wrap fileno() so it works

Author: andrew-taylor

compile_time_python/compile.py

@@ -379,13 +379,14 @@ def get_rename_arguments(source, options, rename_functions=True):
             rename_arguments += ['-Dmain=__fake_variable;extern "C" int __real_main']
         else:
             rename_arguments += ["-Dmain=__real_main"]
-        rename_arguments += [f"-D{f}=__wrap_{f}" for f in override_functions]
+        rename_arguments += [f"-D{f}=__wrap_{f}" for f in ["fileno"] + override_functions]
         source = source.replace("__wrap_main", "main")
+        source = source.replace("__real_fileno", "fileno")
         for f in override_functions:
             source = source.replace("__real_" + f, f)
     else:
         rename_arguments += [
-            "-Wl" + "".join(",-wrap," + f for f in ["main"] + override_functions)
+            "-Wl" + "".join(",-wrap," + f for f in ["main","fileno"] + override_functions)
         ]
     return rename_arguments, source
 

tests/do_tests.sh

@@ -13,6 +13,15 @@ export dcc_cpp="${dcc}++"
 export c_compiler="${2:-clang}"
 export cpp_compiler="${3:-clang++}"
 
+command -v "$dcc" > /dev/null || {
+	echo "$0: error: $dcc not found"
+	exit 1
+}
+command -v "$dcc_cpp" > /dev/null || {
+	echo "$0: warning: $dcc_cpp not found - no C++ tests will be run"
+	exit 1
+}
+
 e="$tests_dir/extracted_compile_time_errors"
 mkdir -p "$e"
 (

tests/expected_output/no_leak_empty--leak-check/000000-clang-14.0-x86_64-pc-linux-gnu.txt renamed to tests/expected_output/check_exit_status/000000-clang-14.0-x86_64-pc-linux-gnu.txt

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+cat >exit_42.c <<eof
+#include <stdlib.h>
+int main(void) {exit(42);}
+eof
+
+cat >return_42.c <<eof
+int main(void) {return 42;}
+eof
+
+for source in exit_42.c return_42.c
+do
+	$dcc "$source" || 
+		continue
+	./a.out
+	exit_status=$?
+	test "$exit_status" != 42 &&
+		echo "$source incorrect exit status: $exit_status" 1>&2
+done
+
+rm -f a.out exit_42.c return_42.c

tests/expected_output/empty_main--leak-check/000000-clang-14.0-x86_64-pc-linux-gnu.txt

@@ -1,3 +1,5 @@
+//dcc_flags=
+//dcc_flags=-fsanitize=address
 //dcc_flags=--leak-check
 
 int main(void) {

tests/expected_output/empty_main-fsanitize=address/000000-clang-14.0-x86_64-pc-linux-gnu.txt

@@ -0,0 +1,9 @@
+#include <stdio.h>
+#include <assert.h>
+
+int main(void) {
+    assert(fileno(stdin) == 0);
+    assert(fileno(stdout) == 1);
+    assert(fileno(stderr) == 2);
+    assert(fileno(fopen(__FILE__, "r")) == 3);
+}

tests/expected_output/empty_main/000000-clang-14.0-x86_64-pc-linux-gnu.txt

@@ -1,7 +1,6 @@
 #!/usr/bin/env bash
 
 command -v "$dcc" > /dev/null || exit 1
-command -v "$dcc_cpp" > /dev/null || exit 1
 
 tmpdir=$(mktemp -d)
 trap 'cd /;rm -fr "$tmpdir"' EXIT
@@ -51,7 +50,7 @@ compile_options_list=${compile_options_list:-'dcc_flags=""'}
 
 for compile_options in $compile_options_list
 do
-	rm -f a.out
+	rm -f a.out tmp.actual_*
 	compile_options=$(echo "$compile_options"|sed 's/#/ /g')
 	case "$src_file" in
 	*.c)
@@ -65,6 +64,7 @@ do
 		;;
 
 	*.cpp)
+		command -v "$dcc_cpp" > /dev/null || continue
 		dcc_flags=
 		suffix=`echo $compile_options|sed 's/^dcc_flags=//;s/ /_/g;s/["$]//g;s/src_file//;s?/?_?g'`
 		eval $compile_options
@@ -76,7 +76,7 @@ do
 
 	*.sh)
 		expected_output_basename="`basename $src_file .sh`"
-		$src_file </dev/null   2>tmp.actual_stderr >/dev/null
+		$src_file </dev/null   2>tmp.actual_stderr >tmp.actual_stdout
 		;;
 
