Handle r/w <clinit> sections

7 files changed, 144 insertions, 32 deletions

diff --git a/chapter25/src/main/java/com/seaofnodes/simple/codegen/ElfWriter.java b/chapter25/src/main/java/com/seaofnodes/simple/codegen/ElfWriter.java
index 7af7e5f1..a74303e6 100644
--- a/chapter25/src/main/java/com/seaofnodes/simple/codegen/ElfWriter.java
+++ b/chapter25/src/main/java/com/seaofnodes/simple/codegen/ElfWriter.java
@@ -319,8 +319,7 @@ public class ElfWriter {
         // Write relocations for the constant pool
         String cpoolPrefix = _code.entryClinitName().replaceAll("[^A-Za-z0-9_$]", "_") + "$CPOOL$";
         for( Encoding.Relo relo : enc._bigCons.values() ) {
-            boolean ro = !(relo._t instanceof TypeStruct ts) || ts.isConstant();
-            DataSection data = ro ? rodata : rwdata;
+            DataSection data = relo.readOnly() ? rodata : rwdata;
             int symidx = symbols.symbol(cpoolPrefix+symbols.gidx(), data._index, SYM_BIND_GLOBAL, SYM_TYPE_FUNC, relo._target, relo._t.size());
             relocations.writeReloOffPlus(relo._opStart+relo._off, symidx, relo._elf );
         }
diff --git a/chapter25/src/main/java/com/seaofnodes/simple/codegen/Encoding.java b/chapter25/src/main/java/com/seaofnodes/simple/codegen/Encoding.java
index 4c7475fd..48ca4335 100644
--- a/chapter25/src/main/java/com/seaofnodes/simple/codegen/Encoding.java
+++ b/chapter25/src/main/java/com/seaofnodes/simple/codegen/Encoding.java
@@ -53,6 +53,12 @@ public class Encoding {
         Relo( Node op, Type t, byte off, byte elf ) {
             _op=op;  _t=t;  _off=off; _elf=elf;
         }
+        public boolean readOnly() {
+            // Class initializers still write their fields, even when every
+            // final value is constant.  Their storage must remain writable.
+            return !(_t instanceof TypeStruct ts) ||
+                (!Parser.startsClzPrefix(ts._name) && ts.isConstant());
+        }
     }
 
     Encoding( CodeGen code ) {
@@ -510,8 +516,7 @@ public class Encoding {
         Ary<Relo>[] raligns = new Ary[5];
         for( Node op : _bigCons.keySet() ) {
             Relo relo = _bigCons.get(op);
-            // non-constant structs in the r/w data, everything else in r/o data
-            if( (relo._t instanceof TypeStruct ts && !ts.isConstant()) == ro )
+            if( relo.readOnly() != ro )
                 continue;
             int align = relo._t.alignment();
             Ary<Relo> relos = raligns[align]==null ? (raligns[align]=new Ary<>(Relo.class)) : raligns[align];
diff --git a/chapter25/src/main/java/com/seaofnodes/simple/codegen/LinkMem.java b/chapter25/src/main/java/com/seaofnodes/simple/codegen/LinkMem.java
index e0b59395..d249b80c 100644
--- a/chapter25/src/main/java/com/seaofnodes/simple/codegen/LinkMem.java
+++ b/chapter25/src/main/java/com/seaofnodes/simple/codegen/LinkMem.java
@@ -23,8 +23,7 @@ public class LinkMem {
         // Patch local ops, e.g. loading float constants from the constant pool
         for( Node op : enc._bigCons.keySet() ) {
             Encoding.Relo relo = enc._bigCons.get(op);
-            boolean ro = !(relo._t instanceof TypeStruct ts) || ts.isConstant();
-            int target = relo._target+(ro ? cpool : sdata);
+            int target = relo._target+(relo.readOnly() ? cpool : sdata);
             ((RIPRelSize)relo._op).patch(enc, relo._opStart, enc.opLen(relo._op), target - relo._opStart);
         }
 
diff --git a/chapter25/src/main/java/com/seaofnodes/simple/print/ASMPrinter.java b/chapter25/src/main/java/com/seaofnodes/simple/print/ASMPrinter.java
index e15d7dbe..7f9f3ad9 100644
--- a/chapter25/src/main/java/com/seaofnodes/simple/print/ASMPrinter.java
+++ b/chapter25/src/main/java/com/seaofnodes/simple/print/ASMPrinter.java
@@ -45,8 +45,7 @@ public abstract class ASMPrinter {
         Ary<Relo>[] raligns = new Ary[5];
         for( Node op : bigCons.keySet() ) {
             Relo relo = bigCons.get(op);
-            // non-constant structs in the r/w data, everything else in r/o data
-            if( (relo._t instanceof TypeStruct ts && !ts.isConstant()) == ro )
+            if( relo.readOnly() != ro )
                 continue;
             int align = relo._t.alignment();
             Ary<Relo> relos = raligns[align]==null ? (raligns[align]=new Ary<>( Relo.class)) : raligns[align];
diff --git a/chapter25/src/test/java/com/seaofnodes/simple/Chapter25Test.java b/chapter25/src/test/java/com/seaofnodes/simple/Chapter25Test.java
index 2966ec04..d2357ef1 100644
--- a/chapter25/src/test/java/com/seaofnodes/simple/Chapter25Test.java
+++ b/chapter25/src/test/java/com/seaofnodes/simple/Chapter25Test.java
@@ -8,6 +8,9 @@ import com.seaofnodes.simple.util.Ary;
 import java.io.File;
 import java.io.FileWriter;
 import java.io.IOException;
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.concurrent.TimeUnit;
@@ -235,21 +238,39 @@ int v0=0^0;
     }
 
