From cc527df652f9f85880fb4a032903742bd555f431 Mon Sep 17 00:00:00 2001
From: Magnus Jacobsson <Magnus.Jacobsson@berotec.se>
Date: Sun, 16 Jan 2022 16:40:29 +0100
Subject: [PATCH] cgraph: add a graphviz_exit function in a new header file
 exit.h

Towards https://gitlab.com/graphviz/graphviz/-/issues/2178.
---
 lib/cgraph/CMakeLists.txt         |  1 +
 lib/cgraph/Makefile.am            |  2 +-
 lib/cgraph/cgraph.vcxproj         |  1 +
 lib/cgraph/cgraph.vcxproj.filters |  3 +++
 lib/cgraph/exit.h                 | 32 +++++++++++++++++++++++++++++++
 5 files changed, 38 insertions(+), 1 deletion(-)
 create mode 100644 lib/cgraph/exit.h

diff --git a/lib/cgraph/CMakeLists.txt b/lib/cgraph/CMakeLists.txt
index 81edb03d7..ab411429a 100644
--- a/lib/cgraph/CMakeLists.txt
+++ b/lib/cgraph/CMakeLists.txt
@@ -13,6 +13,7 @@ add_library(cgraph SHARED
     bitarray.h
     cghdr.h
     cgraph.h
+    exit.h
     itos.h
     likely.h
     prisize_t.h
diff --git a/lib/cgraph/Makefile.am b/lib/cgraph/Makefile.am
index 795c975ce..d7272fda8 100644
--- a/lib/cgraph/Makefile.am
+++ b/lib/cgraph/Makefile.am
@@ -12,7 +12,7 @@ AM_CFLAGS = -DEXPORT_CGRAPH -DEXPORT_AGXBUF -DEXPORT_CGHDR
 endif
 
 pkginclude_HEADERS = cgraph.h
-noinst_HEADERS = agxbuf.h bitarray.h cghdr.h itos.h likely.h prisize_t.h \
+noinst_HEADERS = agxbuf.h bitarray.h cghdr.h exit.h itos.h likely.h prisize_t.h \
 	sprint.h strcasecmp.h unreachable.h
 noinst_LTLIBRARIES = libcgraph_C.la
 lib_LTLIBRARIES = libcgraph.la
diff --git a/lib/cgraph/cgraph.vcxproj b/lib/cgraph/cgraph.vcxproj
index 052a3bba7..99b9de621 100644
--- a/lib/cgraph/cgraph.vcxproj
+++ b/lib/cgraph/cgraph.vcxproj
@@ -101,6 +101,7 @@ win_flex -oscan.c scan.l</Command>
     <ClInclude Include="bitarray.h" />
     <ClInclude Include="cghdr.h" />
     <ClInclude Include="cgraph.h" />
+    <ClInclude Include="exit.h" />
     <ClInclude Include="itos.h" />
     <ClInclude Include="likely.h" />
     <ClInclude Include="prisize_t.h" />
diff --git a/lib/cgraph/cgraph.vcxproj.filters b/lib/cgraph/cgraph.vcxproj.filters
index a20bf8fa7..8c83513d3 100644
--- a/lib/cgraph/cgraph.vcxproj.filters
+++ b/lib/cgraph/cgraph.vcxproj.filters
@@ -27,6 +27,9 @@
     <ClInclude Include="cgraph.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="exit.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
     <ClInclude Include="itos.h">
       <Filter>Header Files</Filter>
     </ClInclude>
diff --git a/lib/cgraph/exit.h b/lib/cgraph/exit.h
new file mode 100644
index 000000000..650951b28
--- /dev/null
+++ b/lib/cgraph/exit.h
@@ -0,0 +1,32 @@
+#pragma once
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef __GNUC__
+// FIXME: use _Noreturn for all compilers when we move to C11
+#define NORETURN __attribute__((noreturn))
+#elif defined(_MSC_VER)
+#define NORETURN __declspec(noreturn)
+#else
+#define NORETURN /* nothing */
+#endif
+
+static inline NORETURN void graphviz_exit(int status) {
+#ifdef __MINGW32__
+  // workaround for https://gitlab.com/graphviz/graphviz/-/issues/2178
+  fflush(stdout);
+  fflush(stderr);
+#endif
+  exit(status);
+}
+
+#undef NORETURN
+
+#ifdef __cplusplus
+}
+#endif
-- 
2.40.0