Use wrappers of PG_DETOAST_DATUM_PACKED() more.

This makes almost all core code follow the policy introduced in the
previous commit.  Specific decisions:

- Text search support functions with char* and length arguments, such as
  prsstart and lexize, may receive unaligned strings.  I doubt
  maintainers of non-core text search code will notice.

- Use plain VARDATA() on values detoasted or synthesized earlier in the
  same function.  Use VARDATA_ANY() on varlenas sourced outside the
  function, even if they happen to always have four-byte headers.  As an
  exception, retain the universal practice of using VARDATA() on return
  values of SendFunctionCall().

- Retain PG_GETARG_BYTEA_P() in pageinspect.  (Page images are too large
  for a one-byte header, so this misses no optimization.)  Sites that do
  not call get_page_from_raw() typically need the four-byte alignment.

- For now, do not change btree_gist.  Its use of four-byte headers in
  memory is partly entangled with storage of 4-byte headers inside
  GBT_VARKEY, on disk.

- For now, do not change gtrgm_consistent() or gtrgm_distance().  They
  incorporate the varlena header into a cache, and there are multiple
  credible implementation strategies to consider.

1 files changed, 4 insertions, 4 deletions

diff --git a/src/backend/utils/adt/genfile.c b/src/backend/utils/adt/genfile.c
index 1a127d9258..2147936dd8 100644
--- a/src/backend/utils/adt/genfile.c
+++ b/src/backend/utils/adt/genfile.c
@@ -187,7 +187,7 @@ read_text_file(const char *filename, int64 seek_offset, int64 bytes_to_read,
 Datum
 pg_read_file(PG_FUNCTION_ARGS)
 {
-	text	   *filename_t = PG_GETARG_TEXT_P(0);
+	text	   *filename_t = PG_GETARG_TEXT_PP(0);
 	int64		seek_offset = 0;
 	int64		bytes_to_read = -1;
 	bool		missing_ok = false;
@@ -228,7 +228,7 @@ pg_read_file(PG_FUNCTION_ARGS)
 Datum
 pg_read_binary_file(PG_FUNCTION_ARGS)
 {
-	text	   *filename_t = PG_GETARG_TEXT_P(0);
+	text	   *filename_t = PG_GETARG_TEXT_PP(0);
 	int64		seek_offset = 0;
 	int64		bytes_to_read = -1;
 	bool		missing_ok = false;
@@ -303,7 +303,7 @@ pg_read_binary_file_all(PG_FUNCTION_ARGS)
 Datum
 pg_stat_file(PG_FUNCTION_ARGS)
 {
-	text	   *filename_t = PG_GETARG_TEXT_P(0);
+	text	   *filename_t = PG_GETARG_TEXT_PP(0);
 	char	   *filename;
 	struct stat fst;
 	Datum		values[6];
@@ -421,7 +421,7 @@ pg_ls_dir(PG_FUNCTION_ARGS)
 		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
 
 		fctx = palloc(sizeof(directory_fctx));
-		fctx->location = convert_and_check_filename(PG_GETARG_TEXT_P(0));
+		fctx->location = convert_and_check_filename(PG_GETARG_TEXT_PP(0));
 
 		fctx->include_dot_dirs = include_dot_dirs;
 		fctx->dirdesc = AllocateDir(fctx->location);