Add stub for getentropy

Example test case that fails with undefined reference to getentropy:

Testing g++.robertl/eb77.C,  -std=c++20
doing compile
Executing on host: /build/gcc-13-2709-g9ac9fde961f/bin/arm-none-eabi-g++  /build/src/gcc/gcc/testsuite/g++.old-deja/g++.robertl/eb77.C  -mthumb -march=armv6s-m -mcpu=cortex-m0 -mfloat-abi=soft -fdiagnostics-plain-output   -fmessage-length=0  -std=c++20 -pedantic-errors -Wno-long-long        -Wl,--start-group -lc -lm -Wl,--end-group --specs=nosys.specs -Wl,--allow-multiple-definition -Wl,-u,_isatty,-u,_fstat   -Wl,-wrap,exit -Wl,-wrap,_exit -Wl,-wrap,main -Wl,-wrap,abort -Wl,g++_tg.o -lm -o ./eb77.exe    (timeout = 800)
spawn -ignore SIGHUP /build/gcc-13-2709-g9ac9fde961f/bin/arm-none-eabi-g++ /build/src/gcc/gcc/testsuite/g++.old-deja/g++.robertl/eb77.C -mthumb -march=armv6s-m -mcpu=cortex-m0 -mfloat-abi=soft -fdiagnostics-plain-output -fmessage-length=0 -std=c++20 -pedantic-errors -Wno-long-long -Wl,--start-group -lc -lm -Wl,--end-group --specs=nosys.specs -Wl,--allow-multiple-definition -Wl,-u,_isatty,-u,_fstat -Wl,-wrap,exit -Wl,-wrap,_exit -Wl,-wrap,main -Wl,-wrap,abort -Wl,g++_tg.o -lm -o ./eb77.exe
pid is 28414 -28414
/build/gcc-13-2709-g9ac9fde961f/bin/../lib/gcc/arm-none-eabi/13.0.0/../../../../arm-none-eabi/bin/ld: /build/gcc-13-2709-g9ac9fde961f/bin/../lib/gcc/arm-none-eabi/13.0.0/../../../../arm-none-eabi/lib/thumb/v6-m/nofp/libstdc++.a(random.o): in function `std::(anonymous namespace)::__libc_getentropy(void*)':
(.text._ZNSt12_GLOBAL__N_117__libc_getentropyEPv+0x8): undefined reference to `getentropy'
/build/gcc-13-2709-g9ac9fde961f/bin/../lib/gcc/arm-none-eabi/13.0.0/../../../../arm-none-eabi/bin/ld: /build/gcc-13-2709-g9ac9fde961f/bin/../lib/gcc/arm-none-eabi/13.0.0/../../../../arm-none-eabi/lib/thumb/v6-m/nofp/libstdc++.a(random.o): in function `std::random_device::_M_init(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)':
(.text._ZNSt13random_device7_M_initERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE+0x58): undefined reference to `getentropy'
/build/gcc-13-2709-g9ac9fde961f/bin/../lib/gcc/arm-none-eabi/13.0.0/../../../../arm-none-eabi/bin/ld: /build/gcc-13-2709-g9ac9fde961f/bin/../lib/gcc/arm-none-eabi/13.0.0/../../../../arm-none-eabi/lib/thumb/v6-m/nofp/libc.a(libc_a-arc4random.o): in function `_rs_stir':
(.text._rs_stir+0x8): undefined reference to `getentropy'
collect2: error: ld returned 1 exit status
pid is -1
close result is 28414 exp6 0 1
output is /build/gcc-13-2709-g9ac9fde961f/bin/../lib/gcc/arm-none-eabi/13.0.0/../../../../arm-none-eabi/bin/ld: /build/gcc-13-2709-g9ac9fde961f/bin/../lib/gcc/arm-none-eabi/13.0.0/../../../../arm-none-eabi/lib/thumb/v6-m/nofp/libstdc++.a(random.o): in function `std::(anonymous namespace)::__libc_getentropy(void*)':
(.text._ZNSt12_GLOBAL__N_117__libc_getentropyEPv+0x8): undefined reference to `getentropy'
/build/gcc-13-2709-g9ac9fde961f/bin/../lib/gcc/arm-none-eabi/13.0.0/../../../../arm-none-eabi/bin/ld: /build/gcc-13-2709-g9ac9fde961f/bin/../lib/gcc/arm-none-eabi/13.0.0/../../../../arm-none-eabi/lib/thumb/v6-m/nofp/libstdc++.a(random.o): in function `std::random_device::_M_init(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)':
(.text._ZNSt13random_device7_M_initERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE+0x58): undefined reference to `getentropy'
/build/gcc-13-2709-g9ac9fde961f/bin/../lib/gcc/arm-none-eabi/13.0.0/../../../../arm-none-eabi/bin/ld: /build/gcc-13-2709-g9ac9fde961f/bin/../lib/gcc/arm-none-eabi/13.0.0/../../../../arm-none-eabi/lib/thumb/v6-m/nofp/libc.a(libc_a-arc4random.o): in function `_rs_stir':
(.text._rs_stir+0x8): undefined reference to `getentropy'
collect2: error: ld returned 1 exit status
 status 1
compiler exited with status 1
FAIL: g++.old-deja/g++.robertl/eb77.C  -std=c++20 (test for excess errors)
Excess errors:
(.text._ZNSt12_GLOBAL__N_117__libc_getentropyEPv+0x8): undefined reference to `getentropy'
(.text._ZNSt13random_device7_M_initERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE+0x58): undefined reference to `getentropy'
(.text._rs_stir+0x8): undefined reference to `getentropy'
UNRESOLVED: g++.old-deja/g++.robertl/eb77.C  -std=c++20 compilation failed to produce executable

