1 files changed, 58 insertions, 0 deletions
diff --git a/chapter28a/src/test/java/com/seaofnodes/simple/PrefixUpdateTest.java b/chapter28a/src/test/java/com/seaofnodes/simple/PrefixUpdateTest.java
new file mode 100644
index 00000000..71612cc0
--- /dev/null
+++ b/chapter28a/src/test/java/com/seaofnodes/simple/PrefixUpdateTest.java
@@ -0,0 +1,58 @@
+package com.seaofnodes.simple;
+
+import com.seaofnodes.simple.codegen.CodeGen;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class PrefixUpdateTest {
+    @Test public void testMethodFieldWrites() {
+        String[] fields = {"int x=0", "int x=3", "u8 x=0", "f32 x=0"};
+        String[] updates = {"++x", "--x", "++x", "++x"};
+        String[] results = {"221", "112", "221", "221.0"};
+        for(int i=0;i<fields.length;i++)
+            for(int seed:new int[]{2,13,123}) {
+                String src="struct C { "+fields[i]+"; val change_noInline={ -> "+updates[i]+"; }; }; "
+                    +"var c=new C; val a=c.change_noInline(); val b=c.change_noInline(); return a+10*b+100*c.x;";
+                CodeGen code=new CodeGen(src,seed,true).driver(CodeGen.Phase.TypeCheck);
+                assertEquals(fields[i],results[i],Eval2.eval(code,0));
+            }
+    }
+
+    @Test public void testLocalAndFinalUpdates() {
+        CodeGen code=new CodeGen("int x=arg; return ++x*100 + --x*10 + x;").driver(CodeGen.Phase.TypeCheck);
+        assertEquals("433",Eval2.eval(code,3));
+        code=new CodeGen("struct C { int x=7; val f={int x -> ++x;}; }; var c=new C; return c.f(3)+10*c.x;")
+            .driver(CodeGen.Phase.TypeCheck);
+        assertEquals("74",Eval2.eval(code,0));
+        for(String src:new String[]{"val x=1; return ++x;",
+                                   "struct C { val x=1; val f={ -> ++x; }; }; var c=new C; return c.f();"}) {
+            try {
+                new CodeGen(src).driver(CodeGen.Phase.TypeCheck);
+                fail("final update");
+            } catch(RuntimeException e) {
+                assertTrue(e.getMessage(),e.getMessage().contains("final"));
+            }
+        }
+    }
+
+    @Test public void testNativeByteOverflow() throws java.io.IOException {
+        String src="val prefixUpdate={int arg -> "
+            +"struct C { u8 x=255; val inc_noInline={ -> ++x; }; }; "
+            +"var c=new C; val a=c.inc_noInline(); val b=c.inc_noInline(); return a+10*b+100*c.x; };";
+        var dir=java.nio.file.Path.of("build/objs");
+        java.nio.file.Files.createDirectories(dir);
+        var driver=dir.resolve("prefixUpdate.c");
+        java.nio.file.Files.writeString(driver,"""
+            __attribute__((CALL_CONV)) extern long long prefixUpdate(long long);
+            int main(void) { return prefixUpdate(0)!=110; }
+            """);
+        String abi=TestC.OS.startsWith("Windows") ? "ms_abi" : "sysv_abi";
+        TestC.run(src,"prefixUpdate",null,TestC.CALL_CONVENTION,abi,driver.toString(),"",-1);
+    }
+
+    @Test public void testModuleFieldWrites() {
+        CodeGen code=new CodeGen("int calls=0; val next_noInline={ -> ++calls; }; return next_noInline()+10*next_noInline();")
+            .driver(CodeGen.Phase.TypeCheck);
+        assertEquals("21",Eval2.eval(code,0));
+    }
+}