![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to internals-1 CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [GCC 1.x] / gcc|
Return to internals-1 CVS log | Up to [GCC 1.x] / gcc |
1.1.1.4 ! root 1: Info file internals, produced by Makeinfo, -*- Text -*- from input ! 2: file internals.texinfo. ! 3: ! 4: This file documents the internals of the GNU compiler. ! 5: ! 6: Copyright (C) 1988 Free Software Foundation, Inc. ! 7: ! 8: Permission is granted to make and distribute verbatim copies of this ! 9: manual provided the copyright notice and this permission notice are ! 10: preserved on all copies. ! 11: ! 12: Permission is granted to copy and distribute modified versions of ! 13: this manual under the conditions for verbatim copying, provided also ! 14: that the section entitled ``GNU CC General Public License'' is ! 15: included exactly as in the original, and provided that the entire ! 16: resulting derived work is distributed under the terms of a permission ! 17: notice identical to this one. ! 18: ! 19: Permission is granted to copy and distribute translations of this ! 20: manual into another language, under the above conditions for modified ! 21: versions, except that the section entitled ``GNU CC General Public ! 22: License'' and this permission notice may be included in translations ! 23: approved by the Free Software Foundation instead of in the original ! 24: English. ! 25: 1.1 root 26: 27: 1.1.1.2 root 28: File: internals, Node: Top, Next: Copying, Up: (DIR) 1.1 root 29: 30: Introduction 31: ************ 32: 1.1.1.4 ! root 33: This manual documents how to run, install and port the GNU C ! 34: compiler, as well as its new features and incompatibilities, and how ! 35: to report bugs. 1.1.1.2 root 36: 1.1 root 37: * Menu: 38: 39: * Copying:: GNU CC General Public License says 40: how you can copy and share GNU CC. 1.1.1.2 root 41: * Contributors:: People who have contributed to GNU CC. 42: * Options:: Command options supported by `gcc'. 1.1 root 43: * Installation:: How to configure, compile and install GNU CC. 1.1.1.3 root 44: * Trouble:: If you have trouble installing GNU CC. 1.1.1.2 root 45: * Incompatibilities:: Incompatibilities of GNU CC. 46: * Extensions:: GNU extensions to the C language. 47: * Bugs:: How to report bugs (if you want to get them fixed). 1.1 root 48: * Portability:: Goals of GNU CC's portability features. 1.1.1.2 root 49: * Interface:: Function-call interface of GNU CC output. 1.1 root 50: * Passes:: Order of passes, what they do, and what each file is for. 51: * RTL:: The intermediate representation that most passes work on. 52: * Machine Desc:: How to write machine description instruction patterns. 53: * Machine Macros:: How to write the machine description C macros. 54: 1.1.1.4 ! root 55: 1.1 root 56: 1.1.1.2 root 57: File: internals, Node: Copying, Next: Contributors, Prev: Top, Up: Top 1.1 root 58: 59: GNU CC GENERAL PUBLIC LICENSE 60: ***************************** 61: 1.1.1.4 ! root 62: (Clarified 11 Feb 1988) 1.1 root 63: 1.1.1.4 ! root 64: The license agreements of most software companies keep you at the ! 65: mercy of those companies. By contrast, our general public license is ! 66: intended to give everyone the right to share GNU CC. To make sure ! 67: that you get the rights we want you to have, we need to make ! 68: restrictions that forbid anyone to deny you these rights or to ask ! 69: you to surrender the rights. Hence this license agreement. ! 70: ! 71: Specifically, we want to make sure that you have the right to give ! 72: away copies of GNU CC, that you receive source code or else can get ! 73: it if you want it, that you can change GNU CC or use pieces of it in ! 74: new free programs, and that you know you can do these things. 1.1 root 75: 1.1.1.2 root 76: To make sure that everyone has such rights, we have to forbid you to 1.1.1.4 ! root 77: deprive anyone else of these rights. For example, if you distribute ! 78: copies of GNU CC, you must give the recipients all the rights that ! 79: you have. You must make sure that they, too, receive or can get the ! 80: source code. And you must tell them their rights. ! 81: ! 82: Also, for our own protection, we must make certain that everyone ! 