Rename //explorer/common to base (#3103)

Renaming per #3100

explorer/BUILD

@@ -24,7 +24,7 @@ cc_library(
     deps = [
         "//common:error",
         "//common:ostream",
-        "//explorer/common:trace_stream",
+        "//explorer/base:trace_stream",
         "//explorer/parse_and_execute",
         "@llvm-project//llvm:Support",
     ],

explorer/README.md

@@ -41,19 +41,19 @@ RTTI switches, so that the compiler can help ensure the code is updated when a
 new type is added.
 
 `explorer` never uses plain pointer types directly. Instead, we use the
-[`Nonnull<T*>`](common/nonnull.h) alias for pointers that are not nullable, or
+[`Nonnull<T*>`](base/nonnull.h) alias for pointers that are not nullable, or
 `std::optional<Nonnull<T*>>` for pointers that are nullable.
 
 Many of the most commonly-used objects in `explorer` have lifetimes that are
 tied to the lifespan of the entire Carbon program. We manage the lifetimes of
-those objects by allocating them through an [`Arena`](common/arena.h) object,
+those objects by allocating them through an [`Arena`](base/arena.h) object,
 which can allocate objects of arbitrary types, and retains ownership of them. As
 of this writing, all of `explorer` uses a single `Arena` object, we may
 introduce multiple `Arena`s for different lifetime groups in the future.
 
 For simplicity, `explorer` generally treats all errors as fatal. Errors caused
 by bugs in the user-provided Carbon code should be reported with the error
-builders in [`error_builders.h`](common/error_builders.h). Errors caused by bugs
+builders in [`error_builders.h`](base/error_builders.h). Errors caused by bugs
 in `explorer` itself should be reported with
 [`CHECK` or `FATAL`](../common/check.h).
 

explorer/ast/BUILD

@@ -51,11 +51,11 @@ cc_library(
         "//common:error",
         "//common:indirect_value",
         "//common:ostream",
-        "//explorer/common:arena",
-        "//explorer/common:decompose",
-        "//explorer/common:error_builders",
-        "//explorer/common:nonnull",
-        "//explorer/common:source_location",
+        "//explorer/base:arena",
+        "//explorer/base:decompose",
+        "//explorer/base:error_builders",
+        "//explorer/base:nonnull",
+        "//explorer/base:source_location",
         "@llvm-project//llvm:Support",
     ],
 )
@@ -81,7 +81,7 @@ cc_test(
     deps = [
         ":ast",
         ":ast_test_matchers",
-        "//explorer/common:arena",
+        "//explorer/base:arena",
         "//testing/util:gtest_main",
         "@com_google_googletest//:gtest",
     ],
@@ -93,7 +93,7 @@ cc_test(
     deps = [
         ":ast",
         ":paren_contents",
-        "//explorer/common:arena",
+        "//explorer/base:arena",
         "//testing/util:gtest_main",
         "@com_google_googletest//:gtest",
         "@llvm-project//llvm:Support",
@@ -109,8 +109,8 @@ cc_library(
     name = "paren_contents",
     hdrs = ["paren_contents.h"],
     deps = [
-        "//explorer/common:error_builders",
-        "//explorer/common:source_location",
+        "//explorer/base:error_builders",
+        "//explorer/base:source_location",
     ],
 )
 
@@ -120,7 +120,7 @@ cc_test(
     deps = [
         ":ast",
         ":paren_contents",
-        "//explorer/common:arena",
+        "//explorer/base:arena",
         "//testing/util:gtest_main",
         "@com_google_googletest//:gtest",
         "@llvm-project//llvm:Support",
@@ -133,7 +133,7 @@ cc_test(
     deps = [
         ":ast",
         ":paren_contents",
-        "//explorer/common:arena",
+        "//explorer/base:arena",
         "//testing/util:gtest_main",
         "@com_google_googletest//:gtest",
         "@llvm-project//llvm:Support",
@@ -149,10 +149,10 @@ cc_library(
         "//common:check",
         "//common:error",
         "//common:ostream",
-        "//explorer/common:error_builders",
-        "//explorer/common:nonnull",
-        "//explorer/common:source_location",
-        "//explorer/common:trace_stream",
+        "//explorer/base:error_builders",
+        "//explorer/base:nonnull",
+        "//explorer/base:source_location",
+        "//explorer/base:trace_stream",
         "@llvm-project//llvm:Support",
     ],
 )

explorer/ast/ast.h

@@ -9,7 +9,7 @@
 
 #include "explorer/ast/declaration.h"
 #include "explorer/ast/library_name.h"
-#include "explorer/common/nonnull.h"
+#include "explorer/base/nonnull.h"
 
 namespace Carbon {
 

explorer/ast/ast_node.h

@@ -6,7 +6,7 @@
 #define CARBON_EXPLORER_AST_AST_NODE_H_
 
 #include "explorer/ast/ast_rtti.h"
-#include "explorer/common/source_location.h"
+#include "explorer/base/source_location.h"
 #include "llvm/Support/Casting.h"
 
 namespace Carbon {

explorer/ast/ast_test_matchers_test.cpp

@@ -11,7 +11,7 @@
 #include "explorer/ast/expression.h"
 #include "explorer/ast/pattern.h"
 #include "explorer/ast/statement.h"
-#include "explorer/common/arena.h"
+#include "explorer/base/arena.h"
 
