[PATCH] D137082: [clang][Interp] Fix dereferencing arrays with no offset applied
Timm Bäder via Phabricator via cfe-commits
cfe-commits at lists.llvm.org
Mon Oct 31 07:51:06 PDT 2022
tbaeder created this revision.
tbaeder added reviewers: aaron.ballman, erichkeane, tahonermann, shafik.
Herald added a project: All.
tbaeder requested review of this revision.
Herald added a project: clang.
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There is a difference between a `Pointer` and a "`Pointer` to the first element of an array".
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D137082
Files:
clang/lib/AST/Interp/Interp.h
clang/test/AST/Interp/arrays.cpp
Index: clang/test/AST/Interp/arrays.cpp
===================================================================
--- clang/test/AST/Interp/arrays.cpp
+++ clang/test/AST/Interp/arrays.cpp
@@ -42,6 +42,12 @@
return *(Arr + index);
}
+constexpr int derefPtr(const int *d) {
+ return *d;
+}
+static_assert(derefPtr(data) == 5, "");
+
+
static_assert(getElement(data, 1) == 4, "");
static_assert(getElement(data, 4) == 1, "");
Index: clang/lib/AST/Interp/Interp.h
===================================================================
--- clang/lib/AST/Interp/Interp.h
+++ clang/lib/AST/Interp/Interp.h
@@ -949,7 +949,12 @@
const Pointer &Ptr = S.Stk.peek<Pointer>();
if (!CheckLoad(S, OpPC, Ptr))
return false;
- S.Stk.push<T>(Ptr.deref<T>());
+ // When getting the first value of an array, we need to offset to the
+ // first element.
+ if (Ptr.inArray() && Ptr.isRoot())
+ S.Stk.push<T>(Ptr.atIndex(0).deref<T>());
+ else
+ S.Stk.push<T>(Ptr.deref<T>());
return true;
}
@@ -958,7 +963,12 @@
const Pointer &Ptr = S.Stk.pop<Pointer>();
if (!CheckLoad(S, OpPC, Ptr))
return false;
- S.Stk.push<T>(Ptr.deref<T>());
+ // When getting the first value of an array, we need to offset to the
+ // first element.
+ if (Ptr.inArray() && Ptr.isRoot())
+ S.Stk.push<T>(Ptr.atIndex(0).deref<T>());
+ else
+ S.Stk.push<T>(Ptr.deref<T>());
return true;
}
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