Use VSCMD_ARG_TGT_ARCH env in mkbundle on Windows when trying to autoetect target architecture. (#7281)

* Use VSCMD_ARG_TGT_ARCH env in mkbundle on Windows when trying to autodetect target architecture.

Using mkbundle on Windows with VS toolchain, mkbundle will detect target
architecture (x86/x64) by looking at the architecture of executing .NET runtime.
This could lead to some surprises when run from a VS development command propmt setup
to target x86 or x64 but running a mono binary using opposite architecture.

To mitigate this issue mkbundle will look now at the VSCMD_ARG_TGT_ARCH
set in VS development command prompts and use target architecture based
on this env variable. If not defined, current behavior will be used, picking the target
architecture based on executed .NET runtime architecture.

* Updated mkbundle documentation.

1 files changed, 59 insertions, 12 deletions

diff --git a/man/mkbundle.1 b/man/mkbundle.1
index 1e2b4d5f3f5..32fcbc6ccea 100644
--- a/man/mkbundle.1
+++ b/man/mkbundle.1
@@ -359,33 +359,80 @@ not require runtime code generation. The "llvmonly" setting does the same, but f
 to go through the llvm backend.
 
 .SH WINDOWS
-If you are using the old embedding on Windows systems, it it necessary
-to have Unix-like toolchain to be installed for \fImkbundle\fP to
-work.  You can use cygwin's and install gcc, gcc-mingw and as
-packages.
+If you are using the old embedding on Windows systems, it possible to use
+a Unix-like toolchain like cygwin's and install gcc, gcc-mingw packages or
+use Visual Studio 2015/2017 VC toolchain together with Clang for Visual Studio as assembler.
+Clang can be installed as an individual component, "Clang/C2", using Visual Studio installer.
+.PP
+Using Visual Studio toolchain, mkbundle will, by default, use latest installed Visual Studio compiler
+and linker as well as Windows SDK. If executed from one of the Visual Studio developer command prompts,
+mkbundle will retrieve information directly from that build environment.
 .SH ENVIRONMENT VARIABLES
 .TP
 .I "AS"
-Assembler command. The default is "as".
+Assembler command. The default is "as". For Visual Studio, default is "clang.exe".
+If "clang.exe" for Visual Studio is not installed, mkbundle will fall back using "as".
 .TP
 .I "CC"
-C compiler command. The default is "cc" under Linux and "gcc"
-under Windows.
+C compiler command. The default is "cc" for Linux, "gcc"
+for cygwin and "cl.exe" for Visual Studio.
 .TP
 .I "MONO_BUNDLED_OPTIONS"
 Options to be passed to the bundled
 Mono runtime, separated by spaces. See the mono(1) manual page or run mono --help.
+.SH WINDOWS VISUAL STUDIO ENVIRONMENT VARIABLES
+.TP
+.I "VisualStudioVersion"
+Visual Studio version used in mkbundle build.
+Default, latest installed Visual Studio version.
+Values, "14.0" for Visual Studio 2015 or "15.0" for Visual Studio 2017.
+.TP
+.I "WindowsSdkVersion"
+Windows SDK version used in mkbundle build.
+Default/unknown, latest installed Windows SDK.
+Values, "8.1", "10.0.10240.0", "10.0.15063.0" etc.
+.TP
+.I "VSCMD_ARG_TGT_ARCH"
+Output target architecture used in mkbundle build.
+Default/unknown, use architecture of .NET runtime executing mkbundle.
+Values, "x86" or "x64".
+NOTE, when running from a Visual Studio command prompt, this variable should already be set
+by the command prompt and match the rest of that build environment.
+.TP
+.I "INCLUDE"
+Override all custom include paths passed to "cl.exe".
+Predefined by Visual Studio developer command prompt or auto detected by mkbundle when undefined.
+.TP
+.I "LIB"
+Override all custom library paths passed to "link.exe".
+Predefined by Visual Studio developer command prompt or auto detected by mkbundle when undefined.
+.TP
+.I "MONOPREFIX"
+Use a custom Mono SDK install root matching the output target architecture (x86/x64).
+Default, mkbundle will look for installed Mono SDK’s matching targeted architecture.
+.TP
+.I "MONOLIB"
+Use a different mono library name or an absolute path to the mono library passed to linker.
+Default, mkbundle will use default mono library name depending on mkbundle dynamic/static use case.
+NOTE, supplied mono library needs to match mkbundle dynamic/static use case and target architecture.
+.TP
+.I "VCCRT"
+Override C-runtime library linker settings.
+Default "MD", mkbundle will use dynamic C-runtime linking on Windows compatible with Mono SDK distribution.
+If a custom built Mono runtime using static C-Runtime linkage is used, setting this variable to "MT"
+will link using static C-runtime libraries.
+.TP
+.I "VCSUBSYSTEM"
+Override Windows subsystem.
+Default, "windows". If console subsystem is preferred, use "console".
+NOTE, if console output is expected from output target process then
+set this variable to "console".
 .SH FILES
 This program will load referenced assemblies from the Mono assembly
 cache. 
 .PP
 Targets are loaded from ~/.mono/targets/TARGETNAME/mono
 .SH BUGS
-The option "--static" is not supported under Windows when using the
-old embedding.
-Moreover, a full cygwin environment containing at least "gcc" and "as"
-is required for the build process. The generated executable does not
-depend on cygwin.
 .SH MAILING LISTS
 Visit http://lists.ximian.com/mailman/listinfo/mono-devel-list for details.
 .SH WEB SITE