Update incremental build checkmain

5 files changed, 239 insertions, 18 deletions

diff --git a/chapter28b/README.ja.md b/chapter28b/README.ja.md
index c4f60712..a3221da5 100644
--- a/chapter28b/README.ja.md
+++ b/chapter28b/README.ja.md
@@ -89,6 +89,16 @@ java -ea -cp "build/classes/main:build/classes/test:lib/*" \
 
 ## 検証と今後
 
+明示的に指定したソースは常にコンパイルします。他のローカルオブジェクトを再利用する前に、
+記録された依存関係をたどり、各オブジェクトにまとめられた全ソースを検査します。
+入力の欠落や、より新しいソース・依存オブジェクトがあれば、保存した型や IR を使わず
+再解析します。A が B をインライン化していれば、B のオブジェクトが未更新でも、
+B のソース変更で A は無効になります。循環は訪問済み集合で処理します。
+
+ライブラリは検査と読み込みで同じ検索パスを使います。ソースのないライブラリは整合した
+組み合わせで提供する必要があります。時刻だけでは互換性は判断できません。入力ハッシュ、
+コンパイラ・ABI のバージョン、自動再リンクを含むビルドドライバは今後の課題です。
+
 リポジトリのルートから次を実行します。
 
 ```sh
@@ -100,6 +110,10 @@ make tests CHAPTERS=chapter28b
 オブジェクトにします。`make release` は jar と標準ライブラリを作り、`make view` は
 共通のグラフビューアーを起動します。
 
+`IncrementalBuildTest` は時刻を明示的に設定し、再利用、間接的な変更、まとめられた
+循環、入力の欠落、ライブラリ更新を検査します。変更後のネイティブ実行結果も
+クリーンビルドと比較します。
+
 保存形式は `C0DE` 以外のバージョン番号をまだ持ちません。コンパイラや形式を変えたら
 オブジェクトを再構築してください。高コストの往復一致検査は無効のままで、古い増分
 ビルドの実験 `testModule0` も実行対象外です。
diff --git a/chapter28b/README.md b/chapter28b/README.md
index f464fed4..0a7baa68 100644
--- a/chapter28b/README.md
+++ b/chapter28b/README.md
@@ -116,10 +116,18 @@ normal inlining heuristics.  The combined graph goes through the normal
 compilation phases, including peepholes, Opto and TypeCheck.
 
 Dependencies between `CompUnit`s are recorded.  An explicitly requested source
-file is always compiled.  Other source files are recompiled if their object is
-missing, their source is newer, or a recorded dependency's object in the build
-directory is newer.  These timestamp checks are not yet a complete incremental
-build system, there is some modest future work needed to finish this.
+file is always compiled.  Before reusing another local object, `CompUnit` walks
+its recorded dependencies and checks every source bundled into each local
+object.  A missing input or a newer source or dependency object forces parsing
+again, before saved types or IR are imported.  This includes transitive
+dependencies: if A has inlined B, editing B's source invalidates A even while
+B's object is unchanged.  A visited set lets this check follow cycles.
+
+Library dependencies use the same search paths for checking and loading.
+Object-only libraries must be supplied as a coherent build; timestamps alone
+cannot establish their compatibility.  These checks are not a complete build
+driver: explicit requests still compile, and input hashes, compiler/ABI
+versions, and automatic relinking remain future work.
 
 Loading currently works at the object granularity.  Unrelated objects can stay
 unloaded, but selecting an object loads its entire saved graph and follows its
@@ -163,6 +171,9 @@ constructors, initialization cycles across objects, shared static data, native
 function thunks, and native library/client execution. Make also builds the
 modular `sys` object used by the library tests. Clients can import that object
 with `-L`; they do not need to parse the standard library's source again.
+`IncrementalBuildTest` checks reuse, transitive edits, bundled cycles, missing
+inputs, and changed library objects using controlled timestamps. It also
+compares native execution after an edit with a clean build.
 `make release` builds the launcher jar and standard library; `make view`
 starts the shared graph viewer.
 
diff --git a/chapter28b/src/main/java/com/seaofnodes/simple/codegen/CompUnit.java b/chapter28b/src/main/java/com/seaofnodes/simple/codegen/CompUnit.java
index 71126795..8b303008 100644
--- a/chapter28b/src/main/java/com/seaofnodes/simple/codegen/CompUnit.java
+++ b/chapter28b/src/main/java/com/seaofnodes/simple/codegen/CompUnit.java
@@ -60,7 +60,7 @@ public class CompUnit {
             ( fname.equals(CODE._srcName) ||   // Explicit input is a compilation request
               !_obj.exists() ||                // No object file
               _smp.lastModified() > _obj.lastModified() || // Out-of-date with source?
