Use LLVM-C APIs for getting/setting linkage

Author: Zalathar

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -5,6 +5,7 @@ use std::fmt::Debug;
 use std::marker::PhantomData;
 
 use libc::{c_char, c_int, c_uint, c_ulonglong, c_void, size_t};
+use rustc_macros::TryFromU32;
 use rustc_target::spec::SymbolVisibility;
 
 use super::RustString;
@@ -132,21 +133,31 @@ pub enum CallConv {
     AvrInterrupt = 85,
 }
 
-/// LLVMRustLinkage
-#[derive(Copy, Clone, PartialEq)]
+/// Must match the layout of `LLVMLinkage`.
+#[derive(Copy, Clone, PartialEq, TryFromU32)]
 #[repr(C)]
 pub enum Linkage {
     ExternalLinkage = 0,
     AvailableExternallyLinkage = 1,
     LinkOnceAnyLinkage = 2,
     LinkOnceODRLinkage = 3,
-    WeakAnyLinkage = 4,
-    WeakODRLinkage = 5,
-    AppendingLinkage = 6,
-    InternalLinkage = 7,
-    PrivateLinkage = 8,
-    ExternalWeakLinkage = 9,
-    CommonLinkage = 10,
+    #[deprecated = "marked obsolete by LLVM"]
+    LinkOnceODRAutoHideLinkage = 4,
+    WeakAnyLinkage = 5,
+    WeakODRLinkage = 6,
+    AppendingLinkage = 7,
+    InternalLinkage = 8,
+    PrivateLinkage = 9,
+    #[deprecated = "marked obsolete by LLVM"]
+    DLLImportLinkage = 10,
+    #[deprecated = "marked obsolete by LLVM"]
+    DLLExportLinkage = 11,
+    ExternalWeakLinkage = 12,
+    #[deprecated = "marked obsolete by LLVM"]
+    GhostLinkage = 13,
+    CommonLinkage = 14,
+    LinkerPrivateLinkage = 15,
+    LinkerPrivateWeakLinkage = 16,
 }
 
 // LLVMRustVisibility
@@ -969,6 +980,8 @@ unsafe extern "C" {
 
     // Operations on global variables, functions, and aliases (globals)
     pub fn LLVMIsDeclaration(Global: &Value) -> Bool;
+    pub fn LLVMGetLinkage(Global: &Value) -> RawEnum<Linkage>;
+    pub fn LLVMSetLinkage(Global: &Value, RustLinkage: Linkage);
     pub fn LLVMSetSection(Global: &Value, Section: *const c_char);
     pub fn LLVMGetAlignment(Global: &Value) -> c_uint;
     pub fn LLVMSetAlignment(Global: &Value, Bytes: c_uint);
@@ -1545,8 +1558,6 @@ unsafe extern "C" {
     ) -> bool;
 
     // Operations on global variables, functions, and aliases (globals)
-    pub fn LLVMRustGetLinkage(Global: &Value) -> Linkage;
-    pub fn LLVMRustSetLinkage(Global: &Value, RustLinkage: Linkage);
     pub fn LLVMRustGetVisibility(Global: &Value) -> Visibility;
     pub fn LLVMRustSetVisibility(Global: &Value, Viz: Visibility);
     pub fn LLVMRustSetDSOLocal(Global: &Value, is_dso_local: bool);

compiler/rustc_codegen_llvm/src/llvm/mod.rs

@@ -233,12 +233,12 @@ pub fn set_global_constant(llglobal: &Value, is_constant: bool) {
 }
 
 pub fn get_linkage(llglobal: &Value) -> Linkage {
-    unsafe { LLVMRustGetLinkage(llglobal) }
+    unsafe { LLVMGetLinkage(llglobal) }.to_rust()
 }
 
 pub fn set_linkage(llglobal: &Value, linkage: Linkage) {
     unsafe {
-        LLVMRustSetLinkage(llglobal, linkage);
+        LLVMSetLinkage(llglobal, linkage);
     }
 }
 