 namespace Carbon::Testing {
 namespace {

explorer/ast/bindings.h

@@ -10,7 +10,7 @@
 
 #include "common/ostream.h"
 #include "explorer/ast/clone_context.h"
-#include "explorer/common/nonnull.h"
+#include "explorer/base/nonnull.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/StringExtras.h"
 

explorer/ast/clone_context.h

@@ -11,7 +11,7 @@
 
 #include "common/check.h"
 #include "explorer/ast/ast_rtti.h"
-#include "explorer/common/arena.h"
+#include "explorer/base/arena.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/Support/Casting.h"
 

explorer/ast/declaration.h

@@ -20,8 +20,8 @@
 #include "explorer/ast/return_term.h"
 #include "explorer/ast/statement.h"
 #include "explorer/ast/value_node.h"
-#include "explorer/common/nonnull.h"
-#include "explorer/common/source_location.h"
+#include "explorer/base/nonnull.h"
+#include "explorer/base/source_location.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/Support/Compiler.h"
 

explorer/ast/element.h

@@ -11,8 +11,8 @@
 
 #include "common/ostream.h"
 #include "explorer/ast/ast_rtti.h"
-#include "explorer/common/decompose.h"
-#include "explorer/common/nonnull.h"
+#include "explorer/base/decompose.h"
+#include "explorer/base/nonnull.h"
 #include "llvm/ADT/PointerUnion.h"
 
 namespace Carbon {

explorer/ast/element_test.cpp

@@ -13,7 +13,7 @@
 #include "explorer/ast/declaration.h"
 #include "explorer/ast/expression.h"
 #include "explorer/ast/value.h"
-#include "explorer/common/arena.h"
+#include "explorer/base/arena.h"
 #include "llvm/Support/Casting.h"
 
 namespace Carbon::Testing {

explorer/ast/expression.cpp

@@ -9,8 +9,8 @@
 
 #include "explorer/ast/pattern.h"
 #include "explorer/ast/value.h"
-#include "explorer/common/arena.h"
-#include "explorer/common/error_builders.h"
+#include "explorer/base/arena.h"
+#include "explorer/base/error_builders.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/raw_ostream.h"

explorer/ast/expression.h

@@ -19,8 +19,8 @@
 #include "explorer/ast/expression_category.h"
 #include "explorer/ast/paren_contents.h"
 #include "explorer/ast/value_node.h"
-#include "explorer/common/arena.h"
-#include "explorer/common/source_location.h"
+#include "explorer/base/arena.h"
+#include "explorer/base/source_location.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/Support/Compiler.h"
 

explorer/ast/expression_test.cpp

@@ -10,7 +10,7 @@
 #include <string>
 
 #include "explorer/ast/paren_contents.h"
-#include "explorer/common/arena.h"
+#include "explorer/base/arena.h"
 #include "llvm/Support/Casting.h"
 
 namespace Carbon::Testing {

explorer/ast/paren_contents.h

@@ -9,8 +9,8 @@
 #include <string>
 #include <vector>
 
-#include "explorer/common/error_builders.h"
-#include "explorer/common/source_location.h"
+#include "explorer/base/error_builders.h"
+#include "explorer/base/source_location.h"
 
 namespace Carbon {
 

explorer/ast/pattern.cpp

@@ -10,8 +10,8 @@
 #include "explorer/ast/expression.h"
 #include "explorer/ast/impl_binding.h"
 #include "explorer/ast/value.h"
-#include "explorer/common/arena.h"
-#include "explorer/common/error_builders.h"
+#include "explorer/base/arena.h"
+#include "explorer/base/error_builders.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/Casting.h"
 

explorer/ast/pattern.h

@@ -17,7 +17,7 @@
 #include "explorer/ast/expression.h"
 #include "explorer/ast/expression_category.h"
 #include "explorer/ast/value_node.h"
-#include "explorer/common/source_location.h"
+#include "explorer/base/source_location.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/STLFunctionalExtras.h"
 

explorer/ast/pattern_test.cpp

@@ -9,7 +9,7 @@
 
 #include "explorer/ast/expression.h"
 #include "explorer/ast/paren_contents.h"
-#include "explorer/common/arena.h"
+#include "explorer/base/arena.h"
 #include "llvm/Support/Casting.h"
 
 namespace Carbon::Testing {

explorer/ast/return_term.h

@@ -12,8 +12,8 @@
 #include "common/ostream.h"
 #include "explorer/ast/clone_context.h"
 #include "explorer/ast/expression.h"
-#include "explorer/common/nonnull.h"
-#include "explorer/common/source_location.h"
+#include "explorer/base/nonnull.h"
+#include "explorer/base/source_location.h"
 
 namespace Carbon {
 

explorer/ast/statement.cpp

@@ -6,7 +6,7 @@
 
 #include "common/check.h"
 #include "explorer/ast/declaration.h"
-#include "explorer/common/arena.h"
+#include "explorer/base/arena.h"
 #include "llvm/Support/Casting.h"
 
 namespace Carbon {

explorer/ast/statement.h

@@ -16,8 +16,8 @@
 #include "explorer/ast/pattern.h"
 #include "explorer/ast/return_term.h"
 #include "explorer/ast/value_node.h"
-#include "explorer/common/arena.h"
-#include "explorer/common/source_location.h"
+#include "explorer/base/arena.h"
+#include "explorer/base/source_location.h"
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/Support/Compiler.h"
 

explorer/ast/static_scope.cpp

@@ -7,7 +7,7 @@
 #include <optional>
 
 #include "common/ostream.h"
-#include "explorer/common/error_builders.h"
+#include "explorer/base/error_builders.h"
 #include "llvm/ADT/ScopeExit.h"
 #include "llvm/Support/Error.h"
 