     @Test
+    public void testConstantClassInitialization() throws IOException {
+        TestC.runSF("val x = 42; return 0;","constantClassInt","",0);
+        TestC.runSF("val f = { -> 7; }; return 0;","constantClassFunction","",0);
+    }
+
+    @Test
     public void testHelloWorld() throws IOException {
         String expected = "Hello, World!\n";
         String prog = "return sys.io.p(\""+expected+"\") - "+expected.length()+";";
-        TestC.run(prog,"helloWorld",new Ary<>(new String[]{SYS_BLDDIR}),
+        // tests_raw1 concurrently builds Chapter22Test's helloWorld executable.
+        TestC.run(prog,"helloWorldSys",new Ary<>(new String[]{SYS_BLDDIR}),
                   TestC.CALL_CONVENTION, null, null, expected,0);
     }
 
     @Test
     public void testHelloWorldDriver() throws Exception {
-        Simple.main(new String[]{"-L",SYS_BLDDIR,"--norun","docs/examples/A_helloWorld.smp"});
+        String out = "build/objs/helloWorldDriver/";
+        Simple.main(new String[]{"-L",SYS_BLDDIR,"-o",out,"--norun","docs/examples/A_helloWorld.smp"});
+        assertTrue(Files.isRegularFile(Path.of(out,"A_helloWorld.o")));
     }
 
     @Test
     public void testHelloWorldDriverLibFile() throws Exception {
-        Simple.main(new String[]{"-L",SYS_FILE.toString(),"docs/examples/A_helloWorld.smp"});
+        ByteArrayOutputStream output = new ByteArrayOutputStream();
+        PrintStream saved = System.out;
+        try( PrintStream capture = new PrintStream(output,true,StandardCharsets.UTF_8) ) {
+            System.setOut(capture);
+            Simple.main(new String[]{"-L",SYS_FILE.toString(),"-o","build/objs/helloWorldDriverLibFile/",
+                                    "docs/examples/A_helloWorld.smp"});
+        } finally {
+            System.setOut(saved);
+        }
+        assertEquals("Hello, World!\n",output.toString(StandardCharsets.UTF_8));
     }
 
     @Test
diff --git a/chapter25/src/test/java/com/seaofnodes/simple/NativeExecutionTest.java b/chapter25/src/test/java/com/seaofnodes/simple/NativeExecutionTest.java
new file mode 100644
index 00000000..f3f65183
--- /dev/null
+++ b/chapter25/src/test/java/com/seaofnodes/simple/NativeExecutionTest.java
@@ -0,0 +1,69 @@
+package com.seaofnodes.simple;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import org.junit.Test;
+import static org.junit.Assert.*;
+import static org.junit.Assume.assumeTrue;
+
+public class NativeExecutionTest {
+    // A subprocess with deterministic stdout, stderr, and process status.
+    public static class Child {
+        public static void main(String[] args) {
+            System.out.println("before exit");
+            System.err.println("child diagnostic");
+            System.exit(Integer.parseInt(args[0]));
+        }
+    }
+
+    private static String child(int exit) throws IOException {
+        String java = Path.of(System.getProperty("java.home"),"bin","java").toString();
+        return TestC.exec(java,"-cp",System.getProperty("java.class.path"),
+                          Child.class.getName(),Integer.toString(exit));
+    }
+
+    private static void checkFailure(int exit) throws IOException {
+        try {
+            child(exit);
+            fail("Accepted process exit "+exit);
+        } catch( IOException e ) {
+            assertTrue(e.getMessage(),e.getMessage().contains("exit code: "+exit));
+            assertTrue(e.getMessage(),e.getMessage().contains("before exit"));
+            assertTrue(e.getMessage(),e.getMessage().contains("child diagnostic"));
+        }
+    }
+
+    @Test public void testNonzeroExit() throws IOException { checkFailure(7); }
+
+    @Test public void testFullWindowsExitCode() throws IOException {
+        assumeTrue(TestC.OS.startsWith("Windows"));
+        checkFailure(256); // Narrowing to a byte incorrectly reports success.
+        checkFailure(2816); // Observed Cygwin status for the Hello World crash.
+    }
+
+    @Test public void testSuccessfulOutput() throws IOException {
+        assertEquals("before exit"+System.lineSeparator(),child(0));
+    }
+
+    @Test public void testHelloWorldArtifacts() throws IOException {
+        new Chapter22Test().testHelloWorld();
+        new Chapter25Test().testHelloWorld();
+        // Model a parallel run paused between Chapter 22's link and execution.
+        // Chapter 25 must not replace the executable Chapter 22 is about to run.
+        String exe = "build/objs/helloWorld"+(TestC.OS.startsWith("Windows") ? ".exe" : "");
+        assertEquals("Hello, World!",TestC.exec(exe));
+    }
+
+    @Test public void testDriverNonzeroExit() throws Exception {
+        Path dir = Files.createTempDirectory(Path.of("build/objs"),"driver-exit-");
+        Path src = dir.resolve("fail.smp");
+        Files.writeString(src,"return 7;");
+        try {
+            Simple.main(new String[]{src.toString()});
+            fail("Driver accepted a failed executable");
+        } catch( IOException e ) {
+            assertTrue(e.getMessage(),e.getMessage().contains("exit code: 7"));
+        }
+    }
+}
diff --git a/chapter25/src/test/java/com/seaofnodes/simple/TestC.java b/chapter25/src/test/java/com/seaofnodes/simple/TestC.java
index d9595282..55c62c37 100644
--- a/chapter25/src/test/java/com/seaofnodes/simple/TestC.java
+++ b/chapter25/src/test/java/com/seaofnodes/simple/TestC.java
@@ -138,7 +138,10 @@ public abstract class TestC {
     public static String gcc( String main, double ignore, String... objs ) throws IOException {
         String BLDDIR = "build/objs/test0/";
         String exe = BLDDIR+main+(OS.startsWith("Windows") ? ".exe" : "");
-        return gcc(objs[0],null,null,false,exe);
+        linkExe(objs[0],null,null,null,exe);
+        // Module tests intentionally use the program exit code as their result.
+        ExecResult result = execute(null,exe);
+        return result.exit==0 ? result.out : "exec exit code: "+result.exit;
     }
 