83: finds out that there is no warranty for GNU CC. If GNU CC is ! 84: modified by someone else and passed on, we want its recipients to ! 85: know that what they have is not what we distributed, so that any ! 86: problems introduced by others will not reflect on our reputation. ! 87: ! 88: Therefore we (Richard Stallman and the Free Software Foundation, ! 89: Inc.) make the following terms which say what you must do to be ! 90: allowed to distribute or change GNU CC. 1.1 root 91: 92: COPYING POLICIES 93: ================ 94: 1.1.1.4 ! root 95: 1. You may copy and distribute verbatim copies of GNU CC source ! 96: code as you receive it, in any medium, provided that you ! 97: conspicuously and appropriately publish on each copy a valid ! 98: copyright notice ``Copyright (C) 1988 Free Software Foundation, ! 99: Inc.'' (or with whatever year is appropriate); keep intact the ! 100: notices on all files that refer to this License Agreement and to ! 101: the absence of any warranty; and give any other recipients of ! 102: the GNU CC program a copy of this License Agreement along with ! 103: the program. You may charge a distribution fee for the physical ! 104: act of transferring a copy. ! 105: ! 106: 2. You may modify your copy or copies of GNU CC or any portion of ! 107: it, and copy and distribute such modifications under the terms ! 108: of Paragraph 1 above, provided that you also do the following: ! 109: ! 110: * cause the modified files to carry prominent notices stating ! 111: that you changed the files and the date of any change; and ! 112: ! 113: * cause the whole of any work that you distribute or publish, ! 114: that in whole or in part contains or is a derivative of GNU ! 115: CC or any part thereof, to be licensed at no charge to all ! 116: third parties on terms identical to those contained in this ! 117: License Agreement (except that you may choose to grant more ! 118: extensive warranty protection to some or all third parties, ! 119: at your option). 1.1.1.2 root 120: 1.1 root 121: * You may charge a distribution fee for the physical act of 1.1.1.4 ! root 122: transferring a copy, and you may at your option offer ! 123: warranty protection in exchange for a fee. 1.1 root 124: 1.1.1.4 ! root 125: Mere aggregation of another unrelated program with this program ! 126: (or its derivative) on a volume of a storage or distribution ! 127: medium does not bring the other program under the scope of these ! 128: terms. ! 129: ! 130: 3. You may copy and distribute GNU CC (or a portion or derivative ! 131: of it, under Paragraph 2) in object code or executable form ! 132: under the terms of Paragraphs 1 and 2 above provided that you ! 133: also do one of the following: ! 134: ! 135: * accompany it with the complete corresponding ! 136: machine-readable source code, which must be distributed ! 137: under the terms of Paragraphs 1 and 2 above; or, 1.1.1.2 root 138: 139: * accompany it with a written offer, valid for at least three 140: years, to give any third party free (except for a nominal 141: shipping charge) a complete machine-readable copy of the 1.1.1.4 ! root 142: corresponding source code, to be distributed under the ! 143: terms of Paragraphs 1 and 2 above; or, 1.1.1.2 root 144: 1.1.1.4 ! root 145: * accompany it with the information you received as to where ! 146: the corresponding source code may be obtained. (This ! 147: alternative is allowed only for noncommercial distribution ! 148: and only if you received the program in object code or ! 149: executable form alone.) ! 150: ! 151: For an executable file, complete source code means all the ! 152: source code for all modules it contains; but, as a special ! 153: exception, it need not include source code for modules which are ! 154: standard libraries that accompany the operating system on which ! 155: the executable file runs. ! 156: ! 157: 4. You may not copy, sublicense, distribute or transfer GNU CC ! 158: except as expressly provided under this License Agreement. Any ! 159: attempt otherwise to copy, sublicense, distribute or transfer ! 160: GNU CC is void and your rights to use the program under this ! 161: License agreement shall be automatically terminated. However, ! 162: parties who have received computer software programs from you ! 