explorer/ast/static_scope.h

@@ -10,9 +10,9 @@
 
 #include "common/error.h"
 #include "explorer/ast/value_node.h"
-#include "explorer/common/nonnull.h"
-#include "explorer/common/source_location.h"
-#include "explorer/common/trace_stream.h"
+#include "explorer/base/nonnull.h"
+#include "explorer/base/source_location.h"
+#include "explorer/base/trace_stream.h"
 #include "llvm/ADT/StringMap.h"
 
 namespace Carbon {

explorer/ast/value.cpp

@@ -14,8 +14,8 @@
 #include "explorer/ast/element.h"
 #include "explorer/ast/element_path.h"
 #include "explorer/ast/value_transform.h"
-#include "explorer/common/arena.h"
-#include "explorer/common/error_builders.h"
+#include "explorer/base/arena.h"
+#include "explorer/base/error_builders.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/Casting.h"

explorer/ast/value.h

@@ -18,7 +18,7 @@
 #include "explorer/ast/element_path.h"
 #include "explorer/ast/expression_category.h"
 #include "explorer/ast/statement.h"
-#include "explorer/common/nonnull.h"
+#include "explorer/base/nonnull.h"
 #include "llvm/ADT/StringMap.h"
 #include "llvm/Support/Compiler.h"
 

explorer/ast/value_node.h

@@ -12,7 +12,7 @@
 #include "explorer/ast/ast_node.h"
 #include "explorer/ast/clone_context.h"
 #include "explorer/ast/expression_category.h"
-#include "explorer/common/nonnull.h"
+#include "explorer/base/nonnull.h"
 
 namespace Carbon {
 

explorer/common/BUILD → explorer/base/BUILD

@@ -86,7 +86,7 @@ cc_library(
         ":source_location",
         "//common:check",
         "//common:ostream",
-        "//explorer/common:nonnull",
+        "//explorer/base:nonnull",
         "@llvm-project//llvm:Support",
     ],
 )

explorer/common/arena.h → explorer/base/arena.h

@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-#ifndef CARBON_EXPLORER_COMMON_ARENA_H_
-#define CARBON_EXPLORER_COMMON_ARENA_H_
+#ifndef CARBON_EXPLORER_BASE_ARENA_H_
+#define CARBON_EXPLORER_BASE_ARENA_H_
 
 #include <any>
 #include <map>
@@ -13,7 +13,7 @@
 #include <utility>
 #include <vector>
 
-#include "explorer/common/nonnull.h"
+#include "explorer/base/nonnull.h"
 #include "llvm/ADT/Hashing.h"
 
 namespace Carbon {
@@ -277,4 +277,4 @@ char Arena::TypeId<T>::id = 1;
 
 }  // namespace Carbon
 
-#endif  // CARBON_EXPLORER_COMMON_ARENA_H_
+#endif  // CARBON_EXPLORER_BASE_ARENA_H_

explorer/common/arena_test.cpp → explorer/base/arena_test.cpp

@@ -2,7 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-#include "explorer/common/arena.h"
+#include "explorer/base/arena.h"
 
 #include <gtest/gtest.h>
 

explorer/common/decompose.h → explorer/base/decompose.h

@@ -4,8 +4,8 @@
 //
 // Utilities for types that support the `Decompose` API.
 
-#ifndef CARBON_EXPLORER_COMMON_DECOMPOSE_H_
-#define CARBON_EXPLORER_COMMON_DECOMPOSE_H_
+#ifndef CARBON_EXPLORER_BASE_DECOMPOSE_H_
+#define CARBON_EXPLORER_BASE_DECOMPOSE_H_
 
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/Hashing.h"
@@ -51,4 +51,4 @@ class HashFromDecompose {
 
 }  // namespace Carbon
 
-#endif  // CARBON_EXPLORER_COMMON_DECOMPOSE_H_
+#endif  // CARBON_EXPLORER_BASE_DECOMPOSE_H_

explorer/common/decompose_test.cpp → explorer/base/decompose_test.cpp

@@ -2,7 +2,7 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-#include "explorer/common/decompose.h"
+#include "explorer/base/decompose.h"
 
 #include <gtest/gtest.h>
 

explorer/common/error_builders.h → explorer/base/error_builders.h

@@ -2,11 +2,11 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-#ifndef CARBON_EXPLORER_COMMON_ERROR_BUILDERS_H_
-#define CARBON_EXPLORER_COMMON_ERROR_BUILDERS_H_
+#ifndef CARBON_EXPLORER_BASE_ERROR_BUILDERS_H_
+#define CARBON_EXPLORER_BASE_ERROR_BUILDERS_H_
 
 #include "common/error.h"
-#include "explorer/common/source_location.h"
+#include "explorer/base/source_location.h"
 
 namespace Carbon {
 
@@ -23,4 +23,4 @@ inline auto ProgramError(SourceLocation loc) -> ErrorBuilder {
 
 }  // namespace Carbon
 
-#endif  // CARBON_EXPLORER_COMMON_ERROR_BUILDERS_H_
+#endif  // CARBON_EXPLORER_BASE_ERROR_BUILDERS_H_

explorer/common/error_builders_test.cpp → explorer/base/error_builders_test.cpp

@@ -2,11 +2,11 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-#include "explorer/common/error_builders.h"
+#include "explorer/base/error_builders.h"
 
