fix check-statement-is-void. add tests

see #291

Author: thejoshwolfe

src/ir.cpp

@@ -12666,7 +12666,7 @@ static TypeTableEntry *ir_analyze_instruction_check_switch_prongs(IrAnalyze *ira
 static TypeTableEntry *ir_analyze_instruction_check_statement_is_void(IrAnalyze *ira,
         IrInstructionCheckStatementIsVoid *instruction)
 {
-    IrInstruction *statement_value = instruction->statement_value;
+    IrInstruction *statement_value = instruction->statement_value->other;
     TypeTableEntry *statement_type = statement_value->value.type;
     if (type_is_invalid(statement_type))
         return ira->codegen->builtin_types.entry_invalid;

std/debug.zig

@@ -217,7 +217,7 @@ fn getString(st: &ElfStackTrace, offset: u64) -> %[]u8 {
 fn readAllocBytes(in_stream: &io.InStream, size: usize) -> %[]u8 {
     const buf = %return global_allocator.alloc(u8, size);
     %defer global_allocator.free(buf);
-    if (size < %return in_stream.read(buf)) return error.Eof;
+    if ((%return in_stream.read(buf)) < size) return error.Eof;
     return buf;
 }
 

test/compile_errors.zig

@@ -1348,6 +1348,37 @@ pub fn addCases(cases: &tests.CompileErrorContext) {
         \\fn bar() -> i32 { 0 }
     , ".tmp_source.zig:2:8: error: expression value is ignored");
 
+    cases.add("ignored assert-err-ok return value",
+        \\export fn foo() {
+        \\    %%bar();
+        \\}
+        \\fn bar() -> %i32 { 0 }
+    , ".tmp_source.zig:2:5: error: expression value is ignored");
+
+    cases.add("ignored statement value",
+        \\export fn foo() {
+        \\    1;
+        \\}
+    , ".tmp_source.zig:2:5: error: expression value is ignored");
+
+    cases.add("ignored comptime statement value",
+        \\export fn foo() {
+        \\    comptime {1;}
+        \\}
+    , ".tmp_source.zig:2:15: error: expression value is ignored");
+
+    cases.add("ignored comptime value",
+        \\export fn foo() {
+        \\    comptime 1;
+        \\}
+    , ".tmp_source.zig:2:5: error: expression value is ignored");
+
+    cases.add("ignored defered statement value",
+        \\export fn foo() {
+        \\    defer {1;}
+        \\}
+    , ".tmp_source.zig:2:12: error: expression value is ignored");
+
     cases.add("integer literal on a non-comptime var",
         \\export fn foo() {
         \\    var i = 0;