163: with this License Agreement will not have their licenses ! 164: terminated so long as such parties remain in full compliance. ! 165: ! 166: 5. If you wish to incorporate parts of GNU CC into other free ! 167: programs whose distribution conditions are different, write to ! 168: the Free Software Foundation at 675 Mass Ave, Cambridge, MA ! 169: 02139. We have not yet worked out a simple rule that can be ! 170: stated here, but we will often permit this. We will be guided ! 171: by the two goals of preserving the free status of all ! 172: derivatives of our free software and of promoting the sharing ! 173: and reuse of software. ! 174: ! 175: Your comments and suggestions about our licensing policies and our ! 176: software are welcome! Please contact the Free Software Foundation, ! 177: Inc., 675 Mass Ave, Cambridge, MA 02139, or call (617) 876-3296. 1.1 root 178: 179: NO WARRANTY 180: =========== 181: 182: BECAUSE GNU CC IS LICENSED FREE OF CHARGE, WE PROVIDE ABSOLUTELY NO 1.1.1.4 ! root 183: WARRANTY, TO THE EXTENT PERMITTED BY APPLICABLE STATE LAW. EXCEPT ! 184: WHEN OTHERWISE STATED IN WRITING, FREE SOFTWARE FOUNDATION, INC, ! 185: RICHARD M. STALLMAN AND/OR OTHER PARTIES PROVIDE GNU CC "AS IS" ! 186: WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, ! 187: BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND ! 188: FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY ! 189: AND PERFORMANCE OF GNU CC IS WITH YOU. SHOULD GNU CC PROVE ! 190: DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR ! 191: CORRECTION. ! 192: ! 193: IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW WILL RICHARD M. ! 194: STALLMAN, THE FREE SOFTWARE FOUNDATION, INC., AND/OR ANY OTHER PARTY ! 195: WHO MAY MODIFY AND REDISTRIBUTE GNU CC AS PERMITTED ABOVE, BE LIABLE ! 196: TO YOU FOR DAMAGES, INCLUDING ANY LOST PROFITS, LOST MONIES, OR OTHER ! 197: SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE ! 198: OR INABILITY TO USE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR ! 199: DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY THIRD PARTIES ! 200: OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS) GNU ! 201: CC, EVEN IF YOU HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, ! 202: OR FOR ANY CLAIM BY ANY OTHER PARTY. ! 203: 1.1 root 204: 205: 1.1.1.2 root 206: File: internals, Node: Contributors, Next: Options, Prev: Copying, Up: Top 207: 208: Contributors to GNU CC 209: ********************** 210: 1.1.1.4 ! root 211: In addition to Richard Stallman, several people have written parts of ! 212: GNU CC. 1.1.1.2 root 213: 1.1.1.4 ! root 214: * The idea of using RTL and some of the optimization ideas came ! 215: from the U. of Arizona Portable Optimizer, written by Jack ! 216: Davidson and Christopher Fraser. See ``Register Allocation and ! 217: Exhaustive Peephole Optimization'', Software Practice and ! 218: Experience 14 (9), Sept. 1984, 857-866. 1.1.1.2 root 219: 220: * Paul Rubin wrote most of the preprocessor. 221: 222: * Leonard Tower wrote parts of the parser, RTL generator, RTL 223: definitions, and of the Vax machine description. 224: 225: * Ted Lemon wrote parts of the RTL reader and printer. 226: 1.1.1.4 ! root 227: * Nobuyuki Hikichi of Software Research Associates, Tokyo, ! 228: contributed the support for the SONY NEWS machine. ! 229: ! 230: * Charles LaBrec contributed the support for the Integrated ! 231: Solutions 68020 system. ! 232: ! 233: * Michael Tiemann of MCC wrote most of the description of the ! 234: National Semiconductor 32000 series cpu. He also wrote the code ! 235: for inline function integration and for the SPARC cpu and ! 236: Motorola 88000 cpu and part of the Sun FPA support. 1.1.1.2 root 237: 1.1.1.4 ! root 238: * Jan Stein of the Chalmers Computer Society provided support for ! 239: Genix, as well as part of the 32000 machine description. 1.1 root 240: 1.1.1.4 ! root 241: * Randy Smith finished the Sun FPA support. 1.1 root 242: 1.1.1.3 root 243: * Robert Brown implemented the support for Encore 32000 systems. 244: 1.1.1.4 ! root 245: * David Kashtan of SRI adapted GNU CC to the Vomit-Making System. 1.1.1.2 root 246: 247: * Alex Crain provided changes for the 3b1. 