[clang] [NFC][Clang] Minor cleanups in UnsafeLibcFunctionCallGadget::matches(). (PR #177514)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Rohan Jacob-Rao (rohanjr)

<details>
<summary>Changes</summary>

- Remove unneeded dynamic cast
- Add consts
- Simplify boolean condition

---
Full diff: https://github.com/llvm/llvm-project/pull/177514.diff


1 Files Affected:

- (modified) clang/lib/Analysis/UnsafeBufferUsage.cpp (+8-9) 


``````````diff
diff --git a/clang/lib/Analysis/UnsafeBufferUsage.cpp b/clang/lib/Analysis/UnsafeBufferUsage.cpp
index a7530d1250729..95316623f5d88 100644
--- a/clang/lib/Analysis/UnsafeBufferUsage.cpp
+++ b/clang/lib/Analysis/UnsafeBufferUsage.cpp
@@ -2143,14 +2143,14 @@ class UnsafeLibcFunctionCallGadget : public WarningGadget {
                       MatchResult &Result) {
     if (ignoreUnsafeLibcCall(Ctx, *S, Handler))
       return false;
-    auto *CE = dyn_cast<CallExpr>(S);
-    if (!CE || !CE->getDirectCallee())
+    const auto *CE = dyn_cast<CallExpr>(S);
+    if (!CE)
       return false;
-    const auto *FD = dyn_cast<FunctionDecl>(CE->getDirectCallee());
+    const auto *FD = CE->getDirectCallee();
     if (!FD)
       return false;
 
-    bool IsGlobalAndNotInAnyNamespace =
+    const bool IsGlobalAndNotInAnyNamespace =
         FD->isGlobal() && !FD->getEnclosingNamespaceContext()->isNamespace();
 
     // A libc function must either be in the std:: namespace or a global
@@ -2161,11 +2161,10 @@ class UnsafeLibcFunctionCallGadget : public WarningGadget {
     //  printf, atoi, we consider it safe:
     if (CE->getNumArgs() == 1 && isNullTermPointer(CE->getArg(0), Ctx))
       return false;
-    auto isSingleStringLiteralArg = false;
-    if (CE->getNumArgs() == 1) {
-      isSingleStringLiteralArg =
-          isa<clang::StringLiteral>(CE->getArg(0)->IgnoreParenImpCasts());
-    }
+
+    const bool isSingleStringLiteralArg =
+        CE->getNumArgs() == 1 &&
+        isa<clang::StringLiteral>(CE->getArg(0)->IgnoreParenImpCasts());
     if (!isSingleStringLiteralArg) {
       // (unless the call has a sole string literal argument):
       if (libc_func_matchers::isPredefinedUnsafeLibcFunc(*FD)) {

``````````

</details>


https://github.com/llvm/llvm-project/pull/177514