-              checkDependentObjs() );                      // Out-of-date with other objs?
+              !current(_obj,new HashSet<>()) ); // Out-of-date anywhere in its inputs?
         _src  = mustCompile ? new String(Files.readAllBytes(_smp.toPath())) : null;
     }
 
@@ -101,16 +101,42 @@ public class CompUnit {
         _src  = null;
     }
 
-    // Return true if _obj is out-of-date relative to dependents.
-    private boolean checkDependentObjs() {
-        ElfReader elf = CODE.getElf(_obj);
+    // Check source-backed inputs before importing any saved types or IR.
+    // A dependency's source can be newer while its object is unchanged.
+    // Use a fresh visited set for each root: encountering a cycle is safe, but
+    // caching a provisional "current" answer from inside it would not be.
+    private static boolean current(File obj, HashSet<File> visit) {
+        if( obj==null || !obj.isFile() ) return false;
+        if( !visit.add(obj.getAbsoluteFile()) ) return true;
+        ElfReader elf = CODE.getElf(obj);
+        if( elf==null ) return false;
         elf.loadPublicSymbols();
+        if( elf._units==null ) return false;
+        long time = obj.lastModified();
+        for( String unit : elf._units ) {
+            // Never import another copy of a unit explicitly being compiled.
+            CompUnit cu = CODE._compunits.get(unit);
+            if( unit.equals(CODE._srcName) || (cu!=null && cu._src!=null) ) return false;
+            File src = new File(CODE._modDir+"/"+unit+".smp");
+            if( !src.isFile() || src.lastModified()>time ) return false;
+        }
         for( String dep : elf._deps ) {
-            File obj = new File(CODE._buildDir+"/"+dep+".o");
-            if( obj.lastModified() > _obj.lastModified() ) // Out-of-date with deps?
-                return true;
+            if( Arrays.asList(elf._units).contains(dep) ) continue; // Owned by this object.
+            File file = dependencyObj(dep,true);
+            if( file==null || !file.isFile() || file.lastModified()>time ) return false;
+            // Object-only libraries are supplied as a coherent build. Their
+            // input versions cannot be inferred from installation timestamps.
+            if( file.equals(new File(CODE._buildDir+"/"+dep+".o")) && !current(file,visit) ) return false;
         }
-        return false;
+        return true;
+    }
+
+    // Resolve dependencies the same way for freshness checks and actual loads.
+    static File dependencyObj(String fname, boolean local) {
+        File obj = new File(CODE._buildDir+"/"+fname+".o");
+        if( local && (obj.isFile() || new File(CODE._modDir+"/"+fname+".smp").isFile()) ) return obj;
+        ElfReader elf = CODE.findExternalSimple(Parser.addClzPrefix(fname.replace('/','.')));
+        return elf==null ? null : elf._file;
     }
 
     // Add a discovered dependency, for later writing out in an ELF file, ".simple" section
diff --git a/chapter28b/src/main/java/com/seaofnodes/simple/codegen/ParseAll.java b/chapter28b/src/main/java/com/seaofnodes/simple/codegen/ParseAll.java
index c55f9a90..d7c0f7e2 100644
--- a/chapter28b/src/main/java/com/seaofnodes/simple/codegen/ParseAll.java
+++ b/chapter28b/src/main/java/com/seaofnodes/simple/codegen/ParseAll.java
@@ -258,12 +258,10 @@ public abstract class ParseAll {
     }
 
     private static File depObj(CodeGen code, CompUnit cunit, String fname) {
-        if( cunit._smp != null )
-            return null;
-        ElfReader elf = code.findExternalSimple(Parser.addClzPrefix(fname.replace('/','.')));
-        if( elf == null )
-            throw new RuntimeException("Cannot find external Simple dependency '"+fname+"'");
-        return elf._file;
+        File obj = CompUnit.dependencyObj(fname,cunit._smp!=null);
+        if( obj == null )
+            throw new RuntimeException("Cannot find Simple dependency '"+fname+"'");
+        return cunit._smp!=null && obj.equals(new File(code._buildDir+"/"+fname+".o")) ? null : obj;
     }
 
     private static File externalObj(CodeGen code, CompUnit par, String name) {
