Rollup merge of #69734 - tmiasko:di-enumerator, r=ecstatic-morse

Change DIBuilderCreateEnumerator signature to match LLVM 9

* Change DIBuilderCreateEnumerator signature to match LLVM 9 C API.
* Use provided is unsigned flag when emitting enumerators.

src/librustc_codegen_llvm/debuginfo/metadata.rs

@@ -1779,13 +1779,20 @@ fn prepare_enum_metadata(
                 .discriminants(cx.tcx)
                 .zip(&def.variants)
                 .map(|((_, discr), v)| {
-                    let name = SmallCStr::new(&v.ident.as_str());
+                    let name = v.ident.as_str();
+                    let is_unsigned = match discr.ty.kind {
+                        ty::Int(_) => false,
+                        ty::Uint(_) => true,
+                        _ => bug!("non integer discriminant"),
+                    };
                     unsafe {
                         Some(llvm::LLVMRustDIBuilderCreateEnumerator(
                             DIB(cx),
-                            name.as_ptr(),
+                            name.as_ptr().cast(),
+                            name.len(),
                             // FIXME: what if enumeration has i128 discriminant?
-                            discr.val as u64,
+                            discr.val as i64,
+                            is_unsigned,
                         ))
                     }
                 })
@@ -1794,13 +1801,15 @@ fn prepare_enum_metadata(
                 .as_generator()
                 .variant_range(enum_def_id, cx.tcx)
                 .map(|variant_index| {
-                    let name = SmallCStr::new(&substs.as_generator().variant_name(variant_index));
+                    let name = substs.as_generator().variant_name(variant_index);
                     unsafe {
                         Some(llvm::LLVMRustDIBuilderCreateEnumerator(
                             DIB(cx),
-                            name.as_ptr(),
-                            // FIXME: what if enumeration has i128 discriminant?
-                            variant_index.as_usize() as u64,
+                            name.as_ptr().cast(),
+                            name.len(),
+                            // Generators use u32 as discriminant type.
+                            variant_index.as_u32().into(),
+                            true, // IsUnsigned
                         ))
                     }
                 })

src/librustc_codegen_llvm/llvm/ffi.rs

@@ -1776,7 +1776,9 @@ extern "C" {
     pub fn LLVMRustDIBuilderCreateEnumerator(
         Builder: &DIBuilder<'a>,
         Name: *const c_char,
-        Val: u64,
+        NameLen: size_t,
+        Value: i64,
+        IsUnsigned: bool,
     ) -> &'a DIEnumerator;
 
     pub fn LLVMRustDIBuilderCreateEnumerationType(

src/rustllvm/RustWrapper.cpp

@@ -891,10 +891,10 @@ extern "C" LLVMValueRef LLVMRustDIBuilderInsertDeclareAtEnd(
       unwrap(InsertAtEnd)));
 }
 
-extern "C" LLVMMetadataRef
-LLVMRustDIBuilderCreateEnumerator(LLVMRustDIBuilderRef Builder,
-                                  const char *Name, uint64_t Val) {
-  return wrap(Builder->createEnumerator(Name, Val));
+extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateEnumerator(
+    LLVMRustDIBuilderRef Builder, const char *Name, size_t NameLen,
+    int64_t Value, bool IsUnsigned) {
+  return wrap(Builder->createEnumerator({Name, NameLen}, Value, IsUnsigned));
 }
 
 extern "C" LLVMMetadataRef LLVMRustDIBuilderCreateEnumerationType(

src/test/codegen/enum-discriminant-value.rs

@@ -0,0 +1,27 @@
+// Verify that DIEnumerator uses isUnsigned flag when appropriate.
+//
+// compile-flags: -g -C no-prepopulate-passes
+
+#[repr(i64)]
+pub enum I64 {
+    I64Min = std::i64::MIN,
+    I64Max = std::i64::MAX,
+}
+
+#[repr(u64)]
+pub enum U64 {
+    U64Min = std::u64::MIN,
+    U64Max = std::u64::MAX,
+}
+
+fn main() {
+    let _a = I64::I64Min;
+    let _b = I64::I64Max;
+    let _c = U64::U64Min;
+    let _d = U64::U64Max;
+}
+
+// CHECK: !DIEnumerator(name: "I64Min", value: -9223372036854775808)
+// CHECK: !DIEnumerator(name: "I64Max", value: 9223372036854775807)
+// CHECK: !DIEnumerator(name: "U64Min", value: 0, isUnsigned: true)
+// CHECK: !DIEnumerator(name: "U64Max", value: 18446744073709551615, isUnsigned: true)