First primitive cut of ccanlint

[ccan] / ccan_tools / ccanlint / idempotent.c

diff --git a/ccan_tools/ccanlint/idempotent.c b/ccan_tools/ccanlint/idempotent.c
new file mode 100644 (file)
index 0000000..4456557
--- /dev/null
+++ b/ccan_tools/ccanlint/idempotent.c
@@ -0,0 +1,71 @@
+#include "ccanlint.h"
+#include <talloc/talloc.h>
+#include <string/string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <limits.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <err.h>
+#include <string.h>
+
+static const char explain[] 
+= "Headers usually start with the C preprocessor lines to prevent multiple\n"
+  "inclusions.  These look like the following:\n"
+  "#ifndef MY_HEADER_H\n"
+  "#define MY_HEADER_H\n"
+  "...\n"
+  "#endif /* MY_HEADER_H */\n";
+
+static char *report_idem(struct ccan_file *f, char *sofar)
+{
+       char **lines;
+       char *secondline;
+
+       lines = get_ccan_file_lines(f);
+       if (f->num_lines < 3)
+               /* FIXME: We assume small headers probably uninteresting. */
+               return NULL;
+
+       if (!strstarts(lines[0], "#ifndef "))
+               return talloc_asprintf_append(sofar,
+                       "%s:1:expect first line to be #ifndef.\n", f->name);
+
+       secondline = talloc_asprintf(f, "#define %s",
+                                    lines[0] + strlen("#ifndef "));
+       if (!streq(lines[1], secondline))
+               return talloc_asprintf_append(sofar,
+                       "%s:2:expect second line to be '%s'.\n",
+                       f->name, secondline);
+
+       return sofar;
+}
+
+static void *check_idempotent(struct manifest *m)
+{
+       struct ccan_file *f;
+       char *report = NULL;
+
+       list_for_each(&m->h_files, f, list)
+               report = report_idem(f, report);
+
+       return report;
+}
+
+static const char *describe_idempotent(struct manifest *m, void *check_result)
+{
+       return talloc_asprintf(check_result, 
+                              "Some headers not idempotent:\n"
+                              "%s\n%s", (char *)check_result,
+                              explain);
+}
+
+struct ccanlint idempotent = {
+       .name = "Headers are #ifndef/#define idempotent wrapped",
+       .total_score = 1,
+       .check = check_idempotent,
+       .describe = describe_idempotent,
+};