kconfig: introduce specialized printer

Make conf_write_symbol() grammar agnostic to be able to use it from different
code path. These path pass a printer callback which will print a symbol's name
and its value in different format.

conf_write_symbol()'s job become mostly only to prepare a string for the
printer. This avoid to have to pass specialized flag to generic
functions

Signed-off-by: Arnaud Lacombe <lacombar@gmail.com>
[mmarek: rebased on top of de12518 (kconfig: autogenerated config_is_xxx
macro)]
Signed-off-by: Michal Marek <mmarek@suse.cz>

4 files changed, 266 insertions, 128 deletions

diff --git a/scripts/kconfig/confdata.c b/scripts/kconfig/confdata.c
index a49cf4f7dca5..be6952c7fb29 100644
--- a/scripts/kconfig/confdata.c
+++ b/scripts/kconfig/confdata.c
@@ -422,64 +422,228 @@ int conf_read(const char *name)
         return 0;
 }
 
-/* Write a S_STRING */
-static void conf_write_string(bool headerfile, const char *name,
-                              const char *str, FILE *out)
+/*
+ * Kconfig configuration printer
+ *
+ * This printer is used when generating the resulting configuration after
+ * kconfig invocation and `defconfig' files. Unset symbol might be omitted by
+ * passing a non-NULL argument to the printer.
+ *
+ */
+static void
+kconfig_print_symbol(FILE *fp, struct symbol *sym, const char *value, void *arg)
+{
+
+        switch (sym->type) {
+        case S_BOOLEAN:
+        case S_TRISTATE:
+                if (*value == 'n') {
+                        bool skip_unset = (arg != NULL);
+
+                        if (!skip_unset)
+                                fprintf(fp, "# %s%s is not set\n",
+                                    CONFIG_, sym->name);
+                        return;
+                }
+                break;
+        default:
+                break;
+        }
+
+        fprintf(fp, "%s%s=%s\n", CONFIG_, sym->name, value);
+}
+
+static void
+kconfig_print_comment(FILE *fp, const char *value, void *arg)
 {
-        int l;
-        if (headerfile)
-                fprintf(out, "#define %s%s \"", CONFIG_, name);
-        else
-                fprintf(out, "%s%s=\"", CONFIG_, name);
-
-        while (1) {
-                l = strcspn(str, "\"\\");
+        const char *p = value;
+        size_t l;
+
+        for (;;) {
+                l = strcspn(p, "\n");
+                fprintf(fp, "#");
                 if (l) {
-                        xfwrite(str, l, 1, out);
-                        str += l;
+                        fprintf(fp, " ");
+                        fwrite(p, l, 1, fp);
+                        p += l;
                 }
-                if (!*str)
+                fprintf(fp, "\n");
+                if (*p++ == '\0')
                         break;
-                fprintf(out, "\\%c", *str++);
         }
-        fputs("\"\n", out);
 }
 
-static void conf_write_symbol(struct symbol *sym, FILE *out, bool write_no)
+static struct conf_printer kconfig_printer_cb =
 {
-        const char *str;
+        .print_symbol = kconfig_print_symbol,
+        .print_comment = kconfig_print_comment,
+};
+
+/*
+ * Header printer
+ *
+ * This printer is used when generating the `include/generated/autoconf.h' file.
+ */
+static void
+header_print_symbol(FILE *fp, struct symbol *sym, const char *value, void *arg)
+{
+        const char *suffix = "";
 
         switch (sym->type) {
         case S_BOOLEAN:
         case S_TRISTATE:
-                switch (sym_get_tristate_value(sym)) {
-                case no:
-                        if (write_no)
-                                fprintf(out, "# %s%s is not set\n",
-                                    CONFIG_, sym->name);
-                        break;
-                case mod:
-                        fprintf(out, "%s%s=m\n", CONFIG_, sym->name);
-                        break;
-                case yes:
-                        fprintf(out, "%s%s=y\n", CONFIG_, sym->name);
-                        break;
+                switch (*value) {
+                case 'n':
+                        return;
+                case 'm':
+                        suffix = "_MODULE";
+                        /* FALLTHROUGH */
+                default:
+                        value = "1";
                 }
                 break;
-        case S_STRING:
-                conf_write_string(false, sym->name, sym_get_string_value(sym), out);
+        default:
                 break;
-        case S_HEX:
-        case S_INT:
-                str = sym_get_string_value(sym);
-                fprintf(out, "%s%s=%s\n", CONFIG_, sym->name, str);
+        }
+
+        fprintf(fp, "#define %s%s%s %s\n",
+            CONFIG_, sym->name, suffix, value);
+}
+
+static void
+header_print_comment(FILE *fp, const char *value, void *arg)
+{
+        const char *p = value;
+        size_t l;
+
+        fprintf(fp, "/*\n");
+        for (;;) {
+                l = strcspn(p, "\n");
+                fprintf(fp, " *");
+                if (l) {
+                        fprintf(fp, " ");
+                        fwrite(p, l, 1, fp);
+                        p += l;
+                }
+                fprintf(fp, "\n");
+                if (*p++ == '\0')
+                        break;
+        }
+        fprintf(fp, " */\n");
+}
+
+static struct conf_printer header_printer_cb =
+{
+        .print_symbol = header_print_symbol,
+        .print_comment = header_print_comment,
+};
+
+/*
+ * Function-style header printer
+ *
+ * This printer is used to generate the config_is_xxx() function-style macros
+ * in `include/generated/autoconf.h' 
+ */
+static void
+header_function_print_symbol(FILE *fp, struct symbol *sym, const char *value, void *arg)
+{
+        int val = 0;
+        char c;
+        char *tmp, *d;
+
+        switch (sym->type) {
+        case S_BOOLEAN:
+        case S_TRISTATE:
                 break;
+        default:
+                return;
+        }
+        if (*value == 'm')
+                val = 2;
+        else if (*value == 'y')
+                val = 1;
+
+        d = strdup(CONFIG_);
+        tmp = d;
+        while ((c = *d)) {
+                *d = tolower(c);
+                d++;
+        }
+
+        fprintf(fp, "#define %sis_", tmp);
+        free(tmp);