[llvm] [NFC] Prefer `str.resize(len)` over `str.substr(0, len)` (PR #91067)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-llvm-analysis

Author: Danny Mösch (SimplyDanny)

<details>
<summary>Changes</summary>

Fixes #<!-- -->90323.

---
Full diff: https://github.com/llvm/llvm-project/pull/91067.diff


1 Files Affected:

- (modified) llvm/include/llvm/Analysis/DOTGraphTraitsPass.h (+4-5) 


``````````diff
diff --git a/llvm/include/llvm/Analysis/DOTGraphTraitsPass.h b/llvm/include/llvm/Analysis/DOTGraphTraitsPass.h
index da72fb511f82d8..7aea7a3b0f6d69 100644
--- a/llvm/include/llvm/Analysis/DOTGraphTraitsPass.h
+++ b/llvm/include/llvm/Analysis/DOTGraphTraitsPass.h
@@ -87,13 +87,12 @@ struct DOTGraphTraitsViewer
 };
 
 static inline void shortenFileName(std::string &FN, unsigned char len = 250) {
-
-  FN = FN.substr(0, len);
-
+  if (FN.length() > len)
+    FN.resize(len);
   auto strLen = FN.length();
   while (strLen > 0) {
-    if (auto it = nameObj.find(FN); it != nameObj.end()) {
-      FN = FN.substr(0, --len);
+    if (nameObj.find(FN) != nameObj.end()) {
+      FN.resize(--len);
     } else {
       nameObj.insert(FN);
       break;

``````````

</details>


https://github.com/llvm/llvm-project/pull/91067