diff --git a/chapter28b/src/test/java/com/seaofnodes/simple/IncrementalBuildTest.java b/chapter28b/src/test/java/com/seaofnodes/simple/IncrementalBuildTest.java
new file mode 100644
index 00000000..501392f3
--- /dev/null
+++ b/chapter28b/src/test/java/com/seaofnodes/simple/IncrementalBuildTest.java
@@ -0,0 +1,172 @@
+package com.seaofnodes.simple;
+
+import com.seaofnodes.simple.codegen.*;
+import com.seaofnodes.simple.type.TypeInteger;
+import com.seaofnodes.simple.util.Ary;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.attribute.FileTime;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+public class IncrementalBuildTest {
+    @Test public void testTransitiveSourceChange() throws Exception {
+        Path base=Path.of("build/objs/incremental");
+        Files.createDirectories(base);
+        Path root=Files.createTempDirectory(base,"chain-");
+        Path src=Files.createDirectory(root.resolve("src"));
+        Path obj=Files.createDirectory(root.resolve("obj"));
+        write(src,"App","val marker=0;",1000);
+        write(src,"App/B","val value={ -> 5; };",1000);
+        write(src,"App/A","val value={ -> B.value()+1; };",1000);
+        write(src,"App/C","val value={ -> A.value()+1; };",1000);
+        write(src,"App/Main","val run={ -> C.value(); }; return run();",1000);
+        compile(src,obj,"App");
+        stamp(obj.resolve("App.o"),1500);
+        compile(src,obj,"App/B");
+        stamp(obj.resolve("App/B.o"),2000);
+        compile(src,obj,"App/A");
+        stamp(obj.resolve("App/A.o"),3000);
+        compile(src,obj,"App/C");
+        stamp(obj.resolve("App/C.o"),3500);
+        CodeGen code=client(src,obj);
+        assertNull("Reuse unchanged A",code._compunits.get("App/A")._src);
+        assertNull("Reuse unchanged B",code._compunits.get("App/B")._src);
+        assertNull("Reuse unchanged C",code._compunits.get("App/C")._src);
+        assertEquals("7",Eval2.eval(code,0));
+
+        write(src,"App/B","val value={ -> 7; };",4000);
+        code=client(src,obj);
+        assertEquals("9",Eval2.eval(code,0));
+        assertNotNull(code._compunits.get("App/C")._src);
+        assertNotNull("Reparse A before loading its stale inlined body",code._compunits.get("App/A")._src);
+        assertNotNull(code._compunits.get("App/B")._src);
+        compile(src,obj,"App/Main");
+        checkNative(obj,new Ary<>(new String[]{obj.resolve("App.o").toString()}));
+
+        Path clean=Files.createDirectory(root.resolve("clean"));
+        assertEquals("9",Eval2.eval(client(src,clean),0));
+        compile(src,clean,"App/Main");
+        checkNative(clean,null);
+    }
+
+    @Test public void testBundledSourceChangeAndCycle() throws Exception {
+        Path root=fixture("bundle-");
+        Path src=root.resolve("src"), obj=root.resolve("obj");
+        write(src,"App/A","val value={int n -> n ? B.value(n-1) : 1; };",1000);
+        write(src,"App/B","val value={int n -> n ? A.value(n-1) : 5; };",1000);
+        write(src,"App/Main","return A.value(1);",1000);
+        compile(src,obj,"App/A");
+        stamp(obj.resolve("App/A.o"),3000);
+        assertFalse("A owns both sides of the cycle",Files.exists(obj.resolve("App/B.o")));
+        CodeGen code=client(src,obj);
+        assertEquals("5",Eval2.eval(code,0));
+        assertNull(code._compunits.get("App/A")._src);
+        assertNull(code._compunits.get("App/B")._src);
+
+        write(src,"App/B","val value={int n -> n ? A.value(n-1) : 7; };",4000);
+        code=client(src,obj);
+        assertEquals("7",Eval2.eval(code,0));
+        assertNotNull(code._compunits.get("App/A")._src);
+        assertNotNull(code._compunits.get("App/B")._src);
+    }
+
+    @Test public void testMissingDependency() throws Exception {
+        Path root=fixture("missing-");
+        Path src=root.resolve("src"), obj=root.resolve("obj");
+        write(src,"App/A","val value={ -> B.value()+1; };",1000);
+        write(src,"App/B","val value={ -> 5; };",1000);
+        write(src,"App/Main","return A.value();",1000);
+        compile(src,obj,"App/B");
+        stamp(obj.resolve("App/B.o"),2000);
+        compile(src,obj,"App/A");
+        stamp(obj.resolve("App/A.o"),3000);
+        Files.delete(obj.resolve("App/B.o"));