 #include <gtest/gtest.h>
 
-#include "explorer/common/source_location.h"
+#include "explorer/base/source_location.h"
 #include "testing/util/test_raw_ostream.h"
 
 namespace Carbon::Testing {

explorer/common/nonnull.h → explorer/base/nonnull.h

@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-#ifndef CARBON_EXPLORER_COMMON_NONNULL_H_
-#define CARBON_EXPLORER_COMMON_NONNULL_H_
+#ifndef CARBON_EXPLORER_BASE_NONNULL_H_
+#define CARBON_EXPLORER_BASE_NONNULL_H_
 
 #include <type_traits>
 
@@ -19,4 +19,4 @@ using Nonnull = T _Nonnull;
 
 }  // namespace Carbon
 
-#endif  // CARBON_EXPLORER_COMMON_NONNULL_H_
+#endif  // CARBON_EXPLORER_BASE_NONNULL_H_

explorer/common/set_file_context_raii_test.cpp → explorer/base/set_file_context_raii_test.cpp

@@ -5,7 +5,7 @@
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
-#include "explorer/common/trace_stream.h"
+#include "explorer/base/trace_stream.h"
 
 namespace Carbon::Testing {
 namespace {

explorer/common/set_program_phase_raii_test.cpp → explorer/base/set_program_phase_raii_test.cpp

@@ -5,7 +5,7 @@
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
 
-#include "explorer/common/trace_stream.h"
+#include "explorer/base/trace_stream.h"
 
 namespace Carbon::Testing {
 namespace {

explorer/common/source_location.h → explorer/base/source_location.h

@@ -2,14 +2,14 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-#ifndef CARBON_EXPLORER_COMMON_SOURCE_LOCATION_H_
-#define CARBON_EXPLORER_COMMON_SOURCE_LOCATION_H_
+#ifndef CARBON_EXPLORER_BASE_SOURCE_LOCATION_H_
+#define CARBON_EXPLORER_BASE_SOURCE_LOCATION_H_
 
 #include <string>
 #include <string_view>
 
 #include "common/ostream.h"
-#include "explorer/common/nonnull.h"
+#include "explorer/base/nonnull.h"
 
 namespace Carbon {
 
@@ -72,4 +72,4 @@ class SourceLocation {
 
 }  // namespace Carbon
 
-#endif  // CARBON_EXPLORER_COMMON_SOURCE_LOCATION_H_
+#endif  // CARBON_EXPLORER_BASE_SOURCE_LOCATION_H_

explorer/common/trace_stream.h → explorer/base/trace_stream.h

@@ -2,8 +2,8 @@
 // Exceptions. See /LICENSE for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-#ifndef CARBON_EXPLORER_COMMON_TRACE_STREAM_H_
-#define CARBON_EXPLORER_COMMON_TRACE_STREAM_H_
+#ifndef CARBON_EXPLORER_BASE_TRACE_STREAM_H_
+#define CARBON_EXPLORER_BASE_TRACE_STREAM_H_
 
 #include <bitset>
 #include <optional>
@@ -13,8 +13,8 @@
 
 #include "common/check.h"
 #include "common/ostream.h"
-#include "explorer/common/nonnull.h"
-#include "explorer/common/source_location.h"
+#include "explorer/base/nonnull.h"
+#include "explorer/base/source_location.h"
 #include "llvm/ADT/ArrayRef.h"
 
 namespace Carbon {
@@ -205,4 +205,4 @@ class SetFileContext {
 
 }  // namespace Carbon
 
-#endif  // CARBON_EXPLORER_COMMON_TRACE_STREAM_H_
+#endif  // CARBON_EXPLORER_BASE_TRACE_STREAM_H_

explorer/fuzzing/BUILD

@@ -25,7 +25,7 @@ cc_binary(
         "//common:bazel_working_dir",
         "//common:error",
         "//explorer/ast",
-        "//explorer/common:arena",
+        "//explorer/base:arena",
         "//explorer/syntax",
         "//testing/fuzzing:carbon_cc_proto",
         "@com_google_protobuf//:protobuf_headers",

explorer/fuzzing/ast_to_proto_main.cpp

@@ -14,7 +14,7 @@
 #include "common/bazel_working_dir.h"
 #include "common/error.h"
 #include "explorer/ast/ast.h"
-#include "explorer/common/arena.h"
+#include "explorer/base/arena.h"
 #include "explorer/fuzzing/ast_to_proto.h"
 #include "explorer/syntax/parse.h"
 #include "testing/fuzzing/carbon.pb.h"

explorer/interpreter/BUILD

@@ -20,10 +20,10 @@ cc_library(
         "//common:error",
         "//common:ostream",
         "//explorer/ast",
-        "//explorer/common:arena",
-        "//explorer/common:error_builders",
-        "//explorer/common:nonnull",
-        "//explorer/common:source_location",
+        "//explorer/base:arena",
+        "//explorer/base:error_builders",
+        "//explorer/base:nonnull",
+        "//explorer/base:source_location",
         "@llvm-project//llvm:Support",
     ],
 )
@@ -43,7 +43,7 @@ cc_library(
         "//common:error",
         "//common:ostream",
         "//explorer/ast",
-        "//explorer/common:trace_stream",
+        "//explorer/base:trace_stream",
         "@llvm-project//llvm:Support",
     ],
 )
@@ -51,7 +51,7 @@ cc_library(
 cc_library(
     name = "dictionary",
     hdrs = ["dictionary.h"],
-    deps = ["//explorer/common:arena"],
+    deps = ["//explorer/base:arena"],
 )
 
