Merge pull request #611 from sourcegraph/olafurpg/no-relative-path

Add `-no-relative-path:` flag to control indexing of generated files

Author: olafurpg

semanticdb-javac/defs.bzl

@@ -1,18 +1,20 @@
 """Java rules that automatically register the SemanticDB compiler plugin based on the presence of a string flag."""
-load("@rules_java//java:defs.bzl", native_java_library="java_library", native_java_binary="java_binary")
 
-def java_library(javacopts=[], plugins=[],**kwargs):
-    native_java_library(
-	    javacopts=_actual_javacopts(javacopts),
-	    plugins=_actual_plugins(plugins),
-	    **kwargs)
+load("@rules_java//java:defs.bzl", native_java_binary = "java_binary", native_java_library = "java_library")
 
+def java_library(javacopts = [], plugins = [], **kwargs):
+    native_java_library(
+        javacopts = _actual_javacopts(javacopts),
+        plugins = _actual_plugins(plugins),
+        **kwargs
+    )
 
-def java_binary(javacopts=[], plugins=[],**kwargs):
+def java_binary(javacopts = [], plugins = [], **kwargs):
     native_java_binary(
-	    javacopts=_actual_javacopts(javacopts),
-	    plugins=_actual_plugins(plugins),
-	    **kwargs)
+        javacopts = _actual_javacopts(javacopts),
+        plugins = _actual_plugins(plugins),
+        **kwargs
+    )
 
 def _actual_javacopts(javacopts):
     return select({

semanticdb-javac/src/main/java/com/sourcegraph/semanticdb_javac/NoRelativePathMode.java

@@ -0,0 +1,28 @@
+package com.sourcegraph.semanticdb_javac;
+
+/**
+ * Configuration options to determine how semanticdb-javac should handle files that have no good
+ * relative paths.
+ *
+ * <p>When indexing a file at an absolute path /project/src/main/example/Foo.java, SemanticDB needs
+ * to know the "sourceroot" path /project in order to relativize the path of the source file into
+ * src/main/example/Foo.java. This configuration option determines what the compiler plugin should
+ * do when it's not able to find a good relative path.
+ */
+public enum NoRelativePathMode {
+
+  /**
+   * Come up with a unique relative path for the SemanticDB path with no guarantee that this path
+   * corresponds to the original path of the generated source file.
+   */
+  INDEX_ANYWAY,
+
+  /** Silently ignore the file, don't index it. */
+  SKIP,
+
+  /** Report an error message and fail the compilation. */
+  ERROR,
+
+  /** Ignore the file, but print a message explaining it's ignored. */
+  WARNING
+}

semanticdb-javac/src/main/java/com/sourcegraph/semanticdb_javac/SemanticdbJavacOptions.java

@@ -5,6 +5,8 @@
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.stream.Collectors;
 import javax.tools.FileObject;
 import javax.tools.JavaFileManager;
 import javax.tools.JavaFileObject;
@@ -26,6 +28,7 @@ public class SemanticdbJavacOptions {
   public final ArrayList<String> errors;
   public boolean alreadyReportedErrors = false;
   public UriScheme uriScheme = UriScheme.DEFAULT;
+  public NoRelativePathMode noRelativePath = NoRelativePathMode.INDEX_ANYWAY;
   public Path generatedTargetRoot;
 
   public static String stubClassName = "META-INF-semanticdb-stub";
@@ -60,6 +63,31 @@ public static SemanticdbJavacOptions parse(String[] args, Context ctx) {
         result.sourceroot = Paths.get(arg.substring("-sourceroot:".length())).normalize();
       } else if (arg.equals("-build-tool:sbt") || arg.equals("-build-tool:mill")) {
         result.uriScheme = UriScheme.ZINC;
+      } else if (arg.startsWith("-no-relative-path:")) {
+        String value = arg.substring("-no-relative-path:".length());
+        switch (value) {
+          case "index_anyway":
+            result.noRelativePath = NoRelativePathMode.INDEX_ANYWAY;
+            break;
+          case "skip":
+            result.noRelativePath = NoRelativePathMode.SKIP;
+            break;
+          case "error":
+            result.noRelativePath = NoRelativePathMode.ERROR;
+            break;
+          case "warning":
+            result.noRelativePath = NoRelativePathMode.WARNING;
+            break;
+          default:
+            String validValues =
+                Arrays.stream(NoRelativePathMode.values())
+                    .map(NoRelativePathMode::toString)
+                    .collect(Collectors.joining(", "));
+            result.errors.add(
+                String.format(
+                    "unknown -no-relative-path mode '%s'. Valid values are %s.",
+                    value, validValues));
+        }
       } else if (arg.equals("-build-tool:bazel")) {
         result.uriScheme = UriScheme.BAZEL;
         useJavacClassesDir = true;

semanticdb-javac/src/main/java/com/sourcegraph/semanticdb_javac/SemanticdbTaskListener.java

@@ -6,7 +6,6 @@
 import com.sun.source.util.Trees;
 import com.sun.tools.javac.model.JavacTypes;
 
