tree-wide: do not compile deprecated functions with hard deprecation

When compiling libgit2 with -DDEPRECATE_HARD, we add a preprocessor
definition `GIT_DEPRECATE_HARD` which causes the "git2/deprecated.h"
header to be empty. As a result, no function declarations are made
available to callers, but the implementations are still available to
link against. This has the problem that function declarations also
aren't visible to the implementations, meaning that the symbol's
visibility will not be set up correctly. As a result, the resulting
library may not expose those deprecated symbols at all on some platforms
and thus cause linking errors.

Fix the issue by conditionally compiling deprecated functions, only.
While it becomes impossible to link against such a library in case one
uses deprecated functions, distributors of libgit2 aren't expected to
pass -DDEPRECATE_HARD anyway. Instead, users of libgit2 should manually
define GIT_DEPRECATE_HARD to hide deprecated functions. Using "real"
hard deprecation still makes sense in the context of CI to test we don't
use deprecated symbols ourselves and in case a dependant uses libgit2 in
a vendored way and knows it won't ever use any of the deprecated symbols
anyway.

31 files changed, 79 insertions, 6 deletions

diff --git a/src/blame.c b/src/blame.c
index 23c21027a..1046dab55 100644
--- a/src/blame.c
+++ b/src/blame.c
@@ -538,7 +538,9 @@ int git_blame_options_init(git_blame_options *opts, unsigned int version)
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_blame_init_options(git_blame_options *opts, unsigned int version)
 {
 	return git_blame_options_init(opts, version);
 }
+#endif
diff --git a/src/blob.c b/src/blob.c
index 5e734e2c1..da4e6ffa5 100644
--- a/src/blob.c
+++ b/src/blob.c
@@ -445,6 +445,7 @@ int git_blob_filter(
 
 /* Deprecated functions */
 
+#ifndef GIT_DEPRECATE_HARD
 int git_blob_create_frombuffer(
 	git_oid *id, git_repository *repo, const void *buffer, size_t len)
 {
@@ -491,3 +492,4 @@ int git_blob_filtered_content(
 
 	return git_blob_filter(out, blob, path, &opts);
 }
+#endif
diff --git a/src/buffer.c b/src/buffer.c
index 328fdfe7f..3ee2775b1 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -133,10 +133,12 @@ void git_buf_dispose(git_buf *buf)
 	git_buf_init(buf, 0);
 }
 
+#ifndef GIT_DEPRECATE_HARD
 void git_buf_free(git_buf *buf)
 {
 	git_buf_dispose(buf);
 }
+#endif
 
 void git_buf_sanitize(git_buf *buf)
 {
diff --git a/src/checkout.c b/src/checkout.c
index 44a867153..b18e8d9e9 100644
--- a/src/checkout.c
+++ b/src/checkout.c
@@ -2820,7 +2820,9 @@ int git_checkout_options_init(git_checkout_options *opts, unsigned int version)
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_checkout_init_options(git_checkout_options *opts, unsigned int version)
 {
 	return git_checkout_options_init(opts, version);
 }
+#endif
diff --git a/src/cherrypick.c b/src/cherrypick.c
index 640d11a7b..103897aae 100644
--- a/src/cherrypick.c
+++ b/src/cherrypick.c
@@ -229,8 +229,10 @@ int git_cherrypick_options_init(
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_cherrypick_init_options(
 	git_cherrypick_options *opts, unsigned int version)
 {
 	return git_cherrypick_options_init(opts, version);
 }
+#endif
diff --git a/src/clone.c b/src/clone.c
index 3d749c32f..8ca6cea1d 100644
--- a/src/clone.c
+++ b/src/clone.c
@@ -479,10 +479,12 @@ int git_clone_options_init(git_clone_options *opts, unsigned int version)
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_clone_init_options(git_clone_options *opts, unsigned int version)
 {
 	return git_clone_options_init(opts, version);
 }
+#endif
 
