Infrastructure for upgraded error reporting mechanism. elog.c is

rewritten and the protocol is changed, but most elog calls are still
elog calls.  Also, we need to contemplate mechanisms for controlling
all this functionality --- eg, how much stuff should appear in the
postmaster log?  And what API should libpq expose for it?

3 files changed, 118 insertions, 155 deletions

diff --git a/src/pl/plpgsql/src/pl_comp.c b/src/pl/plpgsql/src/pl_comp.c
index dedbca9d2fc..feb80f94ae7 100644
--- a/src/pl/plpgsql/src/pl_comp.c
+++ b/src/pl/plpgsql/src/pl_comp.c
@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_comp.c,v 1.55 2003/03/25 00:34:23 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_comp.c,v 1.56 2003/04/24 21:16:44 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -80,6 +80,7 @@ int			plpgsql_DumpExecTree = 0;
 PLpgSQL_function *plpgsql_curr_compile;
 
 
+static void plpgsql_compile_error_callback(void *arg);
 static PLpgSQL_row *build_rowtype(Oid classOid);
 
 
@@ -121,7 +122,7 @@ plpgsql_compile(Oid fn_oid, int functype)
 	PLpgSQL_rec *rec;
 	int			i;
 	int			arg_varnos[FUNC_MAX_ARGS];
-	sigjmp_buf	save_restart;
+	ErrorContextCallback plerrcontext;
 
 	/*
 	 * Lookup the pg_proc tuple by Oid
@@ -133,37 +134,25 @@ plpgsql_compile(Oid fn_oid, int functype)
 		elog(ERROR, "plpgsql: cache lookup for proc %u failed", fn_oid);
 
 	/*
-	 * Setup the scanner input and error info
+	 * Setup the scanner input and error info.  We assume that this function
+	 * cannot be invoked recursively, so there's no need to save and restore
+	 * the static variables used here.
 	 */
 	procStruct = (Form_pg_proc) GETSTRUCT(procTup);
 	proc_source = DatumGetCString(DirectFunctionCall1(textout,
 								  PointerGetDatum(&procStruct->prosrc)));
 	plpgsql_setinput(proc_source, functype);
+
 	plpgsql_error_funcname = pstrdup(NameStr(procStruct->proname));
 	plpgsql_error_lineno = 0;
 
 	/*
-	 * Catch elog() so we can provide notice about where the error is
+	 * Setup error traceback support for ereport()
 	 */
-	memcpy(&save_restart, &Warn_restart, sizeof(save_restart));
-	if (sigsetjmp(Warn_restart, 1) != 0)
-	{
-		memcpy(&Warn_restart, &save_restart, sizeof(Warn_restart));
-
-		/*
-		 * If we are the first of cascaded error catchings, print where
-		 * this happened
-		 */
-		if (plpgsql_error_funcname != NULL)
-		{
-			elog(WARNING, "plpgsql: ERROR during compile of %s near line %d",
-				 plpgsql_error_funcname, plpgsql_error_lineno);
-
-			plpgsql_error_funcname = NULL;
-		}
-
-		siglongjmp(Warn_restart, 1);
-	}
+	plerrcontext.callback = plpgsql_compile_error_callback;
+	plerrcontext.arg = NULL;
+	plerrcontext.previous = error_context_stack;
+	error_context_stack = &plerrcontext;
 
 	/*
 	 * Initialize the compiler
@@ -530,11 +519,11 @@ plpgsql_compile(Oid fn_oid, int functype)
 	ReleaseSysCache(procTup);
 
 	/*
-	 * Restore the previous elog() jump target
+	 * Pop the error context stack
 	 */
+	error_context_stack = plerrcontext.previous;
 	plpgsql_error_funcname = NULL;
 	plpgsql_error_lineno = 0;
-	memcpy(&Warn_restart, &save_restart, sizeof(Warn_restart));
 
