From c514988fa3ff57e7622678963c1141b59b4d88d7 Mon Sep 17 00:00:00 2001
From: David Lutterkort <lutter@watzmann.net>
Date: Mon, 4 Jun 2018 23:19:28 -0700
Subject: [PATCH] Use a safer calling convention for native functions
The native functions in the lens interpreter used a calling convention that
required unsafe casting of function pointers. We now use a calling
convention that does not cause any function pointer casts.
(cherry picked from commit 31c3532e5e8d4707dfb7de12278221001dafdd5a)
---
src/builtin.c | 161 +++++++++++++++++++++++++++++++++-----------------
src/syntax.c | 34 ++---------
src/syntax.h | 11 +++-
3 files changed, 119 insertions(+), 87 deletions(-)
diff --git a/src/builtin.c b/src/builtin.c
index 732ee10c..7cf4fa0a 100644
--- a/src/builtin.c
+++ b/src/builtin.c
@@ -42,8 +42,10 @@
*/
/* V_REGEXP -> V_STRING -> V_LENS */
-static struct value *lns_del(struct info *info,
- struct value *rxp, struct value *dflt) {
+static struct value *lns_del(struct info *info, struct value **argv) {
+ struct value *rxp = argv[0];
+ struct value *dflt = argv[1];
+
assert(rxp->tag == V_REGEXP);
assert(dflt->tag == V_STRING);
return lns_make_prim(L_DEL, ref(info),
@@ -51,44 +53,59 @@ static struct value *lns_del(struct info *info,
}
/* V_REGEXP -> V_LENS */
-static struct value *lns_store(struct info *info, struct value *rxp) {
+static struct value *lns_store(struct info *info, struct value **argv) {
+ struct value *rxp = argv[0];
+
assert(rxp->tag == V_REGEXP);
return lns_make_prim(L_STORE, ref(info), ref(rxp->regexp), NULL);
}
/* V_STRING -> V_LENS */
-static struct value *lns_value(struct info *info, struct value *str) {
+static struct value *lns_value(struct info *info, struct value **argv) {
+ struct value *str = argv[0];
+
assert(str->tag == V_STRING);
return lns_make_prim(L_VALUE, ref(info), NULL, ref(str->string));
}
/* V_REGEXP -> V_LENS */
-static struct value *lns_key(struct info *info, struct value *rxp) {
+static struct value *lns_key(struct info *info, struct value **argv) {
+ struct value *rxp = argv[0];
+
assert(rxp->tag == V_REGEXP);
return lns_make_prim(L_KEY, ref(info), ref(rxp->regexp), NULL);
}
/* V_STRING -> V_LENS */
-static struct value *lns_label(struct info *info, struct value *str) {
+static struct value *lns_label(struct info *info, struct value **argv) {
+ struct value *str = argv[0];
+
assert(str->tag == V_STRING);
return lns_make_prim(L_LABEL, ref(info), NULL, ref(str->string));
}
/* V_STRING -> V_LENS */
-static struct value *lns_seq(struct info *info, struct value *str) {
+static struct value *lns_seq(struct info *info, struct value **argv) {
+ struct value *str = argv[0];
+
assert(str->tag == V_STRING);
return lns_make_prim(L_SEQ, ref(info), NULL, ref(str->string));
}
/* V_STRING -> V_LENS */
-static struct value *lns_counter(struct info *info, struct value *str) {
+static struct value *lns_counter(struct info *info, struct value **argv) {
+ struct value *str = argv[0];
+
assert(str->tag == V_STRING);
return lns_make_prim(L_COUNTER, ref(info), NULL, ref(str->string));
}
/* V_LENS -> V_LENS -> V_LENS -> V_LENS */
-static struct value *lns_square(struct info *info, struct value *l1,
- struct value *l2, struct value *l3) {
+static struct value *lns_square(struct info *info, struct value **argv) {
+ struct value *l1 = argv[0];
+ struct value *l2 = argv[1];
+ struct value *l3 = argv[2];
+
assert(l1->tag == V_LENS);
assert(l2->tag == V_LENS);
assert(l3->tag == V_LENS);
@@ -179,8 +196,10 @@ static struct value *pathx_parse_glue(struct info *info, struct value *tree,
}
/* V_LENS -> V_STRING -> V_TREE */
-static struct value *lens_get(struct info *info, struct value *l,
- struct value *str) {
+static struct value *lens_get(struct info *info, struct value **argv) {
+ struct value *l = argv[0];
+ struct value *str = argv[1];
+
assert(l->tag == V_LENS);
assert(str->tag == V_STRING);
