[compiler-rt] [scudo] Clean up string handling (PR #86364)

[Amy Kwan via llvm-commits]

================
@@ -123,3 +127,31 @@ TEST(ScudoStringsTest, Padding) {
   testAgainstLibc<int>("%03d - %03d", 12, 1234);
   testAgainstLibc<int>("%03d - %03d", -12, -1234);
 }
+
+#if defined(__linux__)
+#include <sys/resource.h>
+
+TEST(ScudoStringsTest, CapacityIncreaseFails) {
+  scudo::ScopedString Str;
+
+  rlimit Limit = {};
+  EXPECT_EQ(0, getrlimit(RLIMIT_AS, &Limit));
+  rlimit EmptyLimit = {.rlim_max = Limit.rlim_max};
----------------
amy-kwan wrote:

Applying this change locally:
```
diff --git a/compiler-rt/lib/scudo/standalone/tests/strings_test.cpp b/compiler-rt/lib/scudo/standalone/tests/strings_test.cpp
index e068c48fc97c..d31ca26d53a1 100644
--- a/compiler-rt/lib/scudo/standalone/tests/strings_test.cpp
+++ b/compiler-rt/lib/scudo/standalone/tests/strings_test.cpp
@@ -136,7 +136,7 @@ TEST(ScudoStringsTest, CapacityIncreaseFails) {

   rlimit Limit = {};
   EXPECT_EQ(0, getrlimit(RLIMIT_AS, &Limit));
-  rlimit EmptyLimit = {.rlim_max = Limit.rlim_max};
+  rlimit EmptyLimit = {.rlim_cur = 0, .rlim_max = Limit.rlim_max};
   EXPECT_EQ(0, setrlimit(RLIMIT_AS, &EmptyLimit));

   // Test requires that the default length is at least 6 characters.
diff --git a/compiler-rt/lib/scudo/standalone/tests/vector_test.cpp b/compiler-rt/lib/scudo/standalone/tests/vector_test.cpp
index b7678678d8a2..add62c5a42a3 100644
--- a/compiler-rt/lib/scudo/standalone/tests/vector_test.cpp
+++ b/compiler-rt/lib/scudo/standalone/tests/vector_test.cpp
@@ -55,7 +55,7 @@ TEST(ScudoVectorTest, ReallocateFails) {
   rlimit Limit = {};
   EXPECT_EQ(0, getrlimit(RLIMIT_AS, &Limit));

-  rlimit EmptyLimit = {.rlim_max = Limit.rlim_max};
+  rlimit EmptyLimit = {.rlim_cur = 0, .rlim_max = Limit.rlim_max};
   EXPECT_EQ(0, setrlimit(RLIMIT_AS, &EmptyLimit));

   V.resize(capacity);
```
Appears to resolve the issue.

https://github.com/llvm/llvm-project/pull/86364