Add lib-srcs to show all sources mentioned in rules.

Counter part of `lib-headers` that now also is accessible via
`lib-hdrs` for symmetry and brevity (and deprecating the `lib-headers`
command).

Author: hzeller

bant/bant.cc

@@ -128,8 +128,10 @@ Commands (unique prefix sufficient):
                      → 2 column table: (target, dependency*)
     has-dependent  : List cc library targets and the libraries that depend on it
                      → 2 column table: (target, dependent*)
-    lib-headers    : Print headers provided by cc_library()s matching pattern.
+    lib-hdrs       : Print headers provided by cc_library()s matching pattern.
                      → 2 column table: (header-filename, cc-library-target)
+    lib-srcs       : Print sources provided by cc_library()s matching pattern.
+                     → 2 column table: (source-filename, cc-library-target)
     genrule-outputs: Print generated files by genrule()s matching pattern.
                      → 2 column table: (filename, genrule-target)
 

bant/cli-commands.cc

@@ -68,6 +68,7 @@ enum class Command {
   kListLeafs,
   kListWorkkspace,
   kLibraryHeaders,
+  kLibrarySources,
   kAliasedBy,
   kGenruleOutputs,
   kDWYU,
@@ -210,6 +211,7 @@ CliStatus RunCommand(Session &session, Command cmd,
   case Command::kDWYU:
   case Command::kParse:
   case Command::kLibraryHeaders:
+  case Command::kLibrarySources:
   case Command::kGenruleOutputs:
   case Command::kListTargets:
   case Command::kListLeafs:
@@ -274,6 +276,12 @@ CliStatus RunCommand(Session &session, Command cmd,
       ExtractHeaderToLibMapping(project, session.info()));
     break;
 
+  case Command::kLibrarySources:  //
+    bant::PrintProvidedSources(
+      session, "source", print_pattern,
+      ExtractSourceToLibMapping(project, session.info()));
+    break;
+
   case Command::kGenruleOutputs:
     bant::PrintProvidedSources(
       session, "generated-file", print_pattern,
@@ -377,7 +385,9 @@ CliStatus RunCliCommand(Session &session, std::span<std::string_view> args) {
     {"list-targets", Command::kListTargets},
     {"list-leafs", Command::kListLeafs},
     {"workspace", Command::kListWorkkspace},
-    {"lib-headers", Command::kLibraryHeaders},
+    {"lib-hdrs", Command::kLibraryHeaders},
+    {"lib-headers", Command::kLibraryHeaders},  // deprecated
+    {"lib-srcs", Command::kLibrarySources},
     {"aliased-by", Command::kAliasedBy},
     {"depends-on", Command::kDependsOn},
     {"has-dependents", Command::kHasDependents},

bant/explore/header-providers.cc

@@ -112,6 +112,7 @@ static void IterateCCLibraryHeaders(const ParsedBuildFile &build_file,
   // Unfortunately, grpc does not simply have a cc_library(), but its own
   // rule or macro, making it invisible if we just look at cc_library.
   // Hacking it up here to look also for the grpc version.
+  // TODO: this might be doable with macros these days ?
   static const std::initializer_list<std::string_view> kInterestingLibRules{
     "cc_library",
     "grpc_cc_library",
@@ -336,6 +337,35 @@ ProvidedFromTargetSet ExtractHeaderToLibMapping(const ParsedProject &project,
   return result;
 }
 
+static void AppendCCLibrarySources(const ParsedBuildFile &build_file,
+                                   std::ostream &info_out,
+                                   ProvidedFromTargetSet &result) {
+  query::FindTargets(
+    build_file.ast, {"cc_library"}, [&](const query::Result &cc_lib) {
+      auto cc_library = build_file.package.QualifiedTarget(cc_lib.name);
+      if (!cc_library.has_value()) return;
+
+      auto srcs = query::ExtractStringList(cc_lib.srcs_list);
+      for (const std::string_view src : srcs) {
+        const std::string src_fqn = build_file.package.QualifiedFile(src);
+        result[src_fqn].emplace(*cc_library);
+      }
+    });
+}
+
+ProvidedFromTargetSet ExtractSourceToLibMapping(const ParsedProject &project,
+                                                std::ostream &info_out) {
+  ProvidedFromTargetSet result;
+
+  for (const auto &[_, build_file] : project.ParsedFiles()) {
+    if (!build_file->ast) continue;
+
+    AppendCCLibrarySources(*build_file, info_out, result);
+  }
+
+  return result;
+}
+
 ProvidedFromTarget ExtractGeneratedFromGenrule(const ParsedProject &project,
                                                std::ostream &info_out,
                                                bool suffix_index) {

bant/explore/header-providers.h

@@ -48,6 +48,11 @@ ProvidedFromTargetSet ExtractHeaderToLibMapping(const ParsedProject &project,
                                                 std::ostream &info_out,
                                                 bool suffix_index = false);
 
+// Similar for sources. Much simpler, as we don't deal with multiple search
+// paths. Mostly just for printing.
+ProvidedFromTargetSet ExtractSourceToLibMapping(const ParsedProject &project,
+                                                std::ostream &info_out);
+
 // Find all the output generated by genrules. Should really only be 1:1.
 // If "suffix_index" is set, output is compatible with FinxBySuffix().
 ProvidedFromTarget ExtractGeneratedFromGenrule(const ParsedProject &project,

bant/explore/header-providers_test.cc

@@ -103,6 +103,24 @@ cc_library(
                                         Ts("//prefix/dir:baz"))));
 }
 
+// Sources are much simpler. Just matter-of-fact, no include path fiddling.
+TEST(SourceToLibMapping, CCRuleExtraction) {
+  ParsedProjectTestUtil pp;
+  pp.Add("//some/path", R"(
+cc_library(
+  name = "foo",
+  srcs = ["foo.cc", "bar.cc"],
+  hdrs = ["foo.h"]
+)
+)");
+  std::stringstream log_absorb;
+  auto srcs_map = ExtractSourceToLibMapping(pp.project(), log_absorb);
+  EXPECT_THAT(srcs_map,
+              Contains(Pair("some/path/foo.cc", Ts("//some/path:foo"))));
+  EXPECT_THAT(srcs_map,
+              Contains(Pair("some/path/bar.cc", Ts("//some/path:foo"))));
+}
+
 TEST(HeaderToLibMapping, InludePathsAreRelativePathCanonicalized) {
   ParsedProjectTestUtil pp;
   pp.Add("//", R"(