Make lib-hdrs and lib-srcs the simple output; lib-headers all reachable paths.

lib-headers emits all reachable ways how to get to a header (e.g. due
to `includes = []`, while lib-hdrs and lib-srcs just plainly emit all
the direct paths.

Author: hzeller

bant/bant.cc

@@ -135,6 +135,10 @@ Commands (unique prefix sufficient):
                      → 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)
+    lib-headers     : like lib-hdrs, but expands all reachable paths due to
+                      includes = [] expansion; so same header can show up
+                      multiple times.
+                     → 2 column table: (header-filename, cc-library-target)
     genrule-outputs: Print generated files by genrule()s matching pattern.
                      → 2 column table: (filename, genrule-target)
 

bant/cli-commands.cc

@@ -67,8 +67,9 @@ enum class Command {
   kListTargets,
   kListLeafs,
   kListWorkkspace,
-  kLibraryHeaders,
-  kLibrarySources,
+  kLibraryHdrs,
+  kLibrarySrcs,
+  kExpandedLibraryHeaders,
   kAliasedBy,
   kGenruleOutputs,
   kDWYU,
@@ -210,8 +211,9 @@ CliStatus RunCommand(Session &session, Command cmd,
   switch (cmd) {
   case Command::kDWYU:
   case Command::kParse:
-  case Command::kLibraryHeaders:
-  case Command::kLibrarySources:
+  case Command::kLibraryHdrs:
+  case Command::kExpandedLibraryHeaders:
+  case Command::kLibrarySrcs:
   case Command::kGenruleOutputs:
   case Command::kListTargets:
   case Command::kListLeafs:
@@ -270,16 +272,24 @@ CliStatus RunCommand(Session &session, Command cmd,
     }
     break;
   }
-  case Command::kLibraryHeaders:  //
+  case Command::kExpandedLibraryHeaders:  //
     bant::PrintProvidedSources(
       session, "header", print_pattern,
-      ExtractHeaderToLibMapping(project, session.info()));
+      ExtractExpandedHeaderToLibMapping(project, session.info()));
     break;
 
-  case Command::kLibrarySources:  //
+  case Command::kLibrarySrcs:  //
     bant::PrintProvidedSources(
       session, "source", print_pattern,
-      ExtractSourceToLibMapping(project, session.info()));
+      ExtractComponentToLibMapping(project, ExtractComponent::kSrcs,
+                                   session.info()));
+    break;
+
+  case Command::kLibraryHdrs:  //
+    bant::PrintProvidedSources(
+      session, "header", print_pattern,
+      ExtractComponentToLibMapping(project, ExtractComponent::kHdrs,
+                                   session.info()));
     break;
 
   case Command::kGenruleOutputs:
@@ -385,9 +395,9 @@ CliStatus RunCliCommand(Session &session, std::span<std::string_view> args) {
     {"list-targets", Command::kListTargets},
     {"list-leafs", Command::kListLeafs},
     {"workspace", Command::kListWorkkspace},
-    {"lib-hdrs", Command::kLibraryHeaders},
-    {"lib-headers", Command::kLibraryHeaders},  // deprecated
-    {"lib-srcs", Command::kLibrarySources},
+    {"lib-hdrs", Command::kLibraryHdrs},
+    {"lib-srcs", Command::kLibrarySrcs},
+    {"lib-headers", Command::kExpandedLibraryHeaders},
     {"aliased-by", Command::kAliasedBy},
     {"depends-on", Command::kDependsOn},
     {"has-dependents", Command::kHasDependents},

bant/explore/header-providers.cc

@@ -316,9 +316,8 @@ static void AppendProtoLibraryHeaders(
 }
 }  // namespace
 
-ProvidedFromTargetSet ExtractHeaderToLibMapping(const ParsedProject &project,
-                                                std::ostream &info_out,
-                                                bool suffix_index) {
+ProvidedFromTargetSet ExtractExpandedHeaderToLibMapping(
+  const ParsedProject &project, std::ostream &info_out, bool suffix_index) {
   ProvidedFromTargetSet result;
 
   const auto aliased_by_index = ExtractAliasedBy(project);
@@ -337,30 +336,27 @@ 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 ExtractComponentToLibMapping(const ParsedProject &project,
+                                                   ExtractComponent which,
+                                                   std::ostream &info_out) {
   ProvidedFromTargetSet result;
 
   for (const auto &[_, build_file] : project.ParsedFiles()) {
     if (!build_file->ast) continue;
 
-    AppendCCLibrarySources(*build_file, info_out, 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((which == ExtractComponent::kSrcs)
+                                               ? cc_lib.srcs_list
+                                               : cc_lib.hdrs_list);
+        for (const std::string_view src : srcs) {
+          const std::string src_fqn = build_file->package.QualifiedFile(src);
+          result[src_fqn].emplace(*cc_library);
+        }
+      });
   }
 
   return result;

bant/explore/header-providers.h

@@ -42,16 +42,23 @@ using ProvidedFromTarget = OneToOne<std::string, BazelTarget>;
 using ProvidedFromTargetSet = OneToNSet<std::string, BazelTarget>;
 
