[lldb] Refactor TypeQuery::ContextMatches, take 2 (llvm#101333)

This is an alternative, much simpler implementation of llvm#99305. In this
version I replace the AnyModule wildcard match with a special TypeQuery
flag which achieves (mostly) the same thing.

It is a preparatory step for teaching ContextMatches about anonymous
namespaces. It started out as a way to remove the assumption that the
pattern and target contexts must be of the same length -- that's will
not be correct with anonymous namespaces, and probably isn't even
correct right now for AnyModule matches.

Author: labath

lldb/include/lldb/Symbol/Type.h

@@ -65,11 +65,6 @@ struct CompilerContext {
 llvm::raw_ostream &operator<<(llvm::raw_ostream &os,
                               const CompilerContext &rhs);
 
-/// Match \p context_chain against \p pattern, which may contain "Any"
-/// kinds. The \p context_chain should *not* contain any "Any" kinds.
-bool contextMatches(llvm::ArrayRef<CompilerContext> context_chain,
-                    llvm::ArrayRef<CompilerContext> pattern);
-
 FLAGS_ENUM(TypeQueryOptions){
     e_none = 0u,
     /// If set, TypeQuery::m_context contains an exact context that must match
@@ -79,10 +74,13 @@ FLAGS_ENUM(TypeQueryOptions){
     /// If set, TypeQuery::m_context is a clang module compiler context. If not
     /// set TypeQuery::m_context is normal type lookup context.
     e_module_search = (1u << 1),
+    /// If set, the query will ignore all Module entries in the type context,
+    /// even for exact matches.
+    e_ignore_modules = (1u << 2),
     /// When true, the find types call should stop the query as soon as a single
     /// matching type is found. When false, the type query should find all
     /// matching types.
-    e_find_one = (1u << 2),
+    e_find_one = (1u << 3),
 };
 LLDB_MARK_AS_BITMASK_ENUM(TypeQueryOptions)
 
@@ -264,6 +262,10 @@ class TypeQuery {
   bool LanguageMatches(lldb::LanguageType language) const;
 
   bool GetExactMatch() const { return (m_options & e_exact_match) != 0; }
+
+  bool GetIgnoreModules() const { return (m_options & e_ignore_modules) != 0; }
+  void SetIgnoreModules() { m_options &= ~e_ignore_modules; }
+
   /// The \a m_context can be used in two ways: normal types searching with
   /// the context containing a stanadard declaration context for a type, or
   /// with the context being more complete for exact matches in clang modules.

lldb/include/lldb/lldb-private-enumerations.h

@@ -207,8 +207,6 @@ enum class CompilerContextKind : uint16_t {
   Builtin = 1 << 10,
 
   Any = 1 << 15,
-  /// Match 0..n nested modules.
-  AnyModule = Any | Module,
   /// Match any type.
   AnyType = Any | ClassOrStruct | Union | Enum | Typedef | Builtin,
   /// Math any declaration context.

lldb/source/Symbol/Type.cpp

@@ -6,7 +6,9 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include <algorithm>
 #include <cstdio>
+#include <iterator>
 #include <optional>
 
 #include "lldb/Core/Module.h"
@@ -30,6 +32,7 @@
 #include "lldb/Target/Process.h"
 #include "lldb/Target/Target.h"
 #include "lldb/lldb-enumerations.h"
+#include "lldb/lldb-private-enumerations.h"
 
 #include "llvm/ADT/StringRef.h"
 
@@ -43,35 +46,6 @@ llvm::raw_ostream &lldb_private::operator<<(llvm::raw_ostream &os,
   return os << lldb_stream.GetString();
 }
 
-bool lldb_private::contextMatches(llvm::ArrayRef<CompilerContext> context_chain,
-                                  llvm::ArrayRef<CompilerContext> pattern) {
-  auto ctx = context_chain.begin();
-  auto ctx_end = context_chain.end();
-  for (const CompilerContext &pat : pattern) {
-    // Early exit if the pattern is too long.
-    if (ctx == ctx_end)
-      return false;
-    if (*ctx != pat) {
-      // Skip any number of module matches.
-      if (pat.kind == CompilerContextKind::AnyModule) {
-        // Greedily match 0..n modules.
-        ctx = std::find_if(ctx, ctx_end, [](const CompilerContext &ctx) {
-          return ctx.kind != CompilerContextKind::Module;
-        });
-        continue;
-      }
-      // See if there is a kind mismatch; they should have 1 bit in common.
-      if (((uint16_t)ctx->kind & (uint16_t)pat.kind) == 0)
-        return false;
-      // The name is ignored for AnyModule, but not for AnyType.
-      if (pat.kind != CompilerContextKind::AnyModule && ctx->name != pat.name)
-        return false;
-    }
-    ++ctx;
-  }
-  return true;
-}
-
 static CompilerContextKind ConvertTypeClass(lldb::TypeClass type_class) {
   if (type_class == eTypeClassAny)
     return CompilerContextKind::AnyType;
@@ -153,19 +127,36 @@ void TypeQuery::SetLanguages(LanguageSet languages) {
 
