Merge branch 'patch-3' into 'master'

Add some more functions (notably __cxa_thread_atexit_impl and realpath) and run clang-format



See merge request !3

CHANGELOG.rst

@@ -17,6 +17,17 @@ Build system
 
 * Allow building against libucontext.
 
+ctype
+-----
+
+* Add __ctype_b.
+
+
+cxx_thread
+----------
+
+* Add __cxa_thread_atexit_impl.
+
 
 math
 ----
@@ -24,6 +35,14 @@ math
 * Add most __*_finite functions, courtesy of Elizabeth Myers.
 
 
+readlink/realpath
+-----------------
+
+* Intercept realpath as well as readlink.
+* Report EIO on /proc read failure.
+* Report ENOSYS on dlsym failure.
+
+
 resolv
 ------
 
@@ -36,6 +55,12 @@ socket
 * Add __poll_chk
 
 
+stdlib
+------
+
+* Add secure_getenv alias to __secure_getenv.
+
+
 string
 ------
 
@@ -43,6 +68,11 @@ string
 * Add memfrob.
 * Add strfry.
 
+unistd
+------
+
+* Add __open_2/__open64_2.
+
 
 malloc
 ------

Makefile

 LIBGCOMPAT_INCLUDE = \
 	libgcompat/alias.h
 LIBGCOMPAT_SRC = \
+	libgcompat/ctype.c		\
+	libgcompat/cxx_thread.c		\
 	libgcompat/dlfcn.c		\
 	libgcompat/error.c		\
 	libgcompat/execinfo.c		\
@@ -14,6 +16,7 @@ LIBGCOMPAT_SRC = \
 	libgcompat/pthread.c		\
 	libgcompat/pwd.c		\
 	libgcompat/readlink.c		\
+	libgcompat/realpath.c		\
 	libgcompat/resolv.c		\
 	libgcompat/resource.c		\
 	libgcompat/setjmp.c		\

libgcompat/ctype.c

+const unsigned short int *__ctype_b;

libgcompat/cxx_thread.c

+#include <pthread.h> /* NULL, pthread_{key,once,{get,set}specific} */
+#include <stdlib.h>  /* malloc, free */
+
+#include "internal.h"
+
+struct dtor_node {
+	struct dtor_node *next;
+	void (*func)(void *);
+	void *obj;
+};
+
+static pthread_key_t key;
+static pthread_once_t once = PTHREAD_ONCE_INIT;
+
+static void run_dtors(void *head)
+{
+	struct dtor_node *next, *node = head;
+
+	while (node != NULL) {
+		next = node->next;
+		node->func(node->obj);
+		free(node);
+		node = next;
+	}
+}
+
+static void create_key(void)
+{
+	int res = pthread_key_create(&key, run_dtors);
+
+	GCOMPAT__assert_with_reason(res, "No key for thread_atexit list");
+}
+
+/**
+ * Register a destructor to run at thread exit.
+ *
+ * See
+ * https://sourceware.org/glibc/wiki/Destructor%20support%20for%20thread_local%20variables
+ */
+int __cxa_thread_atexit_impl(void (*func)(void *), void *obj, void *dso_symbol)
+{
+	struct dtor_node *node;
+
+	pthread_once(&once, create_key);
+
+	node = malloc(sizeof(*node));
+	GCOMPAT__assert_with_reason(node, "No memory for thread_atexit node");
+	node->next = pthread_getspecific(key);
+	node->func = func;
+	node->obj = obj;
+
+	int res = pthread_setspecific(key, node);
+	GCOMPAT__assert_with_reason(!res, "Cannot update thread_atexit list");
+
+	return 0;
+}

libgcompat/gnulib.c

 #include <sys/select.h>
 #include "internal.h"
 