 cc_library(
@@ -68,8 +68,8 @@ cc_library(
         "//common:error",
         "//common:ostream",
         "//explorer/ast",
-        "//explorer/common:arena",
-        "//explorer/common:trace_stream",
+        "//explorer/base:arena",
+        "//explorer/base:trace_stream",
         "@llvm-project//llvm:Support",
     ],
 )
@@ -85,10 +85,10 @@ cc_library(
         "//common:error",
         "//common:ostream",
         "//explorer/ast",
-        "//explorer/common:error_builders",
-        "//explorer/common:nonnull",
-        "//explorer/common:source_location",
-        "//explorer/common:trace_stream",
+        "//explorer/base:error_builders",
+        "//explorer/base:nonnull",
+        "//explorer/base:source_location",
+        "//explorer/base:trace_stream",
         "@llvm-project//llvm:Support",
     ],
 )
@@ -99,9 +99,9 @@ cc_library(
     deps = [
         "//common:error",
         "//explorer/ast",
-        "//explorer/common:arena",
-        "//explorer/common:nonnull",
-        "//explorer/common:source_location",
+        "//explorer/base:arena",
+        "//explorer/base:nonnull",
+        "//explorer/base:source_location",
     ],
 )
 
@@ -125,10 +125,10 @@ cc_library(
         "//common:ostream",
         "//explorer/ast",
         "//explorer/ast:expression_category",
-        "//explorer/common:arena",
-        "//explorer/common:error_builders",
-        "//explorer/common:source_location",
-        "//explorer/common:trace_stream",
+        "//explorer/base:arena",
+        "//explorer/base:error_builders",
+        "//explorer/base:source_location",
+        "//explorer/base:trace_stream",
         "@llvm-project//llvm:Support",
     ],
 )
@@ -140,9 +140,9 @@ cc_library(
     deps = [
         "//common:check",
         "//explorer/ast",
-        "//explorer/common:error_builders",
-        "//explorer/common:nonnull",
-        "//explorer/common:trace_stream",
+        "//explorer/base:error_builders",
+        "//explorer/base:nonnull",
+        "//explorer/base:trace_stream",
         "@llvm-project//llvm:Support",
     ],
 )
@@ -156,8 +156,8 @@ cc_library(
         "//common:check",
         "//explorer/ast",
         "//explorer/ast:static_scope",
-        "//explorer/common:arena",
-        "//explorer/common:trace_stream",
+        "//explorer/base:arena",
+        "//explorer/base:trace_stream",
         "@llvm-project//llvm:Support",
     ],
 )
@@ -180,7 +180,7 @@ cc_library(
         ":action",
         "//common:error",
         "//explorer/ast",
-        "//explorer/common:nonnull",
+        "//explorer/base:nonnull",
         "@llvm-project//llvm:Support",
     ],
 )
@@ -216,11 +216,11 @@ cc_library(
         "//common:error",
         "//common:ostream",
         "//explorer/ast",
-        "//explorer/common:arena",
-        "//explorer/common:error_builders",
-        "//explorer/common:nonnull",
-        "//explorer/common:source_location",
-        "//explorer/common:trace_stream",
+        "//explorer/base:arena",
+        "//explorer/base:error_builders",
+        "//explorer/base:nonnull",
+        "//explorer/base:source_location",
+        "//explorer/base:trace_stream",
         "@llvm-project//llvm:Support",
     ],
 )
@@ -238,9 +238,9 @@ cc_library(
         "//common:check",
         "//explorer/ast",
         "//explorer/ast:static_scope",
-        "//explorer/common:error_builders",
-        "//explorer/common:nonnull",
-        "//explorer/common:trace_stream",
+        "//explorer/base:error_builders",
+        "//explorer/base:nonnull",
+        "//explorer/base:trace_stream",
         "@llvm-project//llvm:Support",
     ],
 )
@@ -268,7 +268,7 @@ cc_library(
         "//common:ostream",
         "//explorer/ast",
         "//explorer/ast:expression_category",
-        "//explorer/common:nonnull",
+        "//explorer/base:nonnull",
         "@llvm-project//llvm:Support",
     ],
 )
@@ -283,7 +283,7 @@ cc_library(
     ],
     deps = [
         "//explorer/ast",
-        "//explorer/common:nonnull",
+        "//explorer/base:nonnull",
         "@llvm-project//llvm:Support",
     ],
 )
@@ -299,10 +299,10 @@ cc_library(
     deps = [
         ":action",
         "//explorer/ast",
-        "//explorer/common:arena",
-        "//explorer/common:nonnull",
-        "//explorer/common:source_location",
-        "//explorer/common:trace_stream",
+        "//explorer/base:arena",
+        "//explorer/base:nonnull",
+        "//explorer/base:source_location",
+        "//explorer/base:trace_stream",
         "@llvm-project//llvm:Support",
     ],
 )

explorer/interpreter/action.cpp

@@ -15,8 +15,8 @@
 #include "explorer/ast/declaration.h"
 #include "explorer/ast/expression.h"
 #include "explorer/ast/value.h"
-#include "explorer/common/arena.h"
-#include "explorer/common/source_location.h"
+#include "explorer/base/arena.h"
+#include "explorer/base/source_location.h"
 #include "explorer/interpreter/stack.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/Casting.h"

explorer/interpreter/action.h

@@ -18,7 +18,7 @@
 #include "explorer/ast/pattern.h"
 #include "explorer/ast/statement.h"
 #include "explorer/ast/value.h"
-#include "explorer/common/source_location.h"
+#include "explorer/base/source_location.h"
 #include "explorer/interpreter/dictionary.h"
 #include "explorer/interpreter/heap_allocation_interface.h"
 #include "explorer/interpreter/stack.h"

explorer/interpreter/action_stack.h

@@ -12,7 +12,7 @@
 #include "common/ostream.h"
 #include "explorer/ast/statement.h"
 #include "explorer/ast/value.h"
-#include "explorer/common/trace_stream.h"
+#include "explorer/base/trace_stream.h"
 #include "explorer/interpreter/action.h"
 
 namespace Carbon {

explorer/interpreter/builtins.cpp

@@ -4,7 +4,7 @@
 
 #include "explorer/interpreter/builtins.h"
 
