codegen_llvm: check inline assembly constraints with LLVM

LLVM provides a way of checking whether the constraints and the actual
inline assembly make sense. This commit introduces a check before
emitting code for the inline assembly. If LLVM rejects the inline
assembly (or its constraints), then the compiler emits an error E0668
("malformed inline assembly").

Signed-off-by: Levente Kurusa <lkurusa@acm.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/src/librustc_codegen_llvm/llvm/ffi.rs b/src/librustc_codegen_llvm/llvm/ffi.rs
index a5f4137c62b..7975e7ad670 100644
--- a/src/librustc_codegen_llvm/llvm/ffi.rs
+++ b/src/librustc_codegen_llvm/llvm/ffi.rs
@@ -1208,6 +1208,9 @@ extern "C" {
                              AlignStack: Bool,
                              Dialect: AsmDialect)
                              -> &Value;
+    pub fn LLVMRustInlineAsmVerify(Ty: &Type,
+                             Constraints: *const c_char)
+                             -> Bool;
 
     pub fn LLVMRustDebugMetadataVersion() -> u32;
     pub fn LLVMRustVersionMajor() -> u32;