+++Date last modified: 05-Jul-1997 Q: Which PC C/C++ compiler is best and what should I buy? A: This is perhaps the commonest of Frequently Asked Questions (FAQ's), especially by beginning C'er. The honest answer is that there is no "best" compiler and what may be best for you depends to a large degree on what you'll be using it for. The PC C/C++ compiler market is quite brutal and the companies that have survived have done so because some number of people think each of them makes the "best" compiler. With the preceding caveat in mind, following are some summaries of the current crop of C/C++ compilers with some of their strengths and weaknesses. Additional recommended reading are the C/C++ compiler reviews appearing in PC Magazine. PC Mag's reviews for many years were highly slanted and suspect, but, in recent years, have become commendably objective and even-handed. MIX POWER C ----------- Power C is the least expensive PC C compiler on the market. The compiler itself is $20, and an additional $30 will buy their source-level debugger along with the complete library source code with an assembler. So, what's the catch? None, actually. Power C is a quite decent and ANSI-conforming compiler which compiles relatively tight, fast code relatively quickly. It's biggest drawback is its use of a non-standard object file format which obviates object-level compatibility with any other compiler using Microsoft/Intel standard object file formats. Another problem is lack of support from 3rd party library vendors. Although Mix sells a wide range of libraries themselves, it's difficult to convince a vendor to produce a $100 add-on library for a $20 compiler. On the plus side, Power C comes with the best user's manual for students in the business. The beginner's tutorial section has enabled many beginning C programmers to get up to speed without spending another dime on any other textbooks. Should you want more instruction, Mix sells a package including Power C with the library source and debugger along with the book "Master C" for only $60. Power C's primary technical claim to fame is its floating point which challenges the industry leader, Watcom, in many cases. It's also the only remaining C compiler which can run effectively on small or older machines without extended memory (SC++ can also, but is limited to *very* small programs). MICROSOFT VISUAL C++ (VC++) --------------------------- Microsoft's professional compiler now comes in two versions with the same name but different version numbers. Version 1.52 is the current 16 bit compiler, and supports DOS and Windows. With some care (and libraries from MS C 6.0) people have gotten it to produce programs for OS/2 as well, but this proposition is not for the faint of heart. Visual C++ 2.x supports only Win32 targets. (Windows NT and Windows 95) It bears a reasonable similarity to the 16 bit compiler, but many of the ancillary tools have changed, particularly those that deal directly with executables, which isn't surprising since the executables themselves have changed considerably. On the plus side, VC++ is an excellent C++ compiler and generates executables which may not always be smaller than Borland, but usually execute faster. Microsoft's C compilers are still the standard for PC C compilers and it shows in the ready availability of 3rd party libraries supporting it. Support for Windows programming is excellent with tools only rivaled by SC++ (which is shipped with licensed copies of the MFC class library). Compile times with full optimization are still quite sluggish, but using the quick compile option can be provide acceptable results. The 32 bit compiler has no explicit quick compile option, but compile times with optimization turned off are fairly reasonable. BORLAND C++ (BC++) ------------------ BC++ carries on Borland's tradition of providing excellent bang for the buck. The latest release (4.5) of their professional compiler is an attractive alternative to shops also considering VC++. BC++ isn't as demanding as VC++ but still requires considerable resources. However, the 32 bit compiler is one of the few 32 bit versions to still run under DOS, reducing its hunger for memory considerably compared to VC++ and SC++, which