Merge pull request #1994 from rtfeldman/wasm-long-string-literal

Wasm long string literal

compiler/gen_wasm/src/backend.rs

@@ -626,8 +626,8 @@ impl<'a> WasmBackend<'a> {
                             self.lookup_string_constant(string, sym, layout);
 
                         self.code_builder.get_local(local_id);
-                        self.code_builder.insert_memory_relocation(linker_sym_index);
-                        self.code_builder.i32_const(elements_addr as i32);
+                        self.code_builder
+                            .i32_const_mem_addr(elements_addr, linker_sym_index);
                         self.code_builder.i32_store(Align::Bytes4, offset);
 
                         self.code_builder.get_local(local_id);

compiler/gen_wasm/src/wasm_module/code_builder.rs

@@ -9,7 +9,7 @@ use super::opcodes::{OpCode, OpCode::*};
 use super::serialize::{SerialBuffer, Serialize};
 use crate::{round_up_to_alignment, FRAME_ALIGNMENT_BYTES, STACK_POINTER_GLOBAL_ID};
 
-const ENABLE_DEBUG_LOG: bool = true;
+const ENABLE_DEBUG_LOG: bool = false;
 macro_rules! log_instruction {
     ($($x: expr),+) => {
         if ENABLE_DEBUG_LOG { println!($($x,)*); }
@@ -572,11 +572,14 @@ impl<'a> CodeBuilder<'a> {
         );
     }
 
-    /// Insert a linker relocation for a memory address
-    pub fn insert_memory_relocation(&mut self, symbol_index: u32) {
+    /// Insert a const reference to a memory address
+    pub fn i32_const_mem_addr(&mut self, addr: u32, symbol_index: u32) {
+        self.inst_base(I32CONST, 0, true);
+        let offset = self.code.len() as u32;
+        self.code.encode_padded_u32(addr);
         self.relocations.push(RelocationEntry::Offset {
             type_id: OffsetRelocType::MemoryAddrLeb,
-            offset: self.code.len() as u32,
+            offset,
             symbol_index,
             addend: 0,
         });

compiler/gen_wasm/src/wasm_module/sections.rs

@@ -29,6 +29,8 @@ pub enum SectionId {
     Element = 9,
     Code = 10,
     Data = 11,
+    /// DataCount section is unused. Only needed for single-pass validation of
+    /// memory.init and data.drop, which we don't use
     DataCount = 12,
 }
 
@@ -525,42 +527,6 @@ impl Serialize for DataSection<'_> {
     }
 }
 
-/*******************************************************************
- *
- * Data Count section
- *
- * Pre-declares the number of segments in the Data section.
- * This helps the runtime to validate the module in a single pass.
- * The order of sections is DataCount -> Code -> Data
- *
- *******************************************************************/
-
-#[derive(Debug)]
-struct DataCountSection {
-    count: u32,
-}
-
-impl DataCountSection {
-    fn new(data_section: &DataSection<'_>) -> Self {
-        let count = data_section
-            .segments
-            .iter()
-            .filter(|seg| !seg.init.is_empty())
-            .count() as u32;
-        DataCountSection { count }
-    }
-}
-
-impl Serialize for DataCountSection {
-    fn serialize<T: SerialBuffer>(&self, buffer: &mut T) {
-        if self.count > 0 {
-            let header_indices = write_section_header(buffer, SectionId::DataCount);
-            buffer.encode_u32(self.count);
-            update_section_size(buffer, header_indices);
-        }
-    }
-}
-
 /*******************************************************************
  *
  * Module
@@ -658,11 +624,6 @@ impl<'a> WasmModule<'a> {
         counter.serialize_and_count(buffer, &self.start);
         counter.serialize_and_count(buffer, &self.element);
 
-        // Data Count section forward-declares the size of the Data section
-        // so that Code section can be validated in one pass
-        let data_count_section = DataCountSection::new(&self.data);
-        counter.serialize_and_count(buffer, &data_count_section);
-
         // Code section is the only one with relocations so we can stop counting
         let code_section_index = counter.section_index;
         let code_section_body_index = self

compiler/test_gen/src/wasm_str.rs

@@ -1,6 +1,6 @@
 // Wasm pointers are only 32bit. This effects RocStr.
 // These are versions of the str tests assuming 32bit pointers.
-#![cfg(not(feature = "gen-dev"))]
+#![cfg(feature = "gen-wasm")]
 
 // TODO: We need to make these tests work with the llvm wasm backend.
 
@@ -12,7 +12,7 @@ use crate::helpers::wasm::assert_evals_to;
 
 #[allow(unused_imports)]
 use indoc::indoc;
-// use roc_std::RocStr;
+use roc_std::RocStr;
 
 // #[test]
 // fn str_split_bigger_delimiter_small_str() {
@@ -287,15 +287,14 @@ fn small_str_zeroed_literal() {
     );
 }
 
-// TODO: fix linking errors for undefined symbols roc_alloc, roc_dealloc
-// #[test]
-// fn long_str_literal() {
-//     assert_evals_to!(
-//         "\"0123456789 123456789 123456789\"",
-//         RocStr::from_slice(b"0123456789 123456789 123456789"),
-//         RocStr
-//     );
-// }
+#[test]
+fn long_str_literal() {
+    assert_evals_to!(
+        "\"0123456789 123456789 123456789\"",
+        RocStr::from_slice(b"0123456789 123456789 123456789"),
+        RocStr
+    );
+}
 
 // #[test]
 // fn small_str_concat_empty_first_arg() {