[PATCH 3/7] grep: typesafe versions of grep_source_init

[Jonathan Tan <jonathantanmy@google.com>]

grep_source_init() can create "struct grep_source" objects and,
depending on the value of the type passed, some void-pointer parameters have
different meanings. Because one of these types (GREP_SOURCE_OID) will
require an additional parameter in a subsequent patch, take the
opportunity to increase clarity and type safety by replacing this
function with individual functions for each type.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
---
 builtin/grep.c |  4 ++--
 grep.c         | 43 +++++++++++++++++++++++++++----------------
 grep.h         |  8 +++++---
 3 files changed, 34 insertions(+), 21 deletions(-)

diff --git a/builtin/grep.c b/builtin/grep.c
index 87bcb934a2..e454335e9d 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -333,7 +333,7 @@ static int grep_oid(struct grep_opt *opt, const struct object_id *oid,
 	struct grep_source gs;
 
 	grep_source_name(opt, filename, tree_name_len, &pathbuf);
-	grep_source_init(&gs, GREP_SOURCE_OID, pathbuf.buf, path, oid);
+	grep_source_init_oid(&gs, pathbuf.buf, path, oid);
 	strbuf_release(&pathbuf);
 
 	if (num_threads > 1) {
@@ -359,7 +359,7 @@ static int grep_file(struct grep_opt *opt, const char *filename)
 	struct grep_source gs;
 
 	grep_source_name(opt, filename, 0, &buf);
-	grep_source_init(&gs, GREP_SOURCE_FILE, buf.buf, filename, filename);
+	grep_source_init_file(&gs, buf.buf, filename);
 	strbuf_release(&buf);
 
 	if (num_threads > 1) {
diff --git a/grep.c b/grep.c
index 424a39591b..ba3711dc56 100644
--- a/grep.c
+++ b/grep.c
@@ -1830,7 +1830,7 @@ int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size)
 	struct grep_source gs;
 	int r;
 
-	grep_source_init(&gs, GREP_SOURCE_BUF, NULL, NULL, NULL);
+	grep_source_init_buf(&gs);
 	gs.buf = buf;
 	gs.size = size;
 
@@ -1840,28 +1840,39 @@ int grep_buffer(struct grep_opt *opt, char *buf, unsigned long size)
 	return r;
 }
 
-void grep_source_init(struct grep_source *gs, enum grep_source_type type,
-		      const char *name, const char *path,
-		      const void *identifier)
+void grep_source_init_file(struct grep_source *gs, const char *name,
+			   const char *path)
 {
-	gs->type = type;
+	gs->type = GREP_SOURCE_FILE;
 	gs->name = xstrdup_or_null(name);
 	gs->path = xstrdup_or_null(path);
 	gs->buf = NULL;
 	gs->size = 0;
 	gs->driver = NULL;
+	gs->identifier = xstrdup(path);
+}
 
-	switch (type) {
-	case GREP_SOURCE_FILE:
-		gs->identifier = xstrdup(identifier);
-		break;
-	case GREP_SOURCE_OID:
-		gs->identifier = oiddup(identifier);
-		break;
-	case GREP_SOURCE_BUF:
-		gs->identifier = NULL;
-		break;
-	}
+void grep_source_init_oid(struct grep_source *gs, const char *name,
+			  const char *path, const struct object_id *oid)
+{
+	gs->type = GREP_SOURCE_OID;
+	gs->name = xstrdup_or_null(name);
+	gs->path = xstrdup_or_null(path);
+	gs->buf = NULL;
+	gs->size = 0;
+	gs->driver = NULL;
+	gs->identifier = oiddup(oid);
+}
+
+void grep_source_init_buf(struct grep_source *gs)
+{
+	gs->type = GREP_SOURCE_BUF;
+	gs->name = NULL;
+	gs->path = NULL;
+	gs->buf = NULL;
+	gs->size = 0;
+	gs->driver = NULL;
+	gs->identifier = NULL;
 }
 
 void grep_source_clear(struct grep_source *gs)
diff --git a/grep.h b/grep.h
index 72f82b1e30..f4a3090f1c 100644
--- a/grep.h
+++ b/grep.h
@@ -195,9 +195,11 @@ struct grep_source {
 	struct userdiff_driver *driver;
 };
 
-void grep_source_init(struct grep_source *gs, enum grep_source_type type,
-		      const char *name, const char *path,
-		      const void *identifier);
+void grep_source_init_file(struct grep_source *gs, const char *name,
+			   const char *path);
+void grep_source_init_oid(struct grep_source *gs, const char *name,
+			  const char *path, const struct object_id *oid);
+void grep_source_init_buf(struct grep_source *gs);
 void grep_source_clear_data(struct grep_source *gs);
 void grep_source_clear(struct grep_source *gs);
 void grep_source_load_driver(struct grep_source *gs,
-- 
2.33.0.rc1.237.g0d66db33f3-goog