Add optional functionality to display source file locations in `outpu…

…t=location `instead of targets.

Added an additional flag `[no]incompatible_display_source_file_location` to override the default behaviour (when false) to print the source file targets instead of their locations. Additionally, the  `relative_locations` flag will similarly display the relative location of the source file.

This #12322 describes the issue and potential migration recipes.

Example of new configurations for blaze query location=output with `incompatible_display_source_file_location` and `relative_locations` flags below:

1. Default behaviour: Displays absolute paths to both BUILD and source file
```
$ bazel query blazetest:main.py --output=location --incompatible_display_source_file_location
/home/tanzhengwei/blazetest/BUILD:1:10: source file /home/tanzhengwei/blazetest/main.py:1:1
```

2. Displays relative paths to both BUILD and source file
```
$ bazel query blazetest:main.py --output=location --relative_locations --incompatible_display_source_file_location
blazetest/BUILD:1:10: source file blazetest/main.py:1:1
```

3. Displays relative path to BUILD file and source file target
```
$ bazel query blazetest:main.py --output=location --relative_locations --noincompatible_display_source_file_location
blazetest/BUILD:1:10: source file //blazetest:main.py
```

4. Displays absolute path to BUILD file and source file target
```
$ bazel query blazetest:main.py --output=location --noincompatible_display_source_file_location
/home/tanzhengwei/blazetest/BUILD:1:10: source file //blazetest:main.py
```

RELNOTES: Added flag `incompatible_display_source_file_location` for `blaze query location=output` to print the location of line 1 of the actual source files instead of the source file targets. Provides a solution to #8900.
PiperOrigin-RevId: 338240601

src/main/java/com/google/devtools/build/lib/query2/common/CommonQueryOptions.java

@@ -23,6 +23,7 @@
 import com.google.devtools.common.options.Option;
 import com.google.devtools.common.options.OptionDocumentationCategory;
 import com.google.devtools.common.options.OptionEffectTag;
+import com.google.devtools.common.options.OptionMetadataTag;
 import com.google.devtools.common.options.OptionsBase;
 import java.util.EnumSet;
 import java.util.List;
@@ -153,6 +154,26 @@ public Set<Setting> toSettings() {
     return settings;
   }
 
+  ///////////////////////////////////////////////////////////
+  // LOCATION OUTPUT FORMATTER OPTIONS                     //
+  ///////////////////////////////////////////////////////////
+
+  // TODO(tanzhengwei): Clean up in next major release
+  @Option(
+      name = "incompatible_display_source_file_location",
+      defaultValue = "false",
+      documentationCategory = OptionDocumentationCategory.QUERY,
+      effectTags = {OptionEffectTag.TERMINAL_OUTPUT},
+      metadataTags = {
+        OptionMetadataTag.INCOMPATIBLE_CHANGE,
+        OptionMetadataTag.TRIGGERED_BY_ALL_INCOMPATIBLE_CHANGES
+      },
+      help =
+          "False by default, displays the target of the source file. "
+              + "If true, displays the location of line 1 of source files in location outputs. "
+              + "This flag only exists for migration purposes.")
+  public boolean displaySourceFileLocation;
+
   ///////////////////////////////////////////////////////////
   // PROTO OUTPUT FORMATTER OPTIONS                        //
   ///////////////////////////////////////////////////////////

src/main/java/com/google/devtools/build/lib/query2/query/output/FormatUtils.java

@@ -15,6 +15,7 @@
 package com.google.devtools.build.lib.query2.query.output;
 
