[PATCH 01/17] libtracefs: Added new API tracefs_sql()

From: Steven Rostedt
Date: Fri Jul 30 2021 - 18:19:24 EST

From: "Steven Rostedt (VMware)" <rostedt@xxxxxxxxxxx>

This adds the API tracefs_sql() that takes a tep_handle handler, a name,
and a SQL string and parses it to produce a tracefs_synth synthetic event
handler.

Currently it only supports simple SQL of the type:

SELECT start.common_pid AS pid, end.common_timestamp.usecs AS usecs
FROM sched_waking AS start on sched_switch AS end
ON start.pid = end.next_pid

Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
include/tracefs.h | 3 +
src/Makefile | 11 +
src/sqlhist-parse.h | 69 +++++
src/sqlhist.l | 88 ++++++
src/sqlhist.y | 143 +++++++++
src/tracefs-sqlhist.c | 691 ++++++++++++++++++++++++++++++++++++++++++
6 files changed, 1005 insertions(+)
create mode 100644 src/sqlhist-parse.h
create mode 100644 src/sqlhist.l
create mode 100644 src/sqlhist.y
create mode 100644 src/tracefs-sqlhist.c

diff --git a/include/tracefs.h b/include/tracefs.h
index 246647f6496d..3d83604031b1 100644
--- a/include/tracefs.h
+++ b/include/tracefs.h
@@ -385,4 +385,7 @@ void tracefs_synth_free(struct tracefs_synth *synth);
int tracefs_synth_show(struct trace_seq *seq, struct tracefs_instance *instance,
struct tracefs_synth *synth);

+struct tracefs_synth *tracefs_sql(struct tep_handle *tep, const char *name,
+ const char *sql_buffer, char **err);
+
#endif /* _TRACE_FS_H */
diff --git a/src/Makefile b/src/Makefile
index 767af49034ee..eac404a1a147 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -12,6 +12,11 @@ OBJS += tracefs-kprobes.o
OBJS += tracefs-hist.o
OBJS += tracefs-filter.o

+# Order matters for the the three below
+OBJS += sqlhist-lex.o
+OBJS += sqlhist.tab.o
+OBJS += tracefs-sqlhist.o
+
OBJS := $(OBJS:%.o=$(bdir)/%.o)
DEPS := $(OBJS:$(bdir)/%.o=$(bdir)/.%.d)

@@ -32,6 +37,12 @@ $(LIBTRACEFS_SHARED_SO): $(LIBTRACEFS_SHARED_VERSION)

libtracefs.so: $(LIBTRACEFS_SHARED_SO)

+sqlhist.tab.c: sqlhist.y
+ bison --debug -v --report-file=bison.report -d -o $@ $^
+
+sqlhist-lex.c: sqlhist.l sqlhist.tab.c
+ flex -o $@ $<
+
$(bdir)/%.o: %.c
$(Q)$(call do_fpic_compile)