 static bool can_link(const char *src, const char *dst, int link)
 {
diff --git a/src/describe.c b/src/describe.c
index 42e5848c2..c8a175214 100644
--- a/src/describe.c
+++ b/src/describe.c
@@ -876,10 +876,12 @@ int git_describe_options_init(git_describe_options *opts, unsigned int version)
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_describe_init_options(git_describe_options *opts, unsigned int version)
 {
 	return git_describe_options_init(opts, version);
 }
+#endif
 
 int git_describe_format_options_init(git_describe_format_options *opts, unsigned int version)
 {
@@ -888,7 +890,9 @@ int git_describe_format_options_init(git_describe_format_options *opts, unsigned
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_describe_init_format_options(git_describe_format_options *opts, unsigned int version)
 {
 	return git_describe_format_options_init(opts, version);
 }
+#endif
diff --git a/src/diff.c b/src/diff.c
index 9fd361343..3e52e3f18 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -352,10 +352,12 @@ int git_diff_options_init(git_diff_options *opts, unsigned int version)
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_diff_init_options(git_diff_options *opts, unsigned int version)
 {
 	return git_diff_options_init(opts, version);
 }
+#endif
 
 int git_diff_find_options_init(
 	git_diff_find_options *opts, unsigned int version)
@@ -365,11 +367,13 @@ int git_diff_find_options_init(
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_diff_find_init_options(
 	git_diff_find_options *opts, unsigned int version)
 {
 	return git_diff_find_options_init(opts, version);
 }
+#endif
 
 int git_diff_format_email_options_init(
 	git_diff_format_email_options *opts, unsigned int version)
@@ -380,11 +384,13 @@ int git_diff_format_email_options_init(
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_diff_format_email_init_options(
 	git_diff_format_email_options *opts, unsigned int version)
 {
 	return git_diff_format_email_options_init(opts, version);
 }
+#endif
 
 static int flush_hunk(git_oid *result, git_hash_ctx *ctx)
 {
diff --git a/src/errors.c b/src/errors.c
index b34aa3abb..8570226b4 100644
--- a/src/errors.c
+++ b/src/errors.c
@@ -210,6 +210,7 @@ void git_error_system_set(int code)
 
 /* Deprecated error values and functions */
 
+#ifndef GIT_DEPRECATE_HARD
 const git_error *giterr_last(void)
 {
 	return git_error_last();
@@ -229,3 +230,4 @@ void giterr_set_oom(void)
 {
 	git_error_set_oom();
 }
+#endif
diff --git a/src/fetch.c b/src/fetch.c
index f2f313192..f4a4c9f81 100644
--- a/src/fetch.c
+++ b/src/fetch.c
@@ -155,7 +155,9 @@ int git_fetch_options_init(git_fetch_options *opts, unsigned int version)
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_fetch_init_options(git_fetch_options *opts, unsigned int version)
 {
 	return git_fetch_options_init(opts, version);
 }
+#endif
diff --git a/src/index.c b/src/index.c
index 774321d90..361288b8d 100644
--- a/src/index.c
+++ b/src/index.c
@@ -3717,9 +3717,11 @@ void git_indexwriter_cleanup(git_indexwriter *writer)
 
 /* Deprecated functions */
 
+#ifndef GIT_DEPRECATE_HARD
 int git_index_add_frombuffer(
     git_index *index, const git_index_entry *source_entry,
     const void *buffer, size_t len)
 {
 	return git_index_add_from_buffer(index, source_entry, buffer, len);
 }
+#endif
diff --git a/src/indexer.c b/src/indexer.c
index 8dc6c7a7f..412dfc92d 100644
--- a/src/indexer.c
+++ b/src/indexer.c
@@ -123,10 +123,12 @@ int git_indexer_options_init(git_indexer_options *opts, unsigned int version)
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_indexer_init_options(git_indexer_options *opts, unsigned int version)
 {
 	return git_indexer_options_init(opts, version);
 }
+#endif
 
