X-Git-Url: https://git.draconx.ca/gitweb/cdecl99.git/blobdiff_plain/0c61f9637a469ac7a28b5a329551b03e6ad14d62..4251b4bd0087752ceddbf95a6a8c928ab2207844:/src/error.c

diff --git a/src/error.c b/src/error.c
index 9b89bac..36e6366 100644
--- a/src/error.c
+++ b/src/error.c
@@ -1,6 +1,6 @@
 /*
  *  Error handling for libcdecl.
- *  Copyright © 2011-2012, 2021 Nick Bowler
+ *  Copyright © 2011-2012, 2021, 2023 Nick Bowler
  *
  *  This program is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -17,41 +17,29 @@
  */
 
 #include <config.h>
+#include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
 #include <assert.h>
-#include <glthread/lock.h>
-#include <glthread/tls.h>
 
 #include "cdecl.h"
 #include "cdecl-internal.h"
 
-gl_once_define(static, tls_initialized);
+#include <glthread/lock.h>
+#include <glthread/tls.h>
+
+#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;
-	char str[];
-};
-
-/* This error is reserved for extremely dire out-of-memory conditions. */
-static struct err_state err_no_mem = {
-	.err = {
-		.code = CDECL_ENOMEM,
-		.str  = NULL,
-	},
+	char str[FLEXIBLE_ARRAY_MEMBER];
 };
 
-const char *cdecl__strerror(unsigned code)
-{
-#	include "errtab.h"
-
-	assert(code < sizeof offtab / sizeof offtab[0]);
-	assert(offtab[code] != 0);
-
-	return gettext((char *)&strtab + offtab[code]);
-}
+/* This pre-initialized error is reserved for dire out-of-memory conditions. */
+static struct cdecl_error err_no_mem;
 
 static void free_err(void *err)
 {
@@ -61,76 +49,109 @@ static void free_err(void *err)
 	free(err);
 }
 
-static void set_error(const struct cdecl_error *err)
+static void set_err(unsigned code, struct cdecl_error *err)
 {
-	struct err_state *state;
-	size_t need_len = 0;
-
-	if (err->str) {
-		need_len = strlen(err->str) + 1;
+	static const char errmsgs[] = STRTAB_INITIALIZER;
+
+	switch (code) {
+	case CDECL__ENOMEM:
+		err->code = CDECL_ENOMEM;
+		break;
+	default:
+		err->code = CDECL_ENOPARSE;
+		break;
 	}
 
-	state = gl_tls_get(tls_key);
-	if (state == &err_no_mem)
-		state = NULL;
-	if (!state || state->nstr < need_len) {
-		struct err_state *tmp;
-		
-		tmp = realloc(state, sizeof *state + need_len);
-		if (!tmp) {
-			/* Re-use the existing state buffer, if any. */
-			if (state)
-				state->err = err_no_mem.err;
-			else
-				state = &err_no_mem;
-			
-			gl_tls_set(tls_key, state);
-			return;
-		}
+	err->str = _(&errmsgs[code]);
+}
 
-		state = tmp;
-		state->nstr = need_len;
-		gl_tls_set(tls_key, state);
-	}
+static void initialize(void)
+{
+	cdecl__init_i18n();
+	set_err(CDECL__ENOMEM, &err_no_mem);
+	gl_tls_key_init(tls_key, free_err);
+}
 
-	state->err = *err;
-	if (err->str) {
-		memcpy(state->str, err->str, need_len);
-		state->err.str = state->str;
+static void *alloc_err_state(void *old, size_t buf_size)
+{
+	struct err_state *state;
+	void *p;
+
+	state = p = realloc(old, offsetof(struct err_state, str) + buf_size);
+	if (state) {
+		state->nstr = buf_size;
+	} else if (old) {
+		/* Failed allocation, but existing state is still good */
+		p = old;
 	} else {
-		state->err.str = cdecl__strerror(state->err.code);
+		/* Failed allocation, no existing state */
+		p = &err_no_mem;
 	}
+
+	gl_tls_set(tls_key, p);
+	return state;
 }
 
-static void initialize(void)
+static struct err_state *get_err_state(void)
 {
-	cdecl__init_i18n();
-	err_no_mem.err.str = cdecl__strerror(CDECL_ENOMEM);
+	void *state;
 
-	gl_tls_key_init(tls_key, free_err);
+	gl_once(tls_initialized, initialize);
 
-	/*
-	 * This default error message is a stop-gap measure until all library
-	 * error conditions use the new interface.
-	 */
-	set_error(&(const struct cdecl_error){ .code = CDECL_ENOPARSE });
+	state = gl_tls_get(tls_key);
+	if (state == &err_no_mem)
+		state = NULL;
+	if (!state)
+		return alloc_err_state(state, 100);
+	return state;
 }
 
-const struct cdecl_error *cdecl_get_error(void)
+/*
+ * Set the library error to one of the preset messages defined in errmsg.h
+ * (CDECL__Exxx).
+ */
+void cdecl__errmsg(unsigned msg)
 {
 	struct err_state *state;
 
-	gl_once(tls_initialized, initialize);
+	state = get_err_state();
+	if (!state)
+		return;
 
-	state = gl_tls_get(tls_key);
-	assert(state);
+	set_err(msg, &state->err);
+}
 
-	return &state->err;
+/*
+ * 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;
+
+	state = get_err_state();
+	if (!state)
+		return;
+
+retry:
+	rc = snprintf(state->str, state->nstr, fmt, arg);
+	if (rc > 0 && rc >= state->nstr) {
+		assert(try++ == 0 && rc < SIZE_MAX / 4);
+		state = alloc_err_state(state, (size_t)(rc+1u) * 3 / 2);
+		if (!state)
+			return;
+
+		goto retry;
+	}
+
+	state->err.str = state->str;
+	state->err.code = code;
 }
 
-void cdecl__set_error(const struct cdecl_error *err)
+const struct cdecl_error *cdecl_get_error(void)
 {
-	gl_once(tls_initialized, initialize);
+	struct err_state *state = get_err_state();
 
-	set_error(err);
+	return state ? &state->err : NULL;
 }