 	/*
 	 * Finally return the compiled function
@@ -545,6 +534,18 @@ plpgsql_compile(Oid fn_oid, int functype)
 }
 
 
+/*
+ * error context callback to let us supply a call-stack traceback
+ */
+static void
+plpgsql_compile_error_callback(void *arg)
+{
+	if (plpgsql_error_funcname)
+		errcontext("compile of PL/pgSQL function %s near line %d",
+				   plpgsql_error_funcname, plpgsql_error_lineno);
+}
+
+
 /* ----------
  * plpgsql_parse_word		The scanner calls this to postparse
  *				any single word not found by a
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index 6620e419703..efb423541a9 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.85 2003/04/08 23:20:04 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.86 2003/04/24 21:16:44 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -55,14 +55,12 @@
 #include "utils/syscache.h"
 
 
-static PLpgSQL_function *error_info_func = NULL;
-static PLpgSQL_stmt *error_info_stmt = NULL;
-static char *error_info_text = NULL;
-
+static const char * const raise_skip_msg = "RAISE";
 
 /************************************************************
  * Local function forward declarations
  ************************************************************/
+static void plpgsql_exec_error_callback(void *arg);
 static PLpgSQL_var *copy_var(PLpgSQL_var * var);
 static PLpgSQL_rec *copy_rec(PLpgSQL_rec * rec);
 
@@ -173,61 +171,26 @@ Datum
 plpgsql_exec_function(PLpgSQL_function * func, FunctionCallInfo fcinfo)
 {
 	PLpgSQL_execstate estate;
+	ErrorContextCallback plerrcontext;
 	int			i;
-	sigjmp_buf	save_restart;
-	PLpgSQL_function *save_efunc;
-	PLpgSQL_stmt *save_estmt;
-	char	   *save_etext;
 
 	/*
-	 * Setup debug error info and catch elog()
+	 * Setup the execution state
 	 */
-	save_efunc = error_info_func;
-	save_estmt = error_info_stmt;
-	save_etext = error_info_text;
-
-	error_info_func = func;
-	error_info_stmt = NULL;
-	error_info_text = "while initialization of execution state";
-
-	memcpy(&save_restart, &Warn_restart, sizeof(save_restart));
-	if (sigsetjmp(Warn_restart, 1) != 0)
-	{
-		memcpy(&Warn_restart, &save_restart, sizeof(Warn_restart));
-
-		/*
-		 * If we are the first of cascaded error catchings, print where
-		 * this happened
-		 */
-		if (error_info_func != NULL)
-		{
-			elog(WARNING, "Error occurred while executing PL/pgSQL function %s",
-				 error_info_func->fn_name);
-			if (error_info_stmt != NULL)
-				elog(WARNING, "line %d at %s", error_info_stmt->lineno,
-					 plpgsql_stmt_typename(error_info_stmt));
-			else if (error_info_text != NULL)
-				elog(WARNING, "%s", error_info_text);
-			else
-				elog(WARNING, "no more error information available");
-
-			error_info_func = NULL;
-			error_info_stmt = NULL;
-			error_info_text = NULL;
-		}
-
-		siglongjmp(Warn_restart, 1);
-	}
-
+	plpgsql_estate_setup(&estate, func, (ReturnSetInfo *) fcinfo->resultinfo);
 
 	/*
-	 * Setup the execution state
+	 * Setup error traceback support for ereport()
 	 */
-	plpgsql_estate_setup(&estate, func, (ReturnSetInfo *) fcinfo->resultinfo);
+	plerrcontext.callback = plpgsql_exec_error_callback;
+	plerrcontext.arg = &estate;
+	plerrcontext.previous = error_context_stack;
+	error_context_stack = &plerrcontext;
 