diff --git a/src/sqlhist-parse.h b/src/sqlhist-parse.h
new file mode 100644
index 000000000000..aa5232eea451
--- /dev/null
+++ b/src/sqlhist-parse.h
@@ -0,0 +1,69 @@
+#ifndef __SQLHIST_PARSE_H
+#define __SQLHIST_PARSE_H
+
+#include <stdarg.h>
+#include <tracefs.h>
+
+struct str_hash;
+#define HASH_BITS 10
+
+struct sql_table;
+
+struct sqlhist_bison {
+ const char *buffer;
+ size_t buffer_size;
+ size_t buffer_idx;
+ int line_no;
+ int line_idx;
+ struct sql_table *table;
+ char *parse_error_str;
+ struct str_hash *str_hash[1 << HASH_BITS];
+};
+
+extern struct sqlhist_bison *sb;
+
+#include "sqlhist.tab.h"
+
+enum filter_type {
+ FILTER_GROUP,
+ FILTER_NOT_GROUP,
+ FILTER_EQ,
+ FILTER_NE,
+ FILTER_LE,
+ FILTER_LT,
+ FILTER_GE,
+ FILTER_GT,
+ FILTER_BIN_AND,
+ FILTER_STR_CMP,
+ FILTER_AND,
+ FILTER_OR,
+};
+
+enum compare_type {
+ COMPARE_GROUP,
+ COMPARE_ADD,
+ COMPARE_SUB,
+ COMPARE_MUL,
+ COMPARE_DIV,
+ COMPARE_BIN_AND,
+ COMPARE_BIN_OR,
+ COMPARE_AND,
+ COMPARE_OR,
+};
+
+char * store_str(struct sqlhist_bison *sb, const char *str);
+
+int table_start(struct sqlhist_bison *sb);
+
+void *add_field(struct sqlhist_bison *sb, const char *field, const char *label);
+
+int add_match(struct sqlhist_bison *sb, void *A, void *B);
+
+int add_selection(struct sqlhist_bison *sb, void *item, const char *label);
+int add_from(struct sqlhist_bison *sb, void *item);
+int add_to(struct sqlhist_bison *sb, void *item);
+
+extern void sql_parse_error(struct sqlhist_bison *sb, const char *text,
+ const char *fmt, va_list ap);
+
+#endif
diff --git a/src/sqlhist.l b/src/sqlhist.l
new file mode 100644
index 000000000000..3f394f37b738
--- /dev/null
+++ b/src/sqlhist.l
@@ -0,0 +1,88 @@
+%{
+/* code here */
+
+#include <stdarg.h>
+#include "sqlhist-parse.h"
+
+extern int my_yyinput(char *buf, int max);
+
+#undef YY_INPUT
+#define YY_INPUT(b, r, m) ({r = my_yyinput(b, m);})
+
+#define YY_NO_INPUT
+#define YY_NO_UNPUT
+
+#define YY_EXTRA_TYPE struct sqlhist_bison *
+
+#define HANDLE_COLUMN do { sb->line_idx += strlen(yytext); } while (0)
+
+%}
+
+%option caseless
+
+field [a-z_][a-z0-9_\.]*
+qstring \"[^\"]*\"
+hexnum 0x[0-9a-z]+
+number [0-9a-z]+
+
+%%
+
+select { HANDLE_COLUMN; return SELECT; }
+as { HANDLE_COLUMN; return AS; }
+from { HANDLE_COLUMN; return FROM; }
+join { HANDLE_COLUMN; return JOIN; }
+on { HANDLE_COLUMN; return ON; }
+
+{qstring} {
+ HANDLE_COLUMN;
+ yylval.string = store_str(sb, yytext);
+ return STRING;
+}
+
+{field} {
+ HANDLE_COLUMN;
+ yylval.string = store_str(sb, yytext);
+ return FIELD;
+}
+
+{hexnum} {
+ HANDLE_COLUMN;
+ yylval.number = strtol(yytext, NULL, 0);
+ return NUMBER;
+}
+
+{number} {
+ HANDLE_COLUMN;
+ yylval.number = strtol(yytext, NULL, 0);
+ return NUMBER;
+}
+
+\!= { HANDLE_COLUMN; return NEQ; }
+\<= { HANDLE_COLUMN; return LE; }
+\>= { HANDLE_COLUMN; return GE; }
+== { HANDLE_COLUMN; return EQ; }
+&& { HANDLE_COLUMN; return AND; }
+"||" { HANDLE_COLUMN; return OR; }
+[<>&~] { HANDLE_COLUMN; return yytext[0]; }
+
+[\!()\-\+\*/,=] { HANDLE_COLUMN; return yytext[0]; }
+
+[ \t] { HANDLE_COLUMN; }
+\n { sb->line_idx = 0; sb->line_no++; }
+
+. { HANDLE_COLUMN; return PARSE_ERROR; }
+%%
+
+int yywrap(void)
+{
+ return 1;
+}
+
+void yyerror(const char *fmt, ...)
+{
+ va_list ap;
+
+ va_start(ap, fmt);
