[llvm] [llvm][utils] Improve the StringRef summary provider (PR #162298)

[Ebuka Ezike via llvm-commits]

https://github.com/da-viper updated https://github.com/llvm/llvm-project/pull/162298

>From e3f090bed709bef5ba7fc4317c7b1d3f20cce967 Mon Sep 17 00:00:00 2001
From: Ebuka Ezike <yerimyah1 at gmail.com>
Date: Tue, 7 Oct 2025 16:06:49 +0100
Subject: [PATCH 1/3] [llvm][utils] Improve the StringRef summary provider

- check the length of data before casting as `char[N]` because the will cause lldb to allocate `N` bytes of memory.
---
 llvm/utils/lldbDataFormatters.py | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/llvm/utils/lldbDataFormatters.py b/llvm/utils/lldbDataFormatters.py
index 5e553caa4446d..06cb8cbb1e068 100644
--- a/llvm/utils/lldbDataFormatters.py
+++ b/llvm/utils/lldbDataFormatters.py
@@ -197,6 +197,13 @@ def StringRefSummaryProvider(valobj, internal_dict):
         return '""'
 
     data = data_pointer.deref
+    # StringRef may be uninitialized with length exceeding available memory,
+    # potentially causing bad_alloc exceptions. Limit the length to max string summary setting.
+    limit_obj = (
+        valobj.GetTarget().GetDebugger().GetSetting("target.max-string-summary-length")
+    )
+    if limit_obj:
+        length = min(length, limit_obj.GetUnsignedIntegerValue())
     # Get a char[N] type, from the underlying char type.
     array_type = data.type.GetArrayType(length)
     # Cast the char* string data to a char[N] array.

>From 1a911a6eb119702dabe60f7903c3aa5b2c541953 Mon Sep 17 00:00:00 2001
From: Ebuka Ezike <yerimyah1 at gmail.com>
Date: Thu, 23 Oct 2025 18:04:29 +0100
Subject: [PATCH 2/3] Update llvm/utils/lldbDataFormatters.py

Co-authored-by: Dave Lee <davelee.com at gmail.com>
---
 llvm/utils/lldbDataFormatters.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/utils/lldbDataFormatters.py b/llvm/utils/lldbDataFormatters.py
index 06cb8cbb1e068..d061127369d9a 100644
--- a/llvm/utils/lldbDataFormatters.py
+++ b/llvm/utils/lldbDataFormatters.py
@@ -200,7 +200,7 @@ def StringRefSummaryProvider(valobj, internal_dict):
     # StringRef may be uninitialized with length exceeding available memory,
     # potentially causing bad_alloc exceptions. Limit the length to max string summary setting.
     limit_obj = (
-        valobj.GetTarget().GetDebugger().GetSetting("target.max-string-summary-length")
+        valobj.target.debugger.GetSetting("target.max-string-summary-length")
     )
     if limit_obj:
         length = min(length, limit_obj.GetUnsignedIntegerValue())

>From 2ed4c24766839e1862476646974ec1fd9bd15147 Mon Sep 17 00:00:00 2001
From: Ebuka Ezike <yerimyah1 at gmail.com>
Date: Thu, 23 Oct 2025 18:08:35 +0100
Subject: [PATCH 3/3] fix format

Refactor string summary length limit retrieval.
---
 llvm/utils/lldbDataFormatters.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/llvm/utils/lldbDataFormatters.py b/llvm/utils/lldbDataFormatters.py
index d061127369d9a..a3e4ae15930d9 100644
--- a/llvm/utils/lldbDataFormatters.py
+++ b/llvm/utils/lldbDataFormatters.py
@@ -199,9 +199,7 @@ def StringRefSummaryProvider(valobj, internal_dict):
     data = data_pointer.deref
     # StringRef may be uninitialized with length exceeding available memory,
     # potentially causing bad_alloc exceptions. Limit the length to max string summary setting.
-    limit_obj = (
-        valobj.target.debugger.GetSetting("target.max-string-summary-length")
-    )
+    limit_obj = valobj.target.debugger.GetSetting("target.max-string-summary-length")
     if limit_obj:
         length = min(length, limit_obj.GetUnsignedIntegerValue())
     # Get a char[N] type, from the underlying char type.