 	/*
 	 * Make local execution copies of all the datums
 	 */
+	estate.err_text = "while initialization of execution state";
 	for (i = 0; i < func->ndatums; i++)
 	{
 		switch (func->datums[i]->dtype)
@@ -257,7 +220,7 @@ plpgsql_exec_function(PLpgSQL_function * func, FunctionCallInfo fcinfo)
 	/*
 	 * Put the actual call argument values into the variables
 	 */
-	error_info_text = "while putting call arguments to local variables";
+	estate.err_text = "while putting call arguments to local variables";
 	for (i = 0; i < func->fn_nargs; i++)
 	{
 		int			n = func->fn_argvarnos[i];
@@ -298,7 +261,7 @@ plpgsql_exec_function(PLpgSQL_function * func, FunctionCallInfo fcinfo)
 	 * Initialize the other variables to NULL values for now. The default
 	 * values are set when the blocks are entered.
 	 */
-	error_info_text = "while initializing local variables to NULL";
+	estate.err_text = "while initializing local variables to NULL";
 	for (i = estate.found_varno; i < estate.ndatums; i++)
 	{
 		switch (estate.datums[i]->dtype)
@@ -333,20 +296,20 @@ plpgsql_exec_function(PLpgSQL_function * func, FunctionCallInfo fcinfo)
 	/*
 	 * Now call the toplevel block of statements
 	 */
-	error_info_text = NULL;
-	error_info_stmt = (PLpgSQL_stmt *) (func->action);
+	estate.err_text = NULL;
+	estate.err_stmt = (PLpgSQL_stmt *) (func->action);
 	if (exec_stmt_block(&estate, func->action) != PLPGSQL_RC_RETURN)
 	{
-		error_info_stmt = NULL;
-		error_info_text = "at END of toplevel PL block";
+		estate.err_stmt = NULL;
+		estate.err_text = "at END of toplevel PL block";
 		elog(ERROR, "control reaches end of function without RETURN");
 	}
 
 	/*
 	 * We got a return value - process it
 	 */
-	error_info_stmt = NULL;
-	error_info_text = "while casting return value to function's return type";
+	estate.err_stmt = NULL;
+	estate.err_text = "while casting return value to function's return type";
 
 	fcinfo->isnull = estate.retisnull;
 
@@ -417,12 +380,9 @@ plpgsql_exec_function(PLpgSQL_function * func, FunctionCallInfo fcinfo)
 	exec_eval_cleanup(&estate);
 
 	/*
-	 * Restore the previous error info and elog() jump target
+	 * Pop the error context stack
 	 */
-	error_info_func = save_efunc;
-	error_info_stmt = save_estmt;
-	error_info_text = save_etext;
-	memcpy(&Warn_restart, &save_restart, sizeof(Warn_restart));
+	error_context_stack = plerrcontext.previous;
 
 	/*
 	 * Return the functions result
@@ -441,65 +401,30 @@ plpgsql_exec_trigger(PLpgSQL_function * func,
 					 TriggerData *trigdata)
 {
 	PLpgSQL_execstate estate;
+	ErrorContextCallback plerrcontext;
 	int			i;
-	sigjmp_buf	save_restart;
-	PLpgSQL_function *save_efunc;
-	PLpgSQL_stmt *save_estmt;
-	char	   *save_etext;
 	PLpgSQL_var *var;
 	PLpgSQL_rec *rec_new,
 				*rec_old;
 	HeapTuple	rettup;
 
 	/*
-	 * Setup debug error info and catch elog()
+	 * Setup the execution state
 	 */
-	save_efunc = error_info_func;
-	save_estmt = error_info_stmt;
-	save_etext = error_info_text;
-
-	error_info_func = func;
-	error_info_stmt = NULL;
-	error_info_text = "while initialization of execution state";
-
-	memcpy(&save_restart, &Warn_restart, sizeof(save_restart));
-	if (sigsetjmp(Warn_restart, 1) != 0)
-	{
-		memcpy(&Warn_restart, &save_restart, sizeof(Warn_restart));
-
-		/*
-		 * If we are the first of cascaded error catchings, print where
-		 * this happened
-		 */
-		if (error_info_func != NULL)
-		{
-			elog(WARNING, "Error occurred while executing PL/pgSQL function %s",
-				 error_info_func->fn_name);
-			if (error_info_stmt != NULL)
-				elog(WARNING, "line %d at %s", error_info_stmt->lineno,
-					 plpgsql_stmt_typename(error_info_stmt));
-			else if (error_info_text != NULL)
-				elog(WARNING, "%s", error_info_text);
-			else
-				elog(WARNING, "no more error information available");
-
-			error_info_func = NULL;
-			error_info_stmt = NULL;
-			error_info_text = NULL;
-		}
-
-		siglongjmp(Warn_restart, 1);
-	}
-
+	plpgsql_estate_setup(&estate, func, NULL);
 