 bool TypeQuery::ContextMatches(
     llvm::ArrayRef<CompilerContext> context_chain) const {
-  if (GetExactMatch() || context_chain.size() == m_context.size())
-    return ::contextMatches(context_chain, m_context);
+  auto ctx = context_chain.rbegin(), ctx_end = context_chain.rend();
+  for (auto pat = m_context.rbegin(), pat_end = m_context.rend();
+       pat != pat_end;) {
+
+    if (ctx == ctx_end)
+      return false; // Pattern too long.
+
+    // See if there is a kind mismatch; they should have 1 bit in common.
+    if ((ctx->kind & pat->kind) == CompilerContextKind())
+      return false;
+
+    if (ctx->name != pat->name)
+      return false;
+
+    ++ctx;
+    ++pat;
+  }
+
+  // Skip over any remaining module entries if we were asked to do that.
+  while (GetIgnoreModules() && ctx != ctx_end &&
+         ctx->kind == CompilerContextKind::Module)
+    ++ctx;
 
-  // We don't have an exact match, we need to bottom m_context.size() items to
-  // match for a successful lookup.
-  if (context_chain.size() < m_context.size())
-    return false; // Not enough items in context_chain to allow for a match.
+  // At this point, we have exhausted the pattern and we have a partial match at
+  // least. If that's all we're looking for, we're done.
+  if (!GetExactMatch())
+    return true;
 
-  size_t compare_count = context_chain.size() - m_context.size();
-  return ::contextMatches(
-      llvm::ArrayRef<CompilerContext>(context_chain.data() + compare_count,
-                                      m_context.size()),
-      m_context);
+  // We have an exact match if we've exhausted the target context as well.
+  return ctx == ctx_end;
 }
 
 bool TypeQuery::LanguageMatches(lldb::LanguageType language) const {
@@ -223,9 +214,6 @@ void CompilerContext::Dump(Stream &s) const {
   case CompilerContextKind::Typedef:
     s << "Typedef";
     break;
-  case CompilerContextKind::AnyModule:
-    s << "AnyModule";
-    break;
   case CompilerContextKind::AnyType:
     s << "AnyType";
     break;

lldb/test/Shell/SymbolFile/DWARF/clang-gmodules-type-lookup.c

@@ -6,8 +6,9 @@
 // RUN: %clangxx_host -g -gmodules -fmodules -std=c99 -x c-header %S/Inputs/pch.h -g -c -o %t.pch
 // RUN: %clangxx_host -g -gmodules -fmodules -std=c99 -x c -include-pch %t.pch %s -c -o %t.o
 // RUN: %clangxx_host %t.o -o %t.exe
-// RUN: lldb-test symbols -dump-clang-ast -find type --language=C99 \
-// RUN:   -compiler-context 'AnyModule:*,ClassOrStruct:TypeFromPCH' %t.exe | FileCheck %s
+// RUN: lldb-test symbols -dump-clang-ast -find type --find-in-any-module \
+// RUN:   --language=C99 -compiler-context 'ClassOrStruct:TypeFromPCH' \
+// RUN:   %t.exe | FileCheck %s
 
 anchor_t anchor;
 

lldb/test/Shell/SymbolFile/DWARF/x86/compilercontext.ll

@@ -9,11 +9,8 @@
 ; RUN: lldb-test symbols %t.o -find=type --language=C99 \
 ; RUN:   -compiler-context="Module:CModule,Module:SubModule,ClassOrStruct:FromSubmodule" \
 ; RUN:   | FileCheck %s
-; RUN: lldb-test symbols %t.o -find=type --language=C99 \
-; RUN:   -compiler-context="Module:CModule,AnyModule:*,ClassOrStruct:FromSubmodule" \
-; RUN:   | FileCheck %s
-; RUN: lldb-test symbols %t.o -find=type --language=C99 \
-; RUN:   -compiler-context="AnyModule:*,ClassOrStruct:FromSubmodule" \
+; RUN: lldb-test symbols %t.o -find=type -find-in-any-module --language=C99 \
+; RUN:   -compiler-context="ClassOrStruct:FromSubmodule" \
 ; RUN:   | FileCheck %s
 ; RUN: lldb-test symbols %t.o -find=type --language=C99 \
 ; RUN:   -compiler-context="Module:CModule,Module:SubModule,AnyType:FromSubmodule" \

lldb/tools/lldb-test/lldb-test.cpp

@@ -194,6 +194,12 @@ static cl::opt<std::string> CompilerContext(
     cl::desc("Specify a compiler context as \"kind:name,...\"."),
     cl::value_desc("context"), cl::sub(SymbolsSubcommand));
 
