Merge branch 'patch-1' into 'master'

Clean up everything and add lots of new functions

I hope everything here is okay. I fixed some bugs in existing functions (mostly wrong prototypes or off-by-one errors) and formatted everything to a consistent style. If you'd like me to adjust the style, that's no problem. It wasn't very consistent to start with (within the code, and compared to the documentation).

*I added specific notes you may want to comment on to some of the commit messages.*

Major features:
* Pass correct `argv[0]` in loader
* Intercept `readlink("/proc/self/exe")` to allow re-exec
* Add almost all reasonable-to-implement functions in LSB 5.0.0 core generic libc. Remaining functions are:
  - Impossible-to-implement: sigreturn
  - Not useful: reentrant random (`*rand48_r`, etc.), argz, envz, pmap, rpc (clnt_*, svc*, xdr*), bindresvport
  - Got tired of it: checked wchar
* Add additional functions used by android and its NDK tools (clang, cmake, lldb, ninja, etc.).

At this point, I am able to run Android Studio with the bundled prebuilt JDK, and compile, install, and run an android application (including one with native libraries) on a real device, with only a few minor issues:
* must export `LD_LIBRARY_PATH=/opt/android-studio/jre/jre/lib/amd64/server` because musl and glibc interpret the variable differently with regards to `dlopen`. This is something that has to be patched in musl builds of openjdk, so it's not a gcompat issue.
* ld.bfd fails to parse the argument `--sysroot=/path`, but can parse `--sysroot /path`. So there's some difference with `getopt_long_only` (or getopt in general). May be a bug, may be just an API difference. May be it can be patched up.
* LLDB fails to connect to the android phone for native debugging -- I haven't tried it on glibc yet, so it may not be a gcompat issue at all (may be a phone or the app issue).

I'd be happy to send some documentation later.

See merge request !1

1 files changed, 40 insertions, 0 deletions

diff --git a/libgcompat/wchar.c b/libgcompat/wchar.c
new file mode 100644
index 0000000..1ddaa1f
--- /dev/null
+++ b/libgcompat/wchar.c
@@ -0,0 +1,40 @@
+#include <assert.h> /* assert */
+#include <stdarg.h> /* va_list, va_start, va_end */
+#include <stddef.h> /* size_t */
+#include <wchar.h>  /* wchar_t, *wprintf */
+
+int __vswprintf_chk(wchar_t *s, size_t n, int flag, size_t slen,
+                    const wchar_t *format, va_list ap);
+
+/**
+ * Convert formatted wide-character output, with stack checking
+ *
+ * LSB 5.0: LSB-Core-generic/baselib---swprintf-chk-1.html
+ */
+int __swprintf_chk(wchar_t *s, size_t n, int flag, size_t slen,
+                   const wchar_t *format, ...)
+{
+	int ret;
+	va_list ap;
+
+	va_start(ap, format);
+	ret = __vswprintf_chk(s, n, flag, slen, format, ap);
+	va_end(ap);
+
+	return ret;
+}
+
+/**
+ * Convert formatted wide-character output, with stack checking
+ *
+ * LSB 5.0: LSB-Core-generic/baselib---vswprintf-chk-1.html
+ */
+int __vswprintf_chk(wchar_t *s, size_t n, int flag, size_t slen,
+                    const wchar_t *format, va_list ap)
+{
+	assert(s != NULL || n == 0);
+	assert(slen >= n);
+	assert(format != NULL);
+
+	return vswprintf(s, n, format, ap);
+}