From b75a3bbad80f91e5176d41a457e26c4d0038237a Mon Sep 17 00:00:00 2001
From: Churkin Aleksey <lekhachurkin@gmail.com>
Date: Thu, 17 Sep 2026 14:17:38 +0300
Subject: [PATCH] llvm2alive: skip string attributes in handleParamAttrs

Guard the loop the same way handleRetAttrs and handleFnAttrs already do:
only enum, int and type attributes reach the switch.
---
 llvm_util/llvm2alive.cpp                         |  4 ++++
 tests/alive-tv/attrs/string-param-attr.srctgt.ll | 16 ++++++++++++++++
 2 files changed, 20 insertions(+)
 create mode 100644 tests/alive-tv/attrs/string-param-attr.srctgt.ll

diff --git a/llvm_util/llvm2alive.cpp b/llvm_util/llvm2alive.cpp
index 393408177..b7e821f99 100644
--- a/llvm_util/llvm2alive.cpp
+++ b/llvm_util/llvm2alive.cpp
@@ -1574,6 +1574,10 @@ class llvm2alive_ : public llvm::InstVisitor<llvm2alive_, unique_ptr<Instr>> {
                         Value **val, bool is_callsite) {
     bool precise = true;
     for (const llvm::Attribute &llvmattr : aset) {
+      if (!llvmattr.isEnumAttribute() && !llvmattr.isIntAttribute() &&
+          !llvmattr.isTypeAttribute())
+        continue;
+
       switch (llvmattr.getKindAsEnum()) {
       case llvm::Attribute::InReg:
         attrs.set(ParamAttrs::InReg);
diff --git a/tests/alive-tv/attrs/string-param-attr.srctgt.ll b/tests/alive-tv/attrs/string-param-attr.srctgt.ll
new file mode 100644
index 000000000..24537d7a2
--- /dev/null
+++ b/tests/alive-tv/attrs/string-param-attr.srctgt.ll
@@ -0,0 +1,16 @@
+; string attributes are legal on parameters (LLVM-C frontends emit them as a
+; fallback when LLVMGetEnumAttributeKindForName returns 0). handleParamAttrs
+; used to call getKindAsEnum() on them, which asserts.
+define i32 @src(ptr "foo"="bar" %p) {
+  %v = load i32, ptr %p
+  call void @g(ptr "baz"="qux" %p)
+  ret i32 %v
+}
+
+define i32 @tgt(ptr "foo"="bar" %p) {
+  %v = load i32, ptr %p
+  call void @g(ptr "baz"="qux" %p)
+  ret i32 %v
+}
+
+declare void @g(ptr)