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-rw-r--r--user/clang/big-endian-32.patch183
1 files changed, 183 insertions, 0 deletions
diff --git a/user/clang/big-endian-32.patch b/user/clang/big-endian-32.patch
new file mode 100644
index 000000000..9235d2f5e
--- /dev/null
+++ b/user/clang/big-endian-32.patch
@@ -0,0 +1,183 @@
+From 4f37ed5ff6c18c8cf0de244bb064d5f4f60065a4 Mon Sep 17 00:00:00 2001
+From: Jessica Clarke <jrtc27@jrtc27.com>
+Date: Fri, 18 Oct 2024 16:50:22 +0100
+Subject: [PATCH 1/2] [clang] Make LazyOffsetPtr more portable
+
+LazyOffsetPtr currently relies on uint64_t being able to store a pointer
+and, unless sizeof(uint64_t) == sizeof(void *), little endianness, since
+getAddressOfPointer reinterprets the memory as a pointer. This also
+doesn't properly respect the C++ object model.
+
+As removing getAddressOfPointer would have wide-reaching implications,
+improve the implementation to account for these problems by using
+placement new and a suitably sized-and-aligned buffer, "right"-aligning
+the objects on big-endian platforms so the LSBs are in the same place
+for use as the discriminator.
+
+Fixes: bc73ef0031b50f7443615fef614fb4ecaaa4bd11
+Fixes: https://github.com/llvm/llvm-project/issues/111993
+---
+ clang/include/clang/AST/ExternalASTSource.h | 48 +++++++++++++++------
+ 1 file changed, 35 insertions(+), 13 deletions(-)
+
+diff --git clang/include/clang/AST/ExternalASTSource.h clang/include/clang/AST/ExternalASTSource.h
+index 385c32edbae0fd..caf37144d5eb73 100644
+--- clang/include/clang/AST/ExternalASTSource.h
++++ clang/include/clang/AST/ExternalASTSource.h
+@@ -25,10 +25,12 @@
+ #include "llvm/ADT/SmallVector.h"
+ #include "llvm/ADT/iterator.h"
+ #include "llvm/Support/PointerLikeTypeTraits.h"
++#include <algorithm>
+ #include <cassert>
+ #include <cstddef>
+ #include <cstdint>
+ #include <iterator>
++#include <new>
+ #include <optional>
+ #include <utility>
+
+@@ -326,29 +328,49 @@ struct LazyOffsetPtr {
+ ///
+ /// If the low bit is clear, a pointer to the AST node. If the low
+ /// bit is set, the upper 63 bits are the offset.
+- mutable uint64_t Ptr = 0;
++ static constexpr size_t DataSize = std::max(sizeof(uint64_t), sizeof(T *));
++ alignas(uint64_t) alignas(T *) mutable unsigned char Data[DataSize] = {};
++
++ unsigned char GetLSB() const {
++ return Data[llvm::sys::IsBigEndianHost ? DataSize - 1 : 0];
++ }
++
++ template <typename U> U &As(bool New) const {
++ unsigned char *Obj =
++ Data + (llvm::sys::IsBigEndianHost ? DataSize - sizeof(U) : 0);
++ if (New)
++ return *new (Obj) U;
++ return *std::launder(reinterpret_cast<U *>(Obj));
++ }
++
++ T *&GetPtr() const { return As<T *>(false); }
++ uint64_t &GetU64() const { return As<uint64_t>(false); }
++ void SetPtr(T *Ptr) const { As<T *>(true) = Ptr; }
++ void SetU64(uint64_t U64) const { As<uint64_t>(true) = U64; }
+
+ public:
+ LazyOffsetPtr() = default;
+- explicit LazyOffsetPtr(T *Ptr) : Ptr(reinterpret_cast<uint64_t>(Ptr)) {}
++ explicit LazyOffsetPtr(T *Ptr) : Data() { SetPtr(Ptr); }
+
+- explicit LazyOffsetPtr(uint64_t Offset) : Ptr((Offset << 1) | 0x01) {
++ explicit LazyOffsetPtr(uint64_t Offset) : Data() {
+ assert((Offset << 1 >> 1) == Offset && "Offsets must require < 63 bits");
+ if (Offset == 0)
+- Ptr = 0;
++ SetPtr(NULL);
++ else
++ SetU64((Offset << 1) | 0x01);
+ }
+
+ LazyOffsetPtr &operator=(T *Ptr) {
+- this->Ptr = reinterpret_cast<uint64_t>(Ptr);
++ SetPtr(Ptr);
+ return *this;
+ }
+
+ LazyOffsetPtr &operator=(uint64_t Offset) {
+ assert((Offset << 1 >> 1) == Offset && "Offsets must require < 63 bits");
+ if (Offset == 0)
+- Ptr = 0;
++ SetPtr(NULL);
+ else
+- Ptr = (Offset << 1) | 0x01;
++ SetU64((Offset << 1) | 0x01);
+
+ return *this;
+ }
+@@ -356,15 +378,15 @@ struct LazyOffsetPtr {
+ /// Whether this pointer is non-NULL.
