Compiler panics when using unary - on enum

[prescientmoon]

Context

Useful information to add to a bug report:

	Odin:    dev-2025-01
	OS:      NixOS 24.11 (Vicuna), Linux 6.12.1
	CPU:     Intel(R) Core(TM) i7-8565U CPU @ 1.80GHz
	RAM:     7823 MiB
	Backend: LLVM 13.0.1

Expected Behavior

The following code should compile

package repro

Chunk_Transform :: struct { side: Side }
Side :: enum {}

main :: proc() {
	first: Side
	side := (Chunk_Transform{-first}).side
}

Current Behavior

Running odin run repro yields the following error

src/llvm_backend_expr.cpp(274): Panic: Unhandled type Side
fish: Job 2, 'odin build repro' terminated by signal SIGILL (Illegal instruction)

[prescientmoon]

Here's a smaller (and slightly better motivated, perhaps) example that fails with a similar error:

Side :: enum {
	Top    = 1,
	Bottom = -1,
}

main :: proc() {
	side: Side
	side = -side
}

[prescientmoon]

Hmm, I'm not familiar with the compiler internals, but it looks like enum negation is allowed here, yet this is not handled here?

[prescientmoon]

I'm not familiar with the codebase, but if anyone is in my situation and wants a temporary (probably incorrect) patch to get around the issue (for now), here it is

diff --git a/src/llvm_backend_expr.cpp b/src/llvm_backend_expr.cpp
index df9dca801..0d9c77a26 100644
--- a/src/llvm_backend_expr.cpp
+++ b/src/llvm_backend_expr.cpp
@@ -231,11 +231,12 @@ gb_internal lbValue lb_emit_unary_arith(lbProcedure *p, TokenKind op, lbValue x,
 		res.type = x.type;
 		return res;
 	case Token_Sub: // Number negation
-		if (is_type_integer(x.type)) {
+		auto ty = core_type(x.type);
+		if (is_type_integer(ty)) {
 			res.value = LLVMBuildNeg(p->builder, x.value, "");
-		} else if (is_type_float(x.type)) {
+		} else if (is_type_float(ty)) {
 			res.value = LLVMBuildFNeg(p->builder, x.value, "");
-		} else if (is_type_complex(x.type)) {
+		} else if (is_type_complex(ty)) {
 			LLVMValueRef v0 = LLVMBuildFNeg(p->builder, LLVMBuildExtractValue(p->builder, x.value, 0, ""), "");
 			LLVMValueRef v1 = LLVMBuildFNeg(p->builder, LLVMBuildExtractValue(p->builder, x.value, 1, ""), "");
 
@@ -245,7 +246,7 @@ gb_internal lbValue lb_emit_unary_arith(lbProcedure *p, TokenKind op, lbValue x,
 			LLVMBuildStore(p->builder, v1, LLVMBuildStructGEP2(p->builder, type, addr.addr.value, 1, ""));
 			return lb_addr_load(p, addr);
 
-		} else if (is_type_quaternion(x.type)) {
+		} else if (is_type_quaternion(ty)) {
 			LLVMValueRef v0 = LLVMBuildFNeg(p->builder, LLVMBuildExtractValue(p->builder, x.value, 0, ""), "");
 			LLVMValueRef v1 = LLVMBuildFNeg(p->builder, LLVMBuildExtractValue(p->builder, x.value, 1, ""), "");
 			LLVMValueRef v2 = LLVMBuildFNeg(p->builder, LLVMBuildExtractValue(p->builder, x.value, 2, ""), "");
@@ -265,7 +266,7 @@ gb_internal lbValue lb_emit_unary_arith(lbProcedure *p, TokenKind op, lbValue x,
 			} else {
 				res.value = LLVMBuildNeg(p->builder, x.value, "");
 			}
-		} else if (is_type_matrix(x.type)) {
+		} else if (is_type_matrix(ty)) {
 			lbValue zero = {};
 			zero.value = LLVMConstNull(lb_type(p->module, type));
 			zero.type = type;