runtime/cgo: deduplicate Android's fatalf

Most of the fatalf code is shared between Android and other Unix-like
platforms, but Android has some special handling for the case where the
fatalf is called from an .apk file.

Put the Android-specific code in the generic fatalf code, and implement
the Android-specific handling using a #ifdef guard.

Change-Id: Ic7a49792648260c83b213380b77c0c352e9486f0
Reviewed-on: https://go-review.googlesource.com/c/go/+/745604
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Auto-Submit: Quim Muntal <quimmuntal@gmail.com>

2 files changed, 14 insertions, 29 deletions

diff --git a/src/runtime/cgo/gcc_android.c b/src/runtime/cgo/gcc_android.c
index 7ea213599d..1373feb47a 100644
--- a/src/runtime/cgo/gcc_android.c
+++ b/src/runtime/cgo/gcc_android.c
@@ -2,36 +2,10 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-#include <stdarg.h>
-#include <android/log.h>
 #include <pthread.h>
 #include <dlfcn.h>
 #include "libcgo.h"
 
-void
-fatalf(const char* format, ...)
-{
-	va_list ap;
-
-	// Write to both stderr and logcat.
-	//
-	// When running from an .apk, /dev/stderr and /dev/stdout
-	// redirect to /dev/null. And when running a test binary
-	// via adb shell, it's easy to miss logcat.
-
-	fprintf(stderr, "runtime/cgo: ");
-	va_start(ap, format);
-	vfprintf(stderr, format, ap);
-	va_end(ap);
-	fprintf(stderr, "\n");
-
-	va_start(ap, format);
-	__android_log_vprint(ANDROID_LOG_FATAL, "runtime/cgo", format, ap);
-	va_end(ap);
-
-	abort();
-}
-
 // Truncated to a different magic value on 32-bit; that's ok.
 #define magic1 (0x23581321345589ULL)
 
diff --git a/src/runtime/cgo/gcc_fatalf.c b/src/runtime/cgo/gcc_fatalf.c
index 8d46e9187d..2754414fc1 100644
--- a/src/runtime/cgo/gcc_fatalf.c
+++ b/src/runtime/cgo/gcc_fatalf.c
@@ -2,11 +2,12 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build unix && !android
+//go:build unix
 
 #include <stdarg.h>
-#include <stdio.h>
-#include <stdlib.h>
+#ifdef __ANDROID__
+#include <android/log.h>
+#endif
 #include "libcgo.h"
 
 void
@@ -19,5 +20,15 @@ fatalf(const char* format, ...)
 	vfprintf(stderr, format, ap);
 	va_end(ap);
 	fprintf(stderr, "\n");
+
+#ifdef __ANDROID__
+	// When running from an Android .apk, /dev/stderr and /dev/stdout
+	// redirect to /dev/null. And when running a test binary
+	// via adb shell, it's easy to miss logcat. So write to both.
+	va_start(ap, format);
+	__android_log_vprint(ANDROID_LOG_FATAL, "runtime/cgo", format, ap);
+	va_end(ap);
+#endif
+
 	abort();
 }