-import javax.tools.Diagnostic;
 import javax.tools.JavaFileObject;
 import java.io.IOException;
 import java.net.URI;
@@ -25,7 +24,7 @@ public final class SemanticdbTaskListener implements TaskListener {
   private final SemanticdbReporter reporter;
   private final JavacTypes javacTypes;
   private final Trees trees;
-  private boolean sourceGeneratorsMessageIsLogged = false;
+  private int noRelativePathCounter = 0;
 
   public SemanticdbTaskListener(
       SemanticdbJavacOptions options,
@@ -130,7 +129,11 @@ public static Path absolutePathFromUri(SemanticdbJavacOptions options, JavaFileO
           new String[] {"SimpleFileObject[", "DirectoryFileObject["};
       for (String pattern : knownBazelToStringPatterns) {
         if (toString.startsWith(pattern) && toString.endsWith("]")) {
-          return Paths.get(toString.substring(pattern.length(), toString.length() - 1));
+          Path path = Paths.get(toString.substring(pattern.length(), toString.length() - 1));
+          if (path.isAbsolute()) {
+            return path;
+          }
+          return options.sourceroot.resolve(path);
         }
       }
       throw new IllegalArgumentException("unsupported source file: " + toString);
@@ -190,32 +193,41 @@ private Result<Path, String> semanticdbOutputPath(SemanticdbJavacOptions options
               .resolve(relativePath)
               .resolveSibling(filename);
       return Result.ok(semanticdbOutputPath);
-    } else {
-
-      if (options.uriScheme == UriScheme.BAZEL && options.generatedTargetRoot != null) {
-        try {
-          if (absolutePath.toRealPath().startsWith(options.generatedTargetRoot)) {
-            if (!sourceGeneratorsMessageIsLogged) {
-              sourceGeneratorsMessageIsLogged = true;
-              reporter.info(
-                  "Usage of source generators detected - scip-java does not produce SemanticDB files for generated files.\n"
-                      + "This message is logged only once",
-                  e);
-            }
-
-            return null;
-          }
-        } catch (IOException exc) {
-          reporter.exception(exc, e);
-          return null;
-        }
-      }
+    }
 
-      return Result.error(
-          String.format(
-              "sourceroot '%s does not contain path '%s'. To fix this problem, update the -sourceroot flag to "
-                  + "be a parent directory of this source file.",
-              options.sourceroot, absolutePath));
+    switch (options.noRelativePath) {
+      case INDEX_ANYWAY:
+        // Come up with a unique relative path for this file even if it's not under the sourceroot.
+        // By indexing auto-generated files, we collect SymbolInformation for auto-generated symbol,
+        // which results in more useful hover tooltips in the editor.
+        // In the future, we may want to additionally embed the full text contents of these files
+        // so that it's possible to browse generated files with precise code navigation.
+        String uniqueFilename =
+            String.format("%d.%s.semanticdb", ++noRelativePathCounter, absolutePath.getFileName());
+        Path semanticdbOutputPath =
+            options
+                .targetroot
+                .resolve("META-INF")
+                .resolve("semanticdb")
+                .resolve("no-relative-path")
+                .resolve(uniqueFilename);
+        return Result.ok(semanticdbOutputPath);
+      case WARNING:
+        reporter.info(
+            String.format(
+                "Skipping file '%s' because it is not under the sourceroot '%s'",
+                absolutePath, options.sourceroot),
+            e);
+      case SKIP:
+        return null;
+      case ERROR:
+      default:
+        return Result.error(
+            String.format(
+                "Unable to detect the relative path of '%s'. A common reason for this error is that the file is that this file is auto-generated. "
+                    + "To fix this problem, either configure the -sourceroot:PATH flag to be the parent directory of all indexed files, or "
+                    + "configure -no-relative-path:VALUE flag to have one of the following values: index_anyway, skip, warning.",
+                absolutePath));
     }
   }
 }

semanticdb-javac/src/main/java/com/sourcegraph/semanticdb_javac/SemanticdbVisitor.java

@@ -436,9 +436,12 @@ private Semanticdb.Access semanticdbAccess(Symbol sym) {
 
   private String semanticdbUri() {
     Path absolutePath = SemanticdbTaskListener.absolutePathFromUri(options, event.getSourceFile());
-    Path relativePath = options.sourceroot.relativize(absolutePath);
+    Path uriPath =
+        absolutePath.startsWith(options.sourceroot)
+            ? options.sourceroot.relativize(absolutePath)
+            : absolutePath;
     StringBuilder out = new StringBuilder();
-    Iterator<Path> it = relativePath.iterator();
+    Iterator<Path> it = uriPath.iterator();
     if (it.hasNext()) out.append(it.next().getFileName().toString());
     while (it.hasNext()) {
       Path part = it.next();
@@ -447,6 +450,10 @@ private String semanticdbUri() {
     return out.toString();
   }
 
+  private Path semanticdbPath() {
+    return SemanticdbTaskListener.absolutePathFromUri(options, event.getSourceFile());
+  }
+
   private Semanticdb.Documentation semanticdbDocumentation(Symbol sym) {
     try {
       Elements elements = task.getElements();