Add declaration-level assertions for compile-time checks

Those new assertions can be used at file scope, outside of any function
for compilation checks.  This commit provides implementations for C and
C++, and fallback implementations.

Author: Peter Smith
Reviewed-by: Andres Freund, Kyotaro Horiguchi, Dagfinn Ilmari Mannsåker,
Michael Paquier
Discussion: https://postgr.es/m/201DD0641B056142AC8C6645EC1B5F62014B8E8030@SYD1217

1 files changed, 39 insertions, 0 deletions

diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index a16fe8cd5bf..9630866a5f9 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -241,6 +241,9 @@ static const struct config_enum_entry bytea_output_options[] = {
 	{NULL, 0, false}
 };
 
+StaticAssertDecl(lengthof(bytea_output_options) == (BYTEA_OUTPUT_HEX + 2),
+				 "array length mismatch");
+
 /*
  * We have different sets for client and server message level options because
  * they sort slightly different (see "log" level), and because "fatal"/"panic"
@@ -286,6 +289,9 @@ static const struct config_enum_entry intervalstyle_options[] = {
 	{NULL, 0, false}
 };
 
+StaticAssertDecl(lengthof(intervalstyle_options) == (INTSTYLE_ISO_8601 + 2),
+				 "array length mismatch");
+
 static const struct config_enum_entry log_error_verbosity_options[] = {
 	{"terse", PGERROR_TERSE, false},
 	{"default", PGERROR_DEFAULT, false},
@@ -293,6 +299,9 @@ static const struct config_enum_entry log_error_verbosity_options[] = {
 	{NULL, 0, false}
 };
 
+StaticAssertDecl(lengthof(log_error_verbosity_options) == (PGERROR_VERBOSE + 2),
+				 "array length mismatch");
+
 static const struct config_enum_entry log_statement_options[] = {
 	{"none", LOGSTMT_NONE, false},
 	{"ddl", LOGSTMT_DDL, false},
@@ -301,6 +310,9 @@ static const struct config_enum_entry log_statement_options[] = {
 	{NULL, 0, false}
 };
 
+StaticAssertDecl(lengthof(log_statement_options) == (LOGSTMT_ALL + 2),
+				 "array length mismatch");
+
 static const struct config_enum_entry isolation_level_options[] = {
 	{"serializable", XACT_SERIALIZABLE, false},
 	{"repeatable read", XACT_REPEATABLE_READ, false},
@@ -316,6 +328,9 @@ static const struct config_enum_entry session_replication_role_options[] = {
 	{NULL, 0, false}
 };
 
+StaticAssertDecl(lengthof(session_replication_role_options) == (SESSION_REPLICATION_ROLE_LOCAL + 2),
+				 "array length mismatch");
+
 static const struct config_enum_entry syslog_facility_options[] = {
 #ifdef HAVE_SYSLOG
 	{"local0", LOG_LOCAL0, false},
@@ -339,18 +354,27 @@ static const struct config_enum_entry track_function_options[] = {
 	{NULL, 0, false}
 };
 
+StaticAssertDecl(lengthof(track_function_options) == (TRACK_FUNC_ALL + 2),
+				 "array length mismatch");
+
 static const struct config_enum_entry xmlbinary_options[] = {
 	{"base64", XMLBINARY_BASE64, false},
 	{"hex", XMLBINARY_HEX, false},
 	{NULL, 0, false}
 };
 
+StaticAssertDecl(lengthof(xmlbinary_options) == (XMLBINARY_HEX + 2),
+				 "array length mismatch");
+
 static const struct config_enum_entry xmloption_options[] = {
 	{"content", XMLOPTION_CONTENT, false},
 	{"document", XMLOPTION_DOCUMENT, false},
 	{NULL, 0, false}
 };
 
+StaticAssertDecl(lengthof(xmloption_options) == (XMLOPTION_CONTENT + 2),
+				 "array length mismatch");
+
 /*
  * Although only "on", "off", and "safe_encoding" are documented, we
  * accept all the likely variants of "on" and "off".
@@ -465,6 +489,9 @@ const struct config_enum_entry ssl_protocol_versions_info[] = {
 	{NULL, 0, false}
 };
 
+StaticAssertDecl(lengthof(ssl_protocol_versions_info) == (PG_TLS1_3_VERSION + 2),
+				 "array length mismatch");
+
 static struct config_enum_entry shared_memory_options[] = {
 #ifndef WIN32
 	{"sysv", SHMEM_TYPE_SYSV, false},
@@ -615,6 +642,9 @@ const char *const GucContext_Names[] =
 	 /* PGC_USERSET */ "user"
 };
 
+StaticAssertDecl(lengthof(GucContext_Names) == (PGC_USERSET + 1),
+				 "array length mismatch");
+
 /*
  * Displayable names for source types (enum GucSource)
  *
@@ -638,6 +668,9 @@ const char *const GucSource_Names[] =
 	 /* PGC_S_SESSION */ "session"
 };
 
+StaticAssertDecl(lengthof(GucSource_Names) == (PGC_S_SESSION + 1),
+				 "array length mismatch");
+
 /*
  * Displayable names for the groupings defined in enum config_group
  */
@@ -749,6 +782,9 @@ const char *const config_group_names[] =
 	NULL
 };
 
+StaticAssertDecl(lengthof(config_group_names) == (DEVELOPER_OPTIONS + 2),
+				 "array length mismatch");
+
 /*
  * Displayable names for GUC variable types (enum config_type)
  *
@@ -763,6 +799,9 @@ const char *const config_type_names[] =
 	 /* PGC_ENUM */ "enum"
 };
 
+StaticAssertDecl(lengthof(config_type_names) == (PGC_ENUM + 1),
+				 "array length mismatch");
+
 /*
  * Unit conversion tables.
  *