-#define REASON_FD_SET_OVERFLOW										\
-	"Fault: Overflow in fd_set detected.\n"								\
-	"Description: This is caused by a programmer naively attempting to redefine FD_SETSIZE,\n"	\
-	"  which is not allowed on POSIX platforms.  The program must be either rebuilt\n"		\
-	"  with the correct FD_SETSIZE definition, or preferably rewritten to avoid use\n"		\
-	"  of select(2) in general.  See also: poll(2).\n"						\
+#define REASON_FD_SET_OVERFLOW                                                 \
+	"Fault: Overflow in fd_set detected.\n"                                \
+	"Description: This is caused by a programmer naively attempting to\n"  \
+	"  redefine FD_SETSIZE, which is not allowed on POSIX platforms.\n"    \
+	"  The program must either be rebuilt with the correct FD_SETSIZE\n"   \
+	"  definition, or else be rewritten to avoid use of select(2) in \n"   \
+	"  general.  See also: poll(2).\n"                                     \
 	"  libgcompat believes FD_SETSIZE to be %zu.\n"
 
 unsigned long __fdelt_chk(unsigned long size)
 {
-	GCOMPAT__assert_with_reason(size < FD_SETSIZE, REASON_FD_SET_OVERFLOW, FD_SETSIZE);
+	GCOMPAT__assert_with_reason(size < FD_SETSIZE, REASON_FD_SET_OVERFLOW,
+	                            FD_SETSIZE);
 	return size / (sizeof(unsigned long) << 3);
 }

libgcompat/internal.c

-#include <stdio.h>
 #include <stdarg.h>
+#include <stdio.h>
 #include <stdlib.h>
 
-
 void GCOMPAT__panic(const char *fmt, ...)
 {
 	va_list va;

libgcompat/math.c

-#define _GNU_SOURCE	/* Extra maths functions */
-#include <math.h>	/* Literally everything */
+#define _GNU_SOURCE /* Extra maths functions */
+#include <math.h>   /* Literally everything */
 
-#include "alias.h"	/* weak_alias */
-#include "internal.h"	/* GCOMPAT__assert_with_reason */
+#include "alias.h"    /* weak_alias */
+#include "internal.h" /* GCOMPAT__assert_with_reason */
 
 /**
  * Multiplies the first argument x by FLT_RADIX (probably 2) to the power of y.
@@ -14,7 +14,7 @@ long double scalbl(long double x, long double y)
 	 * 1) Good Enough(TM)
 	 * 2) scalbl is deprecated anyway
 	 * */
-	return scalblnl(x, (long int)y);
+	return scalblnl(x, (long int) y);
 }
 
 /*
@@ -144,7 +144,6 @@ int __isnan(double arg)
 }
 weak_alias(__isnan, isnan);
 
-
 /**
  * Test for a NaN.
  *
@@ -290,7 +289,6 @@ long double __asinl_finite(long double x)
 	return res;
 }
 
-
 /**
  * Returns the principal value of the arc tangent of x/y, expressed in radians.
  */
@@ -363,7 +361,6 @@ long double __atanhl_finite(long double x)
 	return res;
 }
 
-
 /**
  * Returns the hyperbolic cosine of x.
  */

libgcompat/readlink.c

 #include <dlfcn.h>
+#include <errno.h>
 #include <fcntl.h>
 #include <limits.h>
 #include <stddef.h>
@@ -18,6 +19,7 @@ ssize_t readlink(const char *path, char *buf, size_t len)
 	if (real_readlink == NULL) {
 		real_readlink = dlsym(RTLD_NEXT, "readlink");
 		if (real_readlink == NULL) {
+			errno = ENOSYS;
 			return -1;
 		}
 	}
@@ -78,6 +80,7 @@ ssize_t readlink(const char *path, char *buf, size_t len)
 		close(fd);
 	fail:
 		exe[0] = '\0';
+		errno = EIO;
 		return -1;
 	}
 

