# HG changeset patch
# User David A. Holland
# Date 1434095976 14400
# Node ID 16b4451e34b8aad10e9eaaf294dacaaeea0c4043
# Parent  d359d9b86327c059c2a98c7f690f6ddfcec0f385
Add the ability to output line numbers, sort of.
It is enabled with the intentionally undocumented -p option (similar
to -P but reversed sense) and it might be vaguely useful but only
prints the line number when the file changes and may not get the line
numbers right.

diff -r d359d9b86327 -r 16b4451e34b8 TODO
--- a/TODO	Fri Jun 12 03:35:01 2015 -0400
+++ b/TODO	Fri Jun 12 03:59:36 2015 -0400
@@ -33,3 +33,5 @@
 	  twice, once when the macro is defined and again when it's
 	  expanded. Note that gcc's cpp -traditional is getting t37
 	  wrong, and it gets t36 wrong with -C.
+	- remove the intentionally undocumented -p option and generate
+	  proper linenumber output.
diff -r d359d9b86327 -r 16b4451e34b8 main.c
--- a/main.c	Fri Jun 12 03:35:01 2015 -0400
+++ b/main.c	Fri Jun 12 03:59:36 2015 -0400
@@ -55,6 +55,7 @@
 
 	.do_output = true,
 	.output_linenumbers = true,
+	.output_cheaplinenumbers = false,
 	.output_retain_comments = false,
 	.output_file = NULL,
 
@@ -781,6 +782,7 @@
 	{ "MG",                         &mode.depend_assume_generated, true },
 	{ "MP",                         &mode.depend_issue_fakerules,  true },
 	{ "P",                          &mode.output_linenumbers,      false },
+	{ "p",                          &mode.output_cheaplinenumbers, true },
 	{ "Wcomment",                   &warns.nestcomment,    true },
 	{ "Wendif-labels",              &warns.endiflabels,    true },
 	{ "Werror",                     &mode.werror,          true },
diff -r d359d9b86327 -r 16b4451e34b8 mode.h
--- a/mode.h	Fri Jun 12 03:35:01 2015 -0400
+++ b/mode.h	Fri Jun 12 03:59:36 2015 -0400
@@ -37,6 +37,7 @@
 	bool do_stddef;
 	bool do_output;
 	bool output_linenumbers;
+	bool output_cheaplinenumbers;
 	bool output_retain_comments;
 	const char *output_file;
 	bool do_depend;
diff -r d359d9b86327 -r 16b4451e34b8 output.c
--- a/output.c	Fri Jun 12 03:35:01 2015 -0400
+++ b/output.c	Fri Jun 12 03:59:36 2015 -0400
@@ -27,6 +27,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <stdio.h>
 #include <string.h>
 #include <unistd.h>
 #include <fcntl.h>
@@ -172,6 +173,15 @@
 		linebuf = dorealloc(linebuf, oldmax, linebufmax);
 	}
 	if (linebufpos == 0) {
+		if (!place_samefile(&linebufplace, p)) {
+			if (mode.output_cheaplinenumbers) {
+				char str[256];
+
+				snprintf(str, sizeof(str), "# %u \"%s\"\n",
+					 p->line, place_getname(p));
+				dowrite(str, strlen(str));
+			}
+		}
 		linebufplace = *p;
 	}
 	memcpy(linebuf + linebufpos, buf, len);
diff -r d359d9b86327 -r 16b4451e34b8 place.c
--- a/place.c	Fri Jun 12 03:35:01 2015 -0400
+++ b/place.c	Fri Jun 12 03:59:36 2015 -0400
@@ -102,22 +102,6 @@
 }
 
 static
-bool
-place_eq(const struct place *a, const struct place *b)
-{
-	if (a->type != b->type) {
-		return false;
-	}
-	if (a->file != b->file) {
-		return false;
-	}
-	if (a->line != b->line || a->column != b->column) {
-		return false;
-	}
-	return true;
-}
-
-static
 struct placefile *
 placefile_find(const struct place *incfrom, const char *name)
 {
@@ -219,6 +203,30 @@
 	return NULL;
 }
 
+bool
+place_samefile(const struct place *a, const struct place *b)
+{
+	if (a->type != b->type) {
+		return false;
+	}
+	if (a->file != b->file) {
+		return false;
+	}
+	return true;
+}
+
+bool
+place_eq(const struct place *a, const struct place *b)
+{
+	if (!place_samefile(a, b)) {
+		return false;
+	}
+	if (a->line != b->line || a->column != b->column) {
+		return false;
+	}
+	return true;
+}
+
 static
 void
 place_printfrom(const struct place *p)
diff -r d359d9b86327 -r 16b4451e34b8 place.h
--- a/place.h	Fri Jun 12 03:35:01 2015 -0400
+++ b/place.h	Fri Jun 12 03:59:36 2015 -0400
@@ -55,6 +55,8 @@
 
 const char *place_getname(const struct place *);
 const char *place_getparsedir(const struct place *incplace);
+bool place_eq(const struct place *, const struct place *);
+bool place_samefile(const struct place *, const struct place *);
 
 void place_changefile(struct place *p, const char *name);