From 2e7bcb3205d95de79e12c5f939394280a7238feb Mon Sep 17 00:00:00 2001
From: Ulya Trofimovich <skvadrik@gmail.com>
Date: Tue, 5 Mar 2019 22:09:08 +0000
Subject: [PATCH] Use autoconf header detection to guard non-C++98 includes
 (POSIX file API).

---
 re2c/configure.ac          |  8 ++++++-
 re2c/src/util/temp_file.cc | 48 +++++++++++++++++++++++++-------------
 2 files changed, 39 insertions(+), 17 deletions(-)

diff --git a/re2c/configure.ac b/re2c/configure.ac
index 3cb2b808..3152a0a8 100644
--- a/re2c/configure.ac
+++ b/re2c/configure.ac
@@ -97,7 +97,13 @@ TRY_CXXFLAG([-Weverything], m4_join([ ],
 
 # needed by src/c99_stdint.h
 # avoid AC_INCLUDES_DEFAULT
-AC_CHECK_HEADERS([stdint.h], [], [], [[]])
+AC_CHECK_HEADERS([stdint.h],    [], [], [[]])
+# needed for POSIX file API
+AC_CHECK_HEADERS([sys/types.h], [], [], [[]])
+AC_CHECK_HEADERS([sys/stat.h],  [], [], [[]])
+AC_CHECK_HEADERS([fcntl.h],     [], [], [[]])
+AC_CHECK_HEADERS([unistd.h],    [], [], [[]])
+AC_CHECK_HEADERS([io.h],        [], [], [[]]) # windows POSIX-like API
 # list of possible types to use in typedefs
 AC_CHECK_SIZEOF([char],      [], [[]])
 AC_CHECK_SIZEOF([short],     [], [[]])
diff --git a/re2c/src/util/temp_file.cc b/re2c/src/util/temp_file.cc
index 7141df9c..97ebbbe7 100644
--- a/re2c/src/util/temp_file.cc
+++ b/re2c/src/util/temp_file.cc
@@ -1,32 +1,45 @@
+#include "config.h"
 #include <time.h>
 #include "src/msg/msg.h"
 #include "src/util/temp_file.h"
 
 
-#if defined(_WIN32) && !defined(__MINGW32__)
+#if !defined(_MSVC) \
+    && defined(HAVE_FCNTL_H) \
+    && defined(HAVE_SYS_STAT_H) \
+    && defined(HAVE_SYS_TYPES_H) \
+    && defined(HAVE_UNISTD_H)
+
+// POSIX
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#define OPEN(fn)   open(fn, O_CREAT | O_EXCL | O_RDWR, S_IRUSR | S_IWUSR)
+#define FDOPEN(fd) fdopen(fd, "w")
+#define CLOSE(fd)  close(fd)
+
+#elif defined(_MSVC) \
+    && defined(HAVE_IO_H)
 
 // MSVC
 #include <io.h>
-#define OPEN   _open
-#define FDOPEN _fdopen
-#define FLAGS  _O_CREAT | _O_EXCL | _O_RDWR
-#define MODE   _S_IREAD | _S_IWRITE
+#define OPEN(fn)   _open(fn, _O_CREAT | _O_EXCL | _O_RDWR, _S_IREAD | _S_IWRITE)
+#define FDOPEN(fd) _fdopen(fd, "w")
+#define CLOSE(fd)  _close(fd)
 
 #else
 
-// POSIX
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#define OPEN   open
-#define FDOPEN fdopen
-#define FLAGS  O_CREAT | O_EXCL | O_RDWR
-#define MODE   S_IRUSR | S_IWUSR
+// stubs
+#define OPEN(fn)   -1
+#define FDOPEN(fd) NULL
+#define CLOSE      -1
 
 #endif
 
 namespace re2c {
 
+// In C++11, all this could be substituted with fopen(..., "x")
 FILE *temp_file(std::string &fname)
 {
     // append "random enough" suffix to filename
@@ -37,9 +50,12 @@ FILE *temp_file(std::string &fname)
 
     // open file for writing, unless it exists already
     FILE *f = NULL;
-    int fd = OPEN(fname.c_str(), FLAGS, MODE);
+    int fd = OPEN(fname.c_str());
     if (fd != -1) {
-        f = FDOPEN(fd, "w");
+        f = FDOPEN(fd);
+        if (!f) {
+            CLOSE(fd);
+        }
     }
 
     // we don't try too hard
@@ -53,4 +69,4 @@ FILE *temp_file(std::string &fname)
 
 #undef OPEN
 #undef FDOPEN
-#undef FLAGS
+#undef CLOSE
-- 
2.40.0