From fabdb20dca6d9ab750d4cd1d3d20c30f1c74435f Mon Sep 17 00:00:00 2001
From: "A. Wilcox" <AWilcox@Wilcox-Tech.com>
Date: Fri, 11 Oct 2024 07:46:34 -0500
Subject: user/clang: Fixes for PPC32, and more generally

* Fix upstream issue on all 32-bit BE platforms where pointers are
  cast in an invalid way, causing crashes when building C++ code.

* Improve ppc-interp.patch to ensure *all* executable repl tests will
  be skipped when run on ppc32.

* Disable known-flaky test (found on ppc, but also Gentoo/arm).

Closes: #1255
---
 user/clang/big-endian-32.patch | 52 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 user/clang/big-endian-32.patch

(limited to 'user/clang/big-endian-32.patch')

diff --git a/user/clang/big-endian-32.patch b/user/clang/big-endian-32.patch
new file mode 100644
index 000000000..298137257
--- /dev/null
+++ b/user/clang/big-endian-32.patch
@@ -0,0 +1,52 @@
+We need to use uintptr_t, not uint64_t.
+
+getAddressOfPointer returns a pointer to the Ptr field.  When dereferenced on
+a 32-bit big endian platform, this will be the first (invalid) 32 bits, not the
+actual 32 bits containing the pointer value.  This leads to bad things.
+
+Ref: #1255
+Upstream-URL: https://github.com/llvm/llvm-project/issues/111993
+--- clang/include/clang/AST/ExternalASTSource.h.old	2024-06-15 17:21:32.000000000 +0000
++++ clang/include/clang/AST/ExternalASTSource.h	2024-10-10 16:54:58.013411406 +0000
+@@ -326,25 +326,25 @@
+   ///
+   /// 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;
++  mutable uintptr_t Ptr = 0;
+ 
+ public:
+   LazyOffsetPtr() = default;
+-  explicit LazyOffsetPtr(T *Ptr) : Ptr(reinterpret_cast<uint64_t>(Ptr)) {}
++  explicit LazyOffsetPtr(T *Ptr) : Ptr(reinterpret_cast<uintptr_t>(Ptr)) {}
+ 
+-  explicit LazyOffsetPtr(uint64_t Offset) : Ptr((Offset << 1) | 0x01) {
+-    assert((Offset << 1 >> 1) == Offset && "Offsets must require < 63 bits");
++  explicit LazyOffsetPtr(uintptr_t Offset) : Ptr((Offset << 1) | 0x01) {
++    assert((Offset << 1 >> 1) == Offset && "Offsets must fit in addressable bits");
+     if (Offset == 0)
+       Ptr = 0;
+   }
+ 
+   LazyOffsetPtr &operator=(T *Ptr) {
+-    this->Ptr = reinterpret_cast<uint64_t>(Ptr);
++    this->Ptr = reinterpret_cast<uintptr_t>(Ptr);
+     return *this;
+   }
+ 
+-  LazyOffsetPtr &operator=(uint64_t Offset) {
+-    assert((Offset << 1 >> 1) == Offset && "Offsets must require < 63 bits");
++  LazyOffsetPtr &operator=(uintptr_t Offset) {
++    assert((Offset << 1 >> 1) == Offset && "Offsets must fit in addressable bits");
+     if (Offset == 0)
+       Ptr = 0;
+     else
+@@ -375,7 +375,7 @@
+     if (isOffset()) {
+       assert(Source &&
+              "Cannot deserialize a lazy pointer without an AST source");
+-      Ptr = reinterpret_cast<uint64_t>((Source->*Get)(Ptr >> 1));
++      Ptr = reinterpret_cast<uintptr_t>((Source->*Get)(Ptr >> 1));
+     }
+     return reinterpret_cast<T*>(Ptr);
+   }
-- 
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