both require 16 Megs for 32 bit compilation. The present Windows development tools are roughly on a par with those from Microsoft and Symantec. For unknown reasons, the 32 bit compiler is roughly twice as fast as the 16 bit compiler, given sufficient memory. Borland's tools are uniformly excellent, but the compiler still suffers a bit in comparison to the industry's technological leaders, Microsoft, Watcom, and Symantec - although the gap is closing. As with VC++, it's an excellent C++ compiler and enjoys widespread support among 3rd party library vendors. Like all Borland compilers, ease of use was a design priority, all oriented to the excellent IDE. BC 4.5 followed fairly closely after the (disastrous) release of BC 4.0. While Borland loyalists still miss the DOS IDE, in most other areas, the major problems with BC 4.0 have been ironed out and Turbo Profiler, which was left out of BC 4.0, has been added back in. The single greatest lack at this point is likely the DOS based IDE. At this point, a Win32 and/or OS/2 text mode IDE might be a better choice. OTOH, there are many excellent text editors capable of far more than the DOS IDE ever dreamt of. The final consideration in choosing Borland's tools is the financial soundness of the company. Around the beginning of 1995, Borland seemed almost certain to be gone by the end of the year. However, the recent release of Delphi has apparently been almost as good as BC 4.0 was bad, and their finances seem less a worry at the moment. TURBO C++ (TC++) ---------------- TC++ is to Borland's C++ compiler targeted at the hobbyist market. The latest version (TC++ 3.1) raised quite a stir when Borland released it requiring at least a 286 processor and 1 Mb of *available* extended memory above the normal 640K DOS limit. Many hobbyists running on older XT's, or machines without the excess memory capacity have therefore failed to upgrade to the new release. If you have the machine to support it, TC++ has the usual Borland attributes of extreme ease-of-use, attractive Integrated Development Environment (IDE), and good supporting tools. Based on the facts of BC++ 4.0 cited above, it has become the compiler of choice for many Borland loyalists. SYMANTEC C++ (SC++) ------------------- Symantec C++ (nee Zortech C++) was the industry's first C++ compiler, but fell behind in tracking the C++ language spec. Bought out by Symantec in 1991, the C compiler was always excellent and now its C++ compiler rates among the best. SC++ supports DOS, Mac, Unix, Win32s, and NT (OS/2 was supported in previous Zortech releases and may be again) using an extremely powerful new object- oriented Windows-hosted IDE. It includes excellent libraries and add-ons including a TSR library, swapping spawn functions, a royalty-free 32-bit DOS extender, and an excellent set of ancillary C and C++ tools libraries including MFC 2.0 as previously noted. SC++ can generate true 32-bit code and has a switch for generating Pentium code. At the same time that Symantec bought Zortech, they also bought Multiscope, whose debuggers are included in the package. As with VC++, SC++ includes excellent tools for quickly developing Windows applications. SC++ has always been in the forefront of optimizer technology along with Microsoft and Watcom. A major feature is full IEEE-754 and NCEG (Numerical C Extensions Group (an ANSI working committee trying to make C a suitable replacement for FORTRAN) compatibility. The only negative for the current release is a poor reputation which arose largely during the period following the Symantec acquisition of Zortech. As of version 6.1, the bugs were mostly fixed. Support of DOS graphics was also dropped, but an updated version of the excellent Flash Graphics package shipped with the Zortech versions is available from FlashTek, which also supplies improved versions of the 32-bit DOS extender and the pre-Symantec debugger. The current 7.0 release fixes almost all residual bugs and is significantly enhanced in the area of portability, supporting features of other DOS compilers such as the _interrupt keyword. One caveat - if you have any version prior to the 6.1 release, be sure to upgrade! WATCOM C/C++ (WC++) ------------------- Watcom has