 	/*
-	 * Setup the execution state
+	 * Setup error traceback support for ereport()
 	 */
-	plpgsql_estate_setup(&estate, func, NULL);
+	plerrcontext.callback = plpgsql_exec_error_callback;
+	plerrcontext.arg = &estate;
+	plerrcontext.previous = error_context_stack;
+	error_context_stack = &plerrcontext;
 
 	/*
 	 * Make local execution copies of all the datums
 	 */
+	estate.err_text = "while initialization of execution state";
 	for (i = 0; i < func->ndatums; i++)
 	{
 		switch (func->datums[i]->dtype)
@@ -634,7 +559,7 @@ plpgsql_exec_trigger(PLpgSQL_function * func,
 	 * Put the actual call argument values into the special execution
 	 * state variables
 	 */
-	error_info_text = "while putting call arguments to local variables";
+	estate.err_text = "while putting call arguments to local variables";
 	estate.trig_nargs = trigdata->tg_trigger->tgnargs;
 	if (estate.trig_nargs == 0)
 		estate.trig_argv = NULL;
@@ -650,7 +575,7 @@ plpgsql_exec_trigger(PLpgSQL_function * func,
 	 * Initialize the other variables to NULL values for now. The default
 	 * values are set when the blocks are entered.
 	 */
-	error_info_text = "while initializing local variables to NULL";
+	estate.err_text = "while initializing local variables to NULL";
 	for (i = estate.found_varno; i < estate.ndatums; i++)
 	{
 		switch (estate.datums[i]->dtype)
@@ -686,12 +611,12 @@ plpgsql_exec_trigger(PLpgSQL_function * func,
 	/*
 	 * Now call the toplevel block of statements
 	 */
-	error_info_text = NULL;
-	error_info_stmt = (PLpgSQL_stmt *) (func->action);
+	estate.err_text = NULL;
+	estate.err_stmt = (PLpgSQL_stmt *) (func->action);
 	if (exec_stmt_block(&estate, func->action) != PLPGSQL_RC_RETURN)
 	{
-		error_info_stmt = NULL;
-		error_info_text = "at END of toplevel PL block";
+		estate.err_stmt = NULL;
+		estate.err_text = "at END of toplevel PL block";
 		elog(ERROR, "control reaches end of trigger procedure without RETURN");
 	}
 
@@ -723,12 +648,9 @@ plpgsql_exec_trigger(PLpgSQL_function * func,
 	exec_eval_cleanup(&estate);
 
 	/*
-	 * Restore the previous error info and elog() jump target
+	 * Pop the error context stack
 	 */
-	error_info_func = save_efunc;
-	error_info_stmt = save_estmt;
-	error_info_text = save_etext;
-	memcpy(&Warn_restart, &save_restart, sizeof(Warn_restart));
+	error_context_stack = plerrcontext.previous;
 
 	/*
 	 * Return the triggers result
@@ -737,6 +659,37 @@ plpgsql_exec_trigger(PLpgSQL_function * func,
 }
 
