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Merged
leshy merged 1 commit into from
Jul 30, 2026
Merged

Lua: quote member and constant names that are Lua keywords #2

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91 changes: 71 additions & 20 deletions lcmgen/emit_lua.c
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Original file line number Diff line number Diff line change
Expand Up @@ -44,6 +44,32 @@

#define err(...) fprintf(stderr, __VA_ARGS__)

// LCM lets a member or constant be named after a Lua keyword (ROS's
// geographic_msgs.RouteSegment has a field called "end", for example). Those
// cannot be reached with dot notation, so they are emitted as t["end"].
static const char *const lua_reserved_words[] = {
"and", "break", "do", "else", "elseif", "end", "false", "for",
"function", "goto", "if", "in", "local", "nil", "not", "or",
"repeat", "return", "then", "true", "until", "while", NULL};

static int lua_is_reserved_word(const char *name)
{
for (int i = 0; lua_reserved_words[i] != NULL; i++) {
if (!strcmp(name, lua_reserved_words[i]))
return 1;
}
return 0;
}

// Returns "<table>.<name>", or "<table>[\"<name>\"]" when <name> is a Lua
// keyword. Caller must g_free() the result.
static char *lua_member_ref(const char *table, const char *name)
{
if (lua_is_reserved_word(name))
return g_strdup_printf("%s[\"%s\"]", table, name);
return g_strdup_printf("%s.%s", table, name);
}

static void mkdir_with_parents(const char *path, mode_t mode)
{
#ifdef WIN32
Expand Down Expand Up @@ -241,16 +267,17 @@ static void _emit_decode_list(const lcmgen_t *lcm, FILE *f, lcm_struct_t *ls, lc
emit(indent, "%s = {lcm._pack.unpack('>%s%c', data:read(%d))}", accessor, len,
_struct_format(lm), atoi(len) * _primitive_type_size(tn));
} else {
char *lenref = lua_member_ref("obj", len);
if (_primitive_type_size(tn) > 1) {
emit(indent,
"%s = {lcm._pack.unpack(string.format('>%%d%c', obj.%s), data:read(obj.%s * "
"%s = {lcm._pack.unpack(string.format('>%%d%c', %s), data:read(%s * "
"%d))}",
accessor, _struct_format(lm), len, len, _primitive_type_size(tn));
accessor, _struct_format(lm), lenref, lenref, _primitive_type_size(tn));
} else {
emit(indent,
"%s = {lcm._pack.unpack(string.format('>%%d%c', obj.%s), data:read(obj.%s))}",
accessor, _struct_format(lm), len, len);
emit(indent, "%s = {lcm._pack.unpack(string.format('>%%d%c', %s), data:read(%s))}",
accessor, _struct_format(lm), lenref, lenref);
}
g_free(lenref);
}
} else {
assert(0);
Expand All @@ -268,7 +295,9 @@ static void _flush_read_struct_fmt(const lcmgen_t *lcm, FILE *f, GQueue *formats
int fmtsize = 0;
while (!g_queue_is_empty(members)) {
lcm_member_t *lm = (lcm_member_t *) g_queue_pop_head(members);
emit_continue("obj.%s", lm->membername);
char *ref = lua_member_ref("obj", lm->membername);
emit_continue("%s", ref);
g_free(ref);
if (!g_queue_is_empty(members)) {
emit_continue(", ");
}
Expand Down Expand Up @@ -305,14 +334,16 @@ static void emit_lua_decode_one(const lcmgen_t *lcm, FILE *f, lcm_struct_t *ls)
g_queue_push_tail(struct_members, lm);
} else {
_flush_read_struct_fmt(lcm, f, struct_fmt, struct_members);
char *accessor = g_strdup_printf("obj.%s", lm->membername);
char *accessor = lua_member_ref("obj", lm->membername);
_emit_decode_one(lcm, f, ls, lm, accessor, 1);
g_free(accessor);
}
} else {
_flush_read_struct_fmt(lcm, f, struct_fmt, struct_members);
GString *accessor = g_string_new("");
g_string_append_printf(accessor, "obj.%s", lm->membername);
char *accessor_base = lua_member_ref("obj", lm->membername);
g_string_append(accessor, accessor_base);
g_free(accessor_base);