     // Link with gcc, and execute the resulting binary, returning stdout as a
@@ -209,29 +212,46 @@ public abstract class TestC {
     }
 
     private static String execStdin( String stdin, String... args ) throws IOException {
+        ExecResult result = execute(stdin,args);
+        if( result.exit!=0 )
+            throw new IOException(String.join(" ",args)+"\nexec exit code: "+result.exit+
+                                  "\nstdout:\n"+result.out+"\nstderr:\n"+result.err);
+        return result.out;
+    }
+
+    private record ExecResult(int exit, String out, String err) {}
+
+    private static ExecResult execute( String stdin, String... args ) throws IOException {
         // Execute results
         ProcessBuilder smp = new ProcessBuilder(args);
-        File stdinFile = null;
-        File stdoutFile = File.createTempFile("simple-stdout",".txt");
-        smp.redirectOutput(stdoutFile);
-        if( stdin!=null && stdin.isEmpty() ) smp.redirectInput(ProcessBuilder.Redirect.INHERIT);
-        else if( stdin!=null ) {
-            stdinFile = File.createTempFile("simple-stdin",".txt");
-            Files.writeString(stdinFile.toPath(),stdin);
-            smp.redirectInput(stdinFile);
+        Path stdinFile = null;
+        Path stdoutFile = Files.createTempFile("simple-stdout",".txt");
+        Path stderrFile = Files.createTempFile("simple-stderr",".txt");
+        Process p = null;
+        try {
+            smp.redirectOutput(stdoutFile.toFile());
+            smp.redirectError(stderrFile.toFile());
+            if( stdin!=null && stdin.isEmpty() ) smp.redirectInput(ProcessBuilder.Redirect.INHERIT);
+            else if( stdin!=null ) {
+                stdinFile = Files.createTempFile("simple-stdin",".txt");
+                Files.writeString(stdinFile,stdin);
+                smp.redirectInput(stdinFile.toFile());
+            }
+            p = smp.start();
+            if( stdin==null )
+                p.getOutputStream().close();
+            // Windows statuses have 32 bits; narrowing can turn a failure into 0.
+            int exit = p.waitFor();
+            return new ExecResult(exit,Files.readString(stdoutFile),Files.readString(stderrFile));
+        } catch( InterruptedException e ) {
+            if( p!=null ) p.destroyForcibly();
+            Thread.currentThread().interrupt();
+            throw new IOException("interrupted",e);
+        } finally {
+            if( stdinFile!=null ) Files.deleteIfExists(stdinFile);
+            Files.deleteIfExists(stdoutFile);
+            Files.deleteIfExists(stderrFile);
         }
-        Process p = smp.start();
-        if( stdin==null )
-            p.getOutputStream().close();
-        int exit;
-        try { exit = (byte)p.waitFor(); } catch( InterruptedException e ) { throw new IOException("interrupted"); }
-        String result = Files.readString(stdoutFile.toPath());
-        if( stdinFile != null )
-            stdinFile.delete();
-        stdoutFile.delete();
-        if( exit!=0 )
-            return "exec exit code: "+exit;
-        return result;
     }
 
     static Ary<String> linkObjs(Ary<String> externPaths) {