Chapter 28a: Modules and Lazy Class Initializationlinear-chapter28a

Co-authored-by: Hsiang-Ying Fu <66062782+fuhsnn@users.noreply.github.com>
Co-authored-by: fuhsnn <66062782+fuhsnn@users.noreply.github.com>
Co-authored-by: Symious <14933944+symious@users.noreply.github.com>
Co-authored-by: Jun Kawasaki <jun784@gmail.com>
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

1 files changed, 172 insertions, 0 deletions

diff --git a/src/test/java/com/seaofnodes/simple/StaticDataTest.java b/src/test/java/com/seaofnodes/simple/StaticDataTest.java
new file mode 100644
index 00000000..b8f5f1d1
--- /dev/null
+++ b/src/test/java/com/seaofnodes/simple/StaticDataTest.java
@@ -0,0 +1,172 @@
+package com.seaofnodes.simple;
+
+import com.seaofnodes.simple.codegen.CodeGen;
+import com.seaofnodes.simple.codegen.StaticData;
+import com.seaofnodes.simple.node.ConstantNode;
+import com.seaofnodes.simple.node.StoreNode;
+import com.seaofnodes.simple.type.TypeMem;
+import com.seaofnodes.simple.type.TypeStruct;
+import com.seaofnodes.simple.type.TypeInteger;
+import com.seaofnodes.simple.util.Ary;
+import com.seaofnodes.isa.eval.EvalArm64;
+import com.seaofnodes.isa.eval.EvalRisc5;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class StaticDataTest {
+    private static final String SRC="val n=42; val f={int x -> x+n;}; return 0;";
+
+    private static StaticData.ObjectData root(CodeGen code) {
+        for( var obj : code._encoding._data.entries() )
+            if( obj.symbol.endsWith("Test.$class") ) return obj;
+        throw new AssertionError("Missing Test class object");
+    }
+
+    // Read the image before <clinit>, then call the function through its data slot.
+    @Test public void testEmulatorImage() {
+        for( String cpu : new String[]{"arm","riscv"} ) {
+            CodeGen code=new CodeGen(SRC).driver(CodeGen.Phase.TypeCheck);
+            assertNull("Constant fields fold before instruction selection",
+                       code._stop.walk(n -> n instanceof StoreNode st &&
+                           (st._name.equals("n") || st._name.equals("f")) ? n : null));
+            assertNotNull(code._stop.walk(n -> n instanceof ConstantNode &&
+                n._type instanceof TypeMem mem && mem.isConstant() &&
+                mem._t==TypeInteger.constant(42) ? n : null));
+            assertNotNull("The runtime initialization flag still needs its Store",
+                          code._stop.walk(n -> n instanceof StoreNode st &&
+                              st._name.equals("$init") ? n : null));
+            code.driver(cpu,"SystemV",true,false);
+            var e=code._encoding;
+            var obj=root(code);
+            TypeStruct ts=(TypeStruct)obj.type;
+            int cp=(e._bits.size()+15)&-16, sd=(cp+e._cpool.size()+15)&-16;
+            byte[] image=new byte[1<<20];
+            System.arraycopy(e._bits.buf(),0,image,0,e._bits.size());
+            System.arraycopy(e._cpool.buf(),0,image,cp,e._cpool.size());
+            System.arraycopy(e._sdata.buf(),0,image,sd,e._sdata.size());
+            int n=sd+obj.offset+ts.offset(ts.find("n"));
+            int f=sd+obj.offset+ts.offset(ts.find("f"));
+            if( cpu.equals("arm") ) {
+                var arm=new EvalArm64(image,1<<16);
+                assertEquals(42,arm.ld4s(n));
+                arm._pc=arm.ld4s(f);
+                arm.regs[0]=7;
+                assertEquals(0,arm.step(1000));
+                assertEquals(49,arm.regs[0]);
+            } else {
+                var r5=new EvalRisc5(image,1<<16);
+                assertEquals(42,r5.ld4s(n));
+                r5._pc=r5.ld4s(f);
+                r5.regs[10]=7;
+                assertEquals(0,r5.step(1000));
+                assertEquals(49,r5.regs[10]);
+            }
+        }
+    }
+
+    @Test public void testNativeImage() throws Exception {
+        Path dir=Path.of("build/objs/static-data");
+        Files.createDirectories(dir);
+        CodeGen code=new CodeGen(null,dir.toString(),"Test",SRC,123L,true,
+                                TypeInteger.BOT)
+            .driver(TestC.CPU_PORT,TestC.CALL_CONVENTION,false,false);
+        TypeStruct ts=(TypeStruct)root(code).type;
+        Path driver=dir.resolve("driver.c");
+        Files.writeString(driver,"""
+            #include <stdint.h>
+            #include <string.h>
+            extern unsigned char data[] __asm__("Test.$class");
+            typedef int64_t (__attribute__((CALL_CONV)) *fun)(int64_t);
+            int main(void) {
+                int64_t n; uint32_t f;
+                memcpy(&n,data+%d,sizeof(n));
+                memcpy(&f,data+%d,sizeof(f));