+ ///
+ /// This operation does not require the AST node to be deserialized.
+- explicit operator bool() const { return Ptr != 0; }
++ explicit operator bool() const { return isOffset() || GetPtr() != NULL; }
+
+ /// Whether this pointer is non-NULL.
+ ///
+ /// This operation does not require the AST node to be deserialized.
+- bool isValid() const { return Ptr != 0; }
++ bool isValid() const { return isOffset() || GetPtr() != NULL; }
+
+ /// Whether this pointer is currently stored as an offset.
+- bool isOffset() const { return Ptr & 0x01; }
++ bool isOffset() const { return GetLSB() & 0x01; }
+
+ /// Retrieve the pointer to the AST node that this lazy pointer points to.
+ ///
+@@ -375,9 +397,9 @@ struct LazyOffsetPtr {
+ if (isOffset()) {
+ assert(Source &&
+ "Cannot deserialize a lazy pointer without an AST source");
+- Ptr = reinterpret_cast<uint64_t>((Source->*Get)(Ptr >> 1));
++ SetPtr((Source->*Get)(GetU64() >> 1));
+ }
+- return reinterpret_cast<T*>(Ptr);
++ return GetPtr();
+ }
+
+ /// Retrieve the address of the AST node pointer. Deserializes the pointee if
+@@ -385,7 +407,7 @@ struct LazyOffsetPtr {
+ T **getAddressOfPointer(ExternalASTSource *Source) const {
+ // Ensure the integer is in pointer form.
+ (void)get(Source);
+- return reinterpret_cast<T**>(&Ptr);
++ return &GetPtr();
+ }
+ };
+
+
+From 35eed5f3f5e09c4275cabac09e277a167a98f742 Mon Sep 17 00:00:00 2001
+From: Jessica Clarke <jrtc27@jrtc27.com>
+Date: Fri, 18 Oct 2024 17:45:28 +0100
+Subject: [PATCH 2/2] NULL -> nullptr
+
+---
+ clang/include/clang/AST/ExternalASTSource.h | 8 ++++----
+ 1 file changed, 4 insertions(+), 4 deletions(-)
+
+diff --git clang/include/clang/AST/ExternalASTSource.h clang/include/clang/AST/ExternalASTSource.h
+index caf37144d5eb73..582ed7c65f58ca 100644
+--- clang/include/clang/AST/ExternalASTSource.h
++++ clang/include/clang/AST/ExternalASTSource.h
+@@ -355,7 +355,7 @@ struct LazyOffsetPtr {
+ explicit LazyOffsetPtr(uint64_t Offset) : Data() {
+ assert((Offset << 1 >> 1) == Offset && "Offsets must require < 63 bits");
+ if (Offset == 0)
+- SetPtr(NULL);
++ SetPtr(nullptr);
+ else
+ SetU64((Offset << 1) | 0x01);
+ }
+@@ -368,7 +368,7 @@ struct LazyOffsetPtr {
+ LazyOffsetPtr &operator=(uint64_t Offset) {
+ assert((Offset << 1 >> 1) == Offset && "Offsets must require < 63 bits");
+ if (Offset == 0)
+- SetPtr(NULL);
++ SetPtr(nullptr);
+ else
+ SetU64((Offset << 1) | 0x01);
+
+@@ -378,12 +378,12 @@ struct LazyOffsetPtr {
+ /// Whether this pointer is non-NULL.
+ ///
+ /// This operation does not require the AST node to be deserialized.
+- explicit operator bool() const { return isOffset() || GetPtr() != NULL; }
++ explicit operator bool() const { return isOffset() || GetPtr() != nullptr; }
+
+ /// Whether this pointer is non-NULL.
+ ///
+ /// This operation does not require the AST node to be deserialized.
+- bool isValid() const { return isOffset() || GetPtr() != NULL; }
++ bool isValid() const { return isOffset() || GetPtr() != nullptr; }
+
+ /// Whether this pointer is currently stored as an offset.
+ bool isOffset() const { return GetLSB() & 0x01; }
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-07-01 10:05:41 +0000