Contributed by STMicroelectronics

Signed-off-by: Torbjörn SVENSSON <torbjorn.svensson@foss.st.com>

6 files changed, 71 insertions, 0 deletions

diff --git a/newlib/libc/include/_syslist.h b/newlib/libc/include/_syslist.h
index 271644efa..2946af551 100644
--- a/newlib/libc/include/_syslist.h
+++ b/newlib/libc/include/_syslist.h
@@ -24,6 +24,7 @@
 #define _unlink unlink
 #define _wait wait
 #define _write write
+#define _getentropy getentropy
 #endif /* MISSING_SYSCALL_NAMES */
 
 #if defined MISSING_SYSCALL_NAMES || !defined HAVE_OPENDIR
diff --git a/newlib/libc/include/reent.h b/newlib/libc/include/reent.h
index 23d572cd3..b1dd2a7c4 100644
--- a/newlib/libc/include/reent.h
+++ b/newlib/libc/include/reent.h
@@ -125,6 +125,7 @@ struct timezone;
 #define _unlink_r(__reent, __path)                unlink(__path)
 #define _wait_r(__reent, __status)                wait(__status)
 #define _write_r(__reent, __fd, __buff, __cnt)    write(__fd, __buff, __cnt)
+#define _getentropy_r(__reent, __buff, __cnt)     getentropy(__buff, __cnt)
 #define _gettimeofday_r(__reent, __tp, __tzp)     gettimeofday(__tp, __tzp)
 
 #ifdef __LARGE64_FILES
@@ -156,6 +157,7 @@ extern _CLOCK_T_ _times_r (struct _reent *, struct tms *);
 extern int _unlink_r (struct _reent *, const char *);
 extern int _wait_r (struct _reent *, int *);
 extern _ssize_t _write_r (struct _reent *, int, const void *, size_t);
+extern int _getentropy_r (struct _reent *, void *, size_t);
 