 
+/*
+ * error context callback to let us supply a call-stack traceback
+ */
+static void
+plpgsql_exec_error_callback(void *arg)
+{
+	PLpgSQL_execstate *estate = (PLpgSQL_execstate *) arg;
+
+	/* safety check, shouldn't happen */
+	if (estate->err_func == NULL)
+		return;
+
+	/* if we are doing RAISE, don't report its location */
+	if (estate->err_text == raise_skip_msg)
+		return;
+
+	if (estate->err_stmt != NULL)
+		errcontext("PL/pgSQL function %s line %d at %s",
+				   estate->err_func->fn_name,
+				   estate->err_stmt->lineno,
+				   plpgsql_stmt_typename(estate->err_stmt));
+	else if (estate->err_text != NULL)
+		errcontext("PL/pgSQL function %s %s",
+				   estate->err_func->fn_name,
+				   estate->err_text);
+	else
+		errcontext("PL/pgSQL function %s",
+				   estate->err_func->fn_name);
+}
+
+
 /* ----------
  * Support functions for copying local execution variables
  * ----------
@@ -909,8 +862,8 @@ exec_stmt(PLpgSQL_execstate * estate, PLpgSQL_stmt * stmt)
 	PLpgSQL_stmt *save_estmt;
 	int			rc = -1;
 
-	save_estmt = error_info_stmt;
-	error_info_stmt = stmt;
+	save_estmt = estate->err_stmt;
+	estate->err_stmt = stmt;
 
 	CHECK_FOR_INTERRUPTS();
 
@@ -997,12 +950,12 @@ exec_stmt(PLpgSQL_execstate * estate, PLpgSQL_stmt * stmt)
 			break;
 
 		default:
-			error_info_stmt = save_estmt;
+			estate->err_stmt = save_estmt;
 			elog(ERROR, "unknown cmdtype %d in exec_stmt",
 				 stmt->cmd_type);
 	}
 
-	error_info_stmt = save_estmt;
+	estate->err_stmt = save_estmt;
 
 	return rc;
 }
@@ -1854,15 +1807,15 @@ exec_stmt_raise(PLpgSQL_execstate * estate, PLpgSQL_stmt_raise * stmt)
 	}
 
 	/*
-	 * Now suppress debug info and throw the elog()
+	 * Throw the error (may or may not come back)
 	 */
-	if (stmt->elog_level == ERROR)
-	{
-		error_info_func = NULL;
-		error_info_stmt = NULL;
-		error_info_text = NULL;
-	}
-	elog(stmt->elog_level, "%s", plpgsql_dstring_get(&ds));
+	estate->err_text = raise_skip_msg; /* suppress traceback of raise */
+
+	ereport(stmt->elog_level,
+			(errmsg_internal("%s", plpgsql_dstring_get(&ds))));
+
+	estate->err_text = NULL;	/* un-suppress... */
+
 	plpgsql_dstring_free(&ds);
 
 	return PLPGSQL_RC_OK;
@@ -1905,6 +1858,10 @@ plpgsql_estate_setup(PLpgSQL_execstate * estate,
 	estate->eval_processed = 0;
 	estate->eval_lastoid = InvalidOid;
 	estate->eval_econtext = NULL;
+
+	estate->err_func = func;
+	estate->err_stmt = NULL;
+	estate->err_text = NULL;
 }
 
 /* ----------
diff --git a/src/pl/plpgsql/src/plpgsql.h b/src/pl/plpgsql/src/plpgsql.h
index 9706db602c2..3756d94c911 100644
--- a/src/pl/plpgsql/src/plpgsql.h
+++ b/src/pl/plpgsql/src/plpgsql.h
@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.33 2003/03/25 03:16:41 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/plpgsql.h,v 1.34 2003/04/24 21:16:44 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -552,6 +552,11 @@ typedef struct
 	uint32		eval_processed;
 	Oid			eval_lastoid;
 	ExprContext *eval_econtext;
+
+	/* status information for error context reporting */
+	PLpgSQL_function   *err_func;		/* current func */
+	PLpgSQL_stmt	   *err_stmt;		/* current stmt */
+	const char		   *err_text;		/* additional state info */
 }	PLpgSQL_execstate;