From 8f33b67404160ce8cf35a22c0d0993112b5abe9c Mon Sep 17 00:00:00 2001
From: Henry Gressmann <mail@henrygressmann.de>
Date: Mon, 18 Dec 2023 15:01:30 +0100
Subject: feat: global parsing, improve testsuite

Signed-off-by: Henry Gressmann <mail@henrygressmann.de>
---
 crates/parser/src/conversion.rs | 49 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 48 insertions(+), 1 deletion(-)

(limited to 'crates/parser/src/conversion.rs')

diff --git a/crates/parser/src/conversion.rs b/crates/parser/src/conversion.rs
index 269bb66..9f4930a 100644
--- a/crates/parser/src/conversion.rs
+++ b/crates/parser/src/conversion.rs
@@ -1,10 +1,43 @@
 use alloc::{boxed::Box, format, string::ToString, vec::Vec};
 use log::info;
-use tinywasm_types::{BlockArgs, Export, ExternalKind, FuncType, Instruction, MemArg, ValType};
+use tinywasm_types::{
+    BlockArgs, ConstInstruction, Export, ExternalKind, FuncType, Global, Instruction, MemArg, ValType,
+};
 use wasmparser::{FuncValidator, ValidatorResources};
 
 use crate::{module::CodeSection, Result};
 
+pub(crate) fn convert_module_globals<'a, T: IntoIterator<Item = wasmparser::Result<wasmparser::Global<'a>>>>(
+    globals: T,
+) -> Result<Vec<Global>> {
+    let globals = globals
+        .into_iter()
+        .map(|global| {
+            let global = global?;
+            let ty = convert_valtype(&global.ty.content_type);
+
+            let ops = global
+                .init_expr
+                .get_operators_reader()
+                .into_iter()
+                .collect::<wasmparser::Result<Vec<_>>>()?;
+
+            // In practice, the len can never be something other than 2,
+            // but we'll keep this here since it's part of the spec
+            // Invalid modules will be rejected by the validator anyway (there are also tests for this in the testsuite)
+            assert!(ops.len() >= 2);
+            assert!(matches!(ops[ops.len() - 1], wasmparser::Operator::End));
+
+            Ok(Global {
+                ty,
+                init: process_const_operator(ops[ops.len() - 2].clone())?,
+                mutable: global.ty.mutable,
+            })
+        })
+        .collect::<Result<Vec<_>>>()?;
+    Ok(globals)
+}
+
 pub(crate) fn convert_module_export(export: wasmparser::Export) -> Result<Export> {
     let kind = match export.kind {
         wasmparser::ExternalKind::Func => ExternalKind::Func,
@@ -105,6 +138,20 @@ pub(crate) fn convert_memarg(memarg: wasmparser::MemArg) -> MemArg {
     }
 }
 
+pub fn process_const_operator(op: wasmparser::Operator) -> Result<ConstInstruction> {
+    match op {
+        wasmparser::Operator::I32Const { value } => Ok(ConstInstruction::I32Const(value)),
+        wasmparser::Operator::I64Const { value } => Ok(ConstInstruction::I64Const(value)),
+        wasmparser::Operator::F32Const { value } => Ok(ConstInstruction::F32Const(f32::from_bits(value.bits()))), // TODO: check if this is correct
+        wasmparser::Operator::F64Const { value } => Ok(ConstInstruction::F64Const(f64::from_bits(value.bits()))), // TODO: check if this is correct
+        wasmparser::Operator::GlobalGet { global_index } => Ok(ConstInstruction::GlobalGet(global_index)),
+        op => Err(crate::ParseError::UnsupportedOperator(format!(
+            "Unsupported instruction: {:?}",
+            op
+        ))),
+    }
+}
+
 pub fn process_operators<'a>(
     mut offset: usize,
     ops: impl Iterator<Item = Result<wasmparser::Operator<'a>, wasmparser::BinaryReaderError>>,
-- 
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