[Clang][NFC] Change uses of getAs() to castAs() where the target type is assured.

[tahonermann]

Static analysis identified two uses of getAs() for which the result pointer was unconditionally dereferenced. Source code inspection confirmed that the target type is assured by prior checks. This change replaces these uses of getAs() with castAs().

The first case, in clang/lib/CodeGen/Targets/AArch64.cpp, performs a cast to BuiltinType following a check for isBuiltinType().

The second case, in clang/lib/Sema/SemaTemplateVariadic.cpp, performs a cast to PackExpansionType on the result of a call to getAsType() on an object of type TemplateArgument following confirmation that isPackExpansion() returned true and that getKind() returned TemplateArgument::Type. Inspection of isPackExpansion() revealed that it only returns true when the template argument kind is TemplateArgument::Type if isa<PackExpansionType>(getAsType()) is true.

[llvmbot]

@llvm/pr-subscribers-backend-aarch64

@llvm/pr-subscribers-clang

Author: Tom Honermann (tahonermann)

Changes

Static analysis identified two uses of getAs() for which the result pointer was unconditionally dereferenced. Source code inspection confirmed that the target type is assured by prior checks. This change replaces these uses of getAs() with castAs().

The first case, in clang/lib/CodeGen/Targets/AArch64.cpp, performs a cast to BuiltinType following a check for isBuiltinType().

The second case, in clang/lib/Sema/SemaTemplateVariadic.cpp, performs a cast to PackExpansionType on the result of a call to getAsType() on an object of type TemplateArgument following confirmation that isPackExpansion() returned true and that getKind() returned TemplateArgument::Type. Inspection of isPackExpansion() revealed that it only returns true when the template argument kind is TemplateArgument::Type if isa<PackExpansionType>(getAsType()) is true.

---

Full diff: https://github.com/llvm/llvm-project/pull/130188.diff

2 Files Affected:

• (modified) clang/lib/CodeGen/Targets/AArch64.cpp (+1-1)
• (modified) clang/lib/Sema/SemaTemplateVariadic.cpp (+1-1)

diff --git a/clang/lib/CodeGen/Targets/AArch64.cpp b/clang/lib/CodeGen/Targets/AArch64.cpp
index d6e0e720a0941..073ca3cc82690 100644
--- a/clang/lib/CodeGen/Targets/AArch64.cpp
+++ b/clang/lib/CodeGen/Targets/AArch64.cpp
@@ -763,7 +763,7 @@ bool AArch64ABIInfo::passAsPureScalableType(
     return false;
 
   bool isPredicate;
-  switch (Ty->getAs<BuiltinType>()->getKind()) {
+  switch (Ty->castAs<BuiltinType>()->getKind()) {
 #define SVE_VECTOR_TYPE(Name, MangledName, Id, SingletonId)                    \
   case BuiltinType::Id:                                                        \
     isPredicate = false;                                                       \
diff --git a/clang/lib/Sema/SemaTemplateVariadic.cpp b/clang/lib/Sema/SemaTemplateVariadic.cpp
index fad00f7648848..d9256dbd07d7a 100644
--- a/clang/lib/Sema/SemaTemplateVariadic.cpp
+++ b/clang/lib/Sema/SemaTemplateVariadic.cpp
@@ -834,7 +834,7 @@ bool Sema::CheckParameterPacksForExpansion(
 
             if (TA.getKind() == TemplateArgument::Type)
               return !TA.getAsType()
-                          ->getAs<PackExpansionType>()
+                          ->castAs<PackExpansionType>()
                           ->getNumExpansions();
 
             if (TA.getKind() == TemplateArgument::Expression)

[llvmbot]

@llvm/pr-subscribers-clang-codegen

Author: Tom Honermann (tahonermann)

Changes

Static analysis identified two uses of getAs() for which the result pointer was unconditionally dereferenced. Source code inspection confirmed that the target type is assured by prior checks. This change replaces these uses of getAs() with castAs().

The first case, in clang/lib/CodeGen/Targets/AArch64.cpp, performs a cast to BuiltinType following a check for isBuiltinType().

The second case, in clang/lib/Sema/SemaTemplateVariadic.cpp, performs a cast to PackExpansionType on the result of a call to getAsType() on an object of type TemplateArgument following confirmation that isPackExpansion() returned true and that getKind() returned TemplateArgument::Type. Inspection of isPackExpansion() revealed that it only returns true when the template argument kind is TemplateArgument::Type if isa<PackExpansionType>(getAsType()) is true.

---

Full diff: https://github.com/llvm/llvm-project/pull/130188.diff

2 Files Affected:

• (modified) clang/lib/CodeGen/Targets/AArch64.cpp (+1-1)
• (modified) clang/lib/Sema/SemaTemplateVariadic.cpp (+1-1)

diff --git a/clang/lib/CodeGen/Targets/AArch64.cpp b/clang/lib/CodeGen/Targets/AArch64.cpp
index d6e0e720a0941..073ca3cc82690 100644
--- a/clang/lib/CodeGen/Targets/AArch64.cpp
+++ b/clang/lib/CodeGen/Targets/AArch64.cpp
@@ -763,7 +763,7 @@ bool AArch64ABIInfo::passAsPureScalableType(
     return false;
 
   bool isPredicate;
-  switch (Ty->getAs<BuiltinType>()->getKind()) {
+  switch (Ty->castAs<BuiltinType>()->getKind()) {
 #define SVE_VECTOR_TYPE(Name, MangledName, Id, SingletonId)                    \
   case BuiltinType::Id:                                                        \
     isPredicate = false;                                                       \
diff --git a/clang/lib/Sema/SemaTemplateVariadic.cpp b/clang/lib/Sema/SemaTemplateVariadic.cpp
index fad00f7648848..d9256dbd07d7a 100644
--- a/clang/lib/Sema/SemaTemplateVariadic.cpp
+++ b/clang/lib/Sema/SemaTemplateVariadic.cpp
@@ -834,7 +834,7 @@ bool Sema::CheckParameterPacksForExpansion(
 
             if (TA.getKind() == TemplateArgument::Type)
               return !TA.getAsType()
-                          ->getAs<PackExpansionType>()
+                          ->castAs<PackExpansionType>()
                           ->getNumExpansions();
 
             if (TA.getKind() == TemplateArgument::Expression)