[clang] [NFC][Clang][UnsafeBufferUsage] Remove unnecessary struct. (PR #178801)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Rohan Jacob-Rao (rohanjr)

<details>
<summary>Changes</summary>

The struct has no members and has a surrounding namespace that can be used for disambiguating names. This was also mentioned in a previous PR review: https://github.com/llvm/llvm-project/pull/101583/changes#r1737089937

---
Full diff: https://github.com/llvm/llvm-project/pull/178801.diff


1 Files Affected:

- (modified) clang/lib/Analysis/UnsafeBufferUsage.cpp (+35-43) 


``````````diff
diff --git a/clang/lib/Analysis/UnsafeBufferUsage.cpp b/clang/lib/Analysis/UnsafeBufferUsage.cpp
index 761aedda7eacf..75ce911d3e8dc 100644
--- a/clang/lib/Analysis/UnsafeBufferUsage.cpp
+++ b/clang/lib/Analysis/UnsafeBufferUsage.cpp
@@ -840,14 +840,13 @@ static const Expr *getSubExprInSizeOfExpr(const Expr *E) {
   return SizeOfExpr->getArgumentExpr()->IgnoreParenImpCasts();
 }
 
-namespace libc_func_matchers {
 // Under `libc_func_matchers`, define a set of matchers that match unsafe
 // functions in libc and unsafe calls to them.
-
+namespace libc_func_matchers {
 //  A tiny parser to strip off common prefix and suffix of libc function names
 //  in real code.
 //
-//  Given a function name, `matchName` returns `CoreName` according to the
+//  Given a function name, `matchName()` returns `CoreName` according to the
 //  following grammar:
 //
 //  LibcName     := CoreName | CoreName + "_s"
@@ -855,35 +854,33 @@ namespace libc_func_matchers {
 //                  "__builtin___" + LibcName + "_chk"   |
 //                  "__asan_" + LibcName
 //
-struct LibcFunNamePrefixSuffixParser {
-  StringRef matchName(StringRef FunName, bool isBuiltin) {
-    // Try to match __builtin_:
-    if (isBuiltin && FunName.starts_with("__builtin_"))
-      // Then either it is __builtin_LibcName or __builtin___LibcName_chk or
-      // no match:
-      return matchLibcNameOrBuiltinChk(
-          FunName.drop_front(10 /* truncate "__builtin_" */));
-    // Try to match __asan_:
-    if (FunName.starts_with("__asan_"))
-      return matchLibcName(FunName.drop_front(7 /* truncate of "__asan_" */));
-    return matchLibcName(FunName);
-  }
-
-  // Parameter `Name` is the substring after stripping off the prefix
-  // "__builtin_".
-  StringRef matchLibcNameOrBuiltinChk(StringRef Name) {
-    if (Name.starts_with("__") && Name.ends_with("_chk"))
-      return matchLibcName(
-          Name.drop_front(2).drop_back(4) /* truncate "__" and "_chk" */);
-    return matchLibcName(Name);
-  }
-
-  StringRef matchLibcName(StringRef Name) {
-    if (Name.ends_with("_s"))
-      return Name.drop_back(2 /* truncate "_s" */);
-    return Name;
-  }
-};
+StringRef matchLibcName(StringRef Name) {
+  if (Name.ends_with("_s"))
+    return Name.drop_back(2 /* truncate "_s" */);
+  return Name;
+}
+
+// Parameter `Name` is the substring after stripping off the prefix
+// "__builtin_".
+StringRef matchLibcNameOrBuiltinChk(StringRef Name) {
+  if (Name.starts_with("__") && Name.ends_with("_chk"))
+    return matchLibcName(
+        Name.drop_front(2).drop_back(4) /* truncate "__" and "_chk" */);
+  return matchLibcName(Name);
+}
+
+StringRef matchName(StringRef FunName, bool isBuiltin) {
+  // Try to match __builtin_:
+  if (isBuiltin && FunName.starts_with("__builtin_"))
+    // Then either it is __builtin_LibcName or __builtin___LibcName_chk or no
+    // match:
+    return matchLibcNameOrBuiltinChk(
+        FunName.drop_front(10 /* truncate "__builtin_" */));
+  // Try to match __asan_:
+  if (FunName.starts_with("__asan_"))
+    return matchLibcName(FunName.drop_front(7 /* truncate of "__asan_" */));
+  return matchLibcName(FunName);
+}
 
 // Return true iff at least one of following cases holds:
 //  1. Format string is a literal and there is an unsafe pointer argument
@@ -1038,7 +1035,7 @@ hasUnsafeFormatOrSArg(ASTContext &Ctx, const CallExpr *Call,
 //  2. `CoreName` or `CoreName[str/wcs]` is one of the `PredefinedNames`, which
 //     is a set of libc function names.
 //
-//  Note: For predefined prefix and suffix, see `LibcFunNamePrefixSuffixParser`.
+//  Note: For predefined prefix and suffix, see `matchName()`.
 //  The notation `CoreName[str/wcs]` means a new name obtained from replace
 //  string "wcs" with "str" in `CoreName`.
 static bool isPredefinedUnsafeLibcFunc(const FunctionDecl &Node) {
@@ -1121,8 +1118,7 @@ static bool isPredefinedUnsafeLibcFunc(const FunctionDecl &Node) {
   if (!II)
     return false;
 
-  StringRef Name = LibcFunNamePrefixSuffixParser().matchName(
-      II->getName(), Node.getBuiltinID());
+  StringRef Name = matchName(II->getName(), Node.getBuiltinID());
 
   // Match predefined names:
   if (PredefinedNames->find(Name) != PredefinedNames->end())
@@ -1155,8 +1151,7 @@ static bool isUnsafeMemset(const CallExpr &Node, ASTContext &Ctx) {
   if (!II)
     return false;
 
-  StringRef Name = LibcFunNamePrefixSuffixParser().matchName(
-      II->getName(), FD->getBuiltinID());
+  StringRef Name = matchName(II->getName(), FD->getBuiltinID());
   if (Name != "memset")
     return false;
 
@@ -1191,8 +1186,7 @@ static bool isUnsafeVaListPrintfFunc(const FunctionDecl &Node) {
   if (!II)
     return false;
 
-  StringRef Name = LibcFunNamePrefixSuffixParser().matchName(
-      II->getName(), Node.getBuiltinID());
+  StringRef Name = matchName(II->getName(), Node.getBuiltinID());
 
   if (!Name.ends_with("printf"))
     return false; // neither printf nor scanf
@@ -1207,8 +1201,7 @@ static bool isUnsafeSprintfFunc(const FunctionDecl &Node) {
   if (!II)
     return false;
 
-  StringRef Name = LibcFunNamePrefixSuffixParser().matchName(
-      II->getName(), Node.getBuiltinID());
+  StringRef Name = matchName(II->getName(), Node.getBuiltinID());
 
   if (!Name.ends_with("printf") ||
       // Let `isUnsafeVaListPrintfFunc` check for cases with va-list:
@@ -1231,8 +1224,7 @@ static bool isNormalPrintfFunc(const FunctionDecl &Node) {
   if (!II)
     return false;
 
-  StringRef Name = LibcFunNamePrefixSuffixParser().matchName(
-      II->getName(), Node.getBuiltinID());
+  StringRef Name = matchName(II->getName(), Node.getBuiltinID());
 
   if (!Name.ends_with("printf") || Name.starts_with("v"))
     return false;

``````````

</details>


https://github.com/llvm/llvm-project/pull/178801