-#include "explorer/common/error_builders.h"
+#include "explorer/base/error_builders.h"
 
 using llvm::dyn_cast;
 

explorer/interpreter/builtins.h

@@ -14,8 +14,8 @@
 #include "explorer/ast/declaration.h"
 #include "explorer/ast/expression.h"
 #include "explorer/ast/value.h"
-#include "explorer/common/nonnull.h"
-#include "explorer/common/source_location.h"
+#include "explorer/base/nonnull.h"
+#include "explorer/base/source_location.h"
 
 namespace Carbon {
 

explorer/interpreter/dictionary.h

@@ -8,7 +8,7 @@
 #include <iterator>
 #include <optional>
 
-#include "explorer/common/arena.h"
+#include "explorer/base/arena.h"
 
 namespace Carbon {
 

explorer/interpreter/exec_program.cpp

@@ -9,8 +9,8 @@
 #include "common/check.h"
 #include "common/error.h"
 #include "common/ostream.h"
-#include "explorer/common/arena.h"
-#include "explorer/common/trace_stream.h"
+#include "explorer/base/arena.h"
+#include "explorer/base/trace_stream.h"
 #include "explorer/interpreter/interpreter.h"
 #include "explorer/interpreter/resolve_control_flow.h"
 #include "explorer/interpreter/resolve_names.h"

explorer/interpreter/exec_program.h

@@ -10,7 +10,7 @@
 #define CARBON_EXPLORER_INTERPRETER_EXEC_PROGRAM_H_
 
 #include "explorer/ast/ast.h"
-#include "explorer/common/trace_stream.h"
+#include "explorer/base/trace_stream.h"
 #include "llvm/Support/raw_ostream.h"
 
 namespace Carbon {

explorer/interpreter/heap.cpp

@@ -7,8 +7,8 @@
 #include "common/check.h"
 #include "common/error.h"
 #include "explorer/ast/value.h"
-#include "explorer/common/error_builders.h"
-#include "explorer/common/source_location.h"
+#include "explorer/base/error_builders.h"
+#include "explorer/base/source_location.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/Error.h"
 

explorer/interpreter/heap.h

@@ -11,9 +11,9 @@
 #include "explorer/ast/address.h"
 #include "explorer/ast/value.h"
 #include "explorer/ast/value_node.h"
-#include "explorer/common/nonnull.h"
-#include "explorer/common/source_location.h"
-#include "explorer/common/trace_stream.h"
+#include "explorer/base/nonnull.h"
+#include "explorer/base/source_location.h"
+#include "explorer/base/trace_stream.h"
 #include "explorer/interpreter/heap_allocation_interface.h"
 
 namespace Carbon {

explorer/interpreter/heap_allocation_interface.h

@@ -8,9 +8,9 @@
 #include "common/error.h"
 #include "explorer/ast/address.h"
 #include "explorer/ast/value_node.h"
-#include "explorer/common/arena.h"
-#include "explorer/common/nonnull.h"
-#include "explorer/common/source_location.h"
+#include "explorer/base/arena.h"
+#include "explorer/base/nonnull.h"
+#include "explorer/base/source_location.h"
 
 namespace Carbon {
 

explorer/interpreter/interpreter.cpp

@@ -22,10 +22,10 @@
 #include "explorer/ast/expression.h"
 #include "explorer/ast/expression_category.h"
 #include "explorer/ast/value.h"
-#include "explorer/common/arena.h"
-#include "explorer/common/error_builders.h"
-#include "explorer/common/source_location.h"
-#include "explorer/common/trace_stream.h"
+#include "explorer/base/arena.h"
+#include "explorer/base/error_builders.h"
+#include "explorer/base/source_location.h"
+#include "explorer/base/trace_stream.h"
 #include "explorer/interpreter/action.h"
 #include "explorer/interpreter/action_stack.h"
 #include "explorer/interpreter/pattern_match.h"

explorer/interpreter/interpreter.h

@@ -15,7 +15,7 @@
 #include "explorer/ast/expression.h"
 #include "explorer/ast/pattern.h"
 #include "explorer/ast/value.h"
-#include "explorer/common/trace_stream.h"
+#include "explorer/base/trace_stream.h"
 #include "explorer/interpreter/action.h"
 #include "explorer/interpreter/heap.h"
 #include "llvm/ADT/ArrayRef.h"

explorer/interpreter/matching_impl_set.cpp

@@ -6,9 +6,9 @@
 #include "common/error.h"
 #include "explorer/ast/declaration.h"
 #include "explorer/ast/value.h"
-#include "explorer/common/error_builders.h"
-#include "explorer/common/nonnull.h"
-#include "explorer/common/source_location.h"
+#include "explorer/base/error_builders.h"
+#include "explorer/base/nonnull.h"
+#include "explorer/base/source_location.h"
 #include "explorer/interpreter/type_checker.h"
 
