ref-filter: add return value && strbuf to handlers

Continue removing die() calls from ref-filter formatting logic,
so that it could be used by other commands.

Change the signature of handlers by adding return value
and strbuf parameter for errors.
Return value equals 0 upon success and -1 upon failure.
Upon failure, error message is appended to the strbuf.

Signed-off-by: Olga Telezhnaia <olyatelezhnaya@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/ref-filter.c b/ref-filter.c
index 9833709dbefe3d32dce5737fed971ab39317e4db..a18c86961f08ccf4e466f1ac2d027f4bc0ef8c98 100644 (file)
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -400,7 +400,8 @@ struct ref_formatting_state {
 
 struct atom_value {
        const char *s;
-       void (*handler)(struct atom_value *atomv, struct ref_formatting_state *state);
+       int (*handler)(struct atom_value *atomv, struct ref_formatting_state *state,
+                      struct strbuf *err);
        uintmax_t value; /* used for sorting when not FIELD_STR */
        struct used_atom *atom;
 };
@@ -494,7 +495,8 @@ static void quote_formatting(struct strbuf *s, const char *str, int quote_style)
        }
 }
 
-static void append_atom(struct atom_value *v, struct ref_formatting_state *state)
+static int append_atom(struct atom_value *v, struct ref_formatting_state *state,
+                      struct strbuf *unused_err)
 {
        /*
         * Quote formatting is only done when the stack has a single
@@ -506,6 +508,7 @@ static void append_atom(struct atom_value *v, struct ref_formatting_state *state
                quote_formatting(&state->stack->output, v->s, state->quote_style);
        else
                strbuf_addstr(&state->stack->output, v->s);
+       return 0;
 }
 
 static void push_stack_element(struct ref_formatting_stack **stack)
@@ -540,7 +543,8 @@ static void end_align_handler(struct ref_formatting_stack **stack)
        strbuf_release(&s);
 }
 
-static void align_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+static int align_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state,
+                             struct strbuf *unused_err)
 {
        struct ref_formatting_stack *new_stack;
 
@@ -548,6 +552,7 @@ static void align_atom_handler(struct atom_value *atomv, struct ref_formatting_s
        new_stack = state->stack;
        new_stack->at_end = end_align_handler;
        new_stack->at_end_data = &atomv->atom->u.align;
+       return 0;
 }
 
 static void if_then_else_handler(struct ref_formatting_stack **stack)
@@ -585,7 +590,8 @@ static void if_then_else_handler(struct ref_formatting_stack **stack)
        free(if_then_else);
 }
 
-static void if_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+static int if_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state,
+                          struct strbuf *unused_err)
 {
        struct ref_formatting_stack *new_stack;
        struct if_then_else *if_then_else = xcalloc(sizeof(struct if_then_else), 1);
@@ -597,6 +603,7 @@ static void if_atom_handler(struct atom_value *atomv, struct ref_formatting_stat
        new_stack = state->stack;
        new_stack->at_end = if_then_else_handler;
        new_stack->at_end_data = if_then_else;
+       return 0;
 }
 
 static int is_empty(const char *s)
@@ -609,7 +616,8 @@ static int is_empty(const char *s)
        return 1;
 }
 
-static void then_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+static int then_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state,
+                            struct strbuf *err)
 {
        struct ref_formatting_stack *cur = state->stack;
        struct if_then_else *if_then_else = NULL;
@@ -617,11 +625,11 @@ static void then_atom_handler(struct atom_value *atomv, struct ref_formatting_st
        if (cur->at_end == if_then_else_handler)
                if_then_else = (struct if_then_else *)cur->at_end_data;
        if (!if_then_else)
-               die(_("format: %%(then) atom used without an %%(if) atom"));
+               return strbuf_addf_ret(err, -1, _("format: %%(then) atom used without an %%(if) atom"));
        if (if_then_else->then_atom_seen)
-               die(_("format: %%(then) atom used more than once"));
+               return strbuf_addf_ret(err, -1, _("format: %%(then) atom used more than once"));
        if (if_then_else->else_atom_seen)
-               die(_("format: %%(then) atom used after %%(else)"));
+               return strbuf_addf_ret(err, -1, _("format: %%(then) atom used after %%(else)"));
        if_then_else->then_atom_seen = 1;
        /*
         * If the 'equals' or 'notequals' attribute is used then
@@ -637,9 +645,11 @@ static void then_atom_handler(struct atom_value *atomv, struct ref_formatting_st
        } else if (cur->output.len && !is_empty(cur->output.buf))
                if_then_else->condition_satisfied = 1;
        strbuf_reset(&cur->output);
+       return 0;
 }
 
-static void else_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+static int else_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state,
+                            struct strbuf *err)
 {
        struct ref_formatting_stack *prev = state->stack;
        struct if_then_else *if_then_else = NULL;
@@ -647,24 +657,26 @@ static void else_atom_handler(struct atom_value *atomv, struct ref_formatting_st
        if (prev->at_end == if_then_else_handler)
                if_then_else = (struct if_then_else *)prev->at_end_data;
        if (!if_then_else)
-               die(_("format: %%(else) atom used without an %%(if) atom"));
+               return strbuf_addf_ret(err, -1, _("format: %%(else) atom used without an %%(if) atom"));
        if (!if_then_else->then_atom_seen)
-               die(_("format: %%(else) atom used without a %%(then) atom"));
+               return strbuf_addf_ret(err, -1, _("format: %%(else) atom used without a %%(then) atom"));
        if (if_then_else->else_atom_seen)
-               die(_("format: %%(else) atom used more than once"));
+               return strbuf_addf_ret(err, -1, _("format: %%(else) atom used more than once"));
        if_then_else->else_atom_seen = 1;
        push_stack_element(&state->stack);
        state->stack->at_end_data = prev->at_end_data;
        state->stack->at_end = prev->at_end;
+       return 0;
 }
 
-static void end_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state)
+static int end_atom_handler(struct atom_value *atomv, struct ref_formatting_state *state,
+                           struct strbuf *err)
 {
        struct ref_formatting_stack *current = state->stack;
        struct strbuf s = STRBUF_INIT;
 
        if (!current->at_end)
-               die(_("format: %%(end) atom used without corresponding atom"));
+               return strbuf_addf_ret(err, -1, _("format: %%(end) atom used without corresponding atom"));
        current->at_end(&state->stack);
 
        /*  Stack may have been popped within at_end(), hence reset the current pointer */
@@ -681,6 +693,7 @@ static void end_atom_handler(struct atom_value *atomv, struct ref_formatting_sta
        }
        strbuf_release(&s);
        pop_stack_element(&state->stack);
+       return 0;
 }
 
 /*
@@ -2151,7 +2164,10 @@ int format_ref_array_item(struct ref_array_item *info,
                get_ref_atom_value(info,
                                   parse_ref_filter_atom(format, sp + 2, ep),
                                   &atomv);
-               atomv->handler(atomv, &state);
+               if (atomv->handler(atomv, &state, error_buf)) {
+                       pop_stack_element(&state.stack);
+                       return -1;
+               }
        }
        if (*cp) {
                sp = cp + strlen(cp);
@@ -2160,7 +2176,10 @@ int format_ref_array_item(struct ref_array_item *info,
        if (format->need_color_reset_at_eol) {
                struct atom_value resetv;
                resetv.s = GIT_COLOR_RESET;
-               append_atom(&resetv, &state);
+               if (append_atom(&resetv, &state, error_buf)) {
+                       pop_stack_element(&state.stack);
+                       return -1;
+               }
        }
        if (state.stack->prev) {
                pop_stack_element(&state.stack);