struct lns_error *err;
@@ -210,8 +229,11 @@ static struct value *lens_get(struct info *info, struct value *l,
/* V_LENS -> V_TREE -> V_STRING -> V_STRING */
-static struct value *lens_put(struct info *info, struct value *l,
- struct value *tree, struct value *str) {
+static struct value *lens_put(struct info *info, struct value **argv) {
+ struct value *l = argv[0];
+ struct value *tree = argv[1];
+ struct value *str = argv[2];
+
assert(l->tag == V_LENS);
assert(tree->tag == V_TREE);
assert(str->tag == V_STRING);
@@ -237,11 +259,14 @@ static struct value *lens_put(struct info *info, struct value *l,
}
/* V_STRING -> V_STRING -> V_TREE -> V_TREE */
-static struct value *tree_set_glue(struct info *info, struct value *path,
- struct value *val, struct value *tree) {
+static struct value *tree_set_glue(struct info *info, struct value **argv) {
// FIXME: This only works if TREE is not referenced more than once;
// otherwise we'll have some pretty weird semantics, and would really
// need to copy TREE first
+ struct value *path = argv[0];
+ struct value *val = argv[1];
+ struct value *tree = argv[2];
+
assert(path->tag == V_STRING);
assert(val->tag == V_STRING);
assert(tree->tag == V_TREE);
@@ -277,11 +302,13 @@ static struct value *tree_set_glue(struct info *info, struct value *path,
}
/* V_STRING -> V_TREE -> V_TREE */
-static struct value *tree_clear_glue(struct info *info, struct value *path,
- struct value *tree) {
+static struct value *tree_clear_glue(struct info *info, struct value **argv) {
// FIXME: This only works if TREE is not referenced more than once;
// otherwise we'll have some pretty weird semantics, and would really
// need to copy TREE first
+ struct value *path = argv[0];
+ struct value *tree = argv[1];
+
assert(path->tag == V_STRING);
assert(tree->tag == V_TREE);
@@ -349,25 +376,32 @@ static struct value *tree_insert_glue(struct info *info, struct value *label,
/* Insert after */
/* V_STRING -> V_STRING -> V_TREE -> V_TREE */
-static struct value *tree_insa_glue(struct info *info, struct value *label,
- struct value *path, struct value *tree) {
+static struct value *tree_insa_glue(struct info *info, struct value **argv) {
+ struct value *label = argv[0];
+ struct value *path = argv[1];
+ struct value *tree = argv[2];
+
return tree_insert_glue(info, label, path, tree, 0);
}
/* Insert before */
/* V_STRING -> V_STRING -> V_TREE -> V_TREE */
-static struct value *tree_insb_glue(struct info *info, struct value *label,
- struct value *path, struct value *tree) {
+static struct value *tree_insb_glue(struct info *info, struct value **argv) {
+ struct value *label = argv[0];
+ struct value *path = argv[1];
+ struct value *tree = argv[2];
+
return tree_insert_glue(info, label, path, tree, 1);
}
/* V_STRING -> V_TREE -> V_TREE */
-static struct value *tree_rm_glue(struct info *info,
- struct value *path,
- struct value *tree) {
+static struct value *tree_rm_glue(struct info *info, struct value **argv) {
// FIXME: This only works if TREE is not referenced more than once;
// otherwise we'll have some pretty weird semantics, and would really
// need to copy TREE first
+ struct value *path = argv[0];
+ struct value *tree = argv[1];
+
assert(path->tag == V_STRING);
assert(tree->tag == V_TREE);
@@ -390,7 +424,9 @@ static struct value *tree_rm_glue(struct info *info,
}
/* V_STRING -> V_STRING */
-static struct value *gensym(struct info *info, struct value *prefix) {
+static struct value *gensym(struct info *info, struct value **argv) {
+ struct value *prefix = argv[0];
+
assert(prefix->tag == V_STRING);
static unsigned int count = 0;
struct value *v;
@@ -406,7 +442,9 @@ static struct value *gensym(struct info *info, struct value *prefix) {
}
/* V_STRING -> V_FILTER */
-static struct value *xform_incl(struct info *info, struct value *s) {
+static struct value *xform_incl(struct info *info, struct value **argv) {
