Editing Cross compiler (section)

== Microsoft C cross compilers ==
=== Early history – 1980s ===
[[Microsoft C]] (MSC) has a shorter history than others<ref>[http://support.microsoft.com/kb/93400 Microsoft Language Utility Version History]</ref> dating back to the 1980s. The first Microsoft C Compilers were made by the same company who made [[Lattice C]] and were rebranded by Microsoft as their own, until MSC 4 was released, which was the first version that Microsoft produced themselves.<ref>[http://www.itee.uq.edu.au/~csmweb/decompilation/hist-c-pc.html History of PC based C-compilers] {{webarchive |url=https://web.archive.org/web/20071215083657/http://www.itee.uq.edu.au/~csmweb/decompilation/hist-c-pc.html |date=December 15, 2007 }}</ref>

In 1987, many developers started switching to Microsoft C, and many more would follow throughout the development of Microsoft Windows to its present state. Products like [[Clipper (programming language)|Clipper]] and later [[Clarion (programming language)|Clarion]] emerged that offered easy database application development by using cross language techniques, allowing part of their programs to be compiled with Microsoft C.

[[Borland|Borland C]] (California company) was available for purchase years before Microsoft released its first C product.

=== 1987 ===
C programs had long been linked with modules written in [[assembly language]]. Most C compilers (even current compilers) offer an assembly language pass (that can be tweaked for efficiency then linked to the rest of the program after assembling).

Compilers like Aztec-C converted everything to assembly language as a distinct pass and then assembled the code in a distinct pass, and were noted for their very efficient and small code, but by 1987 the optimizer built into Microsoft C was very good, and only "mission critical" parts of a program were usually considered for rewriting. In fact, C language programming had taken over as the "lowest-level" language, with programming becoming a multi-disciplinary growth industry and projects becoming larger, with programmers writing user interfaces and database interfaces in higher-level languages, and a need had emerged for cross language development that continues to this day.

By 1987, with the release of MSC 5.1, Microsoft offered a cross language development environment for MS-DOS. 16-bit binary object code written in assembly language ([[MASM]]) and Microsoft's other languages including [[QuickBASIC]], [[Pascal (programming language)|Pascal]], and [[Fortran]] could be linked together into one program, in a process they called "Mixed Language Programming" and now "InterLanguage Calling".<ref>[http://support.microsoft.com/kb/35965 Which Basic Versions Can CALL C, FORTRAN, Pascal, MASM]</ref> If [[BASIC]] was used in this mix, the main program needed to be in BASIC to support the internal [[runtime system]] that compiled BASIC required for garbage collection and its other managed operations that simulated a BASIC [[interpreter (computing)|interpreter]] like [[QBasic]] in MS-DOS.

The [[calling convention]] for C code, in particular, was to pass parameters in "reverse order" on the [[call stack|stack]] and return values on the stack rather than in a [[processor register]]. There were other programming rules to make all the languages work together, but this particular rule persisted through the cross language development that continued throughout [[Microsoft Windows|Windows]] 16- and 32-bit versions and in the development of programs for [[OS/2]], and which persists to this day. It is known as the [[Pascal calling convention]].

Another type of cross compilation that Microsoft C was used for during this time was in retail applications that require [[handheld device]]s like the [[Symbol Technologies]] PDT3100 (used to take [[inventory]]), which provided a link library targeted at an [[Intel 8088|8088]] based [[barcode reader]]. The application was built on the host computer then transferred to the handheld device (via a [[serial cable]]) where it was run, similar to what is done today for that same market using [[Windows Mobile]] by companies like [[Motorola]], who bought Symbol.

=== Early 1990s ===
Throughout the 1990s and beginning with MSC 6 (their first [[ANSI C]] compliant compiler) Microsoft re-focused their C compilers on the emerging Windows market, and also on [[OS/2]] and in the development of [[GUI]] programs. Mixed language compatibility remained through MSC 6 on the MS-DOS side, but the [[API]] for Microsoft Windows 3.0 and 3.1 was written in MSC 6. MSC 6 was also extended to provide support for 32-bit assemblies and support for the emerging [[Windows for Workgroups]] and [[Windows NT]] which would form the foundation for [[Windows XP]]. A programming practice called a [[thunk]] was introduced to allow passing between 16- and 32-bit programs that took advantage of runtime binding ([[dynamic linking]]) rather than the [[static binding]] that was favoured in [[Monolithic system|monolithic]] 16-bit MS-DOS applications. Static binding is still favoured by some native code developers but does not generally provide the degree of [[code reuse]] required by newer best practices like the [[Capability Maturity Model]] (CMM).

MS-DOS support was still provided with the release of Microsoft's first C++ Compiler, MSC 7, which was backwardly compatible with the C programming language and MS-DOS and supported both 16- and 32-bit code generation.

MSC took over where [[Aztec C|Aztec C86]] left off. The market share for C compilers had turned to cross compilers which took advantage of the latest and greatest Windows features, offered C and C++ in a single bundle, and still supported MS-DOS systems that were already a decade old, and the smaller companies that produced compilers like Aztec C could no longer compete and either turned to niche markets like [[embedded system]]s or disappeared.

MS-DOS and 16-bit code generation support continued until MSC 8.00c which was bundled with Microsoft C++ and Microsoft Application Studio 1.5, the forerunner of [[Microsoft Visual Studio]] which is the cross development environment that Microsoft provide today.

=== Late 1990s ===
MSC 12 was released with Microsoft Visual Studio 6 and no longer provided support for MS-DOS 16-bit binaries, instead providing support for 32-bit console applications, but provided support for [[Windows 95]] and [[Windows 98]] code generation as well as for [[Windows NT]]. Link libraries were available for other processors that ran Microsoft Windows; a practice that Microsoft continues to this day.

MSC 13 was released with [[Visual Studio 2003]], and MSC 14 was released with [[Visual Studio 2005]], both of which still produce code for older systems like Windows 95, but which will produce code for several target platforms including the mobile market and the [[ARM architecture family|ARM architecture]].

=== .NET and beyond ===
In 2001 Microsoft developed the [[Common Language Runtime]] (CLR), which formed the core for their [[.NET Framework]] compiler in the Visual Studio IDE. This layer on the operating system which is in the [[Application programming interface|API]] allows the mixing of development languages compiled across platforms that run the Windows operating system.

The .NET Framework runtime and CLR provide a mapping layer to the core routines for the processor and the devices on the target computer. The command-line C compiler in Visual Studio will compile native code for a variety of processors and can be used to build the core routines themselves.

Microsoft .NET applications for target platforms like [[Windows Mobile]] on the [[ARM architecture family|ARM architecture]] cross-compile on Windows machines with a variety of processors and Microsoft also offer emulators and remote deployment environments that require very little configuration, unlike the cross compilers in days gone by or on other platforms.

Runtime libraries, such as [[Mono (software)|Mono]], provide compatibility for cross-compiled .NET programs to other operating systems, such as [[Linux]].

Libraries like [[Qt (software)|Qt]] and its predecessors including [[XVT]] provide source code level cross development capability with other platforms, while still using Microsoft C to build the Windows versions. Other compilers like [[MinGW]] have also become popular in this area since they are more directly compatible with the Unixes that comprise the non-Windows side of software development allowing those developers to target all platforms using a familiar build environment.