feat: fib() now compiles to wasm target

2 files changed, 76 insertions, 4 deletions

diff --git a/src/codegen_wasm.c b/src/codegen_wasm.c
index 1072b67..335a527 100644
--- a/src/codegen_wasm.c
+++ b/src/codegen_wasm.c
@@ -39,11 +39,19 @@ static void codegen_func_prologue(CodeGen* g, AstNode* ast) {
 static void codegen_func_epilogue(CodeGen* g, AstNode* ast) {
 }
 
+static void codegen_int_expr(CodeGen* g, AstNode* ast) {
+    fprintf(g->out, "  i32.const %d\n", ast->node_int_value);
+}
+
 static void codegen_binary_expr(CodeGen* g, AstNode* ast, GenMode gen_mode) {
     codegen_expr(g, ast->node_lhs, gen_mode);
     codegen_expr(g, ast->node_rhs, gen_mode);
     if (ast->node_op == TokenKind_plus) {
-        fprintf(g->out, "i32.add\n");
+        fprintf(g->out, "  i32.add\n");
+    } else if (ast->node_op == TokenKind_minus) {
+        fprintf(g->out, "  i32.sub\n");
+    } else if (ast->node_op == TokenKind_le) {
+        fprintf(g->out, "  i32.le_s\n");
     } else {
         unreachable();
     }
@@ -53,11 +61,24 @@ static void codegen_lvar(CodeGen* g, AstNode* ast, GenMode gen_mode) {
     fprintf(g->out, "  local.get $l_%s\n", ast->name);
 }
 
+static void codegen_func_call(CodeGen* g, AstNode* ast) {
+    AstNode* args = ast->node_args;
+    for (int i = 0; i < args->node_len; ++i) {
+        AstNode* arg = args->node_items + i;
+        codegen_expr(g, arg, GenMode_rval);
+    }
+    fprintf(g->out, "  call $%s\n", ast->name);
+}
+
 static void codegen_expr(CodeGen* g, AstNode* ast, GenMode gen_mode) {
-    if (ast->kind == AstNodeKind_binary_expr) {
+    if (ast->kind == AstNodeKind_int_expr) {
+        codegen_int_expr(g, ast);
+    } else if (ast->kind == AstNodeKind_binary_expr) {
         codegen_binary_expr(g, ast, gen_mode);
     } else if (ast->kind == AstNodeKind_lvar) {
         codegen_lvar(g, ast, gen_mode);
+    } else if (ast->kind == AstNodeKind_func_call) {
+        codegen_func_call(g, ast);
     } else {
         unreachable();
     }
@@ -67,7 +88,25 @@ static void codegen_return_stmt(CodeGen* g, AstNode* ast) {
     if (ast->node_expr) {
         codegen_expr(g, ast->node_expr, GenMode_rval);
     }
-    codegen_func_epilogue(g, ast);
+    fprintf(g->out, "  return\n");
+}
+
+static void codegen_if_stmt(CodeGen* g, AstNode* ast) {
+    codegen_expr(g, ast->node_cond, GenMode_rval);
+    fprintf(g->out, "  (if (result i32)\n");
+    fprintf(g->out, "    (then\n");
+    codegen_stmt(g, ast->node_then);
+    fprintf(g->out, "    )\n");
+    if (ast->node_else) {
+        fprintf(g->out, "    (else\n");
+        codegen_stmt(g, ast->node_else);
+        fprintf(g->out, "    )\n");
+    } else {
+        fprintf(g->out, "    (else\n");
+        fprintf(g->out, "      i32.const 0\n");
+        fprintf(g->out, "    )\n");
+    }
+    fprintf(g->out, "  )\n");
 }
 
 static void codegen_nop(CodeGen* g, AstNode* ast) {
@@ -85,6 +124,8 @@ static void codegen_stmt(CodeGen* g, AstNode* ast) {
         codegen_block_stmt(g, ast);
     } else if (ast->kind == AstNodeKind_return_stmt) {
         codegen_return_stmt(g, ast);
+    } else if (ast->kind == AstNodeKind_if_stmt) {
+        codegen_if_stmt(g, ast);
     } else if (ast->kind == AstNodeKind_nop) {
         codegen_nop(g, ast);
     } else {
@@ -95,7 +136,7 @@ static void codegen_stmt(CodeGen* g, AstNode* ast) {
 static void codegen_func(CodeGen* g, AstNode* ast) {
     g->current_func = ast;
 
-    fprintf(g->out, "(func (export \"%s\") \n", ast->name);
+    fprintf(g->out, "(func $%s (export \"%s\")", ast->name, ast->name);
 
     codegen_func_prologue(g, ast);
     codegen_stmt(g, ast->node_body);
diff --git a/tests/wasm.sh b/tests/wasm.sh
index d024989..e97c05f 100644
--- a/tests/wasm.sh
+++ b/tests/wasm.sh
@@ -23,3 +23,34 @@ cat > expected <<'EOF'
 EOF
 
 diff -u expected output
+
+
+cat > main.c <<'EOF'
+int fib(int n) {
+    if (n <= 1) {
+        return 1;
+    } else {
+        return fib(n - 1) + fib(n - 2);
+    }
+}
+EOF
+
+"$ducc" "${CFLAGS:-}" --wasm -o main.wat main.c
+
+wat2wasm main.wat -o main.wasm
+
+cat > main.mjs <<'EOF'
+import { readFile } from 'fs/promises';
+
+const wasmBuffer = await readFile('./main.wasm');
+const { instance } = await WebAssembly.instantiate(wasmBuffer);
+
+console.log(instance.exports.fib(10));
+EOF
+node main.mjs > output
+
+cat > expected <<'EOF'
+89
+EOF
+
+diff -u expected output