 int git_indexer_new(
 		git_indexer **out,
diff --git a/src/merge.c b/src/merge.c
index 652b7ea6e..2f6bf6fe7 100644
--- a/src/merge.c
+++ b/src/merge.c
@@ -3351,10 +3351,12 @@ int git_merge_options_init(git_merge_options *opts, unsigned int version)
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_merge_init_options(git_merge_options *opts, unsigned int version)
 {
 	return git_merge_options_init(opts, version);
 }
+#endif
 
 int git_merge_file_input_init(git_merge_file_input *input, unsigned int version)
 {
@@ -3363,10 +3365,12 @@ int git_merge_file_input_init(git_merge_file_input *input, unsigned int version)
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_merge_file_init_input(git_merge_file_input *input, unsigned int version)
 {
 	return git_merge_file_input_init(input, version);
 }
+#endif
 
 int git_merge_file_options_init(
 	git_merge_file_options *opts, unsigned int version)
@@ -3376,8 +3380,10 @@ int git_merge_file_options_init(
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_merge_file_init_options(
 	git_merge_file_options *opts, unsigned int version)
 {
 	return git_merge_file_options_init(opts, version);
 }
+#endif
diff --git a/src/odb.c b/src/odb.c
index 68d9a9a3f..90565b75b 100644
--- a/src/odb.c
+++ b/src/odb.c
@@ -1510,10 +1510,12 @@ void *git_odb_backend_data_alloc(git_odb_backend *backend, size_t len)
 	return git__malloc(len);
 }
 
+#ifndef GIT_DEPRECATE_HARD
 void *git_odb_backend_malloc(git_odb_backend *backend, size_t len)
 {
 	return git_odb_backend_data_alloc(backend, len);
 }
+#endif
 
 void git_odb_backend_data_free(git_odb_backend *backend, void *data)
 {
diff --git a/src/oid.c b/src/oid.c
index 641956652..7831aca89 100644
--- a/src/oid.c
+++ b/src/oid.c
@@ -253,10 +253,12 @@ int git_oid_is_zero(const git_oid *oid_a)
 	return 1;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_oid_iszero(const git_oid *oid_a)
 {
 	return git_oid_is_zero(oid_a);
 }
+#endif
 
 typedef short node_index;
 
diff --git a/src/proxy.c b/src/proxy.c
index 367c4b1f7..78a4c5535 100644
--- a/src/proxy.c
+++ b/src/proxy.c
@@ -16,10 +16,12 @@ int git_proxy_options_init(git_proxy_options *opts, unsigned int version)
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_proxy_init_options(git_proxy_options *opts, unsigned int version)
 {
 	return git_proxy_options_init(opts, version);
 }
+#endif
 
 int git_proxy_options_dup(git_proxy_options *tgt, const git_proxy_options *src)
 {
diff --git a/src/push.c b/src/push.c
index 34867c2e4..b724188f9 100644
--- a/src/push.c
+++ b/src/push.c
@@ -555,7 +555,9 @@ int git_push_options_init(git_push_options *opts, unsigned int version)
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_push_init_options(git_push_options *opts, unsigned int version)
 {
 	return git_push_options_init(opts, version);
 }
+#endif
diff --git a/src/rebase.c b/src/rebase.c
index 0a38807a7..7c6561195 100644
--- a/src/rebase.c
+++ b/src/rebase.c
@@ -501,10 +501,12 @@ int git_rebase_options_init(git_rebase_options *opts, unsigned int version)
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_rebase_init_options(git_rebase_options *opts, unsigned int version)
 {
 	return git_rebase_options_init(opts, version);
 }
+#endif
 
 static int rebase_ensure_not_in_progress(git_repository *repo)
 {
diff --git a/src/remote.c b/src/remote.c
index 78e056a9d..23054c83b 100644
--- a/src/remote.c
+++ b/src/remote.c
@@ -195,10 +195,12 @@ int git_remote_create_options_init(git_remote_create_options *opts, unsigned int
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_remote_create_init_options(git_remote_create_options *opts, unsigned int version)
 {
 	return git_remote_create_options_init(opts, version);
 }
+#endif
 
