1 files changed, 72 insertions, 0 deletions
diff --git a/src/libc-stdio.h b/src/libc-stdio.h
new file mode 100644
index 0000000..7f09c74
--- /dev/null
+++ b/src/libc-stdio.h
@@ -0,0 +1,72 @@
+#pragma once
+
+struct bionic___sFILE {
+#if defined(__LP64__)
+   char __private[152];
+#else
+   char __private[84];
+#endif
+} __attribute__((aligned(sizeof(void*))));
+
+// Bionic standard stream support pre-M Android
+// Post-M it's saner and they point to stdin/stdout/stderr symbols instead
+const struct bionic___sFILE bionic___sF[3] = {
+   {{ 's', 't', 'd', 'i', 'n' }},
+   {{ 's', 't', 'd', 'o', 'u', 't' }},
+   {{ 's', 't', 'd', 'e', 'r', 'r' }}
+};
+
+static inline FILE*
+bionic_file_to_glibc_file(FILE *f)
+{
+   // Can't compare just memory addresses because GNU libstdc++ copies the FILE struct...
+   // Maybe there could be a cleaner solution, this may in practice break if standard streams
+   // are opened with different flags in C++.
+   if (memcmp(f, "stdin", sizeof("stdin")))
+      return stdin;
+   else if (memcmp(f, "stdout", sizeof("stdout")))
+      return stdout;
+   else if (memcmp(f, "stderr", sizeof("stderr")))
+      return stderr;
+   return f;
+}
+
+FILE*
+bionic_freopen(const char *filename, const char *modes, FILE *stream)
+{
+   return freopen(filename, modes, bionic_file_to_glibc_file(stream));
+}
+
+int
+bionic_fclose(FILE *stream)
+{
+   return fclose(bionic_file_to_glibc_file(stream));
+}
+
+size_t
+bionic_fread(void *ptr, size_t size, size_t nmemb, FILE *stream)
+{
+   char buf[256], fname[256] = {0};
+   stream = bionic_file_to_glibc_file(stream);
+   snprintf(buf, sizeof(buf), "/proc/self/fd/%d", fileno(stream));
+   readlink(buf, fname, sizeof(fname));
+   verbose("%s (%d)\n%p, %zu, %zu, %p", fname, fileno(stream), ptr, size, nmemb, (void*)stream);
+   return fread(ptr, size, nmemb, stream);
+}
+
+size_t
+bionic_fwrite(void *ptr, size_t size, size_t nmemb, FILE *stream)
+{
+   char buf[256], fname[256] = {0};
+   stream = bionic_file_to_glibc_file(stream);
+   snprintf(buf, sizeof(buf), "/proc/self/fd/%d", fileno(stream));
+   readlink(buf, fname, sizeof(fname));
+   verbose("%s (%d)\n%p, %zu, %zu, %p", fname, fileno(stream), ptr, size, nmemb, (void*)stream);
+   return fwrite(ptr, size, nmemb, stream);
+}
+
+int
+bionic_fflush(FILE *stream)
+{
+   return fflush(bionic_file_to_glibc_file(stream));
+}