+        CodeGen code=client(src,obj);
+        assertEquals("6",Eval2.eval(code,0));
+        assertNotNull(code._compunits.get("App/A")._src);
+        assertNotNull(code._compunits.get("App/B")._src);
+        Files.delete(src.resolve("App/B.smp"));
+        try {
+            client(src,obj);
+            fail("Missing source and object must not reuse A's inlined body");
+        } catch( RuntimeException e ) {
+            assertTrue(e.getMessage(),e.getMessage().contains("Undefined name 'B'"));
+        }
+    }
+
+    @Test public void testLibraryDependency() throws Exception {
+        Path root=fixture("library-");
+        Path src=root.resolve("src"), obj=root.resolve("obj");
+        Path lib=Files.createDirectory(root.resolve("lib"));
+        var paths=new Ary<>(new String[]{lib.toString(),obj.toString()});
+        library(lib,5);
+        stamp(lib.resolve("LibB.o"),2000);
+        write(src,"App/A","val value={ -> LibB.value()+1; };",1000);
+        write(src,"App/Main","return A.value();",1000);
+        new CodeGen(src.toString(),obj.toString(),paths,"App/A",null,123,true,TypeInteger.BOT)
+            .driver(TestC.CPU_PORT,TestC.CALL_CONVENTION,false,false);
+        stamp(obj.resolve("App/A.o"),3000);
+        CodeGen code=new CodeGen(src.toString(),obj.toString(),paths,"App/Main",null,123,true,TypeInteger.BOT)
+            .driver(CodeGen.Phase.TypeCheck);
+        assertEquals("6",Eval2.eval(code,0));
+        assertNull("Unchanged library inputs permit reuse",code._compunits.get("App/A")._src);
+
+        library(lib,7);
+        stamp(lib.resolve("LibB.o"),4000);
+        code=new CodeGen(src.toString(),obj.toString(),paths,"App/Main",null,123,true,TypeInteger.BOT)
+            .driver(CodeGen.Phase.TypeCheck);
+        assertEquals("8",Eval2.eval(code,0));
+        assertNotNull(code._compunits.get("App/A")._src);
+    }
+
+    private static void library(Path lib, int value) {
+        new CodeGen(null,lib.toString(),null,"LibB","val value={ -> "+value+"; };",123,true,TypeInteger.BOT)
+            .driver(TestC.CPU_PORT,TestC.CALL_CONVENTION,false,false);
+    }
+
+    private static void checkNative(Path obj, Ary<String> libs) throws Exception {
+        Path driver=obj.resolve("driver.c");
+        Files.writeString(driver,"""
+            __attribute__((CALL_CONV)) extern long long run(void) __asm__("App.Main.run");
+            int main(void) { return run()==9 ? 0 : 1; }
+            """);
+        String exe=obj.resolve(TestC.OS.startsWith("Windows")?"test.exe":"test").toString();
+        TestC.linkExe(obj.resolve("App/Main.o").toString(),
+            TestC.CALL_CONVENTION.equals("win64")?"ms_abi":"sysv_abi",driver.toString(),libs,exe);
+        assertEquals("",TestC.exec(TestC.TEST_TIMEOUT_SECONDS,exe));
+    }
+
+    private static Path fixture(String prefix) throws Exception {
+        Path base=Path.of("build/objs/incremental");
+        Files.createDirectories(base);
+        Path root=Files.createTempDirectory(base,prefix);
+        Path src=Files.createDirectory(root.resolve("src"));
+        Path obj=Files.createDirectory(root.resolve("obj"));
+        write(src,"App","val marker=0;",1000);
+        compile(src,obj,"App");
+        stamp(obj.resolve("App.o"),1500);
+        return root;
+    }
+
+    private static void write(Path src, String name, String text, long time) throws Exception {
+        Path path=src.resolve(name+".smp");
+        Files.createDirectories(path.getParent());
+        Files.writeString(path,text);
+        stamp(path,time);
+    }
+
+    private static void stamp(Path path, long time) throws Exception {
+        Files.setLastModifiedTime(path,FileTime.fromMillis(time));
+    }
+
+    private static void compile(Path src, Path obj, String name) {
+        new CodeGen(src.toString(),obj.toString(),null,name,null,123,true,TypeInteger.BOT)
+            .driver(TestC.CPU_PORT,TestC.CALL_CONVENTION,false,false);
+    }
+
+    private static CodeGen client(Path src, Path obj) {
+        return new CodeGen(src.toString(),obj.toString(),null,"App/Main",null,123,true,TypeInteger.BOT)
+            .driver(CodeGen.Phase.TypeCheck);
+    }
+}