 namespace Carbon {

explorer/interpreter/matching_impl_set.h

@@ -10,7 +10,7 @@
 #include "common/ostream.h"
 #include "explorer/ast/declaration.h"
 #include "explorer/ast/value.h"
-#include "explorer/common/nonnull.h"
+#include "explorer/base/nonnull.h"
 #include "explorer/interpreter/impl_scope.h"
 #include "llvm/ADT/DenseMap.h"
 

explorer/interpreter/pattern_analysis.h

@@ -9,7 +9,7 @@
 
 #include "explorer/ast/pattern.h"
 #include "explorer/ast/value.h"
-#include "explorer/common/nonnull.h"
+#include "explorer/base/nonnull.h"
 #include "llvm/ADT/PointerUnion.h"
 
 namespace Carbon {

explorer/interpreter/pattern_match.cpp

@@ -5,8 +5,8 @@
 #include "explorer/interpreter/pattern_match.h"
 
 #include "explorer/ast/value.h"
-#include "explorer/common/arena.h"
-#include "explorer/common/trace_stream.h"
+#include "explorer/base/arena.h"
+#include "explorer/base/trace_stream.h"
 #include "explorer/interpreter/action.h"
 #include "llvm/Support/Casting.h"
 

explorer/interpreter/pattern_match.h

@@ -9,8 +9,8 @@
 
 #include "explorer/ast/bindings.h"
 #include "explorer/ast/value.h"
-#include "explorer/common/nonnull.h"
-#include "explorer/common/source_location.h"
+#include "explorer/base/nonnull.h"
+#include "explorer/base/source_location.h"
 
 namespace Carbon {
 

explorer/interpreter/resolve_control_flow.cpp

@@ -7,7 +7,7 @@
 #include "explorer/ast/declaration.h"
 #include "explorer/ast/return_term.h"
 #include "explorer/ast/statement.h"
-#include "explorer/common/error_builders.h"
+#include "explorer/base/error_builders.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Error.h"
 

explorer/interpreter/resolve_control_flow.h

@@ -6,8 +6,8 @@
 #define CARBON_EXPLORER_INTERPRETER_RESOLVE_CONTROL_FLOW_H_
 
 #include "explorer/ast/ast.h"
-#include "explorer/common/nonnull.h"
-#include "explorer/common/trace_stream.h"
+#include "explorer/base/nonnull.h"
+#include "explorer/base/trace_stream.h"
 
 namespace Carbon {
 

explorer/interpreter/resolve_names.h

@@ -6,8 +6,8 @@
 #define CARBON_EXPLORER_INTERPRETER_RESOLVE_NAMES_H_
 
 #include "explorer/ast/ast.h"
-#include "explorer/common/arena.h"
-#include "explorer/common/trace_stream.h"
+#include "explorer/base/arena.h"
+#include "explorer/base/trace_stream.h"
 
 namespace Carbon {
 

explorer/interpreter/resolve_unformed.cpp

@@ -10,7 +10,7 @@
 #include "explorer/ast/ast.h"
 #include "explorer/ast/expression.h"
 #include "explorer/ast/pattern.h"
-#include "explorer/common/nonnull.h"
+#include "explorer/base/nonnull.h"
 #include "explorer/interpreter/stack_space.h"
 
 using llvm::cast;

explorer/interpreter/resolve_unformed.h

@@ -9,8 +9,8 @@
 #include <unordered_map>
 
 #include "explorer/ast/ast.h"
-#include "explorer/common/nonnull.h"
-#include "explorer/common/trace_stream.h"
+#include "explorer/base/nonnull.h"
+#include "explorer/base/trace_stream.h"
 
 namespace Carbon {
 

explorer/interpreter/type_checker.cpp

@@ -22,10 +22,10 @@
 #include "explorer/ast/pattern.h"
 #include "explorer/ast/value.h"
 #include "explorer/ast/value_transform.h"
-#include "explorer/common/arena.h"
-#include "explorer/common/error_builders.h"
-#include "explorer/common/source_location.h"
-#include "explorer/common/trace_stream.h"
+#include "explorer/base/arena.h"
+#include "explorer/base/error_builders.h"
+#include "explorer/base/source_location.h"
+#include "explorer/base/trace_stream.h"
 #include "explorer/interpreter/impl_scope.h"
 #include "explorer/interpreter/interpreter.h"
 #include "explorer/interpreter/pattern_analysis.h"

explorer/interpreter/type_checker.h

@@ -18,8 +18,8 @@
 #include "explorer/ast/expression.h"
 #include "explorer/ast/statement.h"
 #include "explorer/ast/value.h"
-#include "explorer/common/nonnull.h"
-#include "explorer/common/trace_stream.h"
+#include "explorer/base/nonnull.h"
+#include "explorer/base/trace_stream.h"
 #include "explorer/interpreter/builtins.h"
 #include "explorer/interpreter/dictionary.h"
 #include "explorer/interpreter/impl_scope.h"

explorer/interpreter/type_structure.h

@@ -8,7 +8,7 @@
 #include <vector>
 
 #include "common/ostream.h"
-#include "explorer/common/nonnull.h"
+#include "explorer/base/nonnull.h"
 #include "llvm/Support/Compiler.h"
 
 namespace Carbon {

explorer/interpreter/type_utils.h

@@ -5,7 +5,7 @@
 #ifndef CARBON_EXPLORER_INTERPRETER_TYPE_UTILS_H_
 #define CARBON_EXPLORER_INTERPRETER_TYPE_UTILS_H_
 
-#include "explorer/common/nonnull.h"
+#include "explorer/base/nonnull.h"
 