traditionally been the technological industry leader, performing feats of optimization and floating point speed other vendors only dreamt of. The cost has been compile speed, which has been described (somewhat unfairly) as glacial. For all its technical excellence, WC++ is still a niche market compiler like SC++. As such, it's 3rd party support is poor, but many have found that Microsoft C libraries can be made to work with WC++, often with nothing more than recompilation. As other compilers (most notably VC++ and SC++) have advanced, WC++'s technological lead has diminished and even been reversed for some applications. Like SC++, and unlike BC++ and VC++, WC++ provides documented support for embedded systems work, although not to nearly the same degree as Metaware (see below). Also, like SC++, WC++ supports 32-bit code generation. WC++ is the compiler of choice for many OEMs, such as Novell, who want only the best supporting code for their products. MSC/VC++ compatibility is excellent, but watch out for Watcom's sensitivity to proper _cdecl declarations, implemented in Watcom via a pragma rather than as a built-in language feature. Watcom sells both 16- and 32-bit versions of its C/C++ compiler. The best deal is to buy the 32-bit compiler and then purchase the 16-bit upgrade pack. Where Watcom really shines is its support for a multitude of environments with the same compiler(s). Supported are DOS, Win3.1, Win32s, NT, OS/2 (1.x & 2.x), Netware 386, AutoCAD ADS, QNX, Phar Lap and Rational DOS extenders. With such a bewildering array of targets, compilation is relatively straightforward but the linker has a steep learning curve. Watcom remains the only one of the "big name" compilers to not offer an IDE, if that's important to you or you don't own a "real" programmer's editor. METAWARE HIGH-C/C++ (HC++) -------------------------- HC++ is the darling of some segments of the embedded systems market. As such, it's a lot like WC++, only not quite as good and a lot weirder since it offers detailed control over every aspect of the executable. Most WC++ comments apply, except for the ones relating to quality of generated code. HC++'s code is quite good, but seems to be showing its niche market orientation (any one remember Manx Aztec C?) TOPSPEED C/C++ (TSC++) ---------------------- TSC++ has had a rocky life, getting off to a late start in the market and never having really quite caught on. Originally, TSC++ was a Turbo C clone which shared tools and environments with its sister Modula-2 compiler. More recent versions have extended this by using a modular approach with an environment supporting "plug-in" compilers for various languages which can all be used together. The company was recently acquired by Clarion. TSC++'s undisputed biggest strength is its smart linker and various features added to facilitate mixed-language programming (Modula-2, for example, supports multi-threaded code). Using this technology, you can count on TSC++ to almost always produce the smallest executables for a given piece of source code. The library, written almost exclusively in assembly, is also excellent and contributes to the frugal use of run-time memory. Unfortunately, the code generated by the compiler - even with full optimization - is typically not of the same quality as the library modules. Drawbacks include almost non-existent 3rd party support and the pervasive IDE which feels more at home to Modula-2 programmers than C programmers. GNU C/C++ (GCC, G++; also DJGPP, EMX) ------------------------------------- Available from the Free Software Foundation (FSF), GCC and G++ are two of only three compilers listed here available for free (the other is Micro-C). Originally written for Unix systems, there are several DOS and OS/2 ports available. All of the DOS ports require some sort of DOS extender technology built-in in order to work in DOS's limited memory. The most popular of the DOS ports is DJGPP. OS/2 ports obviously don't share this limitation. The EMX port for OS/2 is among the best and is quite popular among OS/2 programmers. Along with SC++, WC++, and HC++, the gnu compilers round out the list of full ISO/ANSI/ARM compilers with explicit support for embedded systems. Performance is