+ sql_parse_error(sb, yytext, fmt, ap);
+ va_end(ap);
+}
diff --git a/src/sqlhist.y b/src/sqlhist.y
new file mode 100644
index 000000000000..ecb0a0ed44b3
--- /dev/null
+++ b/src/sqlhist.y
@@ -0,0 +1,143 @@
+%{
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include "sqlhist-parse.h"
+
+extern int yylex(void);
+extern void yyerror(char *fmt, ...);
+
+#define CHECK_RETURN_PTR(x) \
+ do { \
+ if (!(x)) { \
+ printf("FAILED MEMORY: %s\n", #x); \
+ return -ENOMEM; \
+ } \
+ } while (0)
+
+#define CHECK_RETURN_VAL(x) \
+ do { \
+ if ((x) < 0) { \
+ printf("FAILED MEMORY: %s\n", #x); \
+ return -ENOMEM; \
+ } \
+ } while (0)
+
+%}
+
+%union {
+ int s32;
+ char *string;
+ long number;
+ void *expr;
+}
+
+%token AS SELECT FROM JOIN ON PARSE_ERROR
+%token <number> NUMBER
+%token <string> STRING
+%token <string> FIELD
+%token <string> LE GE EQ NEQ AND OR
+
+%left '+' '-'
+%left '*' '/'
+%left '<' '>'
+%left AND OR
+
+%type <string> name label
+
+%type <expr> selection_expr field item named_field join_clause
+
+%%
+
+start :
+ select_statement
+ ;
+
+label : AS name { CHECK_RETURN_PTR($$ = store_str(sb, $2)); }
+ | name { CHECK_RETURN_PTR($$ = store_str(sb, $1)); }
+ ;
+
+select : SELECT { table_start(sb); }
+ ;
+
+select_statement :
+ select selection_list table_exp
+ ;
+
+selection_list :
+ selection
+ | selection ',' selection_list
+ ;
+
+selection :
+ selection_expr
+ {
+ CHECK_RETURN_VAL(add_selection(sb, $1, NULL));
+ }
+ | selection_expr label
+ {
+ CHECK_RETURN_VAL(add_selection(sb, $1, $2));
+ }
+ ;
+
+selection_expr :
+ field
+ | '(' field ')' { $$ = $2; }
+ ;
+
+item :
+ named_field
+ | field
+ ;
+
+field :
+ FIELD { $$ = add_field(sb, $1, NULL); CHECK_RETURN_PTR($$); }
+ ;
+
+named_field :
+ FIELD label { $$ = add_field(sb, $1, $2); CHECK_RETURN_PTR($$); }
+ ;
+
+name :
+ FIELD
+ ;
+
+table_exp :
+ from_clause join_clause
+ ;
+
+from_clause :
+ FROM item { CHECK_RETURN_VAL(add_from(sb, $2)); }
+
+/*
+ * Select from a from clause confuses the variable parsing.
+ * disable it for now.
+
+ | FROM '(' select_statement ')' label
+ {
+ from_table_end($5);
+ $$ = store_printf("FROM (%s) AS %s", $3, $5);
+ }
+*/
+ ;
+
+join_clause :
+ JOIN item ON match_clause { add_to(sb, $2); }
+ ;
+
+match :
+ item '=' item { CHECK_RETURN_VAL(add_match(sb, $1, $3)); }
+ | item EQ item { CHECK_RETURN_VAL(add_match(sb, $1, $3)); }
+
+ ;
+
+match_clause :
+ match
+ | match ',' match_clause
+ ;
+
+%%
+
+
diff --git a/src/tracefs-sqlhist.c b/src/tracefs-sqlhist.c
new file mode 100644
index 000000000000..7ec0c11b902e
--- /dev/null
+++ b/src/tracefs-sqlhist.c
@@ -0,0 +1,691 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ * Copyright (C) 2021 VMware Inc, Steven Rostedt <rostedt@xxxxxxxxxxx>
+ *
+ * Updates:
+ * Copyright (C) 2021, VMware, Tzvetomir Stoyanov <tz.stoyanov@xxxxxxxxx>
+ *
+ */
+#include <trace-seq.h>
+#include <stdlib.h>
+#include <errno.h>
+
+#include "tracefs.h"
+#include "tracefs-local.h"
+#include "sqlhist-parse.h"
+
+struct sqlhist_bison *sb;
+
+extern int yylex_init(void* ptr_yy_globals);
+extern int yylex_init_extra(struct sqlhist_bison *sb, void* ptr_yy_globals);
+extern int yylex_destroy (void * yyscanner );
+
+struct str_hash {
+ struct str_hash *next;
+ char *str;
+};
+
+enum alias_type {
+ ALIAS_EVENT,
