[boost-context] Fixes error with linker for 32-bit GNU assembler files targeting Windows (#13422)

* Patch from official boostorg/context. There is no official version with it yet.

* Apply patch globaly

It is better to check it now, for all triplets as [this script](https://github.com/microsoft/vcpkg/blob/master/scripts/boost/generate-ports.ps1) will regenerate portfile.cmake with patch for all of them not just for subset.

3 files changed, 48 insertions, 1 deletions

diff --git a/ports/boost-context/CONTROL b/ports/boost-context/CONTROL
index a6ba3fa04..3effa3c95 100644
--- a/ports/boost-context/CONTROL
+++ b/ports/boost-context/CONTROL
@@ -1,7 +1,7 @@
 # Automatically generated by boost-vcpkg-helpers/generate-ports.ps1

 Source: boost-context

 Version: 1.73.0

-Port-Version: 1

+Port-Version: 2

 Build-Depends: boost-assert, boost-build, boost-config, boost-detail, boost-integer, boost-modular-build-helper, boost-pool, boost-predef, boost-smart-ptr, boost-thread, boost-vcpkg-helpers

 Homepage: https://github.com/boostorg/context

 Description: Boost context module

diff --git a/ports/boost-context/fix_exports_for_32bit_GNU_asm_for_windows.patch b/ports/boost-context/fix_exports_for_32bit_GNU_asm_for_windows.patch
new file mode 100644
index 000000000..30d38af1e
--- /dev/null
+++ b/ports/boost-context/fix_exports_for_32bit_GNU_asm_for_windows.patch
@@ -0,0 +1,45 @@
+From d52ce8ca89674e31e689a7af3b0fc9304018be5a Mon Sep 17 00:00:00 2001
+From: Julien Schueller <schueller@phimeca.com>
+Date: Thu, 20 Aug 2020 12:51:30 +0200
+Subject: [PATCH] Revert "Fix exports for 32-bit GNU assembler files targeting
+ Windows."
+
+This reverts 85783e8, as the wrong linker was used
+
+Closes #136
+---
+ src/asm/jump_i386_ms_pe_gas.asm  | 2 +-
+ src/asm/make_i386_ms_pe_gas.asm  | 2 +-
+ src/asm/ontop_i386_ms_pe_gas.asm | 2 +-
+ 3 files changed, 3 insertions(+), 3 deletions(-)
+
+diff --git a/src/asm/jump_i386_ms_pe_gas.asm b/src/asm/jump_i386_ms_pe_gas.asm
+index bf5c75a4..6eb45326 100644
+--- a/src/asm/jump_i386_ms_pe_gas.asm
++++ b/src/asm/jump_i386_ms_pe_gas.asm
+@@ -120,4 +120,4 @@ _jump_fcontext:
+     jmp *%ecx
+ 
+ .section .drectve
+-.ascii " -export:\"_jump_fcontext\""
++.ascii " -export:\"jump_fcontext\""
+diff --git a/src/asm/make_i386_ms_pe_gas.asm b/src/asm/make_i386_ms_pe_gas.asm
+index 10277bb5..608ddf3a 100644
+--- a/src/asm/make_i386_ms_pe_gas.asm
++++ b/src/asm/make_i386_ms_pe_gas.asm
+@@ -150,4 +150,4 @@ finish:
+ .def	__exit;	.scl	2;	.type	32;	.endef  /* standard C library function */
+ 
+ .section .drectve
+-.ascii " -export:\"_make_fcontext\""
++.ascii " -export:\"make_fcontext\""
+diff --git a/src/asm/ontop_i386_ms_pe_gas.asm b/src/asm/ontop_i386_ms_pe_gas.asm
+index c23e18a2..abe9002a 100644
+--- a/src/asm/ontop_i386_ms_pe_gas.asm
++++ b/src/asm/ontop_i386_ms_pe_gas.asm
+@@ -128,4 +128,4 @@ _ontop_fcontext:
+     jmp  *%ecx
+ 
+ .section .drectve
+-.ascii " -export:\"_ontop_fcontext\""
++.ascii " -export:\"ontop_fcontext\""
diff --git a/ports/boost-context/portfile.cmake b/ports/boost-context/portfile.cmake
index 66ed9f50f..263b0c872 100644
--- a/ports/boost-context/portfile.cmake
+++ b/ports/boost-context/portfile.cmake
@@ -6,6 +6,8 @@ vcpkg_from_github(
     REF boost-1.73.0

     SHA512 cb460e9d7f5b2782164e49820b097402f6a443718d689b2f793f5ab7030012a80418dfc51154f299c9f987d6864d87f7536476ffa97da1089bf6b70f2990ebea

     HEAD_REF master

+    PATCHES

+        fix_exports_for_32bit_GNU_asm_for_windows.patch

 )

 

 file(READ "${SOURCE_PATH}/build/Jamfile.v2" _contents)