// iterate through the dimensions of the member, building up
// an accessor string, and emitting for loops
Expand All @@ -324,7 +355,9 @@ static void emit_lua_decode_one(const lcmgen_t *lcm, FILE *f, lcm_struct_t *ls)
if (dim->mode == LCM_CONST) {
emit(1 + n, "for i%d = 1, %s do", n, dim->size);
} else {
emit(1 + n, "for i%d = 1, obj.%s do", n, dim->size);
char *dimref = lua_member_ref("obj", dim->size);
emit(1 + n, "for i%d = 1, %s do", n, dimref);
g_free(dimref);
}
g_string_append_printf(accessor, "[i%d]", n);
}
Expand All @@ -348,7 +381,9 @@ static void emit_lua_decode_one(const lcmgen_t *lcm, FILE *f, lcm_struct_t *ls)
if (last_dim_fixed_len) {
emit(1 + n, "for i%d = 1, %s do", n, last_dim->size);
} else {
emit(1 + n, "for i%d = 1, obj.%s do", n, last_dim->size);
char *dimref = lua_member_ref("obj", last_dim->size);
emit(1 + n, "for i%d = 1, %s do", n, dimref);
g_free(dimref);
}
g_string_append_printf(accessor, "[i%d]", n);
_emit_decode_one(lcm, f, ls, lm, accessor->str, n + 2);
Expand Down Expand Up @@ -430,10 +465,12 @@ static void _emit_encode_list(const lcmgen_t *lcm, FILE *f, lcm_struct_t *ls, lc
emit(indent, "table.insert(buf_table, lcm._pack.pack('>%s%c', unpack(%s)))", len,
_struct_format(lm), accessor);
} else {
char *lenref = lua_member_ref("self", len);
emit(indent,
"table.insert(buf_table, lcm._pack.pack(string.format('>%%d%c', self.%s), "
"table.insert(buf_table, lcm._pack.pack(string.format('>%%d%c', %s), "
"unpack(%s)))",
_struct_format(lm), len, accessor);
_struct_format(lm), lenref, accessor);
g_free(lenref);
}
} else {
assert(0);
Expand All @@ -453,7 +490,9 @@ static void _flush_write_struct_fmt(FILE *f, GQueue *formats, GQueue *members)
emit_continue("', ");
while (!g_queue_is_empty(members)) {
lcm_member_t *lm = (lcm_member_t *) g_queue_pop_head(members);
emit_continue("self.%s", lm->membername);
char *ref = lua_member_ref("self", lm->membername);
emit_continue("%s", ref);
g_free(ref);
if (!g_queue_is_empty(members)) {
emit_continue(", ");
}
Expand Down Expand Up @@ -493,15 +532,17 @@ static void emit_lua_encode_one(const lcmgen_t *lcm, FILE *f, lcm_struct_t *ls)
} else {
// XXX not a primitive
_flush_write_struct_fmt(f, struct_fmt, struct_members);
char *accessor = g_strdup_printf("self.%s", lm->membername);
char *accessor = lua_member_ref("self", lm->membername);
_emit_encode_one(lcm, f, ls, lm, accessor, 1);
g_free(accessor);
}
} else {
// XXX this is an array
_flush_write_struct_fmt(f, struct_fmt, struct_members);
GString *accessor = g_string_new("");
g_string_append_printf(accessor, "self.%s", lm->membername);
char *accessor_base = lua_member_ref("self", lm->membername);
g_string_append(accessor, accessor_base);
g_free(accessor_base);

int n;
for (n = 0; n < lm->dimensions->len - 1; n++) {
Expand All @@ -511,7 +552,9 @@ static void emit_lua_encode_one(const lcmgen_t *lcm, FILE *f, lcm_struct_t *ls)
if (dim->mode == LCM_CONST) {
emit(1 + n, "for i%d = 1, %s do", n, dim->size);
} else {
emit(1 + n, "for i%d = 1, self.%s do", n, dim->size);
char *dimref = lua_member_ref("self", dim->size);
emit(1 + n, "for i%d = 1, %s do", n, dimref);
g_free(dimref);
}
}

Expand All @@ -528,7 +571,9 @@ static void emit_lua_encode_one(const lcmgen_t *lcm, FILE *f, lcm_struct_t *ls)
if (last_dim_fixed_len) {
emit(1 + n, "for i%d = 1, %s do", n, last_dim->size);
} else {
emit(1 + n, "for i%d = 1, self.%s do", n, last_dim->size);
char *dimref = lua_member_ref("self", last_dim->size);
emit(1 + n, "for i%d = 1, %s do", n, dimref);
g_free(dimref);
}
g_string_append_printf(accessor, "[i%d]", n);
_emit_encode_one(lcm, f, ls, lm, accessor->str, n + 2);
Expand Down Expand Up @@ -578,7 +623,9 @@ static void emit_member_initializer(const lcmgen_t *lcm, FILE *f, lcm_member_t *
} else {
emit_end("{}");
emit(dim_num + 1, "for d%d = 1, %s do", dim_num, dim->size);
emit_start(dim_num + 2, "obj.%s", lm->membername);
char *ref = lua_member_ref("obj", lm->membername);
emit_start(dim_num + 2, "%s", ref);
g_free(ref);
for (int i = 0; i < dim_num + 1; i++) {
emit_continue("[d%d]", i);
}
Expand All @@ -598,7 +645,9 @@ static void emit_lua_new(const lcmgen_t *lcm, FILE *f, lcm_struct_t *lr)
unsigned int member;
for (member = 0; member < lr->members->len; member++) {
lcm_member_t *lm = (lcm_member_t *) g_ptr_array_index(lr->members, member);
fprintf(f, " obj.%s = ", lm->membername);
char *ref = lua_member_ref("obj", lm->membername);
fprintf(f, " %s = ", ref);
g_free(ref);
// XXX this might need alot of work because lua doesn't have list comprehension
emit_member_initializer(lcm, f, lm, 0);
}
Expand Down Expand Up @@ -1096,7 +1145,9 @@ static int emit_package(lcmgen_t *lcm, _package_contents_t *pc)
for (unsigned int cn = 0; cn < g_ptr_array_size(ls->constants); cn++) {
lcm_constant_t *lc = (lcm_constant_t *) g_ptr_array_index(ls->constants, cn);
assert(lcm_is_legal_const_type(lc->lctypename));
emit(1, "%s.%s = %s", ls->structname->shortname, lc->membername, lc->val_str);
char *ref = lua_member_ref(ls->structname->shortname, lc->membername);
emit(1, "%s = %s", ref, lc->val_str);
g_free(ref);
}
if (g_ptr_array_size(ls->constants) > 0)
emit(0, "");
Expand Down
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