248: 1.1.1.4 ! root 249: * Greg Satz and Chris Hanson assisted in making GNU CC work on ! 250: HP-UX for the 9000 series 300. ! 251: ! 252: * William Schelter did most of the work on the Intel 80386 support. ! 253: 1.1.1.2 root 254: 255: 256: File: internals, Node: Options, Next: Installation, Prev: Contributors, Up: Top 257: 258: GNU CC Command Options 259: ********************** 260: 1.1.1.4 ! root 261: The GNU C compiler uses a command syntax much like the Unix C compiler. ! 262: The `gcc' program accepts options and file names as operands. ! 263: Multiple single-letter options may *not* be grouped: `-dr' is very ! 264: different from `-d -r'. 1.1.1.2 root 265: 266: When you invoke GNU CC, it normally does preprocessing, compilation, 1.1.1.4 ! root 267: assembly and linking. File names which end in `.c' are taken as C ! 268: source to be preprocessed and compiled; compiler output files plus ! 269: any input files with names ending in `.s' are assembled; then the ! 270: resulting object files, plus any other input files, are linked ! 271: together to produce an executable. ! 272: ! 273: Command options allow you to stop this process at an intermediate ! 274: stage. For example, the `-c' option says not to run the linker. ! 275: Then the output consists of object files output by the assembler. ! 276: ! 277: Other command options are passed on to one stage. Some options ! 278: control the preprocessor and others the compiler itself. Yet other ! 279: options control the assembler and linker; these are not documented ! 280: here because the GNU assembler and linker are not yet released. ! 281: ! 282: Here are the options to control the overall compilation process, ! 283: including those that say whether to link, whether to assemble, and so ! 284: on. 1.1.1.2 root 285: 286: `-o FILE' 1.1.1.4 ! root 287: Place output in file FILE. This applies regardless to whatever ! 288: sort of output is being produced, whether it be an executable ! 289: file, an object file, an assembler file or preprocessed C code. ! 290: ! 291: If `-o' is not specified, the default is to put an executable ! 292: file in `a.out', the object file `SOURCE.c' in `SOURCE.o', an ! 293: assembler file in `SOURCE.s', and preprocessed C on standard ! 294: output. 1.1.1.2 root 295: 296: `-c' 1.1.1.4 ! root 297: Compile or assemble the source files, but do not link. Produce ! 298: object files with names made by replacing `.c' or `.s' with `.o' ! 299: at the end of the input file names. Do nothing at all for ! 300: object files specified as input. 1.1.1.2 root 301: 302: `-S' 1.1.1.4 ! root 303: Compile into assembler code but do not assemble. The assembler ! 304: output file name is made by replacing `.c' with `.s' at the end ! 305: of the input file name. Do nothing at all for assembler source ! 306: files or object files specified as input. 1.1.1.2 root 307: 308: `-E' 309: Run only the C preprocessor. Preprocess all the C source files 310: specified and output the results to standard output. 311: 312: `-v' 1.1.1.4 ! root 313: Compiler driver program prints the commands it executes as it ! 314: runs the preprocessor, compiler proper, assembler and linker. ! 315: Some of these are directed to print their own version numbers. 1.1.1.2 root 316: 317: `-BPREFIX' 1.1.1.4 ! root 318: Compiler driver program tries PREFIX as a prefix for each ! 319: program it tries to run. These programs are `cpp', `cc1', `as' ! 320: and `ld'. ! 321: ! 322: For each subprogram to be run, the compiler driver first tries ! 323: the `-B' prefix, if any. If that name is not found, or if `-B' ! 324: was not specified, the driver tries two standard prefixes, which ! 325: are `/usr/lib/gcc-' and `/usr/local/lib/gcc-'. If neither of ! 326: those results in a file name that is found, the unmodified ! 327: program name is searched for using the directories specified in ! 328: your `PATH' environment variable. ! 329: ! 330: The run-time support file `gnulib' is also searched for using ! 331: the `-B' prefix, if needed. If it is not found there, the two ! 332: standard prefixes above are tried, and that is all. The file is ! 333: left out of the link if it is not found by those means. Most of ! 334: the time, on most machines, you can do without it. 1.1.1.2 root 335: 336: These options control the details of C compilation itself. 