+ struct value *s = argv[0];
+
assert(s->tag == V_STRING);
struct value *v = make_value(V_FILTER, ref(info));
v->filter = make_filter(ref(s->string), 1);
@@ -414,7 +452,9 @@ static struct value *xform_incl(struct info *info, struct value *s) {
}
/* V_STRING -> V_FILTER */
-static struct value *xform_excl(struct info *info, struct value *s) {
+static struct value *xform_excl(struct info *info, struct value **argv) {
+ struct value *s = argv[0];
+
assert(s->tag == V_STRING);
struct value *v = make_value(V_FILTER, ref(info));
v->filter = make_filter(ref(s->string), 0);
@@ -422,8 +462,10 @@ static struct value *xform_excl(struct info *info, struct value *s) {
}
/* V_LENS -> V_FILTER -> V_TRANSFORM */
-static struct value *xform_transform(struct info *info, struct value *l,
- struct value *f) {
+static struct value *xform_transform(struct info *info, struct value **argv) {
+ struct value *l = argv[0];
+ struct value *f = argv[1];
+
assert(l->tag == V_LENS);
assert(f->tag == V_FILTER);
if (l->lens->value || l->lens->key) {
@@ -436,14 +478,16 @@ static struct value *xform_transform(struct info *info, struct value *l,
return v;
}
-static struct value *sys_getenv(struct info *info, struct value *n) {
- assert(n->tag == V_STRING);
+static struct value *sys_getenv(struct info *info, struct value **argv) {
+ assert(argv[0]->tag == V_STRING);
struct value *v = make_value(V_STRING, ref(info));
- v->string = dup_string(getenv(n->string->str));
+ v->string = dup_string(getenv(argv[0]->string->str));
return v;
}
-static struct value *sys_read_file(struct info *info, struct value *n) {
+static struct value *sys_read_file(struct info *info, struct value **argv) {
+ struct value *n = argv[0];
+
assert(n->tag == V_STRING);
char *str = NULL;
@@ -464,7 +508,10 @@ static struct value *sys_read_file(struct info *info, struct value *n) {
/* V_LENS -> V_LENS */
static struct value *lns_check_rec_glue(struct info *info,
- struct value *l, struct value *r) {
+ struct value **argv) {
+ struct value *l = argv[0];
+ struct value *r = argv[1];
+
assert(l->tag == V_LENS);
assert(r->tag == V_LENS);
int check = typecheck_p(info);
@@ -477,28 +524,28 @@ static struct value *lns_check_rec_glue(struct info *info,
*/
/* V_STRING -> V_UNIT */
-static struct value *pr_string(struct info *info, struct value *s) {
- printf("%s", s->string->str);
+static struct value *pr_string(struct info *info, struct value **argv) {
+ printf("%s", argv[0]->string->str);
return make_unit(ref(info));
}
/* V_REGEXP -> V_UNIT */
-static struct value *pr_regexp(struct info *info, struct value *r) {
- print_regexp(stdout, r->regexp);
+static struct value *pr_regexp(struct info *info, struct value **argv) {
+ print_regexp(stdout, argv[0]->regexp);
return make_unit(ref(info));
}
/* V_STRING -> V_UNIT */
-static struct value *pr_endline(struct info *info, struct value *s) {
- printf("%s\n", s->string->str);
+static struct value *pr_endline(struct info *info, struct value **argv) {
+ printf("%s\n", argv[0]->string->str);
return make_unit(ref(info));
}
/* V_TREE -> V_TREE */
static struct value *pr_tree(ATTRIBUTE_UNUSED struct info *info,
- struct value *t) {
- print_tree_braces(stdout, 0, t->origin);
- return ref(t);
+ struct value **argv) {
+ print_tree_braces(stdout, 0, argv[0]->origin);
+ return ref(argv[0]);
}
/*
@@ -515,27 +562,29 @@ static struct value *lns_value_of_type(struct info *info, struct regexp *rx) {
}
/* V_LENS -> V_REGEXP */
-static struct value *lns_ctype(struct info *info, struct value *l) {
- return lns_value_of_type(info, l->lens->ctype);
+static struct value *lns_ctype(struct info *info, struct value **argv) {
+ return lns_value_of_type(info, argv[0]->lens->ctype);
}
/* V_LENS -> V_REGEXP */
-static struct value *lns_atype(struct info *info, struct value *l) {
- return lns_value_of_type(info, l->lens->atype);
