libcdecl: reduce snprintf reliance for error reporting.

[cdecl99.git] / src / error.c

diff --git a/src/error.c b/src/error.c
index ef9e4757977621d805b35f6d84174f84feab32ae..758f58e63c50d4159195b08189c10cd6467e06c2 100644 (file)
--- a/src/error.c
+++ b/src/error.c
@@ -19,9 +19,7 @@
 #include <config.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
 #include <assert.h>
-#include <stdarg.h>
 
 #include "cdecl.h"
 #include "cdecl-internal.h"
@@ -31,9 +29,6 @@
 
 #include "errmsg.h"
 
-gl_once_define(static, tls_initialized);
-static gl_tls_key_t tls_key;
-
 struct err_state {
        struct cdecl_error err;
        size_t nstr;
@@ -42,6 +37,7 @@ struct err_state {
 
 /* This pre-initialized error is reserved for dire out-of-memory conditions. */
 static struct cdecl_error err_no_mem;
+static gl_tls_key_t tls_key;
 
 static void free_err(void *err)
 {
@@ -67,9 +63,12 @@ static void set_err(unsigned code, struct cdecl_error *err)
        err->str = _(&errmsgs[code]);
 }
 
-static void initialize(void)
+static void initialize_cb(void)
 {
-       cdecl__init_i18n();
+#if ENABLE_NLS
+       bindtextdomain(PACKAGE, LOCALEDIR);
+       bindtextdomain("bison-runtime", BISON_LOCALEDIR);
+#endif
        set_err(CDECL__ENOMEM, &err_no_mem);
        gl_tls_key_init(tls_key, free_err);
 }
@@ -98,7 +97,8 @@ static struct err_state *get_err_state(void)
 {
        void *state;
 
-       gl_once(tls_initialized, initialize);
+       gl_once_define(static, tls_initialized)
+       gl_once(tls_initialized, initialize_cb);
 
        state = gl_tls_get(tls_key);
        if (state == &err_no_mem)
@@ -108,6 +108,17 @@ static struct err_state *get_err_state(void)
        return state;
 }
 
+
+#if ENABLE_NLS
+/*
+ * Initialize gettext indirectly via get_err_state.
+ */
+void cdecl__init_i18n(void)
+{
+       get_err_state();
+}
+#endif
+
 /*
  * Set the library error to one of the preset messages defined in errmsg.h
  * (CDECL__Exxx).
@@ -124,25 +135,53 @@ void cdecl__errmsg(unsigned msg)
 }
 
 /*
- * Sets the library error to code, with a printf-style error string.
+ * In the NLS-disabled case, all format strings are of the form
+ *
+ *   "blah blah %s"
+ *
+ * so we exploit this to implement a simple snprintf workalike using the
+ * libcdecl output helpers directly.
+ *
+ * In the NLS-enabled case, we have to use snprintf as format strings may
+ * be translated.  GNU libintl ensures a suitable version is available.
  */
-void cdecl__err(unsigned code, const char *fmt, ...)
+static size_t
+fmt_err(struct err_state *state, const char *fmt, const char *arg)
+{
+#if ENABLE_NLS
+       snprintf(state->str, state->nstr, fmt, arg);
+       return strlen(fmt) + strlen(arg);
+#else
+       struct output_state dst = { state->str, state->nstr };
+       size_t rc;
+
+       rc = cdecl__strlcpy(dst.dst, fmt, dst.dstlen);
+       cdecl__advance(&dst, rc-2);
+       cdecl__emit(&dst, arg);
+
+       return dst.accum;
+#endif
+}
+
+/*
+ * Sets the library error to code; fmt is a printf-style string that may use
+ * up to one %s directive, to refer to arg.
+ */
+void cdecl__err(unsigned code, const char *fmt, const char *arg)
 {
        struct err_state *state;
-       int rc, try = 0;
-       va_list ap;
+       unsigned try = 0;
+       size_t rc;
 
        state = get_err_state();
        if (!state)
                return;
 
 retry:
-       va_start(ap, fmt);
-       rc = vsnprintf(state->str, state->nstr, fmt, ap);
-       va_end(ap);
-
-       if (rc > 0 && rc >= state->nstr) {
+       rc = fmt_err(state, fmt, arg);
+       if (rc >= state->nstr) {
                assert(try++ == 0 && rc < SIZE_MAX / 4);
+
                state = alloc_err_state(state, (size_t)(rc+1u) * 3 / 2);
                if (!state)
                        return;