From 0d5ff91cba2a5a79f20cc556394a235641f939b0 Mon Sep 17 00:00:00 2001
From: zhangziyao <zhangziyao8@huawei.com>
Date: Wed, 17 Dec 2025 10:33:39 +0800
Subject: [PATCH 1/2] [borrowck][bugfix] fixed the coredump when reborrowing a
 string literal

---
 clang/lib/Sema/BSC/SemaDeclBSC.cpp              | 17 +++++++++++++----
 .../reborrow_string_literals.cbs                | 16 ++++++++++++++++
 2 files changed, 29 insertions(+), 4 deletions(-)
 create mode 100644 clang/test/BSC/Positive/Ownership/borrow_check_rules/reborrow_string_literals/reborrow_string_literals.cbs

diff --git a/clang/lib/Sema/BSC/SemaDeclBSC.cpp b/clang/lib/Sema/BSC/SemaDeclBSC.cpp
index d4e3711e6b1b..cba5d94f3948 100644
--- a/clang/lib/Sema/BSC/SemaDeclBSC.cpp
+++ b/clang/lib/Sema/BSC/SemaDeclBSC.cpp
@@ -676,6 +676,17 @@ public:
                                      FPOptionsOverride());
         replacedNodesMap.Insert(E, BO);
       }
+    } else if (UO->getOpcode() >= UO_AddrMut && UO->getOpcode() <= UO_AddrConstDeref) {
+      if (isa<StringLiteral>(E->IgnoreParenImpCasts())) {
+        Expr *BaseE = E;
+        DeclRefExpr *DRE = ReplaceWithTemporaryVariable(E);
+        CastKind Kind =
+            DRE->getType()->getAsCXXRecordDecl() ? CK_NoOp : CK_LValueToRValue;
+        E = ImplicitCastExpr::Create(getSema().Context, DRE->getType(), Kind,
+                                     DRE, nullptr, VK_PRValue,
+                                     FPOptionsOverride());
+        replacedNodesMap.Insert(E, BaseE);
+      }
     }
     UO->setSubExpr(E);
     return UO;
@@ -946,10 +957,8 @@ public:
 
   ExprResult TransformUnaryOperator(UnaryOperator *UO) {
     Expr *Sub = UO->getSubExpr();
-    if (UO->getOpcode() == UO_Deref) {
-      if (replacedNodesMap.Contains(Sub)) {
-        Sub = replacedNodesMap.Get(Sub);
-      }
+    if (replacedNodesMap.Contains(Sub)) {
+      Sub = replacedNodesMap.Get(Sub);
     }
     ExprResult Res = getDerived().TransformExpr(Sub);
     UO->setSubExpr(Res.get());
diff --git a/clang/test/BSC/Positive/Ownership/borrow_check_rules/reborrow_string_literals/reborrow_string_literals.cbs b/clang/test/BSC/Positive/Ownership/borrow_check_rules/reborrow_string_literals/reborrow_string_literals.cbs
new file mode 100644
index 000000000000..7c43bab43d79
--- /dev/null
+++ b/clang/test/BSC/Positive/Ownership/borrow_check_rules/reborrow_string_literals/reborrow_string_literals.cbs
@@ -0,0 +1,16 @@
+// RUN: %clang %s -o %test.output
+// RUN: %test.output
+// RUN: %clang -rewrite-bsc %s -o %t-rw.c
+// RUN: %clang %t-rw.c -o %t-rw.output
+// RUN: %t-rw.output
+// expected-no-diagnostics
+
+void bsc_strcpy_s(char* borrow strDest, int destMax, const char* borrow strSrc) {
+  *strDest = *strSrc;
+}
+
+int main(){
+  char db[10] = {0};
+  bsc_strcpy_s(&mut *db, 5, &const *"DB1");
+  return 0;
+}
-- 
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From 26fcd2642da0e7f9bebe38b1f3df51c6915639c2 Mon Sep 17 00:00:00 2001
From: zhangziyao <zhangziyao8@huawei.com>
Date: Wed, 17 Dec 2025 11:48:16 +0800
Subject: [PATCH 2/2] [user manual] fixed the inccorect rrule description of
 conversion from T *borrow to void *borrow

---
 clang/docs/BSC/BiShengCLanguageUserManual.md | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/clang/docs/BSC/BiShengCLanguageUserManual.md b/clang/docs/BSC/BiShengCLanguageUserManual.md
index 189f2e18a1d9..5f0bc1e476db 100644
--- a/clang/docs/BSC/BiShengCLanguageUserManual.md
+++ b/clang/docs/BSC/BiShengCLanguageUserManual.md
@@ -4149,14 +4149,16 @@ int main() {
   return 0;
 }
 ```
-2. 允许指向类型 T 的借用转换为指向 void 类型的借用，反过来从类型 void 的借用往类型 T 借用的转换，是不允许的。
+2. 允许指向类型 T 的借用隐式转换为指向 void 类型的借用，反过来从类型 void 的借用往类型 T 借用的隐式转换，是不允许的，但强制类型转换是允许的。
 ```C
 void test() {
   int x = 10;
   int *borrow r = &mut x;
   void *borrow p = r;
-  // error: 不允许转为 void *borrow 类型
-  int *borrow t = (int *borrow)p;
+  // error: 不允许隐式转为 void *borrow 类型
+  int *borrow t1 = p;
+  // ok：允许强制转换为 void *borrow 类型
+  int *borrow t2 = (int *borrow)p;
 }
 
 int main() {
-- 
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