[v3,05/15] Introduce a variant of the `warning()` function that takes a `FILE *`

Commit Message

Johannes Schindelin Feb. 2, 2022, 7:34 a.m. UTC

From: Johannes Schindelin <[e-mail]>

We are about to teach `diff_warn_rename_limit()` to write into a file
instead of `stderr`. That function wants to call `warning()` when
writing to `stderr`, though, allowing for the `warn_routine` to be
overridden.

Let's introduce a helper for that.

Note: Since there is currently no need to provide similar functions for
`error()` or `die()`, let alone for the `_errno` variants, we will leave
that to a date when the need for those should arise, if ever.

Signed-off-by: Johannes Schindelin <[e-mail]>
Signed-off-by: Elijah Newren <[e-mail]>
---
 git-compat-util.h |  1 +
 usage.c           | 14 ++++++++++++++
 2 files changed, 15 insertions(+)

Patch

diff --git a/git-compat-util.h b/git-compat-util.h
index d70ce142861..64ba60e5c71 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -475,6 +475,7 @@  int error(const char *err, ...) __attribute__((format (printf, 1, 2)));
 int error_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
 void warning(const char *err, ...) __attribute__((format (printf, 1, 2)));
 void warning_errno(const char *err, ...) __attribute__((format (printf, 1, 2)));
+void warning_fp(FILE *out, const char *warn, ...) __attribute__((format (printf, 2, 3)));
 
 #ifndef NO_OPENSSL
 #ifdef APPLE_COMMON_CRYPTO
diff --git a/usage.c b/usage.c
index c7d233b0de9..0bfd2c603c0 100644
--- a/usage.c
+++ b/usage.c
@@ -253,6 +253,20 @@  void warning(const char *warn, ...)
 	va_end(params);
 }
 
+void warning_fp(FILE *out, const char *warn, ...)
+{
+	va_list params;
+
+	va_start(params, warn);
+	if (out == stderr)
+		warn_routine(warn, params);
+	else {
+		vfprintf(out, warn, params);
+		fputc('\n', out);
+	}
+	va_end(params);
+}
+
 /* Only set this, ever, from t/helper/, when verifying that bugs are caught. */
 int BUG_exit_code;