+static cl::opt<bool> FindInAnyModule(
+    "find-in-any-module",
+    cl::desc("If true, the type will be searched for in all modules. Otherwise "
+             "the modules must be provided in -compiler-context"),
+    cl::sub(SymbolsSubcommand));
+
 static cl::opt<std::string>
     Language("language", cl::desc("Specify a language type, like C99."),
              cl::value_desc("language"), cl::sub(SymbolsSubcommand));
@@ -312,7 +318,6 @@ llvm::SmallVector<CompilerContext, 4> parseCompilerContext() {
             .Case("Variable", CompilerContextKind::Variable)
             .Case("Enum", CompilerContextKind::Enum)
             .Case("Typedef", CompilerContextKind::Typedef)
-            .Case("AnyModule", CompilerContextKind::AnyModule)
             .Case("AnyType", CompilerContextKind::AnyType)
             .Default(CompilerContextKind::Invalid);
     if (value.empty()) {
@@ -581,11 +586,13 @@ Error opts::symbols::findTypes(lldb_private::Module &Module) {
   if (!ContextOr)
     return ContextOr.takeError();
 
+  TypeQueryOptions Opts = TypeQueryOptions::e_module_search;
+  if (FindInAnyModule)
+    Opts |= TypeQueryOptions::e_ignore_modules;
   TypeResults results;
   if (!Name.empty()) {
     if (ContextOr->IsValid()) {
-      TypeQuery query(*ContextOr, ConstString(Name),
-                      TypeQueryOptions::e_module_search);
+      TypeQuery query(*ContextOr, ConstString(Name), Opts);
       if (!Language.empty())
         query.AddLanguage(Language::GetLanguageTypeFromString(Language));
       Symfile.FindTypes(query, results);
@@ -596,7 +603,7 @@ Error opts::symbols::findTypes(lldb_private::Module &Module) {
       Symfile.FindTypes(query, results);
     }
   } else {
-    TypeQuery query(parseCompilerContext(), TypeQueryOptions::e_module_search);
+    TypeQuery query(parseCompilerContext(), Opts);
     if (!Language.empty())
       query.AddLanguage(Language::GetLanguageTypeFromString(Language));
     Symfile.FindTypes(query, results);
@@ -816,6 +823,9 @@ Expected<Error (*)(lldb_private::Module &)> opts::symbols::getAction() {
   if (Regex && Name.empty())
     return make_string_error("-regex used without a -name");
 
+  if (FindInAnyModule && (Find != FindType::Type))
+    return make_string_error("-find-in-any-module only works with -find=type");
+
   switch (Find) {
   case FindType::None:
     if (!Context.empty() || !Name.empty() || !File.empty() || Line != 0)

lldb/unittests/Symbol/TestType.cpp

@@ -7,13 +7,16 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
 #include "lldb/Symbol/Type.h"
 #include "lldb/lldb-enumerations.h"
+#include "lldb/lldb-private-enumerations.h"
 
 using namespace lldb;
 using namespace lldb_private;
+using testing::Not;
 
 TEST(Type, GetTypeScopeAndBasename) {
   EXPECT_EQ(Type::GetTypeScopeAndBasename("int"),
@@ -47,40 +50,65 @@ TEST(Type, GetTypeScopeAndBasename) {
   EXPECT_EQ(Type::GetTypeScopeAndBasename("foo<::bar"), std::nullopt);
 }
 