 /* This one is not guaranteed to be available on all targets.  */
 extern int _gettimeofday_r (struct _reent *, struct timeval *__tp, void *__tzp);
diff --git a/newlib/libc/reent/Makefile.inc b/newlib/libc/reent/Makefile.inc
index 38ddf5766..26f952bfa 100644
--- a/newlib/libc/reent/Makefile.inc
+++ b/newlib/libc/reent/Makefile.inc
@@ -4,6 +4,7 @@ libc_a_SOURCES += \
 	%D%/impure.c \
 	%D%/fcntlr.c \
 	%D%/fstatr.c \
+	%D%/getentropyr.c \
 	%D%/getreent.c \
 	%D%/gettimeofdayr.c \
 	%D%/isattyr.c \
@@ -46,6 +47,7 @@ LIBC_CHEWOUT_FILES += \
 	%D%/execr.def \
 	%D%/fcntlr.def \
 	%D%/fstatr.def \
+	%D%/getentropyr.def \
 	%D%/gettimeofdayr.def \
 	%D%/linkr.def \
 	%D%/lseekr.def \
diff --git a/newlib/libc/reent/getentropyr.c b/newlib/libc/reent/getentropyr.c
new file mode 100644
index 000000000..e3f85e41b
--- /dev/null
+++ b/newlib/libc/reent/getentropyr.c
@@ -0,0 +1,53 @@
+/* Reentrant version of getentropy system call. */
+
+#include <reent.h>
+#include <unistd.h>
+#include <_syslist.h>
+
+/* Some targets provides their own versions of these functions.  Those
+   targets should define REENTRANT_SYSCALLS_PROVIDED in TARGET_CFLAGS.  */
+
+#ifdef _REENT_ONLY
+#ifndef REENTRANT_SYSCALLS_PROVIDED
+#define REENTRANT_SYSCALLS_PROVIDED
+#endif
+#endif
+
+#ifndef REENTRANT_SYSCALLS_PROVIDED
+
+/* We use the errno variable used by the system dependent layer.  */
+#undef errno
+extern int errno;
+
+/*
+FUNCTION
+	<<_getentropy_r>>---Reentrant version of getentropy
+
+INDEX
+	_getentropy_r
+
+SYNOPSIS
+	#include <reent.h>
+	int _getentropy_r(struct _reent *<[ptr]>,
+		          void *<[buf]>, size_t <[buflen]>);
+
+DESCRIPTION
+	This is a reentrant version of <<getentropy>>.  It
+	takes a pointer to the global data block, which holds
+	<<errno>>.
+*/
+
+int
+_getentropy_r (struct _reent *ptr,
+     void *buf,
+     size_t buflen)
+{
+  int ret;
+
+  errno = 0;
+  if ((ret = _getentropy (buf, buflen)) == -1 && errno != 0)
+    _REENT_ERRNO(ptr) = errno;
+  return ret;
+}
+
+#endif /* ! defined (REENTRANT_SYSCALLS_PROVIDED) */
diff --git a/newlib/libc/syscalls/Makefile.inc b/newlib/libc/syscalls/Makefile.inc
index 627a4dfd2..7f7bbbddb 100644
--- a/newlib/libc/syscalls/Makefile.inc
+++ b/newlib/libc/syscalls/Makefile.inc
@@ -4,6 +4,7 @@ libc_a_SOURCES += \
 	%D%/sysclose.c \
 	%D%/sysfcntl.c \
 	%D%/sysfstat.c \
+	%D%/sysgetentropy.c \
 	%D%/sysgetpid.c \
 	%D%/sysgettod.c \
 	%D%/sysisatty.c \
diff --git a/newlib/libc/syscalls/sysgetentropy.c b/newlib/libc/syscalls/sysgetentropy.c
new file mode 100644
index 000000000..d68ccbc72
--- /dev/null
+++ b/newlib/libc/syscalls/sysgetentropy.c
@@ -0,0 +1,12 @@
+/* connector for getentropy */
+
+#include <reent.h>
+#include <sys/types.h>
+#include <sys/time.h>
+
+int
+getentropy (void *buf,
+     size_t buflen)
+{
+  return _getentropy_r (_REENT, buf, buflen);
+}