Migrate to LLVM{Get,Set}ValueName2

The deprecated `LLVM{Get,Set}ValueName` only work with NUL-terminated
strings, but the `2` variants use explicit lengths, which fits better
with Rust strings and slices. We now use these in new helper functions
`llvm::{get,set}_value_name` that convert to/from `&[u8]`.

2 files changed, 24 insertions, 5 deletions

diff --git a/src/librustc_codegen_llvm/llvm/ffi.rs b/src/librustc_codegen_llvm/llvm/ffi.rs
index fd31e65c9d3..296b6876c4a 100644
--- a/src/librustc_codegen_llvm/llvm/ffi.rs
+++ b/src/librustc_codegen_llvm/llvm/ffi.rs
@@ -701,8 +701,8 @@ extern "C" {
 
     // Operations on all values
     pub fn LLVMTypeOf(Val: &Value) -> &Type;
-    pub fn LLVMGetValueName(Val: &Value) -> *const c_char;
-    pub fn LLVMSetValueName(Val: &Value, Name: *const c_char);
+    pub fn LLVMGetValueName2(Val: &Value, Length: *mut size_t) -> *const c_char;
+    pub fn LLVMSetValueName2(Val: &Value, Name: *const c_char, NameLen: size_t);
     pub fn LLVMReplaceAllUsesWith(OldVal: &'a Value, NewVal: &'a Value);
     pub fn LLVMSetMetadata(Val: &'a Value, KindID: c_uint, Node: &'a Value);
 
@@ -774,7 +774,8 @@ extern "C" {
     pub fn LLVMIsAGlobalVariable(GlobalVar: &Value) -> Option<&Value>;
     pub fn LLVMAddGlobal(M: &'a Module, Ty: &'a Type, Name: *const c_char) -> &'a Value;
     pub fn LLVMGetNamedGlobal(M: &Module, Name: *const c_char) -> Option<&Value>;
-    pub fn LLVMRustGetOrInsertGlobal(M: &'a Module, Name: *const c_char, T: &'a Type) -> &'a Value;
+    pub fn LLVMRustGetOrInsertGlobal(M: &'a Module, Name: *const c_char, NameLen: size_t,
+                                     T: &'a Type) -> &'a Value;
     pub fn LLVMRustInsertPrivateGlobal(M: &'a Module, T: &'a Type) -> &'a Value;
     pub fn LLVMGetFirstGlobal(M: &Module) -> Option<&Value>;
     pub fn LLVMGetNextGlobal(GlobalVar: &Value) -> Option<&Value>;
@@ -1812,7 +1813,7 @@ extern "C" {
 
     pub fn LLVMRustPositionBuilderAtStart(B: &Builder<'a>, BB: &'a BasicBlock);
 
-    pub fn LLVMRustSetComdat(M: &'a Module, V: &'a Value, Name: *const c_char);
+    pub fn LLVMRustSetComdat(M: &'a Module, V: &'a Value, Name: *const c_char, NameLen: size_t);
     pub fn LLVMRustUnsetComdat(V: &Value);
     pub fn LLVMRustSetModulePICLevel(M: &Module);
     pub fn LLVMRustSetModulePIELevel(M: &Module);
diff --git a/src/librustc_codegen_llvm/llvm/mod.rs b/src/librustc_codegen_llvm/llvm/mod.rs
index 57815933af0..d2d41876239 100644
--- a/src/librustc_codegen_llvm/llvm/mod.rs
+++ b/src/librustc_codegen_llvm/llvm/mod.rs
@@ -115,7 +115,8 @@ pub fn SetFunctionCallConv(fn_: &'a Value, cc: CallConv) {
 // For more details on COMDAT sections see e.g., http://www.airs.com/blog/archives/52
 pub fn SetUniqueComdat(llmod: &Module, val: &'a Value) {
     unsafe {
-        LLVMRustSetComdat(llmod, val, LLVMGetValueName(val));
+        let name = get_value_name(val);
+        LLVMRustSetComdat(llmod, val, name.as_ptr().cast(), name.len());
     }
 }
 
@@ -217,6 +218,23 @@ pub fn get_param(llfn: &'a Value, index: c_uint) -> &'a Value {
     }
 }
 
+/// Safe wrapper for `LLVMGetValueName2` into a byte slice
+pub fn get_value_name(value: &'a Value) -> &'a [u8] {
+    unsafe {
+        let mut len = 0;
+        let data = LLVMGetValueName2(value, &mut len);
+        std::slice::from_raw_parts(data.cast(), len)
+    }
+}
+
+/// Safe wrapper for `LLVMSetValueName2` from a byte slice
+pub fn set_value_name(value: &Value, name: &[u8]) {
+    unsafe {
+        let data = name.as_ptr().cast();
+        LLVMSetValueName2(value, data, name.len());
+    }
+}
+
 pub fn build_string(f: impl FnOnce(&RustString)) -> Result<String, FromUtf8Error> {
     let sr = RustString {
         bytes: RefCell::new(Vec::new()),