 int git_remote_create_with_opts(git_remote **out, const char *url, const git_remote_create_options *opts)
 {
diff --git a/src/repository.c b/src/repository.c
index 580615577..5e818fb82 100644
--- a/src/repository.c
+++ b/src/repository.c
@@ -2928,11 +2928,13 @@ int git_repository_init_options_init(
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_repository_init_init_options(
 	git_repository_init_options *opts, unsigned int version)
 {
 	return git_repository_init_options_init(opts, version);
 }
+#endif
 
 int git_repository_ident(const char **name, const char **email, const git_repository *repo)
 {
diff --git a/src/revert.c b/src/revert.c
index b41a2a131..b84bc7d79 100644
--- a/src/revert.c
+++ b/src/revert.c
@@ -231,7 +231,9 @@ int git_revert_options_init(git_revert_options *opts, unsigned int version)
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_revert_init_options(git_revert_options *opts, unsigned int version)
 {
 	return git_revert_options_init(opts, version);
 }
+#endif
diff --git a/src/stash.c b/src/stash.c
index 790f56fdd..0d5dc4351 100644
--- a/src/stash.c
+++ b/src/stash.c
@@ -776,10 +776,12 @@ int git_stash_apply_options_init(git_stash_apply_options *opts, unsigned int ver
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_stash_apply_init_options(git_stash_apply_options *opts, unsigned int version)
 {
 	return git_stash_apply_options_init(opts, version);
 }
+#endif
 
 #define NOTIFY_PROGRESS(opts, progress_type)				\
 	do {								\
diff --git a/src/status.c b/src/status.c
index 6a1284415..eca1f4912 100644
--- a/src/status.c
+++ b/src/status.c
@@ -548,10 +548,12 @@ int git_status_options_init(git_status_options *opts, unsigned int version)
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_status_init_options(git_status_options *opts, unsigned int version)
 {
 	return git_status_options_init(opts, version);
 }
+#endif
 
 int git_status_list_get_perfdata(
 	git_diff_perfdata *out, const git_status_list *status)
diff --git a/src/strarray.c b/src/strarray.c
index 7ad413404..54fe9fbfb 100644
--- a/src/strarray.c
+++ b/src/strarray.c
@@ -55,7 +55,9 @@ void git_strarray_dispose(git_strarray *array)
 	memset(array, 0, sizeof(*array));
 }
 
+#ifndef GIT_DEPRECATE_HARD
 void git_strarray_free(git_strarray *array)
 {
 	git_strarray_dispose(array);
 }
+#endif
diff --git a/src/streams/registry.c b/src/streams/registry.c
index a5fa84931..284431207 100644
--- a/src/streams/registry.c
+++ b/src/streams/registry.c
@@ -101,7 +101,7 @@ int git_stream_register(git_stream_t type, git_stream_registration *registration
 	return 0;
 }
 
-
+#ifndef GIT_DEPRECATE_HARD
 int git_stream_register_tls(
 	int GIT_CALLBACK(ctor)(git_stream **out, const char *host, const char *port))
 {
@@ -117,3 +117,4 @@ int git_stream_register_tls(
 		return git_stream_register(GIT_STREAM_TLS, NULL);
 	}
 }
+#endif
diff --git a/src/submodule.c b/src/submodule.c
index 7ae78c181..c32b9770a 100644
--- a/src/submodule.c
+++ b/src/submodule.c
@@ -1240,10 +1240,12 @@ int git_submodule_update_options_init(git_submodule_update_options *opts, unsign
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_submodule_update_init_options(git_submodule_update_options *opts, unsigned int version)
 {
 	return git_submodule_update_options_init(opts, version);
 }
+#endif
 
 int git_submodule_update(git_submodule *sm, int init, git_submodule_update_options *_update_options)
 {
diff --git a/src/tag.c b/src/tag.c
index a7a005ca1..037dc6664 100644
--- a/src/tag.c
+++ b/src/tag.c
@@ -524,7 +524,9 @@ int git_tag_peel(git_object **tag_target, const git_tag *tag)
 
