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, 118 insertions, 6 deletions

diff --git a/libgcompat/stdlib.c b/libgcompat/stdlib.c
index 30c904e..a08f914 100644
--- a/libgcompat/stdlib.c
+++ b/libgcompat/stdlib.c
@@ -1,14 +1,126 @@
-#include <assert.h>	// assert
-#include <stdlib.h>	// strtod
+#include <assert.h> /* assert */
+#include <limits.h> /* PATH_MAX */
+#include <locale.h> /* locale_t */
+#include <stddef.h> /* NULL, size_t */
+#include <stdlib.h> /* getenv, realpath, strto* */
+#include <unistd.h> /* get*id */
 
-char *__realpath_chk(const char *path, char *resolved_path)
+/**
+ * Resolve a pathname, with buffer overflow checking.
+ *
+ * LSB 5.0: LSB-Core-generic/baselib---realpath-chk-1.html
+ */
+char *__realpath_chk(const char *path, char *resolved_path, size_t resolved_len)
 {
 	assert(path != NULL);
+	assert(resolved_path != NULL);
+	assert(resolved_len >= PATH_MAX);
+
 	return realpath(path, resolved_path);
 }
 
-double __strtod_internal(const char *__nptr, char **__endptr, int __group)
+/**
+ * Get an environment variable.
+ */
+char *__secure_getenv(const char *name)
+{
+	if (geteuid() != getuid() || getegid() != getgid()) {
+		return NULL;
+	}
+
+	return getenv(name);
+}
+
+/**
+ * Underlying function for strtod.
+ *
+ * "__group shall be 0 or the behavior of __strtod_internal() is undefined."
+ *
+ * LSB 5.0: LSB-Core-generic/baselib---strtod-internal-1.html
+ */
+double __strtod_internal(const char *nptr, char **endptr, int group)
+{
+	assert(group == 0);
+
+	return strtod(nptr, endptr);
+}
+
+/**
+ * Underlying function for strtof.
+ *
+ * "__group shall be 0 or the behavior of __strtof_internal() is undefined."
+ *
+ * LSB 5.0: LSB-Core-generic/baselib---strtof-internal.html
+ */
+float __strtof_internal(const char *nptr, char **endptr, int group)
+{
+	assert(group == 0);
+
+	return strtof(nptr, endptr);
+}
+
+/**
+ * Underlying function for strtol.
+ */
+long __strtol_internal(const char *nptr, char **endptr, int base, int group)
+{
+	assert(group == 0);
+
+	return strtol(nptr, endptr, base);
+}
+
+/**
+ * Underlying function for strtold.
+ *
+ * "__group shall be 0 or the behavior of __strtold_internal() is undefined."
+ *
+ * LSB 5.0: LSB-Core-generic/baselib---strtold-internal-1.html
+ */
+long double __strtold_internal(const char *nptr, char **endptr, int group)
+{
+	assert(group == 0);
+
+	return strtold(nptr, endptr);
+}
+
+/**
+ * Convert string value to a long long integer.
+ *
+ * Some day, when musl supports LC_NUMERIC, we can probably remove this.
+ */
+long long int strtoll_l(const char *nptr, char **endptr, int base,
+                        locale_t locale)
+{
+	return strtoll(nptr, endptr, base);
+}
+
+/**
+ * Convert string value to a long long integer.
+ *
+ * LSB 5.0: LSB-Core-generic/baselib-strtoq-3.html
+ */
+long long strtoq(const char *nptr, char **endptr, int base)
+{
+	return strtoll(nptr, endptr, base);
+}
+
+/**
+ * Convert a string to an unsigned long long.
+ *
+ * Some day, when musl supports LC_NUMERIC, we can probably remove this.
+ */
+unsigned long long int strtoull_l(const char *nptr, char **endptr, int base,
+                                  locale_t locale)
+{
+	return strtoull(nptr, endptr, base);
+}
+
+/**
+ * Convert a string to an unsigned long long.
+ *
+ * LSB 5.0: LSB-Core-generic/baselib-strtouq-3.html
+ */
+unsigned long long strtouq(const char *nptr, char **endptr, int base)
 {
-	assert(__group == 0);
-	return strtod(__nptr, __endptr);
+	return strtoull(nptr, endptr, base);
 }