From 52155e1d78650fd0360104f70df987dceed06cb2 Mon Sep 17 00:00:00 2001
From: Ben Hamilton <beng@fb.com>
Date: Fri, 10 Jun 2016 16:01:34 -0700
Subject: [PATCH] Make Fibers library conditional on working Boost.Context
 fcontext_t

Summary:
Boost 1.61 removes the `boost::context::fcontext_t` type
which Folly Fibers depends on.

This makes the Fibers library conditional on a working `fcontext_t`,
so Folly will build (just without Fibers) if it's not present.

Depends On D3419638

Fixes https://github.com/facebook/folly/issues/413

Reviewed By: Orvid

Differential Revision: D3420097

fbshipit-source-id: 876f8f76a2d0dda4ce5085c27875ab6aaa7b86c0
---
 folly/Makefile.am  | 70 +++++++++++++++++++++++++---------------------
 folly/configure.ac |  1 +
 2 files changed, 39 insertions(+), 32 deletions(-)

diff --git a/folly/Makefile.am b/folly/Makefile.am
index 45547c9d..bfd670cd 100644
--- a/folly/Makefile.am
+++ b/folly/Makefile.am
@@ -97,32 +97,6 @@ nobase_follyinclude_HEADERS = \
 	experimental/EventCount.h \
 	experimental/Instructions.h \
 	experimental/bser/Bser.h \
-	fibers/AddTasks.h \
-	fibers/AddTasks-inl.h \
-	fibers/Baton.h \
-	fibers/Baton-inl.h \
-	fibers/BoostContextCompatibility.h \
-	fibers/EventBaseLoopController.h \
-	fibers/EventBaseLoopController-inl.h \
-	fibers/Fiber.h \
-	fibers/Fiber-inl.h \
-	fibers/FiberManager.h \
-	fibers/FiberManager-inl.h \
-	fibers/FiberManagerMap.h \
-	fibers/ForEach.h \
-	fibers/ForEach-inl.h \
-	fibers/GenericBaton.h \
-	fibers/GuardPageAllocator.h \
-	fibers/LoopController.h \
-	fibers/Promise.h \
-	fibers/Promise-inl.h \
-	fibers/SimpleLoopController.h \
-	fibers/TimedMutex.h \
-	fibers/TimedMutex-inl.h \
-	fibers/TimeoutController.h \
-	fibers/traits.h \
-	fibers/WhenN.h \
-	fibers/WhenN-inl.h \
 	experimental/FunctionScheduler.h \
 	experimental/FutureDAG.h \
 	experimental/io/FsUtil.h \
@@ -467,12 +441,6 @@ libfolly_la_SOURCES = \
 	experimental/bser/Dump.cpp \
 	experimental/bser/Load.cpp \
 	experimental/DynamicParser.cpp \
-	fibers/Baton.cpp \
-	fibers/Fiber.cpp \
-	fibers/FiberManager.cpp \
-	fibers/FiberManagerMap.cpp \
-	fibers/GuardPageAllocator.cpp \
-	fibers/TimeoutController.cpp \
 	experimental/FunctionScheduler.cpp \
 	experimental/io/FsUtil.cpp \
 	experimental/JSONSchema.cpp \
@@ -496,6 +464,44 @@ if !HAVE_BITS_FUNCTEXCEPT_H
 libfollybase_la_SOURCES += detail/FunctionalExcept.cpp
 endif
 
+if HAVE_BOOST_CONTEXT
+nobase_follyinclude_HEADERS += \
+	fibers/AddTasks.h \
+	fibers/AddTasks-inl.h \
+	fibers/Baton.h \
+	fibers/Baton-inl.h \
+	fibers/BoostContextCompatibility.h \
+	fibers/EventBaseLoopController.h \
+	fibers/EventBaseLoopController-inl.h \
+	fibers/Fiber.h \
+	fibers/Fiber-inl.h \
+	fibers/FiberManager.h \
+	fibers/FiberManager-inl.h \
+	fibers/FiberManagerMap.h \
+	fibers/ForEach.h \
+	fibers/ForEach-inl.h \
+	fibers/GenericBaton.h \
+	fibers/GuardPageAllocator.h \
+	fibers/LoopController.h \
+	fibers/Promise.h \
+	fibers/Promise-inl.h \
+	fibers/SimpleLoopController.h \
+	fibers/TimedMutex.h \
+	fibers/TimedMutex-inl.h \
+	fibers/TimeoutController.h \
+	fibers/traits.h \
+	fibers/WhenN.h \
+	fibers/WhenN-inl.h
+
+libfolly_la_SOURCES += \
+	fibers/Baton.cpp \
+	fibers/Fiber.cpp \
+	fibers/FiberManager.cpp \
+	fibers/FiberManagerMap.cpp \
+	fibers/GuardPageAllocator.cpp \
+	fibers/TimeoutController.cpp
+endif
+
 libfollybase_la_LDFLAGS = $(AM_LDFLAGS) -version-info $(LT_VERSION)
 
 libfolly_la_LIBADD = libfollybase.la
diff --git a/folly/configure.ac b/folly/configure.ac
index e3981b2c..48a99b5b 100644
--- a/folly/configure.ac
+++ b/folly/configure.ac
@@ -536,6 +536,7 @@ AM_CONDITIONAL([HAVE_BITS_FUNCTEXCEPT_H], [test "$ac_cv_header_bits_functexcept_
 AM_CONDITIONAL([HAVE_EXTRANDOM_SFMT19937],
                [test "$folly_cv_prog_cc_have_extrandom_sfmt19937" = "yes"])
 AM_CONDITIONAL([FOLLY_TESTMAIN], [test "x${use_follytestmain}" = "xyes"])
+AM_CONDITIONAL([HAVE_BOOST_CONTEXT], [test "x${ax_cv_boost_context}" = "xyes"])
 
 # Output
 AC_CONFIG_FILES([Makefile
-- 
2.34.1