1 files changed, 102 insertions, 0 deletions
diff --git a/experimental/mrustc/mrustc-0007-HIR-Typecheck-Properly-pass-type-params-to-const-eva.patch b/experimental/mrustc/mrustc-0007-HIR-Typecheck-Properly-pass-type-params-to-const-eva.patch
new file mode 100644
index 000000000..d190dbb40
--- /dev/null
+++ b/experimental/mrustc/mrustc-0007-HIR-Typecheck-Properly-pass-type-params-to-const-eva.patch
@@ -0,0 +1,102 @@
+From 5e01a76097265f4bb27b18885b9af3f2778180f9 Mon Sep 17 00:00:00 2001
+From: John Hodge <tpg@mutabah.net>
+Date: Tue, 17 Dec 2024 12:13:04 +0800
+Subject: [PATCH] HIR Typecheck - Properly pass type params to const evaluation
+ (re #322)
+
+
+diff --git a/samples/test/mrustc-322.rs b/samples/test/mrustc-322.rs
+new file mode 100644
+index 00000000..654f3ef7
+--- /dev/null
++++ b/samples/test/mrustc-322.rs
+@@ -0,0 +1,14 @@
++// ignore-test - Rustc doesn't allow this, plus it doesn't specify the type for the `Vec<_>`
++#![crate_type = "lib"]
++struct Assert<const COND: bool>;
++trait IsTrue {}
++impl IsTrue for Assert<true> {}
++trait IsNotZst {}
++impl<T> IsNotZst for T
++where
++    Assert<{ std::mem::size_of::<T>() > 0 }>: IsTrue,
++{}
++fn assert_not_zero_sized<T: IsNotZst>(_: T) {}
++fn main() {
++    assert_not_zero_sized(vec![]);
++}
+diff --git a/src/hir_conv/constant_evaluation.cpp b/src/hir_conv/constant_evaluation.cpp
+index 77d0e25a..9ae98604 100644
+--- a/src/hir_conv/constant_evaluation.cpp
++++ b/src/hir_conv/constant_evaluation.cpp
+@@ -3729,6 +3729,22 @@ void ConvertHIR_ConstantEvaluate_ArraySize(const Span& sp, const ::HIR::Crate& c
+     }
+ }
+ 
++namespace {
++    bool params_contain_ivars(const ::HIR::PathParams& params) {
++        for(const auto& t : params.m_types) {
++            if( visit_ty_with(t, [](const HIR::TypeRef& t){ return t.data().is_Infer(); })) {
++                return true;
++            }
++        }
++        for(const auto& v : params.m_values) {
++            if( v.is_Infer() ) {
++                return true;
++            }
++        }
++        return false;
++    }
++}
++
+ void ConvertHIR_ConstantEvaluate_MethodParams(
+     const Span& sp,
+     const ::HIR::Crate& crate, const HIR::SimplePath& mod_path, const ::HIR::GenericParams* impl_generics, const ::HIR::GenericParams* item_generics,
+@@ -3740,7 +3756,8 @@ void ConvertHIR_ConstantEvaluate_MethodParams(
+     {
+         if(v.is_Unevaluated())
+         {
+-            const auto& e = *v.as_Unevaluated()->expr;
++            const auto& ue = *v.as_Unevaluated();
++            const auto& e = *ue.expr;
+             auto name = FMT("param_" << &v << "#");
+             TRACE_FUNCTION_FR(name, name);
+             auto nvs = NewvalState { crate.get_mod_by_path(Span(), mod_path), mod_path, name };
+@@ -3751,12 +3768,21 @@ void ConvertHIR_ConstantEvaluate_MethodParams(
+             // - Which, might not be known at this point - might be a UfcsInherent
+             try
+             {
++                // TODO: if there's an ivar in the param list, then throw defer
++                // - Caller should ensure that known ivars are expanded.
++                if( params_contain_ivars(ue.params_impl) || params_contain_ivars(ue.params_item) ) {
++                    throw Defer();
++                }
++
+                 auto idx = static_cast<size_t>(&v - &params.m_values.front());
+                 ASSERT_BUG(sp, idx < params_def.m_values.size(), "");
+                 const auto& ty = params_def.m_values[idx].m_type;
+                 ASSERT_BUG(sp, !monomorphise_type_needed(ty), "" << ty);
++                MonomorphState  ms;
++                ms.pp_impl = &ue.params_impl;
++                ms.pp_method = &ue.params_item;
+ 
+-                auto val = eval.evaluate_constant( ::HIR::ItemPath(mod_path, name.c_str()), e, ty.clone() );
++                auto val = eval.evaluate_constant( ::HIR::ItemPath(mod_path, name.c_str()), e, ty.clone(), std::move(ms) );
+                 v = ::HIR::ConstGeneric::make_Evaluated(std::move(val));
+             }
+             catch(const Defer& )
+diff --git a/src/hir_typeck/expr_cs.cpp b/src/hir_typeck/expr_cs.cpp
+index 63754207..02b333bd 100644
+--- a/src/hir_typeck/expr_cs.cpp
++++ b/src/hir_typeck/expr_cs.cpp
+@@ -2385,6 +2385,7 @@ void Context::equate_values(const Span& sp, const ::HIR::ConstGeneric& rl, const
+                 this->m_ivars.set_ivar_val_to(r.as_Infer().index, l.clone());
+             }
+             else {
++                // TODO: What about unevaluated values due to type inference?
+                 ERROR(sp, E0000, "Value mismatch between " << l << " and " << r);
+             }
+         }
+-- 
+2.40.0
+