Revert [wgsl-out] Write const named expr as const declarations

Signed-off-by: sagudev <[email protected]>

Author: sagudev

naga/src/back/glsl/mod.rs

@@ -64,7 +64,7 @@ use thiserror::Error;
 use crate::{
     back::{self, Baked},
     common,
-    proc::{self, ExpressionKindTracker, NameKey},
+    proc::{self, NameKey},
     valid, Handle, ShaderStage, TypeInner,
 };
 use features::FeaturesManager;
@@ -1678,7 +1678,6 @@ impl<'a, W: Write> Writer<'a, W> {
             info,
             expressions: &func.expressions,
             named_expressions: &func.named_expressions,
-            expr_kind_tracker: ExpressionKindTracker::from_arena(&func.expressions),
         };
 
         self.named_expressions.clear();

naga/src/back/hlsl/writer.rs

@@ -17,7 +17,7 @@ use super::{
 use crate::{
     back::{self, Baked},
     common,
-    proc::{self, index, ExpressionKindTracker, NameKey},
+    proc::{self, index, NameKey},
     valid, Handle, Module, RayQueryFunction, Scalar, ScalarKind, ShaderStage, TypeInner,
 };
 
@@ -426,7 +426,6 @@ impl<'a, W: fmt::Write> super::Writer<'a, W> {
                 info,
                 expressions: &function.expressions,
                 named_expressions: &function.named_expressions,
-                expr_kind_tracker: ExpressionKindTracker::from_arena(&function.expressions),
             };
             let name = self.names[&NameKey::Function(handle)].clone();
 
@@ -467,7 +466,6 @@ impl<'a, W: fmt::Write> super::Writer<'a, W> {
                 info,
                 expressions: &ep.function.expressions,
                 named_expressions: &ep.function.named_expressions,
-                expr_kind_tracker: ExpressionKindTracker::from_arena(&ep.function.expressions),
             };
 
             self.write_wrapped_functions(module, &ctx)?;

naga/src/back/mod.rs

@@ -11,8 +11,6 @@ Backend functions that export shader [`Module`](super::Module)s into binary and
 
 use alloc::string::String;
 
-use crate::proc::ExpressionKindTracker;
-
 #[cfg(dot_out)]
 pub mod dot;
 #[cfg(glsl_out)]
@@ -128,8 +126,6 @@ pub struct FunctionCtx<'a> {
     pub expressions: &'a crate::Arena<crate::Expression>,
     /// Map of expressions that have associated variable names
     pub named_expressions: &'a crate::NamedExpressions,
-    /// For constness checks
-    pub expr_kind_tracker: ExpressionKindTracker,
 }
 
 impl FunctionCtx<'_> {

naga/src/back/msl/writer.rs

@@ -17,7 +17,7 @@ use crate::{
     arena::{Handle, HandleSet},
     back::{self, Baked},
     common,
-    proc::{self, index, ExpressionKindTracker, NameKey, TypeResolution},
+    proc::{self, index, NameKey, TypeResolution},
     valid, FastHashMap, FastHashSet,
 };
 
@@ -5572,7 +5572,6 @@ template <typename A>
                 info: &mod_info[fun_handle],
                 expressions: &fun.expressions,
                 named_expressions: &fun.named_expressions,
-                expr_kind_tracker: ExpressionKindTracker::from_arena(&fun.expressions),
             };
 
             writeln!(self.out)?;
@@ -5729,7 +5728,6 @@ template <typename A>
                 info: fun_info,
                 expressions: &fun.expressions,
                 named_expressions: &fun.named_expressions,
-                expr_kind_tracker: ExpressionKindTracker::from_arena(&fun.expressions),
             };
 
             self.write_wrapped_functions(module, &ctx)?;

naga/src/back/wgsl/writer.rs

@@ -16,7 +16,7 @@ use crate::{
         self,
         wgsl::{address_space_str, ToWgsl, TryToWgsl},
     },
-    proc::{self, ExpressionKindTracker, NameKey},
+    proc::{self, NameKey},
     valid, Handle, Module, ShaderStage, TypeInner,
 };
 
@@ -178,7 +178,6 @@ impl<W: Write> Writer<W> {
                 info: fun_info,
                 expressions: &function.expressions,
                 named_expressions: &function.named_expressions,
-                expr_kind_tracker: ExpressionKindTracker::from_arena(&function.expressions),
             };
 
             // Write the function
@@ -207,7 +206,6 @@ impl<W: Write> Writer<W> {
                 info: info.get_entry_point(index),
                 expressions: &ep.function.expressions,
                 named_expressions: &ep.function.named_expressions,
-                expr_kind_tracker: ExpressionKindTracker::from_arena(&ep.function.expressions),
             };
             self.write_function(module, &ep.function, &func_ctx)?;
 
@@ -1029,14 +1027,8 @@ impl<W: Write> Writer<W> {
         func_ctx: &back::FunctionCtx,
         name: &str,
     ) -> BackendResult {
-        // Some functions are marked as const, but are not yet implemented as constant expression
-        let quantifier = if func_ctx.expr_kind_tracker.is_impl_const(handle) {
-            "const"
-        } else {
-            "let"
-        };
         // Write variable name
-        write!(self.out, "{quantifier} {name}")?;
+        write!(self.out, "let {name}")?;
         if self.flags.contains(WriterFlags::EXPLICIT_TYPES) {
             write!(self.out, ": ")?;
             let ty = &func_ctx.info[handle].ty;