Prefer LLVMGetVersion for runtime info

compiler/rustc_codegen_llvm/src/llvm/ffi.rs

@@ -2172,9 +2172,13 @@ unsafe extern "C" {
 
     pub(crate) safe fn LLVMRustCoverageMappingVersion() -> u32;
     pub(crate) fn LLVMRustDebugMetadataVersion() -> u32;
+
+    /// Returns the LLVM major version that the compiler was built with.
+    ///
+    /// Note that this is hard-coded as `LLVM_VERSION_MAJOR` when `RustWrapper.cpp` is built. This
+    /// could be different than what the runtime LLVM library reports in `LLVMGetVersion`, so we
+    /// assert their equality in `configure_llvm`.
     pub(crate) fn LLVMRustVersionMajor() -> u32;
-    pub(crate) fn LLVMRustVersionMinor() -> u32;
-    pub(crate) fn LLVMRustVersionPatch() -> u32;
 
     /// Add LLVM module flags.
     ///

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -50,10 +50,7 @@ unsafe fn configure_llvm(sess: &Session) {
 
     // Check to ensure we're running against the correct LLVM version.
     unsafe {
-        let mut llvm_major = 0;
-        let mut llvm_minor = 0;
-        let mut llvm_patch = 0;
-        llvm::LLVMGetVersion(&mut llvm_major, &mut llvm_minor, &mut llvm_patch);
+        let (llvm_major, llvm_minor, llvm_patch) = get_version();
         let expected_version = llvm::LLVMRustVersionMajor();
         if llvm_major != expected_version {
             sess.dcx().emit_fatal(diagnostics::LlvmVersionMismatch {
@@ -465,7 +462,11 @@ pub(crate) fn print_version() {
 pub(crate) fn get_version() -> (u32, u32, u32) {
     // Can be called without initializing LLVM
     unsafe {
-        (llvm::LLVMRustVersionMajor(), llvm::LLVMRustVersionMinor(), llvm::LLVMRustVersionPatch())
+        let mut llvm_major = 0;
+        let mut llvm_minor = 0;
+        let mut llvm_patch = 0;
+        llvm::LLVMGetVersion(&mut llvm_major, &mut llvm_minor, &mut llvm_patch);
+        (llvm_major, llvm_minor, llvm_patch)
     }
 }
 

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -885,10 +885,6 @@ extern "C" uint32_t LLVMRustDebugMetadataVersion() {
   return DEBUG_METADATA_VERSION;
 }
 
-extern "C" uint32_t LLVMRustVersionPatch() { return LLVM_VERSION_PATCH; }
-
-extern "C" uint32_t LLVMRustVersionMinor() { return LLVM_VERSION_MINOR; }
-
 extern "C" uint32_t LLVMRustVersionMajor() { return LLVM_VERSION_MAJOR; }
 
 // FFI equivalent of LLVM's `llvm::Module::ModFlagBehavior`.