CXXOperatorCallExpr>(Call) && isa<CXXMethodDecl>(FunD))
- Offset = 1; // first argument is 'this'
-
// check explicit parameters
- for (unsigned Index = Offset; Index < Call->getNumArgs(); ++Index) {
+ unsigned Index = 0;
+ for (const Expr *Arg : Args) {
// Skip variable argument lists.
- if (Index - Offset >= FunD->getNumParams())
+ if (Index >= FunD->getNumParams())
break;
- const ParmVarDecl *Param = FunD->getParamDecl(Index - Offset);
+ const ParmVarDecl *Param = FunD->getParamDecl(Index++);
QualType ParamType = Param->getType();
- InfoEntry Entry = findInfo(Call->getArg(Index));
+ InfoEntry Entry = findInfo(Arg);
if (Entry == PropagationMap.end() || Entry->second.isTest())
continue;
@@ -636,7 +637,7 @@
if (ParamState != ExpectedState)
Analyzer.WarningsHandler.warnParamTypestateMismatch(
- Call->getArg(Index)->getExprLoc(),
+ Arg->getExprLoc(),
stateToString(ExpectedState), stateToString(ParamState));
}
@@ -749,7 +750,7 @@
return;
}
- handleCall(Call, nullptr, FunDecl);
+ handleCall(Call, nullptr, Call->arguments(), FunDecl);
propagateReturnType(Call, FunDecl);
}
@@ -805,7 +806,7 @@
if (!MD)
return;
- handleCall(Call, Call->getImplicitObjectArgument(), MD);
+ handleCall(Call, Call->getImplicitObjectArgument(), Call->arguments(), MD);
propagateReturnType(Call, MD);
}
@@ -813,18 +814,19 @@
const CXXOperatorCallExpr *Call) {
const auto *FunDecl = dyn_cast_or_null<FunctionDecl>(Call->getDirectCallee());
if (!FunDecl) return;
+ ArgRange Args = Call->arguments();
if (Call->getOperator() == OO_Equal) {
- ConsumedState CS = getInfo(Call->getArg(1));
- if (!handleCall(Call, Call->getArg(0), FunDecl))
- setInfo(Call->getArg(0), CS);
+ ConsumedState CS = getInfo(Args[1]);
+ if (!handleCall(Call, Args[0], llvm::drop_begin(Args, 1), FunDecl))
+ setInfo(Args[0], CS);
return;
}
- if (const auto *MCall = dyn_cast<CXXMemberCallExpr>(Call))
- handleCall(MCall, MCall->getImplicitObjectArgument(), FunDecl);
+ if (isa<CXXMethodDecl>(FunDecl))
+ handleCall(Call, Args[0], llvm::drop_begin(Args, 1), FunDecl);
else
- handleCall(Call, Call->getArg(0), FunDecl);
+ handleCall(Call, nullptr, Args, FunDecl);
propagateReturnType(Call, FunDecl);
}
Index: clang/include/clang/AST/Stmt.h
===================================================================
--- clang/include/clang/AST/Stmt.h
+++ clang/include/clang/AST/Stmt.h
@@ -1041,7 +1041,8 @@
template<typename T, typename TPtr = T *, typename StmtPtr = Stmt *>
struct CastIterator
: llvm::iterator_adaptor_base<CastIterator<T, TPtr, StmtPtr>, StmtPtr *,
- std::random_access_iterator_tag, TPtr> {
+ std::random_access_iterator_tag, TPtr,
+ int, void, TPtr> {
using Base = typename CastIterator::iterator_adaptor_base;
CastIterator() : Base(nullptr) {}
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