Add and fix clang -Wshift-sign-overflow (#7431)

Summary:
This option is apparently used by some teams within Facebook
(internal ref T75998621)

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7431

Test Plan: USE_CLANG=1 make check before (fails) and after

Reviewed By: jay-zhuang

Differential Revision: D23876584

Pulled By: pdillinger

fbshipit-source-id: abb8b67a1f1aac75327944d266e284b2b6727191

Makefile

@@ -421,6 +421,11 @@ default: all
 WARNING_FLAGS = -W -Wextra -Wall -Wsign-compare -Wshadow \
   -Wunused-parameter
 
+ifdef USE_CLANG
+	# Used by some teams in Facebook
+	WARNING_FLAGS += -Wshift-sign-overflow
+endif
+
 ifeq ($(PLATFORM), OS_OPENBSD)
 	WARNING_FLAGS += -Wno-unused-lambda-capture
 endif

db/write_batch_test.cc

@@ -419,7 +419,7 @@ TEST_F(WriteBatchTest, PrepareCommit) {
 TEST_F(WriteBatchTest, DISABLED_ManyUpdates) {
   // Insert key and value of 3GB and push total batch size to 12GB.
   static const size_t kKeyValueSize = 4u;
-  static const uint32_t kNumUpdates = uint32_t(3 << 30);
+  static const uint32_t kNumUpdates = uint32_t{3} << 30;
   std::string raw(kKeyValueSize, 'A');
   WriteBatch batch(kNumUpdates * (4 + kKeyValueSize * 2) + 1024u);
   char c = 'A';

include/rocksdb/utilities/backupable_db.h

@@ -129,7 +129,7 @@ struct BackupableDBOptions {
   // table file names when the table files are stored in the shared_checksum
   // directory (i.e., both share_table_files and share_files_with_checksum
   // are true).
-  enum ShareFilesNaming : int {
+  enum ShareFilesNaming : uint32_t {
     // Backup SST filenames are <file_number>_<crc32c>_<file_size>.sst
     // where <crc32c> is an unsigned decimal integer. This is the
     // original/legacy naming scheme for share_files_with_checksum,
@@ -140,7 +140,7 @@ struct BackupableDBOptions {
     //   so generally requires reading the whole file even if the file
     //   is already backed up.
     // ** ONLY RECOMMENDED FOR PRESERVING OLD BEHAVIOR **
-    kLegacyCrc32cAndFileSize = 1,
+    kLegacyCrc32cAndFileSize = 1U,
 
     // Backup SST filenames are <file_number>_s<db_session_id>.sst. This
     // pair of values should be very strongly unique for a given SST file
@@ -152,9 +152,9 @@ struct BackupableDBOptions {
     //   will be used instead, matching the names assigned by RocksDB versions
     //   not supporting the newer naming scheme.
     // * See also flags below.
-    kUseDbSessionId = 2,
+    kUseDbSessionId = 2U,
 
-    kMaskNoNamingFlags = 0xffff,
+    kMaskNoNamingFlags = 0xffffU,
 
     // If not already part of the naming scheme, insert
     //   _<file_size>
@@ -165,7 +165,7 @@ struct BackupableDBOptions {
     //
     // We do not consider SST file sizes to have sufficient entropy to
     // contribute significantly to naming uniqueness.
-    kFlagIncludeFileSize = 1 << 31,
+    kFlagIncludeFileSize = 1U << 31,
 
     // When encountering an SST file from a Facebook-internal early
     // release of 6.12, use the default naming scheme in effect for
@@ -175,7 +175,7 @@ struct BackupableDBOptions {
     // and ignores kFlagIncludeFileSize setting.
     // NOTE: This flag is intended to be temporary and should be removed
     // in a later release.
-    kFlagMatchInterimNaming = 1 << 30,
+    kFlagMatchInterimNaming = 1U << 30,
 
     kMaskNamingFlags = ~kMaskNoNamingFlags,
   };
@@ -234,8 +234,8 @@ struct BackupableDBOptions {
 inline BackupableDBOptions::ShareFilesNaming operator&(
     BackupableDBOptions::ShareFilesNaming lhs,
     BackupableDBOptions::ShareFilesNaming rhs) {
-  int l = static_cast<int>(lhs);
+  uint32_t l = static_cast<uint32_t>(lhs);
-  int r = static_cast<int>(rhs);
+  uint32_t r = static_cast<uint32_t>(rhs);
   assert(r == BackupableDBOptions::kMaskNoNamingFlags ||
          (r & BackupableDBOptions::kMaskNoNamingFlags) == 0);
   return static_cast<BackupableDBOptions::ShareFilesNaming>(l & r);
@@ -244,8 +244,8 @@ inline BackupableDBOptions::ShareFilesNaming operator&(
 inline BackupableDBOptions::ShareFilesNaming operator|(
     BackupableDBOptions::ShareFilesNaming lhs,
     BackupableDBOptions::ShareFilesNaming rhs) {
-  int l = static_cast<int>(lhs);
+  uint32_t l = static_cast<uint32_t>(lhs);
-  int r = static_cast<int>(rhs);
+  uint32_t r = static_cast<uint32_t>(rhs);
   assert((r & BackupableDBOptions::kMaskNoNamingFlags) == 0);
   return static_cast<BackupableDBOptions::ShareFilesNaming>(l | r);
 }