+static struct value *lns_atype(struct info *info, struct value **argv) {
+ return lns_value_of_type(info, argv[0]->lens->atype);
}
/* V_LENS -> V_REGEXP */
-static struct value *lns_vtype(struct info *info, struct value *l) {
- return lns_value_of_type(info, l->lens->vtype);
+static struct value *lns_vtype(struct info *info, struct value **argv) {
+ return lns_value_of_type(info, argv[0]->lens->vtype);
}
/* V_LENS -> V_REGEXP */
-static struct value *lns_ktype(struct info *info, struct value *l) {
- return lns_value_of_type(info, l->lens->ktype);
+static struct value *lns_ktype(struct info *info, struct value **argv) {
+ return lns_value_of_type(info, argv[0]->lens->ktype);
}
/* V_LENS -> V_STRING */
-static struct value *lns_fmt_atype(struct info *info, struct value *l) {
+static struct value *lns_fmt_atype(struct info *info, struct value **argv) {
+ struct value *l = argv[0];
+
struct value *result = NULL;
char *s = NULL;
int r;
@@ -549,8 +598,10 @@ static struct value *lns_fmt_atype(struct info *info, struct value *l) {
}
/* V_REGEXP -> V_STRING -> V_STRING */
-static struct value *rx_match(struct info *info,
- struct value *rx, struct value *s) {
+static struct value *rx_match(struct info *info, struct value **argv) {
+ struct value *rx = argv[0];
+ struct value *s = argv[1];
+
struct value *result = NULL;
const char *str = s->string->str;
struct re_registers regs;
diff --git a/src/syntax.c b/src/syntax.c
index 612544c7..d26babcc 100644
--- a/src/syntax.c
+++ b/src/syntax.c
@@ -1023,42 +1023,16 @@ typedef struct value *(*impl5)(struct info *, struct value *, struct value *,
static struct value *native_call(struct info *info,
struct native *func, struct ctx *ctx) {
- struct value *argv[func->argc];
+ struct value *argv[func->argc + 1];
struct binding *b = ctx->local;
- struct value *result;
for (int i = func->argc - 1; i >= 0; i--) {
argv[i] = b->value;
b = b->next;
}
+ argv[func->argc] = NULL;
- switch(func->argc) {
- case 0:
- result = ((impl0) *func->impl)(info);
- break;
- case 1:
- result = ((impl1) *func->impl)(info, argv[0]);
- break;
- case 2:
- result = ((impl2) *func->impl)(info, argv[0], argv[1]);
- break;
- case 3:
- result = ((impl3) *func->impl)(info, argv[0], argv[1], argv[2]);
- break;
- case 4:
- result = ((impl4) *func->impl)(info, argv[0], argv[1], argv[2], argv[3]);
- break;
- case 5:
- result = ((impl5) *func->impl)(info, argv[0], argv[1], argv[2], argv[3],
- argv[4]);
- break;
- default:
- assert(0);
- abort();
- break;
- }
-
- return result;
+ return func->impl(info, argv);
}
static void type_error1(struct info *info, const char *msg, struct type *type) {
@@ -1857,7 +1831,7 @@ make_native_info(struct error *error, const char *fname, int line) {
int define_native_intl(const char *file, int line,
struct error *error,
struct module *module, const char *name,
- int argc, void *impl, ...) {
+ int argc, func_impl impl, ...) {
assert(argc > 0); /* We have no unit type */
assert(argc <= 5);
va_list ap;
diff --git a/src/syntax.h b/src/syntax.h
index 12c3bae4..30aefe58 100644
--- a/src/syntax.h
+++ b/src/syntax.h
@@ -112,10 +112,17 @@ struct param {
struct type *type;
};
+/* The protoype for the implementation of a native/builtin function in the
+ * interpreter.
+ *
+ * The arguments are passed as a NULL-terminated array of values.
+ */
+typedef struct value *(*func_impl)(struct info *, struct value *argv[]);
+
struct native {
unsigned int argc;
struct type *type;
- struct value *(*impl)(void);
+ func_impl impl;
};
/* An exception in the interpreter. Some exceptions are reported directly
@@ -270,7 +277,7 @@ ATTRIBUTE_RETURN_CHECK
int define_native_intl(const char *fname, int line,
struct error *error,
struct module *module, const char *name,
- int argc, void *impl, ...);
+ int argc, func_impl impl, ...);
struct module *builtin_init(struct error *);
--
2.17.2