+namespace {
+MATCHER_P(Matches, pattern, "") {
+  TypeQuery query(pattern, TypeQueryOptions::e_none);
+  return query.ContextMatches(arg);
+}
+MATCHER_P(MatchesIgnoringModules, pattern, "") {
+  TypeQuery query(pattern, TypeQueryOptions::e_ignore_modules);
+  return query.ContextMatches(arg);
+}
+} // namespace
+
 TEST(Type, CompilerContextPattern) {
-  std::vector<CompilerContext> mmc = {
-      {CompilerContextKind::Module, ConstString("A")},
-      {CompilerContextKind::Module, ConstString("B")},
-      {CompilerContextKind::ClassOrStruct, ConstString("S")}};
-  std::vector<CompilerContext> mc = {
-      {CompilerContextKind::Module, ConstString("A")},
-      {CompilerContextKind::ClassOrStruct, ConstString("S")}};
-  std::vector<CompilerContext> mac = {
-      {CompilerContextKind::Module, ConstString("A")},
-      {CompilerContextKind::AnyModule, ConstString("*")},
-      {CompilerContextKind::ClassOrStruct, ConstString("S")}};
-  EXPECT_TRUE(contextMatches(mmc, mac));
-  EXPECT_TRUE(contextMatches(mc, mac));
-  EXPECT_FALSE(contextMatches(mac, mc));
-  std::vector<CompilerContext> mmmc = {
-      {CompilerContextKind::Module, ConstString("A")},
-      {CompilerContextKind::Module, ConstString("B")},
-      {CompilerContextKind::Module, ConstString("C")},
-      {CompilerContextKind::ClassOrStruct, ConstString("S")}};
-  EXPECT_TRUE(contextMatches(mmmc, mac));
-  std::vector<CompilerContext> mme = {
-      {CompilerContextKind::Module, ConstString("A")},
-      {CompilerContextKind::Module, ConstString("B")},
-      {CompilerContextKind::Enum, ConstString("S")}};
-  std::vector<CompilerContext> mma = {
-      {CompilerContextKind::Module, ConstString("A")},
-      {CompilerContextKind::Module, ConstString("B")},
-      {CompilerContextKind::AnyType, ConstString("S")}};
-  EXPECT_TRUE(contextMatches(mme, mma));
-  EXPECT_TRUE(contextMatches(mmc, mma));
-  std::vector<CompilerContext> mme2 = {
-      {CompilerContextKind::Module, ConstString("A")},
-      {CompilerContextKind::Module, ConstString("B")},
-      {CompilerContextKind::Enum, ConstString("S2")}};
-  EXPECT_FALSE(contextMatches(mme2, mma));
+  auto make_module = [](llvm::StringRef name) {
+    return CompilerContext(CompilerContextKind::Module, ConstString(name));
+  };
+  auto make_class = [](llvm::StringRef name) {
+    return CompilerContext(CompilerContextKind::ClassOrStruct,
+                           ConstString(name));
+  };
+  auto make_any_type = [](llvm::StringRef name) {
+    return CompilerContext(CompilerContextKind::AnyType, ConstString(name));
+  };
+  auto make_enum = [](llvm::StringRef name) {
+    return CompilerContext(CompilerContextKind::Enum, ConstString(name));
+  };
+  auto make_namespace = [](llvm::StringRef name) {
+    return CompilerContext(CompilerContextKind::Namespace, ConstString(name));
+  };
+
+  EXPECT_THAT(
+      (std::vector{make_module("A"), make_module("B"), make_class("C")}),
+      Matches(
+          std::vector{make_module("A"), make_module("B"), make_class("C")}));
+  EXPECT_THAT(
+      (std::vector{make_module("A"), make_module("B"), make_class("C")}),
+      Not(Matches(std::vector{make_class("C")})));
+  EXPECT_THAT(
+      (std::vector{make_module("A"), make_module("B"), make_class("C")}),
+      MatchesIgnoringModules(std::vector{make_class("C")}));
+  EXPECT_THAT(
+      (std::vector{make_module("A"), make_module("B"), make_class("C")}),
+      MatchesIgnoringModules(std::vector{make_module("B"), make_class("C")}));
+  EXPECT_THAT(
+      (std::vector{make_module("A"), make_module("B"), make_class("C")}),
+      Not(MatchesIgnoringModules(
+          std::vector{make_module("A"), make_class("C")})));
+  EXPECT_THAT((std::vector{make_module("A"), make_module("B"), make_enum("C")}),
+              Matches(std::vector{make_module("A"), make_module("B"),
+                                  make_any_type("C")}));
+  EXPECT_THAT(
+      (std::vector{make_module("A"), make_module("B"), make_class("C")}),
+      Matches(
+          std::vector{make_module("A"), make_module("B"), make_any_type("C")}));
+  EXPECT_THAT(
+      (std::vector{make_module("A"), make_module("B"), make_enum("C2")}),
+      Not(Matches(std::vector{make_module("A"), make_module("B"),
+                              make_any_type("C")})));
+  EXPECT_THAT((std::vector{make_class("C")}),
+              Matches(std::vector{make_class("C")}));
+  EXPECT_THAT((std::vector{make_namespace("NS"), make_class("C")}),
+              Not(Matches(std::vector{make_any_type("C")})));
 }