+                return n!=42 || ((fun)(uintptr_t)f)(7)!=49;
+            }
+            """.formatted(ts.offset(ts.find("n")),ts.offset(ts.find("f"))));
+        String exe=dir.resolve(TestC.OS.startsWith("Windows")?"test.exe":"test").toString();
+        TestC.linkExe(dir.resolve("Test.o").toString(),
+                      TestC.CALL_CONVENTION.equals("win64")?"ms_abi":"sysv_abi",
+                      driver.toString(),null,exe);
+        assertEquals("",TestC.exec(TestC.TEST_TIMEOUT_SECONDS,exe));
+    }
+
+    // Native entries must agree too, both in static fields (before <clinit>)
+    // and when code materializes the address. The native body may live above 4G.
+    @Test public void testNativeFunctionIdentity() throws Exception {
+        Path dir=Path.of("build/objs/static-native-functions");
+        Files.createDirectories(dir);
+        int[] offsets=new int[2];
+        for( int i=0; i<2; i++ ) {
+            String name=i==0 ? "A" : "B";
+            String src="{ i32 -> i32 } abs = \"C\"; val get"+name+"={ -> abs; }; return 0;";
+            CodeGen code=new CodeGen(null,dir.toString(),name,src,123L,true,TypeInteger.BOT)
+                .driver(CodeGen.Phase.TypeCheck);
+            assertNull("The native address is initialized in the static image",
+                       code._stop.walk(n -> n instanceof StoreNode st && st._name.equals("abs") ? n : null));
+            code.driver(TestC.CPU_PORT,TestC.CALL_CONVENTION,false,false);
+            for( var obj : code._encoding._data.entries() )
+                if( obj.symbol.equals(name+".$class") ) {
+                    TypeStruct ts=(TypeStruct)obj.type;
+                    offsets[i]=ts.offset(ts.find("abs"));
+                }
+        }
+        Path driver=dir.resolve("driver.c");
+        Files.writeString(driver,"""
+            #include <stdint.h>
+            #include <string.h>
+            extern unsigned char a[] __asm__("A.$class"), b[] __asm__("B.$class");
+            typedef int32_t (__attribute__((CALL_CONV)) *fun)(int32_t);
+            __attribute__((CALL_CONV)) extern fun getA(void), getB(void);
+            int main(void) {
+                uint32_t x,y;
+                memcpy(&x,a+%d,sizeof(x));
+                memcpy(&y,b+%d,sizeof(y));
+                fun f=(fun)(uintptr_t)x;
+                if(!x || x!=y || f!=getA() || f!=getB()) return 1;
+                return f(-7)!=7;
+            }
+            """.formatted(offsets[0],offsets[1]));
+        String exe=dir.resolve(TestC.OS.startsWith("Windows")?"test.exe":"test").toString();
+        String conv=TestC.CALL_CONVENTION.equals("win64")?"ms_abi":"sysv_abi";
+        // Either object's weak definition can win; every reference must agree.
+        for( String first : new String[]{"A","B"} ) {
+            String second=first.equals("A")?"B":"A";
+            TestC.linkExe(dir.resolve(first+".o").toString(),conv,driver.toString(),
+                          new Ary<>(new String[]{dir.resolve(second+".o").toString()}),exe);
+            assertEquals("",TestC.exec(TestC.TEST_TIMEOUT_SECONDS,exe));
+        }
+    }
+
+    // Two source files must reference the same mutable class object.
+    @Test public void testSharedClass() throws Exception {
+        Path dir=Path.of("build/objs/static-data-shared");
+        Files.createDirectories(dir);
+        Files.createDirectories(dir.resolve("Main"));
+        String[] names={"Globals","A","B"};
+        String[] sources={"int count=0;",
+                          "val a={ -> Globals; };", "val b={ -> Globals; };"};
+        for( int i=0; i<names.length; i++ )
+            Files.writeString(dir.resolve("Main/"+names[i]+".smp"),sources[i]);
+        new CodeGen(dir.toString(),dir.toString(),"Main","val a={ -> A.a(); }; val b={ -> B.b(); };",123L,true,TypeInteger.BOT)
+            .driver(TestC.CPU_PORT,TestC.CALL_CONVENTION,false,false);
+        Path driver=dir.resolve("driver.c");
+        Files.writeString(driver,"""
+            #include <stdint.h>
+            __attribute__((CALL_CONV)) extern int64_t *a(void),*b(void);
+            int main(void) {
+                int64_t *x=a(),*y=b();
+                if(x!=y) return 1;
+                *x=37;
+                return *y!=37;
+            }
+            """);
+        String exe=dir.resolve(TestC.OS.startsWith("Windows")?"test.exe":"test").toString();
+        TestC.linkExe(dir.resolve("Main.o").toString(),
+                      TestC.CALL_CONVENTION.equals("win64")?"ms_abi":"sysv_abi",
+                      driver.toString(),null,exe);
+        assertEquals("",TestC.exec(TestC.TEST_TIMEOUT_SECONDS,exe));
+    }
+}