Add alloca_sourceloc(), refactored from log.c

log.c

@@ -243,31 +243,11 @@ static void _log_prefix(_log_iterator *it, int level)
   }
 }
 
-static const char *_trimbuildpath(const char *path)
-{
-  /* Remove common path prefix */
-  int lastsep = 0;
-  int i;
-  for (i = 0; __FILE__[i] && path[i]; ++i) {
-    if (i && path[i - 1] == '/')
-      lastsep = i;
-    if (__FILE__[i] != path[i])
-      break;
-  }
-  return &path[lastsep];
-}
-
 static void _log_prefix_whence(_log_iterator *it, struct __sourceloc whence)
 {
-  if (whence.file && whence.file[0]) {
-    xprintf(it->xpf, "%s", _trimbuildpath(whence.file));
-    if (whence.line)
-      xprintf(it->xpf, ":%u", whence.line);
-    if (whence.function)
-      xprintf(it->xpf, ":%s()", whence.function);
+  if ((whence.file && whence.file[0]) || (whence.function && whence.function[0])) {
+    xprint_sourceloc(it->xpf, whence);
     xputs("  ", it->xpf);
-  } else if (whence.function && whence.function[0]) {
-    xprintf(it->xpf, "%s()  ", whence.function);
   }
 }
 

strbuf_helpers.c

@@ -67,6 +67,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #include "strbuf_helpers.h"
 #include "str.h"
 #include "socket.h"
+#include "whence.h"
 
 static inline strbuf _toprint(strbuf sb, char c)
 {
@@ -151,6 +152,12 @@ strbuf strbuf_toprint_quoted(strbuf sb, const char quotes[2], const char *str)
   return _overrun_quote(sb, quotes ? quotes[1] : '\0', "...");
 }
 
+strbuf strbuf_append_sourceloc(strbuf sb, struct __sourceloc loc)
+{
+  xprint_sourceloc(XPRINTF_STRBUF(sb), loc);
+  return sb;
+}
+
 strbuf strbuf_path_join(strbuf sb, ...)
 {
   va_list ap;

strbuf_helpers.h

@@ -56,6 +56,12 @@ strbuf strbuf_toprint_quoted_len(strbuf sb, const char quotes[2], const char *bu
  */
 strbuf strbuf_toprint_quoted(strbuf sb, const char quotes[2], const char *str);
 
+/* Append a symbolic representation of a struct __sourceloc.
+ * @author Andrew Bettison <andrew@servalproject.com>
+ */
+struct __sourceloc;
+strbuf strbuf_append_sourceloc(strbuf sb, struct __sourceloc);
+
 /* Join Unix file path segments together with separator characters '/' to form
  * a complete path.  Any segment that starts with '/' is taken as the start of
  * an absolute path, and all prior segments are discarded.

whence.c

@@ -17,5 +17,54 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
 
 #include "whence.h"
+#include "strbuf.h"
+#include "strbuf_helpers.h"
 
 const struct __sourceloc __whence = __NOWHERE__;
+
+char *sourceloc_tostr(char *dstStr, ssize_t dstBufSiz, struct __sourceloc loc)
+{
+  strbuf b = strbuf_local(dstStr, dstBufSiz);
+  strbuf_append_sourceloc(b, loc);
+  return dstStr;
+}
+
+size_t sourceloc_tostr_len(struct __sourceloc loc)
+{
+  return strbuf_count(strbuf_append_sourceloc(strbuf_local(NULL, 0), loc));
+}
+
+static const char *_trimbuildpath(const char *path)
+{
+  /* Remove common path prefix */
+  int lastsep = 0;
+  int i;
+  for (i = 0; __FILE__[i] && path[i]; ++i) {
+    if (i && path[i - 1] == '/')
+      lastsep = i;
+    if (__FILE__[i] != path[i])
+      break;
+  }
+  return &path[lastsep];
+}
+
+void xprint_sourceloc(XPRINTF xpf, struct __sourceloc loc)
+{
+  int flag = 0;
+  if (loc.file && loc.file[0]) {
+    xprintf(xpf, "%s", _trimbuildpath(loc.file));
+    ++flag;
+  }
+  if (loc.line) {
+    if (flag)
+      xputc(':', xpf);
+    xprintf(xpf, "%u", loc.line);
+    ++flag;
+  }
+  if (loc.function && loc.function[0]) {
+    if (flag)
+      xputc(':', xpf);
+    xprintf(xpf, "%s()", loc.function);
+    ++flag;
+  }
+}

whence.h

@@ -20,6 +20,8 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #define __SERVAL_DNA__WHENCE_H
 
 #include <stdio.h> // for NULL
+#include <alloca.h>
+#include "xprintf.h"
 
 /*
  * Every log message identifies the location in the source code at which the
@@ -80,4 +82,11 @@ extern const struct __sourceloc __whence; // see above
 #define __NOWHENCE__        ((struct __sourceloc){ .file = "", .line = 0, .function = NULL })
 #define __WHENCE__          (__whence.file ? __whence : __HERE__)
 
+void xprint_sourceloc(XPRINTF, struct __sourceloc);
+
+#define alloca_str_sourceloc(s) (sourceloc_tostr(alloca(sourceloc_tostr_len(s) + 1), (s)))
+
+extern char *sourceloc_tostr(char *dstStr, ssize_t dstBufSiz, struct __sourceloc);
+extern size_t sourceloc_tostr_len(struct __sourceloc);
+
 #endif // __SERVAL_DNA__WHENCE_H