From 7bda2a03d0d05034c122df22d476d7bb5c6acb09 Mon Sep 17 00:00:00 2001
From: Andres Freund <andres@anarazel.de>
Date: Thu, 19 Mar 2020 18:54:08 -0700
Subject: [PATCH v2 2/3] WIP: reimplement elog() using ereport().

Author: Andres Freund
Discussion: https://postgr.es/m/5995.1584660775@sss.pgh.pa.us
---
 src/include/utils/elog.h       |  31 +---------
 src/backend/utils/error/elog.c | 103 ---------------------------------
 2 files changed, 1 insertion(+), 133 deletions(-)

diff --git a/src/include/utils/elog.h b/src/include/utils/elog.h
index 241457f35bd..8404760ae39 100644
--- a/src/include/utils/elog.h
+++ b/src/include/utils/elog.h
@@ -215,37 +215,8 @@ extern int	getinternalerrposition(void);
  *		elog(ERROR, "portal \"%s\" not found", stmt->portalname);
  *----------
  */
-/*
- * Using variadic macros, we can give the compiler a hint about the
- * call not returning when elevel >= ERROR.  See comments for ereport().
- * Note that historically elog() has called elog_start (which saves errno)
- * before evaluating "elevel", so we preserve that behavior here.
- */
-#ifdef HAVE__BUILTIN_CONSTANT_P
 #define elog(elevel, ...)  \
-	do { \
-		pg_prevent_errno_in_scope(); \
-		elog_start(__FILE__, __LINE__, PG_FUNCNAME_MACRO); \
-		elog_finish(elevel, __VA_ARGS__); \
-		if (__builtin_constant_p(elevel) && (elevel) >= ERROR) \
-			pg_unreachable(); \
-	} while(0)
-#else							/* !HAVE__BUILTIN_CONSTANT_P */
-#define elog(elevel, ...)  \
-	do { \
-		pg_prevent_errno_in_scope(); \
-		elog_start(__FILE__, __LINE__, PG_FUNCNAME_MACRO); \
-		{ \
-			const int elevel_ = (elevel); \
-			elog_finish(elevel_, __VA_ARGS__); \
-			if (elevel_ >= ERROR) \
-				pg_unreachable(); \
-		} \
-	} while(0)
-#endif							/* HAVE__BUILTIN_CONSTANT_P */
-
-extern void elog_start(const char *filename, int lineno, const char *funcname);
-extern void elog_finish(int elevel, const char *fmt,...) pg_attribute_printf(2, 3);
+	ereport(elevel, errmsg(__VA_ARGS__))
 
 
 /* Support for constructing error strings separately from ereport() calls */
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index dc1fda03a8f..141eddeeeba 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -1330,109 +1330,6 @@ getinternalerrposition(void)
 	return edata->internalpos;
 }
 
-
-/*
- * elog_start --- startup for old-style API
- *
- * All that we do here is stash the hidden filename/lineno/funcname
- * arguments into a stack entry, along with the current value of errno.
- *
- * We need this to be separate from elog_finish because there's no other
- * C89-compliant way to deal with inserting extra arguments into the elog
- * call.  (When using C99's __VA_ARGS__, we could possibly merge this with
- * elog_finish, but there doesn't seem to be a good way to save errno before
- * evaluating the format arguments if we do that.)
- */
-void
-elog_start(const char *filename, int lineno, const char *funcname)
-{
-	ErrorData  *edata;
-
-	/* Make sure that memory context initialization has finished */
-	if (ErrorContext == NULL)
-	{
-		/* Oops, hard crash time; very little we can do safely here */
-		write_stderr("error occurred at %s:%d before error message processing is available\n",
-					 filename ? filename : "(unknown file)", lineno);
-		exit(2);
-	}
-
-	if (++errordata_stack_depth >= ERRORDATA_STACK_SIZE)
-	{
-		/*
-		 * Wups, stack not big enough.  We treat this as a PANIC condition
-		 * because it suggests an infinite loop of errors during error
-		 * recovery.  Note that the message is intentionally not localized,
-		 * else failure to convert it to client encoding could cause further
-		 * recursion.
-		 */
-		errordata_stack_depth = -1; /* make room on stack */
-		ereport(PANIC, (errmsg_internal("ERRORDATA_STACK_SIZE exceeded")));
-	}
-
-	edata = &errordata[errordata_stack_depth];
-	if (filename)
-	{
-		const char *slash;
-
-		/* keep only base name, useful especially for vpath builds */
-		slash = strrchr(filename, '/');
-		if (slash)
-			filename = slash + 1;
-	}
-	edata->filename = filename;
-	edata->lineno = lineno;
-	edata->funcname = funcname;
-	/* errno is saved now so that error parameter eval can't change it */
-	edata->saved_errno = errno;
-
-	/* Use ErrorContext for any allocations done at this level. */
-	edata->assoc_context = ErrorContext;
-}
-
-/*
- * elog_finish --- finish up for old-style API
- */
-void
-elog_finish(int elevel, const char *fmt,...)
-{
-	ErrorData  *edata = &errordata[errordata_stack_depth];
-	MemoryContext oldcontext;
-
-	CHECK_STACK_DEPTH();
-
-	/*
-	 * Do errstart() to see if we actually want to report the message.
-	 */
-	errordata_stack_depth--;
-	errno = edata->saved_errno;
-	if (!errstart(elevel, edata->filename, edata->lineno, edata->funcname, NULL))
-		return;					/* nothing to do */
-
-	/*
-	 * Format error message just like errmsg_internal().
-	 */
-	recursion_depth++;
-	oldcontext = MemoryContextSwitchTo(edata->assoc_context);
-
-	if (!edata->backtrace &&
-		edata->funcname &&
-		matches_backtrace_functions(edata->funcname))
-		set_backtrace(edata, 2);
-
-	edata->message_id = fmt;
-	EVALUATE_MESSAGE(edata->domain, message, false, false);
-
-	MemoryContextSwitchTo(oldcontext);
-	recursion_depth--;
-
-	/*
-	 * And let errfinish() finish up.
-	 */
-	errfinish();
-}
-
-
 /*
  * Functions to allow construction of error message strings separately from
  * the ereport() call itself.
-- 
2.25.0.114.g5b0ca878e0