 namespace Carbon {
 

explorer/main.cpp

@@ -15,7 +15,7 @@
 #include <vector>
 
 #include "common/error.h"
-#include "explorer/common/trace_stream.h"
+#include "explorer/base/trace_stream.h"
 #include "explorer/parse_and_execute/parse_and_execute.h"
 #include "llvm/ADT/ScopeExit.h"
 #include "llvm/ADT/SmallString.h"

explorer/parse_and_execute/BUILD

@@ -14,7 +14,7 @@ cc_library(
     deps = [
         "//common:check",
         "//common:error",
-        "//explorer/common:trace_stream",
+        "//explorer/base:trace_stream",
         "//explorer/interpreter:exec_program",
         "//explorer/interpreter:stack_space",
         "//explorer/syntax",

explorer/parse_and_execute/parse_and_execute.cpp

@@ -7,7 +7,7 @@
 #include <locale>
 
 #include "common/error.h"
-#include "explorer/common/trace_stream.h"
+#include "explorer/base/trace_stream.h"
 #include "explorer/interpreter/exec_program.h"
 #include "explorer/interpreter/stack_space.h"
 #include "explorer/syntax/parse.h"

explorer/parse_and_execute/parse_and_execute.h

@@ -6,7 +6,7 @@
 #define CARBON_EXPLORER_PARSE_AND_EXECUTE_PARSE_AND_EXECUTE_H_
 
 #include "common/error.h"
-#include "explorer/common/trace_stream.h"
+#include "explorer/base/trace_stream.h"
 #include "llvm/Support/VirtualFileSystem.h"
 
 namespace Carbon {

explorer/syntax/BUILD

@@ -15,7 +15,7 @@ cc_test(
     srcs = ["parse_test.cpp"],
     deps = [
         ":syntax",
-        "//explorer/common:arena",
+        "//explorer/base:arena",
         "//testing/util:gtest_main",
         "@com_google_googletest//:gtest",
     ],
@@ -42,8 +42,8 @@ cc_library(
         ":syntax",
         "//common:error",
         "//explorer/ast",
-        "//explorer/common:arena",
-        "//explorer/common:nonnull",
+        "//explorer/base:arena",
+        "//explorer/base:nonnull",
         "@llvm-project//llvm:Support",
     ],
 )
@@ -86,10 +86,10 @@ cc_library(
         "//explorer/ast",
         "//explorer/ast:expression_category",
         "//explorer/ast:paren_contents",
-        "//explorer/common:arena",
-        "//explorer/common:error_builders",
-        "//explorer/common:nonnull",
-        "//explorer/common:source_location",
+        "//explorer/base:arena",
+        "//explorer/base:error_builders",
+        "//explorer/base:nonnull",
+        "//explorer/base:source_location",
         "@llvm-project//llvm:Support",
     ],
 )

explorer/syntax/parse.cpp

@@ -6,7 +6,7 @@
 
 #include "common/check.h"
 #include "common/error.h"
-#include "explorer/common/error_builders.h"
+#include "explorer/base/error_builders.h"
 #include "explorer/syntax/lexer.h"
 #include "explorer/syntax/parse_and_lex_context.h"
 #include "explorer/syntax/parser.h"

explorer/syntax/parse.h

@@ -9,8 +9,8 @@
 #include <variant>
 
 #include "explorer/ast/ast.h"
-#include "explorer/common/arena.h"
-#include "explorer/common/source_location.h"
+#include "explorer/base/arena.h"
+#include "explorer/base/source_location.h"
 #include "llvm/Support/VirtualFileSystem.h"
 
 namespace Carbon {

explorer/syntax/parse_and_lex_context.cpp

@@ -4,7 +4,7 @@
 
 #include "explorer/syntax/parse_and_lex_context.h"
 
-#include "explorer/common/error_builders.h"
+#include "explorer/base/error_builders.h"
 
 namespace Carbon {
 

explorer/syntax/parse_and_lex_context.h

@@ -8,7 +8,7 @@
 #include <variant>
 
 #include "explorer/ast/ast.h"
-#include "explorer/common/source_location.h"
+#include "explorer/base/source_location.h"
 #include "explorer/syntax/parser.h"  // from parser.ypp
 
 namespace Carbon {

explorer/syntax/parse_test.cpp

@@ -10,7 +10,7 @@
 #include <string>
 #include <variant>
 
-#include "explorer/common/arena.h"
+#include "explorer/base/arena.h"
 
 namespace Carbon::Testing {
 namespace {

explorer/syntax/parser.ypp

@@ -74,8 +74,8 @@
   #include "explorer/ast/expression_category.h"
   #include "explorer/ast/paren_contents.h"
   #include "explorer/ast/pattern.h"
-  #include "explorer/common/arena.h"
-  #include "explorer/common/nonnull.h"
+  #include "explorer/base/arena.h"
+  #include "explorer/base/nonnull.h"
   #include "explorer/syntax/bison_wrap.h"
 
   namespace Carbon {

explorer/syntax/prelude.h

@@ -8,8 +8,8 @@
 #include <string_view>
 
 #include "explorer/ast/declaration.h"
-#include "explorer/common/arena.h"
-#include "explorer/common/nonnull.h"
+#include "explorer/base/arena.h"
+#include "explorer/base/nonnull.h"
 #include "llvm/Support/VirtualFileSystem.h"
 
 namespace Carbon {