+ ALIAS_FIELD,
+};
+
+#define for_each_field(expr, field, table) \
+ for (expr = (table)->fields; expr; expr = (field)->next)
+
+struct field {
+ struct expr *next; /* private link list */
+ const char *system;
+ const char *event;
+ const char *raw;
+ const char *label;
+ const char *field;
+};
+
+struct match {
+ struct match *next;
+ struct expr *lval;
+ struct expr *rval;
+};
+
+enum expr_type
+{
+ EXPR_NUMBER,
+ EXPR_STRING,
+ EXPR_FIELD,
+};
+
+struct expr {
+ struct expr *free_list;
+ struct expr *next;
+ enum expr_type type;
+ union {
+ struct field field;
+ const char *string;
+ long number;
+ };
+};
+
+struct sql_table {
+ struct sqlhist_bison *sb;
+ const char *name;
+ struct expr *exprs;
+ struct expr *fields;
+ struct expr *from;
+ struct expr *to;
+ struct match *matches;
+ struct match **next_match;
+ struct expr *selections;
+ struct expr **next_selection;
+};
+
+__hidden int my_yyinput(char *buf, int max)
+{
+ if (!sb || !sb->buffer)
+ return -1;
+
+ if (sb->buffer_idx + max > sb->buffer_size)
+ max = sb->buffer_size - sb->buffer_idx;
+
+ if (max)
+ memcpy(buf, sb->buffer + sb->buffer_idx, max);
+
+ sb->buffer_idx += max;
+
+ return max;
+}
+
+__hidden void sql_parse_error(struct sqlhist_bison *sb, const char *text,
+ const char *fmt, va_list ap)
+{
+ const char *buffer = sb->buffer;
+ struct trace_seq s;
+ int line = sb->line_no;
+ int idx = sb->line_idx - strlen(text);
+ int i;
+
+ if (!buffer)
+ return;
+
+ trace_seq_init(&s);
+ if (!s.buffer) {
+ fprintf(stderr, "Error allocating internal buffer\n");
+ return;
+ }
+
+ for (i = 0; line && buffer[i]; i++) {
+ if (buffer[i] == '\n')
+ line--;
+ }
+ for (; buffer[i] && buffer[i] != '\n'; i++)
+ trace_seq_putc(&s, buffer[i]);
+ trace_seq_putc(&s, '\n');
+ for (i = idx; i > 0; i--)
+ trace_seq_putc(&s, ' ');
+ trace_seq_puts(&s, "^\n");
+ trace_seq_printf(&s, "ERROR: '%s'\n", text);
+ trace_seq_vprintf(&s, fmt, ap);
+
+ trace_seq_terminate(&s);
+
+ sb->parse_error_str = strdup(s.buffer);
+ trace_seq_destroy(&s);
+}
+
+static inline unsigned int quick_hash(const char *str)
+{
+ unsigned int val = 0;
+ int len = strlen(str);
+
+ for (; len >= 4; str += 4, len -= 4) {
+ val += str[0];
+ val += str[1] << 8;
+ val += str[2] << 16;
+ val += str[3] << 24;
+ }
+ for (; len > 0; str++, len--)
+ val += str[0] << (len * 8);
+
+ val *= 2654435761;
+
+ return val & ((1 << HASH_BITS) - 1);
+}
+
+
+static struct str_hash *find_string(struct sqlhist_bison *sb, const char *str)
+{
+ unsigned int key = quick_hash(str);
+ struct str_hash *hash = sb->str_hash[key];
+
+ for (; hash; hash = hash->next) {
+ if (!strcmp(hash->str, str))
+ return hash;
+ }
+ return NULL;
+}
+
+/*
+ * If @str is found, then return the hash string.
+ * This lets store_str() know to free str.
+ */
+static char **add_hash(struct sqlhist_bison *sb, const char *str)
+{
+ struct str_hash *hash;
+ unsigned int key;
+
+ if ((hash = find_string(sb, str))) {
+ return &hash->str;
+ }
+
+ hash = malloc(sizeof(*hash));
+ if (!hash)
+ return NULL;
+ key = quick_hash(str);
+ hash->next = sb->str_hash[key];
+ sb->str_hash[key] = hash;
+ hash->str = NULL;
+ return &hash->str;
+}
+
+__hidden char *store_str(struct sqlhist_bison *sb, const char *str)
+{
+ char **pstr = add_hash(sb, str);
+
+ if (!pstr)
