From: NeilBrown <neil@brown.name>
Date: Fri, 26 Feb 2021 06:33:43 +0000 (+1100)
Subject: parsergen: don't use static buffer for result value.
X-Git-Url: https://ocean-lang.org/code/?p=ocean;a=commitdiff_plain;h=0b4b292a5e6744bcf7f35e012466c969c115c1b5

parsergen: don't use static buffer for result value.

Add the size of the result value to the per-state information, so it can
be allocated before calling do_reduce(), thus removing the need for a
overly large static buffer.

Signed-off-by: NeilBrown <neil@brown.name>
---

diff --git a/csrc/parsergen.mdc b/csrc/parsergen.mdc
index 5d2e164..a140e37 100644
--- a/csrc/parsergen.mdc
+++ b/csrc/parsergen.mdc
@@ -2056,6 +2056,7 @@ The go to table is stored in a simple array of `sym` and corresponding
 		char starts_line;
 		char newline_only;
 		short min_prefix;
+		short result_size;
 	};
 
 ###### functions
@@ -2109,14 +2110,22 @@ The go to table is stored in a simple array of `sym` and corresponding
 				fprintf(f, "\t[%d] = { 0, NULL, ", i);
 			if (prod >= 0) {
 				struct production *pr = g->productions[prod];
-				fprintf(f, "%d, %d, %d, %d, %d, %d },\n", prod,
+				struct symbol *hd = pr->head;
+				fprintf(f, "%d, %d, %d, %d, %d, %d, ", prod,
 					pr->body_size,
 					pr->head->num,
 					is->starts_line,
 					pr->line_like,
 					is->min_prefix);
+				if (hd->struct_name.txt == NULL)
+					fprintf(f, "0 },\n");
+				else
+					fprintf(f, "sizeof(struct %.*s%s) },\n",
+						hd->struct_name.len,
+						hd->struct_name.txt,
+						hd->isref ? "*" : "");
 			} else
-				fprintf(f, "-1, -1, -1, %d, 0, %d },\n",
+				fprintf(f, "-1, -1, -1, %d, 0, %d, -1 },\n",
 					is->starts_line, is->min_prefix);
 		}
 		fprintf(f, "};\n\n");
@@ -2674,25 +2683,14 @@ table.
 ### Memory allocation
 
 The `scanner` returns tokens in a local variable - we want them in allocated
-memory so they can live in the `asn_stack`.  Similarly the `asn` produced by
-a reduce is in a large buffer.  Both of these require some allocation and
-copying, hence `memdup` and `tok_copy`.
+memory so they can live in the `asn_stack`.  So we provide `tok_copy` to
+make an allocated copy as required.
 
 ###### parser includes
 	#include <memory.h>
 
 ###### parser functions
 
-	void *memdup(void *m, int len)
-	{
-		void *ret;
-		if (len == 0)
-			return NULL;
-		ret = malloc(len);
-		memcpy(ret, m, len);
-		return ret;
-	}
-
 	static struct token *tok_copy(struct token tk)
 	{
 		struct token *new = malloc(sizeof(*new));
@@ -3060,18 +3058,18 @@ checks if a given token is in any of these look-ahead sets.
 				const struct state *nextstate = &states[tos->state];
 				int prod = nextstate->reduce_prod;
 				int size = nextstate->reduce_size;
-				int bufsize;
-				static char buf[16*1024];
+				int res_size = nextstate->result_size;
 				short indents, start_of_line;
 
 				body = p.asn_stack + (p.tos - size);
-
-				bufsize = do_reduce(prod, body, config, buf);
+				res = res_size ? calloc(1, res_size) : NULL;
+				res_size = do_reduce(prod, body, config, res);
+				if (res_size != nextstate->result_size)
+					abort();
 
 				indents = pop(&p, size, &start_of_line,
 				              do_free);
-				res = memdup(buf, bufsize);
-				memset(buf, 0, bufsize);
+
 				if (!shift(&p, nextstate->reduce_sym,
 				           indents, start_of_line,
 				           res, states)) {