From 156506e8fa483e273097c3a7d060de37849b94bc Mon Sep 17 00:00:00 2001
From: Eugen Wissner <belka@caraus.de>
Date: Tue, 21 Jan 2025 20:18:27 +0100
Subject: [PATCH] Force the execution of expression statements

---
 example.elna        | 109 +++++++++++++++++++++-----------------------
 gcc/elna-generic.cc |   1 +
 source/parser.yy    |   2 +-
 3 files changed, 54 insertions(+), 58 deletions(-)

diff --git a/example.elna b/example.elna
index 3b728bc..080c6cd 100644
--- a/example.elna
+++ b/example.elna
@@ -1,26 +1,17 @@
 type
   T = array 5 of Int,
-  R = record
-    x: Int;
-    y: Int
+  TokenValue = union
+    intValue: Int;
+    stringValue: String
+  end,
+  Token = record
+    kind: Int;
+    value: TokenValue
   end,
   FILE = record
-    x: Int
-  end,
-  U = union
-    a: Int;
-    b: Int
+    dummy: Int
   end;
 
-proc test_string();
-var s: String;
-begin
-  s := "Test string.";
-
-  writei("");
-  writei(s)
-end;
-
 proc test_array();
 var a: T, x: Int;
 begin
@@ -38,26 +29,15 @@ begin
 end;
 
 proc test_record();
-var r: R;
+var r: Token;
 begin
   writei("");
   writei("Test record:");
 
-  r.x := 4;
-  r.y := 8;
+  r.kind := 4;
+  r.value.intValue := 8;
 
-  writei(r.y)
-end;
-
-proc test_union();
-var u: U;
-begin
-  writei("");
-  writei("Test union:");
-
-  u.a := 9;
-
-  writei(u.b)
+  writei(r.value.intValue)
 end;
 
 proc test_primitive();
@@ -72,17 +52,6 @@ begin
   writei(z)
 end;
 
-proc test_const();
-const t = 5;
-var x: Int;
-begin
-  x := t;
-
-  writei("");
-  writei("Test const:");
-  writei(x)
-end;
-
 proc test_if();
 var x: Bool, y: Bool;
 begin
@@ -153,40 +122,66 @@ proc fopen(pathname: String, mode: String): pointer to FILE; extern;
 proc fclose(stream: pointer to FILE): Int; extern;
 proc fseek(stream: pointer to FILE, off: Int, whence: Int): Int; extern;
 proc ftell(stream: pointer to FILE): Int; extern;
+proc fread(ptr: pointer to Char, size: Int, nmemb: Int, stream: pointer to FILE): Int; extern;
+proc write(fd: Int, buf: pointer to Char, count: Int): Int; extern;
+proc malloc(size: Int): pointer to Char; extern;
+proc free(ptr: pointer to Char); extern;
+proc memset(ptr: pointer to Char, c: Int, n: Int): pointer to Char; extern;
 
-proc compile();
+proc read_source(filename: String): pointer to Char;
 const
+  -- Bug: The procedure doesn't see global constants.
   SEEK_SET = 0, SEEK_CUR = 1, SEEK_END = 2;
 var
   input_file: pointer to FILE,
-  source_size: Int, ret: Int;
+  source_size: Int,
+  input: pointer to Char;
 begin
-  input_file := fopen("example.elna", "rb");
+  input_file := fopen(filename, "rb");
 
-  // Bug: Functions as statements aren't called.
-  ret := fseek(input_file, 0, SEEK_END);
+  fseek(input_file, 0, SEEK_END);
   source_size := ftell(input_file);
-  ret := fseek(input_file, 0, SEEK_SET);
+  fseek(input_file, 0, SEEK_SET);
 
-  writei("");
-  writei("File size: ");
-  writei(input_file);
-  writei(source_size);
+  input := malloc(source_size + 1);
+  memset(input, 0, source_size + 1);
+  fread(input, source_size, 1, input_file);
 
-  ret := fclose(input_file)
+  fclose(input_file);
+
+  return input
+end;
+
+-- Bug: "while not is_eof(…) do" is a syntax error.
+proc is_not_eof(buffer: pointer to Int): Bool;
+begin
+  return buffer^ /= 0
+end;
+
+proc compile();
+var
+  input: pointer to Char,
+  input_pointer: pointer to Char;
+begin
+  input := read_source("example.elna");
+
+  input_pointer := input;
+  while is_not_eof(input_pointer) do
+    write(0, input_pointer, 1);
+    input_pointer := input_pointer + 1
+  end;
+
+  free(input)
 end;
 
 begin
   test_primitive();
-  test_string();
   test_array();
   test_record();
-  test_const();
   test_if();
   test_not();
   test_param(8, 7);
   test_const_char();
-  test_union();
   writei(test_return_int());
   test_add_pointer();
 
diff --git a/gcc/elna-generic.cc b/gcc/elna-generic.cc
index 0c38694..e4339ea 100644
--- a/gcc/elna-generic.cc
+++ b/gcc/elna-generic.cc
@@ -852,6 +852,7 @@ namespace gcc
     void generic_visitor::visit(source::expression_statement *statement)
     {
         statement->body().accept(this);
+        append_to_statement_list(this->current_expression, &this->current_statements);
     }
 
     void generic_visitor::visit(source::return_statement *statement)
diff --git a/source/parser.yy b/source/parser.yy
index af6b388..7ebf4a5 100644
--- a/source/parser.yy
+++ b/source/parser.yy
@@ -311,7 +311,7 @@ designator_expression:
         }
     | designator_expression DOT IDENTIFIER
         {
-            $$ = new elna::source::field_access_expression(elna::source::make_position(@1), $1, $3);
+            $$ = new elna::source::field_access_expression(elna::source::make_position(@2), $1, $3);
         }
     | designator_expression HAT
         {