+ return NULL;
+
+ if (!(*pstr))
+ *pstr = strdup(str);
+
+ return *pstr;
+}
+
+__hidden int add_selection(struct sqlhist_bison *sb, void *select,
+ const char *name)
+{
+ struct sql_table *table = sb->table;
+ struct expr *expr = select;
+
+ switch (expr->type) {
+ case EXPR_FIELD:
+ break;
+ case EXPR_NUMBER:
+ case EXPR_STRING:
+ default:
+ return -1;
+ }
+
+ if (expr->next)
+ return -1;
+
+ *table->next_selection = expr;
+ table->next_selection = &expr->next;
+
+ return 0;
+}
+
+static struct expr *find_field(struct sqlhist_bison *sb,
+ const char *raw, const char *label)
+{
+ struct field *field;
+ struct expr *expr;
+
+ for_each_field(expr, field, sb->table) {
+ field = &expr->field;
+
+ if (!strcmp(field->raw, raw)) {
+ if (label && !field->label)
+ field->label = label;
+ return expr;
+ }
+
+ if (label && !strcmp(field->raw, label)) {
+ if (!field->label) {
+ field->label = label;
+ field->raw = raw;
+ }
+ return expr;
+ }
+
+ if (!field->label)
+ continue;
+
+ if (!strcmp(field->label, raw))
+ return expr;
+
+ if (label && !strcmp(field->label, label))
+ return expr;
+ }
+ return NULL;
+}
+
+static void *create_expr(enum expr_type type, struct expr **expr_p)
+{
+ struct expr *expr;
+
+ expr = calloc(1, sizeof(*expr));
+ if (!expr)
+ return NULL;
+
+ if (expr_p)
+ *expr_p = expr;
+
+ expr->free_list = sb->table->exprs;
+ sb->table->exprs = expr;
+
+ expr->type = type;
+
+ switch (type) {
+ case EXPR_FIELD: return &expr->field;
+ case EXPR_NUMBER: return &expr->number;
+ case EXPR_STRING: return &expr->string;
+ }
+
+ return NULL;
+}
+
+#define __create_expr(var, type, ENUM, expr) \
+ do { \
+ var = (type *)create_expr(EXPR_##ENUM, expr); \
+ } while(0)
+
+#define create_field(var, expr) \
+ __create_expr(var, struct field, FIELD, expr)
+
+__hidden void *add_field(struct sqlhist_bison *sb,
+ const char *field_name, const char *label)
+{
+ struct sql_table *table = sb->table;
+ struct expr *expr;
+ struct field *field;
+
+ expr = find_field(sb, field_name, label);
+ if (expr)
+ return expr;
+
+ create_field(field, &expr);
+
+ field->next = table->fields;
+ table->fields = expr;
+
+ field->raw = field_name;
+ field->label = label;
+
+ return expr;
+}
+
+__hidden int add_match(struct sqlhist_bison *sb, void *A, void *B)
+{
+ struct sql_table *table = sb->table;
+ struct match *match;
+
+ match = calloc(1, sizeof(*match));
+ if (!match)
+ return -1;
+
+ match->lval = A;
+ match->rval = B;
+
+ *table->next_match = match;
+ table->next_match = &match->next;
+
+ return 0;
+}
+
+__hidden int add_from(struct sqlhist_bison *sb, void *item)
+{
+ struct expr *expr = item;
+
+ if (expr->type != EXPR_FIELD)
+ return -1;
+
+ sb->table->from = expr;
+
+ return 0;
+}
+
+__hidden int add_to(struct sqlhist_bison *sb, void *item)
+{
+ struct expr *expr = item;
+
+ if (expr->type != EXPR_FIELD)
+ return -1;
+
+ sb->table->to = expr;
+
+ return 0;
+}
+
+__hidden int table_start(struct sqlhist_bison *sb)
+{
+ struct sql_table *table;
+
+ table = calloc(1, sizeof(*table));
+ if (!table)
+ return -ENOMEM;
+
+ table->sb = sb;
+ sb->table = table;
+
+ table->next_match = &table->matches;
+ table->next_selection = &table->selections;
+
+ return 0;
+}
+
+static int update_vars(struct sql_table *table, struct field *event)
+{
