[clang] [NFC][c-index-test] factor data len out (PR #129971)

[Jinsong Ji via cfe-commits]

https://github.com/jsji created https://github.com/llvm/llvm-project/pull/129971

None

>From 801d92357366d95bc5bd044125eefc25862b6fee Mon Sep 17 00:00:00 2001
From: Jinsong Ji <jinsong.ji at intel.com>
Date: Wed, 5 Mar 2025 17:54:48 -0800
Subject: [PATCH] [NFC][c-index-test] factor data len out

---
 clang/tools/c-index-test/c-index-test.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/clang/tools/c-index-test/c-index-test.c b/clang/tools/c-index-test/c-index-test.c
index 50f32c0a20e5a..1ad2e44aae3f7 100644
--- a/clang/tools/c-index-test/c-index-test.c
+++ b/clang/tools/c-index-test/c-index-test.c
@@ -3554,13 +3554,11 @@ static CXIdxClientContainer makeClientContainer(CXClientData *client_data,
 
   clang_indexLoc_getFileLocation(loc, &file, 0, &line, &column, 0);
 
-  len = sizeof(IndexDataStringList) + strlen(name) + digitCount(line) +
-        digitCount(column) + 3;
-  node = (IndexDataStringList *)malloc(len);
+  datalen = strlen(name) + digitCount(line) + digitCount(column) + 3;
+  node = (IndexDataStringList *)malloc(len + sizeof(IndexDataStringList));
   assert(node);
   newStr = node->data;
-  snprintf(newStr, len - sizeof(IndexDataStringList), "%s:%d:%d", name, line,
-           column);
+  snprintf(newStr, datalen, "%s:%d:%d", name, line, column);
 
   /* Remember string so it can be freed later. */
   index_data = (IndexData *)client_data;