[llvm] [LLVM][Attribute/DataLayout] Assert failed parse / Test for self assignment (NFCI) (PR #169711)

[JP Hafer via llvm-commits]

https://github.com/jph-13 created https://github.com/llvm/llvm-project/pull/169711

Up-streaming more static analysis findings.

In Attributes.cpp:
Local variable CallerStackProbeSize "could" be read before it is initialized. -> added assertion

In DataLayout.cpp:
DataLayout doesn't test for self assignment. -> added

>From 6c4c34dc1c0a4e1a1daf52d7bebf0dd30b9a6db0 Mon Sep 17 00:00:00 2001
From: JP Hafer <jhafer at mathworks.com>
Date: Wed, 26 Nov 2025 13:47:43 -0500
Subject: [PATCH] [Attribute/DataLayout] Assert for failed integer parse / Test
 for self assignment. (NFCI)

---
 llvm/lib/IR/Attributes.cpp | 8 ++++++--
 llvm/lib/IR/DataLayout.cpp | 3 +++
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/llvm/lib/IR/Attributes.cpp b/llvm/lib/IR/Attributes.cpp
index 4ac2ebd55dcac..ca2488a761141 100644
--- a/llvm/lib/IR/Attributes.cpp
+++ b/llvm/lib/IR/Attributes.cpp
@@ -2605,8 +2605,12 @@ adjustCallerStackProbeSize(Function &Caller, const Function &Callee) {
     Attribute CallerAttr = Caller.getFnAttribute("stack-probe-size");
     if (CallerAttr.isValid()) {
       uint64_t CallerStackProbeSize, CalleeStackProbeSize;
-      CallerAttr.getValueAsString().getAsInteger(0, CallerStackProbeSize);
-      CalleeAttr.getValueAsString().getAsInteger(0, CalleeStackProbeSize);
+      bool CallerParseError =
+          CallerAttr.getValueAsString().getAsInteger(0, CallerStackProbeSize);
+      bool CalleeParseError =
+          CalleeAttr.getValueAsString().getAsInteger(0, CalleeStackProbeSize);
+      assert((!CallerParseError && !CalleeParseError) &&
+             "Failed to parse stack-probe-size as integer");
 
       if (CallerStackProbeSize > CalleeStackProbeSize) {
         Caller.addFnAttr(CalleeAttr);
diff --git a/llvm/lib/IR/DataLayout.cpp b/llvm/lib/IR/DataLayout.cpp
index 49e1f898ca594..3553e788f7793 100644
--- a/llvm/lib/IR/DataLayout.cpp
+++ b/llvm/lib/IR/DataLayout.cpp
@@ -210,6 +210,9 @@ DataLayout::DataLayout(StringRef LayoutString) : DataLayout() {
 }
 
 DataLayout &DataLayout::operator=(const DataLayout &Other) {
+  if (this == &Other)
+    return *this;
+
   delete static_cast<StructLayoutMap *>(LayoutMap);
   LayoutMap = nullptr;
   StringRepresentation = Other.StringRepresentation;