+ struct sqlhist_bison *sb = table->sb;
+ struct expr *expr;
+ struct field *field;
+ const char *label;
+ const char *p, *r;
+ char *system;
+ int len;
+
+ p = strchr(event->raw, '.');
+ if (p) {
+ system = strndup(event->raw, p - event->raw);
+ if (!system)
+ return -1;
+ event->system = store_str(sb, system);
+ free(system);
+ if (!event->system)
+ return -1;
+ p++;
+ } else {
+ p = event->raw;
+ }
+
+ event->event = store_str(sb, p);
+ if (!event->event)
+ return -1;
+
+ if (!event->label)
+ event->label = event->event;
+
+ label = event->label;
+ len = strlen(label);
+
+ for_each_field(expr, field, table) {
+ field = &expr->field;
+
+ if (field->event)
+ continue;
+
+ p = strchr(field->raw, '.');
+ if (p) {
+ /* Does this field have a system */
+ r = strchr(p + 1, '.');
+ if (r) {
+ /* This has a system, and is not a alias */
+ system = strndup(field->raw, p - field->raw);
+ if (!system)
+ return -1;
+ field->system = store_str(sb, system);
+ free(system);
+ if (!field->system)
+ return -1;
+
+ /* save the event as well */
+ p++;
+ system = strndup(p, r - p);
+ if (!system)
+ return -1;
+ field->event = store_str(sb, system);
+ free(system);
+ if (!field->event)
+ return -1;
+ r++;
+ field->field = store_str(sb, r);
+ goto check_timestamps;
+ }
+ }
+
+ if (strncmp(field->raw, label, len))
+ continue;
+
+ if (field->raw[len] != '.')
+ continue;
+
+ field->system = event->system;
+ field->event = event->event;
+ field->field = field->raw + len + 1;
+ check_timestamps:
+ if (!strcmp(field->field, "TIMESTAMP"))
+ field->field = store_str(sb, TRACEFS_TIMESTAMP);
+ else if (!strcmp(field->field, "TIMESTAMP_USECS"))
+ field->field = store_str(sb, TRACEFS_TIMESTAMP_USECS);
+ }
+
+ return 0;
+}
+
+static int test_match(struct sql_table *table, struct match *match)
+{
+ struct field *lval, *rval;
+ struct field *to, *from;
+
+ if (!match->lval || !match->rval)
+ return -1;
+
+ if (match->lval->type != EXPR_FIELD || match->rval->type != EXPR_FIELD)
+ return -1;
+
+ to = &table->to->field;
+ from = &table->from->field;
+
+ lval = &match->lval->field;
+ rval = &match->rval->field;
+
+ /*
+ * Note, strings are stored in the string store, so all
+ * duplicate strings are the same value, and we can use
+ * normal "==" and "!=" instead of strcmp().
+ *
+ * Either lval == to and rval == from
+ * or lval == from and rval == to.
+ */
+ if ((lval->system != to->system) ||
+ (lval->event != to->event)) {
+ if ((rval->system != to->system) ||
+ (rval->event != to->event) ||
+ (lval->system != from->system) ||
+ (lval->event != from->event))
+ return -1;
+ } else {
+ if ((rval->system != from->system) ||
+ (rval->event != from->event) ||
+ (lval->system != to->system) ||
+ (lval->event != to->event))
+ return -1;
+ }
+ return 0;
+}
+
+static void assign_match(const char *system, const char *event,
+ struct match *match,
+ const char **start_match, const char **end_match)
+{
+ struct field *lval, *rval;
+
+ lval = &match->lval->field;
+ rval = &match->rval->field;
+
+ if (lval->system == system &&
+ lval->event == event) {
+ *start_match = lval->field;
+ *end_match = rval->field;
+ } else {
+ *start_match = rval->field;
+ *end_match = lval->field;
+ }
+}
+
+static struct tracefs_synth *build_synth(struct tep_handle *tep,