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -1619,86 +1619,6 @@ extern "C" void LLVMRustPositionBuilderAtStart(LLVMBuilderRef B,
   unwrap(B)->SetInsertPoint(unwrap(BB), Point);
 }
 
-enum class LLVMRustLinkage {
-  ExternalLinkage = 0,
-  AvailableExternallyLinkage = 1,
-  LinkOnceAnyLinkage = 2,
-  LinkOnceODRLinkage = 3,
-  WeakAnyLinkage = 4,
-  WeakODRLinkage = 5,
-  AppendingLinkage = 6,
-  InternalLinkage = 7,
-  PrivateLinkage = 8,
-  ExternalWeakLinkage = 9,
-  CommonLinkage = 10,
-};
-
-static LLVMRustLinkage toRust(LLVMLinkage Linkage) {
-  switch (Linkage) {
-  case LLVMExternalLinkage:
-    return LLVMRustLinkage::ExternalLinkage;
-  case LLVMAvailableExternallyLinkage:
-    return LLVMRustLinkage::AvailableExternallyLinkage;
-  case LLVMLinkOnceAnyLinkage:
-    return LLVMRustLinkage::LinkOnceAnyLinkage;
-  case LLVMLinkOnceODRLinkage:
-    return LLVMRustLinkage::LinkOnceODRLinkage;
-  case LLVMWeakAnyLinkage:
-    return LLVMRustLinkage::WeakAnyLinkage;
-  case LLVMWeakODRLinkage:
-    return LLVMRustLinkage::WeakODRLinkage;
-  case LLVMAppendingLinkage:
-    return LLVMRustLinkage::AppendingLinkage;
-  case LLVMInternalLinkage:
-    return LLVMRustLinkage::InternalLinkage;
-  case LLVMPrivateLinkage:
-    return LLVMRustLinkage::PrivateLinkage;
-  case LLVMExternalWeakLinkage:
-    return LLVMRustLinkage::ExternalWeakLinkage;
-  case LLVMCommonLinkage:
-    return LLVMRustLinkage::CommonLinkage;
-  default:
-    report_fatal_error("Invalid LLVMRustLinkage value!");
-  }
-}
-
-static LLVMLinkage fromRust(LLVMRustLinkage Linkage) {
-  switch (Linkage) {
-  case LLVMRustLinkage::ExternalLinkage:
-    return LLVMExternalLinkage;
-  case LLVMRustLinkage::AvailableExternallyLinkage:
-    return LLVMAvailableExternallyLinkage;
-  case LLVMRustLinkage::LinkOnceAnyLinkage:
-    return LLVMLinkOnceAnyLinkage;
-  case LLVMRustLinkage::LinkOnceODRLinkage:
-    return LLVMLinkOnceODRLinkage;
-  case LLVMRustLinkage::WeakAnyLinkage:
-    return LLVMWeakAnyLinkage;
-  case LLVMRustLinkage::WeakODRLinkage:
-    return LLVMWeakODRLinkage;
-  case LLVMRustLinkage::AppendingLinkage:
-    return LLVMAppendingLinkage;
-  case LLVMRustLinkage::InternalLinkage:
-    return LLVMInternalLinkage;
-  case LLVMRustLinkage::PrivateLinkage:
-    return LLVMPrivateLinkage;
-  case LLVMRustLinkage::ExternalWeakLinkage:
-    return LLVMExternalWeakLinkage;
-  case LLVMRustLinkage::CommonLinkage:
-    return LLVMCommonLinkage;
-  }
-  report_fatal_error("Invalid LLVMRustLinkage value!");
-}
-
-extern "C" LLVMRustLinkage LLVMRustGetLinkage(LLVMValueRef V) {
-  return toRust(LLVMGetLinkage(V));
-}
-
-extern "C" void LLVMRustSetLinkage(LLVMValueRef V,
-                                   LLVMRustLinkage RustLinkage) {
-  LLVMSetLinkage(V, fromRust(RustLinkage));
-}
-
 extern "C" bool LLVMRustConstIntGetZExtValue(LLVMValueRef CV, uint64_t *value) {
   auto C = unwrap<llvm::ConstantInt>(CV);
   if (C->getBitWidth() > 64)