[Clang] Assert non-null enum definition in CGDebugInfo::CreateTypeDefinition(const EnumType*)

[smanna12]

This commit adds an assert to check for a non-null enum definition in CGDebugInfo::CreateTypeDefinition(const EnumType*), ensuring precondition validity.

Previous discussion on #97105

[llvmbot]

@llvm/pr-subscribers-clang-codegen

@llvm/pr-subscribers-debuginfo

Author: None (smanna12)

Changes

This commit adds an assertion to the CreateTypeDefinition function in CGDebugInfo.cpp to verify that an enumeration definition (ED) is available before iterating over its enumerators. This prevents potential null pointer dereferences and ensures that the function operates on a valid enumeration definition.

---

Full diff: https://github.com/llvm/llvm-project/pull/105556.diff

1 Files Affected:

• (modified) clang/lib/CodeGen/CGDebugInfo.cpp (+1)

diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 7ad3088f0ab756..dc83d596e3cb06 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -3561,6 +3561,7 @@ llvm::DIType *CGDebugInfo::CreateTypeDefinition(const EnumType *Ty) {
 
   SmallVector<llvm::Metadata *, 16> Enumerators;
   ED = ED->getDefinition();
+  assert(ED && "An enumeration definition is required");
   for (const auto *Enum : ED->enumerators()) {
     Enumerators.push_back(
         DBuilder.createEnumerator(Enum->getName(), Enum->getInitVal()));

[llvmbot]

@llvm/pr-subscribers-clang

Author: None (smanna12)

Changes

This commit adds an assertion to the CreateTypeDefinition function in CGDebugInfo.cpp to verify that an enumeration definition (ED) is available before iterating over its enumerators. This prevents potential null pointer dereferences and ensures that the function operates on a valid enumeration definition.

---

Full diff: https://github.com/llvm/llvm-project/pull/105556.diff

1 Files Affected:

• (modified) clang/lib/CodeGen/CGDebugInfo.cpp (+1)

diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 7ad3088f0ab756..dc83d596e3cb06 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -3561,6 +3561,7 @@ llvm::DIType *CGDebugInfo::CreateTypeDefinition(const EnumType *Ty) {
 
   SmallVector<llvm::Metadata *, 16> Enumerators;
   ED = ED->getDefinition();
+  assert(ED && "An enumeration definition is required");
   for (const auto *Enum : ED->enumerators()) {
     Enumerators.push_back(
         DBuilder.createEnumerator(Enum->getName(), Enum->getInitVal()));

[pogo59]

The patch title and description claims more than it actually does. The assertion does not "fix" or prevent a null dereference, it's simply documenting a requirement. Please update the title and description.

[tahonermann]

Per discussion in #97105, this looks good to me.

However, please do update the PR title and adjust the commit message accordingly when merging the change as requested by @pogo59.

[smanna12]

Per discussion in #97105, this looks good to me.

However, please do update the PR title and adjust the commit message accordingly when merging the change as requested by @pogo59.

Thanks @tahonermann and @pogo59 for reviews.

I have updated title and commit messages.

[dwblaikie]

What static analysis tool flagged this? Any idea why this particular null dereference, when LLVM/Clang have loads of assumed-non-null pointers that are dereferenced in a great many places?