decent, but not earth-shattering, and executables - especially small utilities - tend to exhibit some bloat. This may be overcome by using some non-standard compiler features unique to FSF compilers at the expense of portability. All GNU software carries the FSF's "GNU General Public License". This is their infamous "copyleft" license that guarantees their software tools remain free, yet imposes restrictions on redistribution and commercial distribution of the GNU tools and software developed with them. If you plan to use one of these to write commercial code, be sure and read the license agreement *very* closely. Note that simply producing an executable with the compiler does not subject the resulting program to copyleft, but use of GNU's run time library code subjects the program to their special library license, which is separate from the standard GNU license. Be *sure* to get the correct license and read it carefully before deciding on GCC/G++ for commercial use. In the case of DJGCC, the DOS extender used is subject to another license of its own. DUNFIELD MICRO-C ---------------- There have been many "small" or "tiny" C's over the years, some useful for teaching the rudiments of compiler construction, others not much use for anything. Small C's typically lack structs, unions, bit fields, and even long integers. Why bother listing this one then? First of all, Micro-C is an evolving product which, as of version 3, now includes many features such as structs and unions not normally associated with small C's. Secondly, Dave Dunfield recently made the DOS version of Micro-C freeware. You can use it without restriction or licensing fees to create DOS programs. Third, the source code (available when you register the shareware version) is quite decent and really can teach you something about compiler internals. But Micro-C is genuinely useful for a lot more reasons. Finally, the PC library includes support for writing TSR's, interrupt-driven serial I/O, and screen windowing. Amazingly, it also sports an optimizer, but requires MASM or equivalent for compiling PC applications. How does Dave provide such a nifty tool for free? Simple - he makes his money off of Micro-C by producing cross-assemblers for a variety of microprocessors and provides plug-in code generators for his C compiler to use with those chips as well. The 80x86 version comes ready to compile either PC or embedded code. Supporting small and tiny model only, Micro-C executables are phenomenally small. "Hello world" programs that run 5-6K on other compilers run under 600 bytes when compiled with Micro-C. One other point needs to be mentioned with respect to Micro-C... Although it is *a* small C, it has no code commonality with *the* Small C from the book of the same name. This is important since there are a number of variants of Small C available, all not much better than the original. Micro-C, OTOH, was written by Dave Dunfield completely from scratch and is a *much* better designed piece of code and certainly much more instructive to fledgling compiler writers. His better design is evinced in code quality and execution speed. PCC --- The Personal C Compiler is available as shareware. It used to be marketed as the deSmet C compiler and had a generally good reputation for quick compile times and tight code. Unfortunately, the product hasn't been seriously upgraded in quite a while and can't stand too much comparison. It's horribly non-ANSI compliant, has a weaker set of library functions than Micro-C, features non-standard file formats, and is generally incompatible with most published C code. Even Micro-C, which makes no claim to ANSI compliance, is still considerably closer to it than PCC. The current version of Micro-C accepts function prototypes, likely the single most important addition made to C in the ANSI standard. If price is your concern, Mix Power C costs less to buy than PCC does to register and offers better performance along with the ANSI compliance that PCC lacks. If you plan on using an unregistered copy, Gnu C/C++ is vastly superior and is legally free. If you're attracted to its tight, fast code and can live with quirks and without ANSI compliance, go with Dunfield Micro-C. Q. Do have any