From c3b7d7e78330649fe05c8e5f97626e7eb03d2827 Mon Sep 17 00:00:00 2001 From: Daniel Gustafsson Date: Sat, 19 Apr 2025 21:32:40 +0200 Subject: [PATCH v2] Allocate JsonLexContexts on the heap to avoid warnings The stack allocated JsonLexContexts, in combination with codepaths using goto, were causing warnings when compiling with LTO enabled as the optimizer is unable to figure out that is safe. Rather than contort the code with workarounds for this simply heap allocate the structs instead as these are not in any performance critical paths. Reported-by: Tom Lane Reviewed-by: Jacob Champion Reviewed-by: Tom Lane Discussion: https://postgr.es/m/2074634.1744839761@sss.pgh.pa.us --- src/interfaces/libpq/fe-auth-oauth.c | 24 ++++++++++++++----- .../test_json_parser_incremental.c | 22 ++++++++++------- 2 files changed, 31 insertions(+), 15 deletions(-) diff --git a/src/interfaces/libpq/fe-auth-oauth.c b/src/interfaces/libpq/fe-auth-oauth.c index cf1a25e2ccc..5ebca6a0ef6 100644 --- a/src/interfaces/libpq/fe-auth-oauth.c +++ b/src/interfaces/libpq/fe-auth-oauth.c @@ -476,7 +476,7 @@ issuer_from_well_known_uri(PGconn *conn, const char *wkuri) static bool handle_oauth_sasl_error(PGconn *conn, const char *msg, int msglen) { - JsonLexContext lex = {0}; + JsonLexContext *lex; JsonSemAction sem = {0}; JsonParseErrorType err; struct json_ctx ctx = {0}; @@ -504,8 +504,19 @@ handle_oauth_sasl_error(PGconn *conn, const char *msg, int msglen) return false; } - makeJsonLexContextCstringLen(&lex, msg, msglen, PG_UTF8, true); - setJsonLexContextOwnsTokens(&lex, true); /* must not leak on error */ + /* + * Later error paths need to go via the cleanup label but since ctx hasn't + * been initiated yet we return immediately here. + */ + lex = calloc(1, sizeof(JsonLexContext)); + if (!lex) + { + libpq_append_conn_error(conn, "out of memory"); + return false; + } + + makeJsonLexContextCstringLen(lex, msg, msglen, PG_UTF8, true); + setJsonLexContextOwnsTokens(lex, true); /* must not leak on error */ initPQExpBuffer(&ctx.errbuf); sem.semstate = &ctx; @@ -516,7 +527,7 @@ handle_oauth_sasl_error(PGconn *conn, const char *msg, int msglen) sem.array_start = oauth_json_array_start; sem.scalar = oauth_json_scalar; - err = pg_parse_json(&lex, &sem); + err = pg_parse_json(lex, &sem); if (err == JSON_SEM_ACTION_FAILED) { @@ -535,7 +546,7 @@ handle_oauth_sasl_error(PGconn *conn, const char *msg, int msglen) } } else if (err != JSON_SUCCESS) - errmsg = json_errdetail(err, &lex); + errmsg = json_errdetail(err, lex); if (errmsg) libpq_append_conn_error(conn, @@ -544,7 +555,8 @@ handle_oauth_sasl_error(PGconn *conn, const char *msg, int msglen) /* Don't need the error buffer or the JSON lexer anymore. */ termPQExpBuffer(&ctx.errbuf); - freeJsonLexContext(&lex); + freeJsonLexContext(lex); + free(lex); if (errmsg) goto cleanup; diff --git a/src/test/modules/test_json_parser/test_json_parser_incremental.c b/src/test/modules/test_json_parser/test_json_parser_incremental.c index a529ee47e9b..357152e0ae0 100644 --- a/src/test/modules/test_json_parser/test_json_parser_incremental.c +++ b/src/test/modules/test_json_parser/test_json_parser_incremental.c @@ -84,7 +84,7 @@ main(int argc, char **argv) char buff[BUFSIZE]; FILE *json_file; JsonParseErrorType result; - JsonLexContext lex; + JsonLexContext *lex; StringInfoData json; int n_read; size_t chunk_size = DEFAULT_CHUNK_SIZE; @@ -98,6 +98,10 @@ main(int argc, char **argv) pg_logging_init(argv[0]); + lex = calloc(1, sizeof(JsonLexContext)); + if (!lex) + pg_fatal("out of memory"); + while ((c = getopt(argc, argv, "c:os")) != -1) { switch (c) @@ -113,7 +117,7 @@ main(int argc, char **argv) case 's': /* do semantic processing */ testsem = &sem; sem.semstate = palloc(sizeof(struct DoState)); - ((struct DoState *) sem.semstate)->lex = &lex; + ((struct DoState *) sem.semstate)->lex = lex; ((struct DoState *) sem.semstate)->buf = makeStringInfo(); need_strings = true; break; @@ -131,8 +135,8 @@ main(int argc, char **argv) exit(1); } - makeJsonLexContextIncremental(&lex, PG_UTF8, need_strings); - setJsonLexContextOwnsTokens(&lex, lex_owns_tokens); + makeJsonLexContextIncremental(lex, PG_UTF8, need_strings); + setJsonLexContextOwnsTokens(lex, lex_owns_tokens); initStringInfo(&json); if ((json_file = fopen(testfile, PG_BINARY_R)) == NULL) @@ -165,12 +169,12 @@ main(int argc, char **argv) bytes_left -= n_read; if (bytes_left > 0) { - result = pg_parse_json_incremental(&lex, testsem, + result = pg_parse_json_incremental(lex, testsem, json.data, n_read, false); if (result != JSON_INCOMPLETE) { - fprintf(stderr, "%s\n", json_errdetail(result, &lex)); + fprintf(stderr, "%s\n", json_errdetail(result, lex)); ret = 1; goto cleanup; } @@ -178,12 +182,12 @@ main(int argc, char **argv) } else { - result = pg_parse_json_incremental(&lex, testsem, + result = pg_parse_json_incremental(lex, testsem, json.data, n_read, true); if (result != JSON_SUCCESS) { - fprintf(stderr, "%s\n", json_errdetail(result, &lex)); + fprintf(stderr, "%s\n", json_errdetail(result, lex)); ret = 1; goto cleanup; } @@ -195,7 +199,7 @@ main(int argc, char **argv) cleanup: fclose(json_file); - freeJsonLexContext(&lex); + freeJsonLexContext(lex); free(json.data); return ret; -- 2.39.3 (Apple Git-146)