 import com.google.devtools.build.lib.packages.DependencyFilter;
+import com.google.devtools.build.lib.packages.InputFile;
 import com.google.devtools.build.lib.packages.Package;
 import com.google.devtools.build.lib.packages.Rule;
 import com.google.devtools.build.lib.packages.Target;
@@ -80,4 +81,30 @@ static Location getRootRelativeLocation(Location location, @Nullable Package bas
     }
     return location;
   }
+
+  /**
+   * Returns the target label string. For {@link InputFile} targets, displays the location of line 1
+   * of the actual source file by default.
+   *
+   * @param target the target to get the label from
+   * @param displaySourceFileLocation displays the location of line 1 of the actual source file
+   *     instead of its target if true.
+   * @param relativeLocations displays the location of the source file relative to its package's
+   *     source root directory
+   */
+  static String getLabel(
+      Target target, boolean displaySourceFileLocation, boolean relativeLocations) {
+    if (!(target instanceof InputFile) || !displaySourceFileLocation) {
+      return target.getLabel().getDefaultCanonicalForm();
+    }
+
+    // Default behaviour for source files without the incompatible_display_source_file_location flag
+    PathFragment packageDir = target.getPackage().getPackageDirectory().asFragment();
+    Location sourceFileLoc =
+        Location.fromFileLineColumn(packageDir.getRelative(target.getName()).toString(), 1, 1);
+    if (relativeLocations) {
+      sourceFileLoc = getRootRelativeLocation(sourceFileLoc, target.getPackage());
+    }
+    return sourceFileLoc.toString();
+  }
 }

src/main/java/com/google/devtools/build/lib/query2/query/output/LocationOutputFormatter.java

@@ -40,6 +40,7 @@
 class LocationOutputFormatter extends AbstractUnorderedFormatter {
 
   private boolean relativeLocations;
+  private boolean displaySourceFileLocation;
 
   @Override
   public String getName() {
@@ -51,6 +52,7 @@ public void setOptions(
       CommonQueryOptions options, AspectResolver aspectResolver, HashFunction hashFunction) {
     super.setOptions(options, aspectResolver, hashFunction);
     this.relativeLocations = options.relativeLocations;
+    this.displaySourceFileLocation = options.displaySourceFileLocation;
   }
 
   @Override
@@ -85,7 +87,7 @@ public void processOutput(Iterable<Target> partialResult) throws IOException {
               .append(": ")
               .append(target.getTargetKind())
               .append(" ")
-              .append(target.getLabel().getDefaultCanonicalForm())
+              .append(FormatUtils.getLabel(target, displaySourceFileLocation, relativeLocations))
               .append(lineTerm);
         }
       }

src/test/shell/integration/bazel_query_test.sh

@@ -497,6 +497,57 @@ EOF
   expect_log "//foo:foo"
 }
 
+test_location_output_source_files() {
+  rm -rf foo
+  mkdir -p foo
+  cat > foo/BUILD <<EOF
+py_binary(
+  name = "main",
+  srcs = ["main.py"],
+)
+EOF
+  touch foo/main.py || fail "Could not touch foo/main.py"
+
+  # The incompatible_display_source_file_location flag displays the location of
+  # line 1 of the actual source file
+  bazel query \
+    --output=location \
+    --incompatible_display_source_file_location \
+    '//foo:main.py' >& $TEST_log || fail "Expected success"
+  expect_log "source file ${TEST_TMPDIR}/.*/foo/main.py:1:1"
+  expect_not_log "source file //foo:main.py"
+
+  # Default behavior overridden by noincompatible_display_source_file_location
+  # flag to display the source file target instead
+  bazel query \
+    --output=location \
+    --noincompatible_display_source_file_location \
+    '//foo:main.py' >& $TEST_log || fail "Expected success"
+  expect_log "source file //foo:main.py"
+  expect_not_log "source file ${TEST_TMPDIR}/.*/foo/main.py:1:1"
+
+  # Adding relative_locations flag should modify default behavior and
+  # make location of source file be relative
+  bazel query \
+    --output=location \
+    --relative_locations \
+    --incompatible_display_source_file_location \
+    '//foo:main.py' >& $TEST_log || fail "Expected success"
+  expect_log "source file foo/main.py:1:1"
+  expect_not_log "source file ${TEST_TMPDIR}/.*/foo/main.py:1:1"
+
+  # Adding noincompatible_display_source_file_location flag should still
+  # override default behaviour regardless of relative_locations to
+  # display the source file target
+  bazel query --output=location \
+    --relative_locations \
+    --noincompatible_display_source_file_location \
+    '//foo:main.py' >& $TEST_log || fail "Expected success"
+  expect_log "source file //foo:main.py"
+  expect_not_log "source file foo/main.py:1:1"
+  expect_not_log "source file ${TEST_TMPDIR}/.*/foo/main.py:1:1"
+}
+
 function test_subdirectory_named_external() {
   mkdir -p foo/external foo/bar
   cat > foo/external/BUILD <<EOF