libgcompat/realpath.c

+#include <dlfcn.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#ifndef LINKER
+#error LINKER must be defined
+#endif
+
+static char *(*real_realpath)(const char *restrict, char *restrict);
+
+char *realpath(const char *restrict path, char *restrict resolved)
+{
+	if (real_realpath == NULL) {
+		real_realpath = dlsym(RTLD_NEXT, "realpath");
+		if (real_realpath == NULL) {
+			errno = ENOSYS;
+			return NULL;
+		}
+	}
+
+	if (!strcmp(path, "/proc/self/exe")) {
+		char *fixed = resolved;
+
+		if (fixed == NULL) {
+			fixed = malloc(PATH_MAX);
+			if (fixed == NULL) {
+				errno = ENOMEM;
+				return NULL;
+			}
+		}
+
+		/* If passed in, the buffer is at least PATH_MAX per POSIX. */
+		ssize_t written = readlink(path, fixed, PATH_MAX - 1);
+		if (written == -1) {
+			/* Free the buffer iff we allocated it. */
+			if (fixed != resolved)
+				free(fixed);
+			return NULL;
+		}
+		fixed[written] = '\0';
+
+		return fixed;
+	}
+
+	return real_realpath(path, resolved);
+}

libgcompat/resolv.c

@@ -42,7 +42,7 @@ int __res_nclose(res_state statp)
 weak_alias(__res_nclose, res_nclose);
 
 int __res_search(const char *dname, int class, int type, unsigned char *answer,
-		 int anslen)
+                 int anslen)
 {
 	return res_search(dname, class, type, answer, anslen);
 }

libgcompat/socket.c

 #include <assert.h>     /* assert */
+#include <poll.h>       /* poll, pollfd, nfds_t */
 #include <stddef.h>     /* NULL */
-#include <poll.h>	/* poll, pollfd, nfds_t */
 #include <sys/socket.h> /* recv, recvfrom */
 
 /**

libgcompat/stdlib.c

@@ -5,6 +5,8 @@
 #include <stdlib.h> /* getenv, realpath, strto* */
 #include <unistd.h> /* get*id */
 
+#include "alias.h"
+
 /**
  * Resolve a pathname, with buffer overflow checking.
  *
@@ -30,6 +32,7 @@ char *__secure_getenv(const char *name)
 
 	return getenv(name);
 }
+weak_alias(__secure_getenv, secure_getenv);
 
 /**
  * Underlying function for strtod.

libgcompat/string.c

@@ -2,10 +2,10 @@
 #include <assert.h> /* assert */
 #include <stddef.h> /* NULL, size_t */
 #include <stdint.h> /* SIZE_MAX */
-#include <string.h> /* memcpy, strcpy, strncat, strndup */
 #include <stdlib.h> /* rand_r */
-#include <unistd.h> /* getpid */
+#include <string.h> /* memcpy, strcpy, strncat, strndup */
 #include <time.h>   /* time */
+#include <unistd.h> /* getpid */
 
 #include "alias.h" /* weak_alias */
 
@@ -189,8 +189,7 @@ size_t __strcspn_c2(const char *str, int bad, int bad2)
 {
 	size_t length = 0;
 	const char *s = str;
-	while(*s != bad && *s != bad2 && *s != '\0')
-	{
+	while (*s != bad && *s != bad2 && *s != '\0') {
 		length++;
 		s++;
 	}
@@ -285,7 +284,7 @@ char *strfry(char *s)
 	if (!len)
 		return s;
 
-	seed += time(NULL) ^ getpid() ^ (uintptr_t)s;
+	seed += time(NULL) ^ getpid() ^ (uintptr_t) s;
 
 	for (i = 0; i < len - 1; ++i) {
 		j = rand_r(&seed) % (len - i) + i;

libgcompat/unistd.c

 #include <assert.h> /* assert */
+#include <fcntl.h>  /* O_CREAT */
 #include <limits.h> /* NGROUPS_MAX */
 #include <stddef.h> /* NULL, size_t */
 #include <unistd.h> /* confstr, getcwd, getgroups, ... */
@@ -90,6 +91,14 @@ pid_t __getpgid(pid_t pid)
 	return getpgid(pid);
 }
 
+int __open_2(const char *path, int oflag)
+{
+	assert(!(oflag & O_CREAT));
+
+	return open(path, oflag);
+}
+alias(__open_2, __open64_2);
+
 /**
  * Read from a file, with buffer overflow checking.
  *