Support for source_target_relative expansion in GN

tools/gn/substitution_writer_unittest.cc

Index: tools/gn/substitution_writer_unittest.cc
diff --git a/tools/gn/substitution_writer_unittest.cc b/tools/gn/substitution_writer_unittest.cc
index d252c79f54cbd5d4cf250bbd4099a80bafbc529a..d98d4cee5f5ef18060d2c28e437f081c72e042e9 100644
--- a/tools/gn/substitution_writer_unittest.cc
+++ b/tools/gn/substitution_writer_unittest.cc
@@ -43,7 +43,7 @@ TEST(SubstitutionWriter, ApplyPatternToSource) {
                             nullptr, &err));
 
   SourceFile result = SubstitutionWriter::ApplyPatternToSource(
-      setup.settings(), pattern, SourceFile("//foo/bar/myfile.txt"));
+      nullptr, setup.settings(), pattern, SourceFile("//foo/bar/myfile.txt"));
   ASSERT_EQ("//out/Debug/gen/foo/bar/myfile.tmp", result.value());
 }
 
@@ -56,7 +56,7 @@ TEST(SubstitutionWriter, ApplyPatternToSourceAsOutputFile) {
                             nullptr, &err));
 
   OutputFile result = SubstitutionWriter::ApplyPatternToSourceAsOutputFile(
-      setup.settings(), pattern, SourceFile("//foo/bar/myfile.txt"));
+      nullptr, setup.settings(), pattern, SourceFile("//foo/bar/myfile.txt"));
   ASSERT_EQ("gen/foo/bar/myfile.tmp", result.value());
 }
 
@@ -73,7 +73,8 @@ TEST(SubstitutionWriter, WriteNinjaVariablesForSource) {
 
   std::ostringstream out;
   SubstitutionWriter::WriteNinjaVariablesForSource(
-      setup.settings(), SourceFile("//foo/bar/baz.txt"), types, options, out);
+      nullptr, setup.settings(), SourceFile("//foo/bar/baz.txt"), types,
+      options, out);
 
   // The "source" should be skipped since that will expand to $in which is
   // implicit.
@@ -103,10 +104,17 @@ TEST(SubstitutionWriter, WriteWithNinjaVariables) {
 
 TEST(SubstitutionWriter, SourceSubstitutions) {
   TestWithScope setup;
+  Err err;
+
+  Target target(setup.settings(), Label(SourceDir("//foo/bar/"), "baz"));
+  target.set_output_type(Target::STATIC_LIBRARY);
+  target.SetToolchain(setup.toolchain());
+  ASSERT_TRUE(target.OnResolved(&err));
 
   // Call to get substitutions relative to the build dir.
   #define GetRelSubst(str, what) \
       SubstitutionWriter::GetSourceSubstitution( \
+          &target, \
           setup.settings(), \
           SourceFile(str), \
           what, \
@@ -116,6 +124,7 @@ TEST(SubstitutionWriter, SourceSubstitutions) {
   // Call to get absolute directory substitutions.
   #define GetAbsSubst(str, what) \
       SubstitutionWriter::GetSourceSubstitution( \
+          &target, \
           setup.settings(), \
           SourceFile(str), \
           what, \
@@ -175,6 +184,11 @@ TEST(SubstitutionWriter, SourceSubstitutions) {
   EXPECT_EQ(".",
             GetRelSubst("//baz.txt", SUBSTITUTION_SOURCE_ROOT_RELATIVE_DIR));
 
+  EXPECT_EQ("baz.txt",
+      GetRelSubst("//foo/bar/baz.txt", SUBSTITUTION_SOURCE_TARGET_RELATIVE));
+  EXPECT_EQ("baz.txt",
+      GetAbsSubst("//foo/bar/baz.txt", SUBSTITUTION_SOURCE_TARGET_RELATIVE));
+
   #undef GetAbsSubst
   #undef GetRelSubst
 }