 // Givent the "project", creates a mapping of all headers that are exported by
-// cc_library() targets to their respective targets.
+// cc_library() targets to their respective targets. If a header can be reached
+// multiple ways (e.g. due to include = [] directives), thes are also part
+// of the target set.
 // If "suffix_index" is set, output is compatible with FinxBySuffix()
-ProvidedFromTargetSet ExtractHeaderToLibMapping(const ParsedProject &project,
-                                                std::ostream &info_out,
-                                                bool suffix_index = false);
+ProvidedFromTargetSet ExtractExpandedHeaderToLibMapping(
+  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);
+// Unlike the Expanded*, this is much simpler, as we don't deal with multiple
+// search paths. Just extract the mentioned component.
+enum class ExtractComponent {
+  kSrcs,
+  kHdrs,
+};
+ProvidedFromTargetSet ExtractComponentToLibMapping(const ParsedProject &project,
+                                                   ExtractComponent which,
+                                                   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().

bant/explore/header-providers_test.cc

@@ -85,7 +85,7 @@ cc_library(
 )
 )");
   std::stringstream log_absorb;
-  auto header_map = ExtractHeaderToLibMapping(pp.project(), log_absorb);
+  auto header_map = ExtractExpandedHeaderToLibMapping(pp.project(), log_absorb);
   EXPECT_THAT(header_map,
               Contains(Pair("some/path/foo.h", Ts("//some/path:foo"))));
 
@@ -110,15 +110,20 @@ TEST(SourceToLibMapping, CCRuleExtraction) {
 cc_library(
   name = "foo",
   srcs = ["foo.cc", "bar.cc"],
-  hdrs = ["foo.h"]
+  hdrs = ["baz.h"]
 )
 )");
   std::stringstream log_absorb;
-  auto srcs_map = ExtractSourceToLibMapping(pp.project(), log_absorb);
+  auto srcs_map = ExtractComponentToLibMapping(
+    pp.project(), ExtractComponent::kSrcs, 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"))));
+  auto hdrs_map = ExtractComponentToLibMapping(
+    pp.project(), ExtractComponent::kHdrs, log_absorb);
+  EXPECT_THAT(hdrs_map,
+              Contains(Pair("some/path/baz.h", Ts("//some/path:foo"))));
 }
 
 TEST(HeaderToLibMapping, InludePathsAreRelativePathCanonicalized) {
@@ -140,7 +145,7 @@ cc_library(
 )");
 
   std::stringstream log_absorb;
-  auto header_map = ExtractHeaderToLibMapping(pp.project(), log_absorb);
+  auto header_map = ExtractExpandedHeaderToLibMapping(pp.project(), log_absorb);
   EXPECT_THAT(header_map, Contains(Pair("foo.h", Ts("//:foo"))));
   EXPECT_THAT(header_map, Contains(Pair("bar.h", Ts("//:bar"))));
 }
@@ -161,7 +166,7 @@ cc_library(
 )
 )");
   std::stringstream log_absorb;
-  auto header_map = ExtractHeaderToLibMapping(pp.project(), log_absorb);
+  auto header_map = ExtractExpandedHeaderToLibMapping(pp.project(), log_absorb);
   const ProvidedFromTargetSet::mapped_type expected_set{T("//some/path:foo"),
                                                         T("//some/path:bar")};
   EXPECT_THAT(header_map, Contains(Pair("some/path/foo.h", expected_set)));
@@ -188,7 +193,7 @@ cc_grpc_library(              # GRPC form of a proto library.
 )
 )");
   std::stringstream log_absorb;
-  auto header_map = ExtractHeaderToLibMapping(pp.project(), log_absorb);
+  auto header_map = ExtractExpandedHeaderToLibMapping(pp.project(), log_absorb);
   EXPECT_THAT(header_map, Contains(Pair("ptest/data.pb.h", Ts("//ptest:foo"))));
   EXPECT_THAT(header_map,
               Contains(Pair("ptest/general.pb.h", Ts("//ptest:foo"))));

bant/tool/dwyu.cc

@@ -671,8 +671,9 @@ DWYUGenerator::DWYUGenerator(Session &session, const ParsedProject &project,
   Stat &stats = session_.GetStatsFor("DWYU preparation", "indexed targets");
   const ScopedTimer timer(&stats.duration);
 
-  headers_from_libs_ = ExtractHeaderToLibMapping(project, session.info(),
-                                                 /*suffix_index=*/true);
+  headers_from_libs_ =
+    ExtractExpandedHeaderToLibMapping(project, session.info(),
+                                      /*suffix_index=*/true);
   files_from_genrules_ = ExtractGeneratedFromGenrule(project, session.info());
   InitKnownLibraries();
   stats.count = known_libs_.size();