Support input from file in oneliner executable

When no arguments are given, read input from stdin.  Any line that is
not indented relative to the start of the current test starts a new
test.  Comments start with # and "literate programming" mode is enabled
with the "-l" option and causes it ignore all lines not starting with
"> ".

Signed-off-by: Erik Boasson <eb@ilities.com>

src/core/ddsc/tests/oneliner.c

@@ -10,16 +10,104 @@
  * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
  */
 #include <stdio.h>
+#include <ctype.h>
 #include <stdlib.h>
+#include <string.h>
 
 #include "test_oneliner.h"
 
 int main (int argc, char **argv)
 {
+  bool litmode = false;
+  if (argc == 2 && strcmp (argv[1], "-l") == 0)
+  {
+    /* literate mode: test code lines start with "> ", everything
+       else is just gobbledygook to be ignored */
+    argc--;
+    argv++;
+    litmode = true;
+  }
+  if (argc > 1)
+  {
+    /* treat each argument as a test to execute */
     for (int i = 1; i < argc; i++)
     {
       if (test_oneliner (argv[i]) <= 0)
         return 1;
     }
+  }
+  else
+  {
+    /* read from stdin, # starts a comment, any line with an indent no greater
+       than the current test's indent starts a new test, i.e.,
+         # this is a comment
+         r wr w 1
+           take{(1,0,0)} r
+         r disp w 1 # this is also a comment
+           take{1} r
+       contains two tests */
+    struct oneliner_ctx ctx;
+    size_t test_indent = SIZE_MAX;
+    unsigned lineno = 0, test_begin = 0, test_end = 0;
+    char buf[4096];
+    while (fgets (buf, (int) sizeof (buf), stdin) != NULL)
+    {
+      lineno++;
+      if (buf[strlen (buf) - 1] != '\n' && !feof (stdin))
+      {
+        if (test_indent < SIZE_MAX)
+          (void) test_oneliner_fini (&ctx);
+        fprintf (stderr, "stdin:%u: line too long\n", lineno);
+        return 1;
+      }
+
+      if (litmode)
+      {
+        if (strncmp (buf, "> ", 2) != 0)
+          continue;
+        buf[0] = ' ';
+      }
+
+      char *cmt = strchr (buf, '#');
+      if (cmt)
+        *cmt = 0;
+
+      size_t indent = 0, idx = 0;
+      while (buf[idx] == ' ' || buf[idx] == '\t')
+        indent += (buf[idx++] == ' ' ? 1 : 8 - (indent % 8));
+      while (isspace ((unsigned char) buf[idx]))
+        idx++;
+      if (buf[idx] == 0)
+        continue;
+
+      if (indent <= test_indent)
+      {
+        if (test_indent < SIZE_MAX)
+        {
+          if (test_oneliner_fini (&ctx) <= 0)
+          {
+            fprintf (stderr, "stdin:%u-%u: FAIL: %s\n", test_begin, test_end, test_oneliner_message (&ctx));
+            return 1;
+          }
+          printf ("\n");
+        }
+        printf ("------ stdin:%u ------\n", lineno);
+        test_indent = indent;
+        test_begin = lineno;
+        test_oneliner_init (&ctx);
+      }
+
+      test_oneliner_step (&ctx, buf + idx);
+      test_end = lineno;
+    }
+
+    if (test_indent < SIZE_MAX && test_oneliner_fini (&ctx) <= 0)
+      fprintf (stderr, "stdin:%u-%u: FAIL: %s\n", test_begin, test_end, test_oneliner_message (&ctx));
+    if (ferror (stdin))
+    {
+      fprintf (stderr, "error reading stdin\n");
+      return 1;
+    }
+  }
   return 0;
 }