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Merged
hchataing merged 3 commits into from
Jun 18, 2026
Merged

cxx backend #177

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8137f9f
cxx: Add snapshot test for big endian backend
hchataing Jun 17, 2026
926bfc0
Remove test exclusions for PartialChild, PartialParent
hchataing Jun 17, 2026
b0a59ca
cxx: Enable support for _elementsize_
hchataing Jun 17, 2026
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6 changes: 0 additions & 6 deletions pdl-compiler/scripts/generate_cxx_backend_tests.py
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Original file line number Diff line number Diff line change
Expand Up @@ -352,12 +352,6 @@ def run(input: argparse.FileType, output: argparse.FileType, test_vectors: argpa
'Packet_Checksum_Field_FromEnd',
'Struct_Checksum_Field_FromStart',
'Struct_Checksum_Field_FromEnd',
'PartialParent5',
'PartialParent12',
'Packet_Array_Field_VariableElementSize_ConstantSize',
'Packet_Array_Field_VariableElementSize_VariableSize',
'Packet_Array_Field_VariableElementSize_VariableCount',
'Packet_Array_Field_VariableElementSize_UnknownSize',
]

output.write(
Expand Down
103 changes: 89 additions & 14 deletions pdl-compiler/src/backends/cxx.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -890,15 +890,21 @@ impl<'a> FieldParser<'a> {
let out = self.parse_array_element(field, "element_span".to_string());
self.append(format!(" output->{id}_[n] = {out};"));
self.append("}".to_string());
self.append(format!("span.skip(output->{id}_element_size_ * output->{id}_count_);"));
self.append(format!(
"span.skip(output->{id}_element_size_ * output->{id}_count_);"
));
}

(ElementSize::Dynamic, ArraySize::DynamicSize) => {
self.check_size(&format!("output->{id}_size_"));
self.append(format!("if ((output->{id}_size_ % output->{id}_element_size_) != 0) {{"));
self.append(format!(
"if ((output->{id}_size_ % output->{id}_element_size_) != 0) {{"
));
self.append(" return false;".to_string());
self.append("}".to_string());
self.append(format!("auto {id}_count_ = output->{id}_size_ / output->{id}_element_size_;"));
self.append(format!(
"auto {id}_count_ = output->{id}_size_ / output->{id}_element_size_;"
));
self.append(format!("for (size_t n = 0; n < {id}_count_; n++) {{"));
self.append(format!(" auto element_span = span.subrange(n * output->{id}_element_size_, output->{id}_element_size_);"));
let out = self.parse_array_element(field, "element_span".to_string());
Expand All @@ -911,7 +917,9 @@ impl<'a> FieldParser<'a> {
self.append(format!("if ((span.size() % output->{id}_element_size_) != 0) {{"));
self.append(" return false;".to_string());
self.append("}".to_string());
self.append(format!("auto {id}_count_ = span.size() / output->{id}_element_size_;"));
self.append(format!(
"auto {id}_count_ = span.size() / output->{id}_element_size_;"
));
self.append(format!("for (size_t n = 0; n < {id}_count_; n++) {{"));
self.append(format!(" auto element_span = span.subrange(n * output->{id}_element_size_, output->{id}_element_size_);"));
let out = self.parse_array_element(field, "element_span".to_string());
Expand Down Expand Up @@ -1491,12 +1499,23 @@ impl<'a> FieldSerializer<'a> {
self.values.push((format!("{}.size()", get_field_expr(f)), shift));
}
ast::FieldDesc::ElementSize { field_id, .. } => {
let f = self
.scope
.iter_fields(decl)
.find(|f| f.id() == Some(field_id))
.expect("Field not found");
let array_expr = get_field_expr(f);
let field_name = if field_id == "_payload_" || field_id == "_body_" {
"payload"
} else {
field_id
};
self.append(&format!("size_t {field_name}_element_size = 0; // TODO"));
let element_size = analyzer::element_size(self.scope, self.schema, decl, f);
let size_expr = match element_size {
analyzer::ElementSize::Static(size) => format!("{}", size),
_ => format!("{array_expr}.empty() ? 0 : {array_expr}[0].GetSize()"),
};
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self.append(&format!("size_t {field_name}_element_size = {size_expr};"));
self.values.push((format!("{}_element_size", field_name), shift));
}
ast::FieldDesc::Flag { .. } => {
Expand Down Expand Up @@ -1727,12 +1746,25 @@ fn generate_packet_view(
format!("std::vector<{}>", element_type)
};