 /* Deprecated Functions */
 
+#ifndef GIT_DEPRECATE_HARD
 int git_tag_create_frombuffer(git_oid *oid, git_repository *repo, const char *buffer, int allow_ref_overwrite)
 {
 	return git_tag_create_from_buffer(oid, repo, buffer, allow_ref_overwrite);
 }
+#endif
diff --git a/src/transports/credential.c b/src/transports/credential.c
index 0cf50a029..7b2836445 100644
--- a/src/transports/credential.c
+++ b/src/transports/credential.c
@@ -391,6 +391,7 @@ void git_credential_free(git_credential *cred)
 
 /* Deprecated credential functions */
 
+#ifndef GIT_DEPRECATE_HARD
 int git_cred_has_username(git_credential *cred)
 {
 	return git_credential_has_username(cred);
@@ -474,3 +475,4 @@ void git_cred_free(git_credential *cred)
 {
 	git_credential_free(cred);
 }
+#endif
diff --git a/src/transports/credential_helpers.c b/src/transports/credential_helpers.c
index 6b975e126..6d34a4e97 100644
--- a/src/transports/credential_helpers.c
+++ b/src/transports/credential_helpers.c
@@ -54,6 +54,7 @@ int git_credential_userpass(
 
 /* Deprecated credential functions */
 
+#ifndef GIT_DEPRECATE_HARD
 int git_cred_userpass(
 	git_credential **out,
 	const char *url,
@@ -64,3 +65,4 @@ int git_cred_userpass(
 	return git_credential_userpass(out, url, user_from_url,
 		allowed_types, payload);
 }
+#endif
diff --git a/src/worktree.c b/src/worktree.c
index 74b32f97c..fda9b0b71 100644
--- a/src/worktree.c
+++ b/src/worktree.c
@@ -271,11 +271,13 @@ int git_worktree_add_options_init(git_worktree_add_options *opts,
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_worktree_add_init_options(git_worktree_add_options *opts,
 	unsigned int version)
 {
 	return git_worktree_add_options_init(opts, version);
 }
+#endif
 
 int git_worktree_add(git_worktree **out, git_repository *repo,
 	const char *name, const char *worktree,
@@ -506,11 +508,13 @@ int git_worktree_prune_options_init(
 	return 0;
 }
 
+#ifndef GIT_DEPRECATE_HARD
 int git_worktree_prune_init_options(git_worktree_prune_options *opts,
 	unsigned int version)
 {
 	return git_worktree_prune_options_init(opts, version);
 }
+#endif
 
 int git_worktree_is_prunable(git_worktree *wt,
 	git_worktree_prune_options *opts)
diff --git a/tests/stream/deprecated.c b/tests/stream/deprecated.c
index 2c2bbfdc3..fecd1be03 100644
--- a/tests/stream/deprecated.c
+++ b/tests/stream/deprecated.c
@@ -1,19 +1,18 @@
-#undef GIT_DEPRECATE_HARD
-
 #include "clar_libgit2.h"
 #include "git2/sys/stream.h"
 #include "streams/tls.h"
 #include "streams/socket.h"
 #include "stream.h"
 
-static git_stream test_stream;
-static int ctor_called;
-
 void test_stream_deprecated__cleanup(void)
 {
 	cl_git_pass(git_stream_register(GIT_STREAM_TLS | GIT_STREAM_STANDARD, NULL));
 }
 
+#ifndef GIT_DEPRECATE_HARD
+static git_stream test_stream;
+static int ctor_called;
+
 static int test_stream_init(git_stream **out, const char *host, const char *port)
 {
 	GIT_UNUSED(host);
@@ -24,9 +23,11 @@ static int test_stream_init(git_stream **out, const char *host, const char *port
 
 	return 0;
 }
+#endif
 
 void test_stream_deprecated__register_tls(void)
 {
+#ifndef GIT_DEPRECATE_HARD
 	git_stream *stream;
 	int error;
 
@@ -55,4 +56,5 @@ void test_stream_deprecated__register_tls(void)
 	cl_assert(&test_stream != stream);
 
 	git_stream_free(stream);
+#endif
 }