[libcxx-commits] [libcxx] Revert "[libc++] Fix incorrect size check when growing std::string" (PR #234545)

[via libcxx-commits]

llvmorg-github-actions[bot] wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-libcxx

Author: Nikita Popov (nikic)

<details>
<summary>Changes</summary>

Reverts llvm/llvm-project#<!-- -->232737

Broke premerge CI.

---
Full diff: https://github.com/llvm/llvm-project/pull/234545.diff


4 Files Affected:

- (modified) libcxx/include/string (+8-8) 
- (modified) libcxx/test/std/strings/basic.string/string.modifiers/string_append/size_char.pass.cpp (-11) 
- (modified) libcxx/test/std/strings/basic.string/string.modifiers/string_insert/iter_size_char.pass.cpp (-11) 
- (modified) libcxx/test/std/strings/basic.string/string.modifiers/string_insert/size_size_char.pass.cpp (-11) 


``````````diff
diff --git a/libcxx/include/string b/libcxx/include/string
index b5a2db6c43a2ef..33175c115fd10c 100644
--- a/libcxx/include/string
+++ b/libcxx/include/string
@@ -2306,16 +2306,16 @@ private:
   }
 
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 size_type
-  __get_amortized_growth_capacity(size_type __old_cap, size_type __additional_characters) {
+  __get_amortized_growth_capacity(size_type __required_capacity) {
     size_type __max_size = max_size();
-    if (__additional_characters > __max_size - __old_cap)
+    if (__required_capacity > __max_size)
       __throw_length_error();
     size_type __current_cap = capacity();
-    _LIBCPP_ASSERT_INTERNAL(__current_cap < __old_cap + __additional_characters,
-                            "Trying to grow string even though there is enough capacity already?");
+    _LIBCPP_ASSERT_INTERNAL(
+        __current_cap < __required_capacity, "Trying to grow string even though there is enough capacity already?");
     if (__current_cap > __max_size / 2 - __alignment)
       return __max_size;
-    return std::max(__old_cap + __additional_characters, 2 * __current_cap);
+    return std::max(__required_capacity, 2 * __current_cap);
   }
 
   inline _LIBCPP_CONSTEXPR_SINCE_CXX20 void __init(const value_type* __s, size_type __sz);
@@ -2659,7 +2659,7 @@ _LIBCPP_CONSTEXPR_SINCE_CXX20 void basic_string<_CharT, _Traits, _Allocator>::__
     size_type __n_del,
     size_type __n_add,
     const value_type* __p_new_stuff) {
-  __long __buffer     = __allocate_long_buffer(__alloc_, 0, __get_amortized_growth_capacity(__old_cap, __delta_cap));
+  __long __buffer     = __allocate_long_buffer(__alloc_, 0, __get_amortized_growth_capacity(__old_cap + __delta_cap));
   value_type* __old_p = __data();
   __annotate_delete();
   auto __guard = std::__make_scope_guard(__annotate_new_size(*this));
@@ -2691,7 +2691,7 @@ basic_string<_CharT, _Traits, _Allocator>::__grow_by(
     size_type __n_copy,
     size_type __n_del,
     size_type __n_add) {
-  __long __buffer     = __allocate_long_buffer(__alloc_, 0, __get_amortized_growth_capacity(__old_cap, __delta_cap));
+  __long __buffer     = __allocate_long_buffer(__alloc_, 0, __get_amortized_growth_capacity(__old_cap + __delta_cap));
   value_type* __old_p = __data();
   if (__n_copy != 0)
     traits_type::copy(std::__to_address(__buffer.__data_), __old_p, __n_copy);
@@ -2744,7 +2744,7 @@ basic_string<_CharT, _Traits, _Allocator>::__assign_c_str(const value_type* __s,
         if _LIBCPP_CONSTEXPR (!__is_short)
           __this.__rep_ = __rep();
       });
-      auto __new_cap = __this.__get_amortized_growth_capacity(0, __ln);
+      auto __new_cap = __this.__get_amortized_growth_capacity(__ln);
       std::__assume(__new_cap <= __this.max_size());
       __this.__init_internal_buffer(__new_cap);
       __this.__set_long_size(__ln);
diff --git a/libcxx/test/std/strings/basic.string/string.modifiers/string_append/size_char.pass.cpp b/libcxx/test/std/strings/basic.string/string.modifiers/string_append/size_char.pass.cpp
index 608c9dec5c328d..a898efcf21855f 100644
--- a/libcxx/test/std/strings/basic.string/string.modifiers/string_append/size_char.pass.cpp
+++ b/libcxx/test/std/strings/basic.string/string.modifiers/string_append/size_char.pass.cpp
@@ -63,16 +63,5 @@ int main(int, char**) {
   static_assert(test());
 #endif
 
-#ifndef TEST_HAS_NO_EXCEPTIONS
-  { // Append with invalid parameters
-    std::string str = "Banane";
-    try {
-      str.append(std::string::npos, 'a');
-      assert(false);
-    } catch (const std::length_error&) {
-    }
-  }
-#endif
-
   return 0;
 }
diff --git a/libcxx/test/std/strings/basic.string/string.modifiers/string_insert/iter_size_char.pass.cpp b/libcxx/test/std/strings/basic.string/string.modifiers/string_insert/iter_size_char.pass.cpp
index 9107939ed420ce..6937ccc0d540a4 100644
--- a/libcxx/test/std/strings/basic.string/string.modifiers/string_insert/iter_size_char.pass.cpp
+++ b/libcxx/test/std/strings/basic.string/string.modifiers/string_insert/iter_size_char.pass.cpp
@@ -112,16 +112,5 @@ int main(int, char**) {
   static_assert(test());
 #endif
 
-#ifndef TEST_HAS_NO_EXCEPTIONS
-  { // Append with invalid parameters
-    std::string str = "Banane";
-    try {
-      str.insert(str.begin(), std::string::npos, 'a');
-      assert(false);
-    } catch (const std::length_error&) {
-    }
-  }
-#endif
-
   return 0;
 }
diff --git a/libcxx/test/std/strings/basic.string/string.modifiers/string_insert/size_size_char.pass.cpp b/libcxx/test/std/strings/basic.string/string.modifiers/string_insert/size_size_char.pass.cpp
index 15a652fce07d24..0023014976ec51 100644
--- a/libcxx/test/std/strings/basic.string/string.modifiers/string_insert/size_size_char.pass.cpp
+++ b/libcxx/test/std/strings/basic.string/string.modifiers/string_insert/size_size_char.pass.cpp
@@ -143,16 +143,5 @@ int main(int, char**) {
   static_assert(test());
 #endif
 
-#ifndef TEST_HAS_NO_EXCEPTIONS
-  { // Append with invalid parameters
-    std::string str = "Banane";
-    try {
-      str.insert(0, std::string::npos, 'a');
-      assert(false);
-    } catch (const std::length_error&) {
-    }
-  }
-#endif
-
   return 0;
 }

``````````

</details>


https://github.com/llvm/llvm-project/pull/234545