+ const char *name,
+ struct sql_table *table)
+{
+ struct tracefs_synth *synth;
+ struct field *field;
+ struct match *match;
+ struct expr *expr;
+ const char *start_system;
+ const char *start_event;
+ const char *end_system;
+ const char *end_event;
+ const char *start_match;
+ const char *end_match;
+ int ret;
+
+ if (!table->to || !table->from)
+ return NULL;
+
+ ret = update_vars(table, &table->to->field);
+ if (ret < 0)
+ return NULL;
+
+ ret = update_vars(table, &table->from->field);
+ if (ret < 0)
+ return NULL;
+
+ match = table->matches;
+ if (!match)
+ return NULL;
+
+ ret = test_match(table, match);
+ if (ret < 0)
+ return NULL;
+
+ start_system = table->from->field.system;
+ start_event = table->from->field.event;
+
+ end_system = table->to->field.system;
+ end_event = table->to->field.event;
+
+ assign_match(start_system, start_event, match,
+ &start_match, &end_match);
+
+ synth = tracefs_synth_init(tep, name, start_system,
+ start_event, end_system, end_event,
+ start_match, end_match, NULL);
+ if (!synth)
+ return NULL;
+
+ for (match = match->next; match; match = match->next) {
+ ret = test_match(table, match);
+ if (ret < 0)
+ goto free;
+
+ assign_match(start_system, start_event, match,
+ &start_match, &end_match);
+
+ ret = tracefs_synth_add_match_field(synth,
+ start_match,
+ end_match, NULL);
+ if (ret < 0)
+ goto free;
+ }
+
+ for (expr = table->selections; expr; expr = expr->next) {
+ if (expr->type == EXPR_FIELD) {
+ field = &expr->field;
+ if (field->system == start_system &&
+ field->event == start_event) {
+ ret = tracefs_synth_add_start_field(synth,
+ field->field, field->label);
+ } else {
+ ret = tracefs_synth_add_end_field(synth,
+ field->field, field->label);
+ }
+ if (ret < 0)
+ goto free;
+ continue;
+ }
+ goto free;
+ }
+
+ return synth;
+ free:
+ tracefs_synth_free(synth);
+ return NULL;
+}
+
+static void free_sql_table(struct sql_table *table)
+{
+ struct match *match;
+ struct expr *expr;
+
+ if (!table)
+ return;
+
+ while ((expr = table->exprs)) {
+ table->exprs = expr->next;
+ free(expr);
+ }
+
+ while ((match = table->matches)) {
+ table->matches = match->next;
+ free(match);
+ }
+
+ free(table);
+}
+
+static void free_str_hash(struct str_hash **hash)
+{
+ struct str_hash *item;
+ int i;
+
+ for (i = 0; i < 1 << HASH_BITS; i++) {
+ while ((item = hash[i])) {
+ hash[i] = item->next;
+ free(item->str);
+ free(item);
+ }
+ }
+}
+
+static void free_sb(struct sqlhist_bison *sb)
+{
+ free_sql_table(sb->table);
+ free_str_hash(sb->str_hash);
+ free(sb->parse_error_str);
+}
+
+struct tracefs_synth *tracefs_sql(struct tep_handle *tep, const char *name,
+ const char *sql_buffer, char **err)
+{
+ struct sqlhist_bison local_sb;
+ struct tracefs_synth *synth = NULL;
+ int ret;
+
+ if (!tep || !sql_buffer) {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ memset(&local_sb, 0, sizeof(local_sb));
+
+ local_sb.buffer = sql_buffer;
+ local_sb.buffer_size = strlen(sql_buffer);
+ local_sb.buffer_idx = 0;
+
+ sb = &local_sb;
+ ret = yyparse();
+
+ if (ret)
+ goto free;
+
+ synth = build_synth(tep, name, sb->table);
+
+ free:
+ if (!synth) {
+ if (sb->parse_error_str && err) {
+ *err = sb->parse_error_str;
+ sb->parse_error_str = NULL;
+ }
+ }
+ free_sb(sb);
+ return synth;
+}
--
2.30.2