samples? A: The following program was compiled using several DOS compilers with the results as noted below. The compilers tested are noted in the executable program's name as follows: Suffix Compiler Notes ------ -------- ----- _b45 Borland C 4.5 _b31 Borland C 3.1 _g32 gnu C (DJGPP 1.12M2) GO32 32-bit DOS extender _mc Dunfield Micro-C 3.13 _ms Microsoft C 8.0 Part of Visual C++ 1.5 _pc Mix Power C 2.2 _sc Symantec C 7.0 _s32 Symantec C 7.0 DOSX 32-bit DOS extender _wc Watcom C 10.0 _w32 Watcom C 10.0 DOS/4GW 32-bit DOS extender _zc Zortech C 3.0r4 _z32 Zortech C 3.0r4 DOSX 32-bit DOS extender All executables were compiled with maximum optimization and with other options (e.g. no exception handling for Borland 4.5) to assure minimum size of the executables. The results for Zortech and Borland are for comarison since both are several revision obsolete (however they do highlight the fact that if all you want to do is compile straight C code, sometimes the latest isn't always the greatest). The test file was selected as an example of a minimally useful standard C program. Some coding peculiarities were introduced to accomodate some non-standard features of the Micro-C library. The program listing is followed by execution and compile times. The machine used for the test was a 486/DX50 using Golden Bow's Vcache. Due to the presense of the cache and the small size of the program, the execution timings are probably only grossly representative. The timings for the DJGPP-compiled test includes timings for both the compilation and COFF-to-.EXE conversion required to produce a stand-alone executable. The compilation time listing for WCL386 is for the Watcom-compiled version using the DOS/4GW 32-bit DOS extender. ----[ Size.C ]---------------------------------------------------------------- #include #ifndef __MICROC__ #include #endif main(int argc, char *argv[]) { char buf[80], *ptr; FILE *me; if (NULL == (me = fopen("size.c", "r"))) { fputs("Can't open SIZE.C\n", stderr); return -1; } while (1) { if (NULL == fgets(buf, 80, me)) break; for (ptr = buf + strlen(buf) - 1; ptr >= buf && *ptr == '\n'; --ptr) { *ptr = '\0'; } printf("%s\n", buf); } return 0; } ----[ Dr.Out ]----------------------------------------------------------------  DR 3.00á  Disk vol "STACVOL_DSK" Directory of D:\BINK\CODE\WIP 12 Files totalling 192,477 bytes 602,865,664 Bytes free Size_mc Com 2,105 ..a.rwx 20 Nov 95 9:59:42 < Micro-C 3.13 Size_zc Com 8,035 ..a.rwx 20 Nov 95 9:59:00 < ZTC 3.0r4 Size_ms Com 8,049 ..a.rwx 20 Nov 95 10:09:50 < MSC 8.0 Size_b31 Com 8,776 ..a.rwx 20 Nov 95 10:11:24 < BC++ 3.1 Size_wc Com 9,318 ..a.rwx 20 Nov 95 10:03:46 < WC 10.0 Size_sc Com 10,528 ..a.rwx 20 Nov 95 10:04:48 < SC++ 7.0 Size_b45 Com 11,216 ..a.rwx 20 Nov 95 10:07:20 < BC++ 4.5 Size_pc Exe 13,312 ..a.rwx 20 Nov 95 10:12:40 < Mix Power C 2.2 Size_w32 Exe 25,994 ..a.rwx 20 Nov 95 10:21:44 < WC/DOS 4G/W Size_z32 Exe 27,941 ..a.rwx 20 Nov 95 10:17:44 < ZTC/DOSX Size_s32 Exe 29,149 ..a.rwx 20 Nov 95 10:18:42 < SC++/DOSX Size_g32 Exe 38,054 ..a.rwx 20 Nov 95 10:23:44 < DJGPP 1.12M2 ----[ Execution times ]------------------------------------------------------- SIZE_WC Elapsed time = 0.116001 Seconds < WC 10.0 SIZE_MS Elapsed time = 0.116579 Seconds < MSC 8.0 SIZE_B31 Elapsed time = 0.121079 Seconds < BC++ 3.1 SIZE_PC Elapsed time = 0.127011 Seconds < Mix Power C 2.2 SIZE_ZC Elapsed time = 0.218889 Seconds < ZTC 3.0r4 SIZE_SC Elapsed time = 0.221269 Seconds < SC++ 7.0 SIZE_MC Elapsed time = 0.226919 Seconds < Micro-C 3.13 SIZE_B45 Elapsed time = 0.232461 Seconds < BC++ 4.5 SIZE_Z32 Elapsed time = 0.233987 Seconds < ZTC/DOSX SIZE_G32 Elapsed time = 0.406291 Seconds < DJGPP 1.12M2 SIZE_S32 Elapsed time = 0.461156 Seconds < SC++/DOSX SIZE_W32 Elapsed time = 1.299404 Seconds < WC/DOS 4GW ----[ Compile times ]--------------------------------------------------------- PC (Mix Power C) 2.2 1.505081 Seconds CC (Micro-C) 3.13 1.843561 Seconds ZTC 3.0r4 1.948132 Seconds SC 7.0 3.002091 Seconds BCC 4.5 4.108201 Seconds BCC 3.1 4.586260 Seconds WCL 10.0 5.669630 Seconds WCL386 10.0 6.342555 Seconds CL (MSC) 8.0 6.697373 Seconds GCC (djgpp) 1.12M2 8.287935 Seconds ----[ finis ]-----------------------------------------------------------------