let is_dynamic_element_size = matches!(
analyzer::element_size(scope, schema, decl, field),
analyzer::ElementSize::Dynamic
);
let mut accessor_code = Vec::new();
accessor_code.push(format!("pdl::packet::slice span = {}_;", id));
if let Some(s) = size {
accessor_code.push(format!("{} elements;", array_type));
accessor_code.push(format!("for (int n = 0; n < {}; n++) {{", s));
if let Some(tid) = type_id {
if is_dynamic_element_size {
let tid = type_id.as_deref().unwrap();
accessor_code.push(format!(
" auto element_span = span.subrange(0, {}_element_size_);",
id
));
accessor_code
.push(format!(" {}::Parse(element_span, &elements[n]);", tid));
accessor_code.push(format!(" span.skip({}_element_size_);", id));
} else if let Some(tid) = type_id {
let td = scope.typedef.get(tid).unwrap();
match &td.desc {
ast::DeclDesc::Enum { width, .. } => {
Expand Down Expand Up @@ -1773,7 +1805,23 @@ fn generate_packet_view(
}
}

if let Some(tid) = type_id {
if is_dynamic_element_size {
let tid = type_id.as_deref().unwrap();
accessor_code.push(format!("while ({}) {{", count_limit));
accessor_code.push(format!(
" auto element_span = span.subrange(0, {}_element_size_);",
id
));
accessor_code.push(format!(" {} element;", tid));
accessor_code.push(format!(
" if (!{}::Parse(element_span, &element)) break;",
tid
));
accessor_code
.push(" elements.emplace_back(std::move(element));".to_string());
accessor_code.push(format!(" span.skip({}_element_size_);", id));
accessor_code.push("}".to_string());
} else if let Some(tid) = type_id {
let td = scope.typedef.get(tid).unwrap();
match &td.desc {
ast::DeclDesc::Enum { width, .. } => {
Expand Down Expand Up @@ -2508,7 +2556,7 @@ mod test {
use crate::{analyzer, ast, parser};

#[test]
fn test_canonical() {
fn test_canonical_le() {
let mut db = ast::SourceDatabase::new();
let input_file = "tests/canonical/le_test_file.pdl";
let file = parser::parse_file(&mut db, input_file).unwrap();
Expand All @@ -2532,14 +2580,41 @@ mod test {
"Struct_Custom_Field_VariableSize_".to_string(),
"Struct_Checksum_Field_FromStart_".to_string(),
"Struct_Checksum_Field_FromEnd_".to_string(),
"PartialParent5".to_string(),
"PartialChild5_A".to_string(),
"PartialChild5_B".to_string(),
"PartialParent12".to_string(),
"PartialChild12_A".to_string(),
"PartialChild12_B".to_string(),
],
);
assert_snapshot_eq("tests/generated/cxx/le_backend.h", &actual_code);
}

#[test]
fn test_canonical_be() {
let mut db = ast::SourceDatabase::new();
let input_file = "tests/canonical/le_test_file.pdl";
let source = std::fs::read_to_string(input_file).unwrap();
let source = source.replace("little_endian_packets", "big_endian_packets");
let file =
parser::parse_inline(&mut db, "tests/canonical/be_test_file.pdl", source).unwrap();
let file = analyzer::analyze(&file).unwrap();
let actual_code = generate(
&db,
&file,
Some("be_backend"),
&[],
&[],
&[
"Packet_Custom_Field_ConstantSize".to_string(),
"Packet_Custom_Field_VariableSize".to_string(),
"Packet_Checksum_Field_FromStart".to_string(),
"Packet_Checksum_Field_FromEnd".to_string(),
"Struct_Custom_Field_ConstantSize".to_string(),
"Struct_Custom_Field_VariableSize".to_string(),
"Struct_Checksum_Field_FromStart".to_string(),
"Struct_Checksum_Field_FromEnd".to_string(),
"Struct_Custom_Field_ConstantSize_".to_string(),
"Struct_Custom_Field_VariableSize_".to_string(),
"Struct_Checksum_Field_FromStart_".to_string(),
"Struct_Checksum_Field_FromEnd_".to_string(),
],
);
assert_snapshot_eq("tests/generated/cxx/be_backend.h", &actual_code);
}
}
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