From 537fb5b20744f4e94695e2f606b3a4dec9a1a28b Mon Sep 17 00:00:00 2001
From: Mart Lubbers <mart@martlubbers.net>
Date: Wed, 24 Feb 2021 12:54:36 +0100
Subject: [PATCH] remove memory leaks, fix function inferring

---
 in.txt          |  1 -
 sem.c           | 10 ++++++----
 sem/hm.c        | 14 +++++++++++---
 sem/hm/gamma.c  |  5 +++--
 sem/hm/scheme.c |  3 ++-
 type.c          |  4 +---
 6 files changed, 23 insertions(+), 14 deletions(-)
 delete mode 100644 in.txt

diff --git a/in.txt b/in.txt
deleted file mode 100644
index 564415e..0000000
--- a/in.txt
+++ /dev/null
@@ -1 +0,0 @@
-fun (x) { return fun(x); }
diff --git a/sem.c b/sem.c
index 7fd0c7a..9df5bbf 100644
--- a/sem.c
+++ b/sem.c
@@ -69,13 +69,15 @@ struct ast *sem(struct ast *ast)
 			break;
 		case dfundecl: {
 			struct type *f1 = gamma_fresh(gamma);
-			struct subst *s = infer_fundecl(gamma, ast->decls[i]->data.dfun, f1);
+			struct subst *s = infer_fundecl(gamma,
+				ast->decls[i]->data.dfun, f1);
 			f1 = subst_apply_t(s, f1);
-			gamma_insert(gamma, ast->decls[i]->data.dfun->ident, scheme_generalise(gamma, subst_apply_t(s, f1)));
-//			type_free(f1);
-			subst_free(s);
+			gamma_insert(gamma, ast->decls[i]->data.dfun->ident,
+				scheme_generalise(gamma, f1));
 			gamma_print(gamma, stderr);
 			fprintf(stderr, "done\n");
+			subst_free(s);
+			type_free(f1);
 			break;
 		}
 		case dcomp:
diff --git a/sem/hm.c b/sem/hm.c
index ebc21dd..8de1088 100644
--- a/sem/hm.c
+++ b/sem/hm.c
@@ -243,13 +243,16 @@ struct subst *infer_stmt(struct gamma *gamma, struct stmt *stmt, struct type *ty
 	type_print(type, stderr);
 	fprintf(stderr, "\n");
 
-//	struct subst *s1, *s2;
+	struct subst *s1;//, *s2;
 //	struct type *f1, *f2, *f3;
 //	struct scheme *s;
 	switch (stmt->type) {
 	case sassign:
 		break;
 	case sif:
+		s1 = infer_expr(gamma, stmt->data.sif.pred, &tybool);
+		subst_apply_g(s1, gamma);
+		subst_free(s1);
 		break;
 	case sreturn:
 		return infer_expr(gamma, stmt->data.sreturn, type);
@@ -319,11 +322,16 @@ struct subst *infer_fundecl(struct gamma *gamma, struct fundecl *fundecl, struct
 		subst_free(s2);
 	}
 
-	for (int i = 0; i<fundecl->nargs; i++)
-		fundecl->atypes[i] = subst_apply_t(s, fundecl->atypes[i]);
+	for (int i = 0; i<fundecl->nargs; i++) {
+		struct type *t = subst_apply_t(s, fundecl->atypes[i]);
+		type_free(fundecl->atypes[i]);
+		fundecl->atypes[i] = t;
+	}
 	fundecl->rtype = subst_apply_t(s, fundecl->rtype);
 
+	ftype = subst_apply_t(s, ftype);
 	struct subst *r = unify(fundecl->loc, fty, ftype);
 	type_free(ftype);
+	subst_free(s);
 	return r;
 }
diff --git a/sem/hm/gamma.c b/sem/hm/gamma.c
index 4202154..a5b46c5 100644
--- a/sem/hm/gamma.c
+++ b/sem/hm/gamma.c
@@ -23,8 +23,9 @@ void gamma_insert(struct gamma *gamma, char *ident, struct scheme *scheme)
 		}
 	}
 	gamma->nschemes++;
-	gamma->vars = realloc(gamma->vars, gamma->nschemes*sizeof(char *));
-	gamma->schemes = realloc(gamma->schemes,
+	gamma->vars = safe_realloc(gamma->vars,
+		gamma->nschemes*sizeof(char *));
+	gamma->schemes = safe_realloc(gamma->schemes,
 		gamma->nschemes*sizeof(struct scheme *));
 	gamma->vars[gamma->nschemes-1] = safe_strdup(ident);
 	gamma->schemes[gamma->nschemes-1] = scheme;
diff --git a/sem/hm/scheme.c b/sem/hm/scheme.c
index 33ff121..8d65075 100644
--- a/sem/hm/scheme.c
+++ b/sem/hm/scheme.c
@@ -43,8 +43,9 @@ struct scheme *scheme_generalise(struct gamma *gamma, struct type *t)
 		if (skip)
 			continue;
 		s->nvar++;
-		s->var[i] = ftv[i];
+		s->var[i] = safe_strdup(ftv[i]);
 	}
+	free(ftv);
 	return s;
 }
 
diff --git a/type.c b/type.c
index 39d67b5..18c8151 100644
--- a/type.c
+++ b/type.c
@@ -178,9 +178,7 @@ void type_ftv(struct type *r, int *nftv, char ***ftv)
 		for (int i = 0; i<*nftv; i++)
 			if (strcmp((*ftv)[i], r->data.tvar) == 0)
 				return;
-		*ftv = realloc(*ftv, (*nftv+1)*sizeof(char *));
-		if (*ftv == NULL)
-			perror("realloc");
+		*ftv = safe_realloc(*ftv, (*nftv+1)*sizeof(char *));
 		(*ftv)[(*nftv)++] = r->data.tvar;
 		break;
 	default:
-- 
2.20.1