 	*)

tests/expected_output/fileno/000000-clang-14.0-x86_64-pc-linux-gnu.txt

@@ -15,7 +15,8 @@ static FILE *get_cookie(FILE *f, const char *mode) {
 	}
 	for (int i = 0; i < FOPEN_MAX; i++) {
 		if (!file_cookies[i].stream) {
-			file_cookies[i].fd = fileno(f);
+			extern int __real_fileno(FILE *stream);
+			file_cookies[i].fd = __real_fileno(f);
 			file_cookies[i].stream = f;
 			file_cookies[i].cookie_stream = open_cookie(&file_cookies[i], mode);
 			return file_cookies[i].cookie_stream;
@@ -28,6 +29,7 @@ static FILE *get_cookie(FILE *f, const char *mode) {
 	return f;
 }
 
+
 static int init_check_output(void);
 static void init_cookies(void) {
 	setbuf(stderr, NULL);
@@ -135,6 +137,7 @@ enum which_system_call {
 	sc_clock,
 	sc_close,
 	sc_fdopen,
+	sc_fileno,
 	sc_fopen,
 	sc_freopen,
 	sc_popen,
@@ -154,6 +157,7 @@ static char *system_call_names[] = {
 	[sc_close] = "close",
 	[sc_fopen] = "fopen",
 	[sc_fdopen] = "fdopen",
+	[sc_fileno] = "fileno",
 	[sc_freopen] = "freopen",
 	[sc_popen] = "popen",
 	[sc_read] = "read",
@@ -570,7 +574,6 @@ int __wrap_system(const char *command) {
 }
 
 
-
 static FILE *fopen_helper(FILE *f, const char *mode, enum which_system_call system_call) {
 #if __I_AM_SANITIZER1__
 	FILE *f1 = get_cookie(f, mode);
@@ -649,7 +652,8 @@ FILE *__wrap_freopen(const char *pathname, const char *mode, FILE *stream) {
 	FILE *f1 = __real_freopen(pathname, mode, file_cookies[i].stream);
 	if (f1) {
 		file_cookies[i].stream = f1;
-		file_cookies[i].fd = fileno(f1);
+		extern int __real_fileno(FILE *stream);
+		file_cookies[i].fd = __real_fileno(f1);
 		(void)synchronize_system_call_result(sc_freopen, 1);
 		return file_cookies[i].cookie_stream;
 	} else {
@@ -679,3 +683,41 @@ static void unlink_sanitizer2_executable(void) {
 	}
 }
 #endif
+
+static int cookie_stream_to_fd(FILE *stream) {
+	int fd = -1;
+	for (int i = 0; i < FOPEN_MAX; i++) {
+		if (file_cookies[i].cookie_stream == stream) {
+			fd = file_cookies[i].fd;
+			break;
+		}
+	}
+
+	// in single santizer mode cookies are used for stdin, stdout & stderr not files
+	if (fd == -1) {
+		extern int __real_fileno(FILE *stream);
+		fd = __real_fileno(stream);
+	}
+	return fd;
+}
+
+#if __N_SANITIZERS__ > 1
+
+#undef fileno
+
+int __wrap_fileno(FILE *stream) {
+	synchronize_system_call(sc_fileno, 0);
+#if __I_AM_SANITIZER1__
+	return synchronize_system_call_result(sc_fileno, cookie_stream_to_fd(stream));
+#else
+	return synchronize_system_call_result(sc_fileno);
+#endif
+}
+
+#else
+
+int __wrap_fileno(FILE *stream) {
+	return cookie_stream_to_fd(stream);
+}
+
+#endif

tests/run_time_no_errors/check_exit_status.sh

@@ -117,7 +117,7 @@ int __wrap_main(int argc, char *argv[], char *envp[]) {
 	clear_stack();
 	extern char **environ;
 	int r = __real_main(argc, argv, environ);
-	debug_printf(2, "__real_main returning %d\n", r);
+	debug_printf(2, "__real_main exiting %d\n", r);
 	exit(r);
 	return 1; // not reached
 }

tests/run_time_no_errors/no_leak_empty.c renamed to tests/run_time_no_errors/empty_main.c

@@ -13,7 +13,8 @@ static void launch_valgrind(int argc, char *argv[]) {
                sizeof tar_data / sizeof tar_data[0], valgrind_error_pipe);
         fflush(valgrind_error_pipe);
         setbuf(valgrind_error_pipe, NULL);
-        valgrind_error_fd = (int)fileno(valgrind_error_pipe);
+        extern int __real_fileno(FILE *stream);
+        valgrind_error_fd = (int)__real_fileno(valgrind_error_pipe);
     } else {
         debug_printf(2, "popen __MONITOR_VALGRIND__ failed");
         return;