Rollup merge of #127654 - nikic:llvm-ndebug-fix, r=cuviper

Fix incorrect NDEBUG handling in LLVM bindings

We currently compile our LLVM bindings using `-DNDEBUG` if debuginfo for LLVM is disabled. However, `NDEBUG` doesn't have any relation to debuginfo, it controls whether assertions are enabled.

Split the LLVM_NDEBUG environment variable into two, so that assertions and debuginfo are controlled independently.

After this change, `LLVMRustDIBuilderInsertDeclareAtEnd` triggers an assertion failure on LLVM 19 due to an incorrect cast. Fix it by removing the unused return value entirely.

r? `@cuviper`

1 files changed, 2 insertions, 2 deletions

diff --git a/src/bootstrap/src/core/build_steps/compile.rs b/src/bootstrap/src/core/build_steps/compile.rs
index 11a7a404535..714a1004281 100644
--- a/src/bootstrap/src/core/build_steps/compile.rs
+++ b/src/bootstrap/src/core/build_steps/compile.rs
@@ -1213,8 +1213,8 @@ fn rustc_llvm_env(builder: &Builder<'_>, cargo: &mut Cargo, target: TargetSelect
     if builder.config.llvm_use_libcxx {
         cargo.env("LLVM_USE_LIBCXX", "1");
     }
-    if builder.config.llvm_optimize && !builder.config.llvm_release_debuginfo {
-        cargo.env("LLVM_NDEBUG", "1");
+    if builder.config.llvm_assertions {
+        cargo.env("LLVM_ASSERTIONS", "1");
     }
 }