From 65163ab8c318a501f019c64490aea188e258b954 Mon Sep 17 00:00:00 2001 From: Bruce Korb Date: Tue, 19 Apr 2022 09:10:37 -0700 Subject: [PATCH] avoid GCC code analysis bug --- agen5/defLoad.c | 47 ++++++++++++++++++++++++++--------------------- 1 file changed, 26 insertions(+), 21 deletions(-) diff --git a/agen5/defLoad.c b/agen5/defLoad.c index e40f2e80..99258cd6 100644 --- a/agen5/defLoad.c +++ b/agen5/defLoad.c @@ -453,17 +453,28 @@ read_defs(void) FILE * fp; def_input_mode_t in_mode = ready_def_input(&def_fname, &data_sz); + /* + * "ready_def_input" has a lot of side effects. It's possible that + * there are no definitions, so "in_mode" is set to DONE and there's + * nothing to do. + */ if (in_mode == INPUT_DONE) return; /* * Allocate the space we need for our definitions. + * "data_sz" was set by read_def_input to the size of the + * definitions file (or 4096 if we're reading from a fifo file). + * In that alternate case, we'll start the input size at 4096 bytes. + * The allocation includes space for context and a NUL byte or two */ - rem_sz = data_sz+4+sizeof(*base_ctx); - base_ctx = (scan_ctx_t *)AGALOC(rem_sz, "file buf"); - memset(VOIDP(base_ctx), 0, rem_sz); + { + size_t sz = data_sz + sizeof(long) + sizeof(*base_ctx); + base_ctx = (scan_ctx_t *)AGALOC(sz, "file buf"); + memset(VOIDP(base_ctx), 0, sz); + } base_ctx->scx_line = 1; - rem_sz = data_sz; + rem_sz = data_sz; // size available for storing def text /* * Our base context will have its currency pointer set to this @@ -487,6 +498,9 @@ read_defs(void) if (fp == NULL) AG_CANT(READ_DEF_OPEN, def_fname); + /* + * If we're emitting dependency information, then do so. + */ if (dep_fp != NULL) add_source_file(def_fname); } @@ -521,8 +535,7 @@ read_defs(void) * See if there is any space left */ if (rem_sz == 0) { - scan_ctx_t * p; - off_t dataOff; + off_t scan_off; /* * IF it is a regular file, then we are done @@ -532,24 +545,16 @@ read_defs(void) /* * We have more data and we are out of space. - * Try to reallocate our input buffer. + * AGREALOC will succeed or not return. */ data_sz += (rem_sz = 0x1000); - dataOff = data - base_ctx->scx_data; - p = AGREALOC(VOIDP(base_ctx), data_sz + 4 + sizeof(*base_ctx), - "expand f buf"); + scan_off = data - base_ctx->scx_data; + base_ctx = AGREALOC(VOIDP(base_ctx), data_sz + 4 + sizeof(*base_ctx), + "expand f buf"); - /* - * The buffer may have moved. Set the data pointer at an - * offset within the new buffer and make sure our base pointer - * has been corrected as well. - */ - if (p != base_ctx) { - p->scx_scan = \ - p->scx_data = (char *)(p + 1); - data = p->scx_data + dataOff; - base_ctx = p; - } + base_ctx->scx_scan = \ + base_ctx->scx_data = (char *)(base_ctx + 1); + data = base_ctx->scx_data + scan_off; } } -- 2.35.3