337: 338: `-ansi' 339: Support all ANSI standard C programs. 340: 1.1.1.4 ! root 341: This turns off certain features of GNU C that are incompatible ! 342: with ANSI C, such as the `asm', `inline' and `typeof' keywords, ! 343: and predefined macros such as `unix' and `vax' that identify the ! 344: type of system you are using. It also enables the undesirable ! 345: and rarely used ANSI trigraph feature. ! 346: ! 347: The `-ansi' option does not cause non-ANSI programs to be ! 348: rejected gratuitously. For that, `-pedantic' is required in ! 349: addition to `-ansi'. ! 350: ! 351: The macro `__STRICT_ANSI__' is predefined when the `-ansi' ! 352: option is used. Some header files may notice this macro and ! 353: refrain from declaring certain functions or defining certain ! 354: macros that the ANSI standard doesn't call for; this is to avoid ! 355: interfering with any programs that might use these names for ! 356: other things. 1.1.1.2 root 357: 358: `-traditional' 359: Attempt to support some aspects of traditional C compilers. 360: Specifically: 361: 1.1.1.4 ! root 362: * All `extern' declarations take effect globally even if they ! 363: are written inside of a function definition. This includes ! 364: implicit declarations of functions. 1.1.1.2 root 365: 1.1.1.4 ! root 366: * The keywords `typeof', `inline', `signed', `const' and ! 367: `volatile' are not recognized. 1.1.1.2 root 368: 369: * Comparisons between pointers and integers are always allowed. 370: 1.1.1.4 ! root 371: * Integer types `unsigned short' and `unsigned char' promote ! 372: to `unsigned int'. 1.1.1.2 root 373: 1.1.1.4 ! root 374: * Out-of-range floating point literals are not an error. 1.1.1.2 root 375: 1.1.1.4 ! root 376: * In the preprocessor, comments convert to nothing at all, ! 377: rather than to a space. This allows traditional token ! 378: concatenation. ! 379: ! 380: * In the preprocessor, macro arguments are recognized within ! 381: string constants in a macro definition (and their values ! 382: are stringified, though without additional quote marks, ! 383: when they appear in such a context). The preprocessor ! 384: always considers a string constant to end at a newline. 1.1.1.2 root 385: 386: `-O' 1.1.1.4 ! root 387: Optimize. Optimizing compilation takes somewhat more time, and ! 388: a lot more memory for a large function. 1.1.1.2 root 389: 1.1.1.4 ! root 390: Without `-O', the compiler's goal is to reduce the cost of ! 391: compilation and to make debugging produce the expected results. ! 392: Statements are independent: if you stop the program with a ! 393: breakpoint between statements, you can then assign a new value ! 394: to any variable or change the program counter to any other ! 395: statement in the function and get exactly the results you would ! 396: expect from the source code. ! 397: ! 398: Without `-O', only variables declared `register' are allocated ! 399: in registers. The resulting compiled code is a little worse ! 400: than produced by PCC without `-O'. 1.1.1.2 root 401: 1.1.1.4 ! root 402: With `-O', the compiler tries to reduce code size and execution ! 403: time. 1.1.1.2 root 404: 405: Some of the `-f' options described below turn specific kinds of 406: optimization on or off. 407: 408: `-g' 1.1.1.4 ! root 409: Produce debugging information in the operating system's native ! 410: format (for DBX or SDB). 1.1.1.2 root 411: 1.1.1.4 ! root 412: Unlike most other C compilers, GNU CC allows you to use `-g' ! 413: with `-O'. The shortcuts taken by optimized code may ! 414: occasionally produce surprising results: some variables you ! 415: declared may not exist at all; flow of control may briefly move ! 416: where you did not expect it; some statements may not be executed ! 417: because they compute constant results or their values were ! 418: already at hand; some statements may execute in different places ! 419: because they were moved out of loops. Nevertheless it proves ! 420: possible to debug optimized output. This makes it reasonable to ! 421: use the optimizer for programs that might have bugs. 1.1.1.2 root 422: 423: `-gg' 1.1.1.4 ! root 424: Produce debugging information in GDB's own format. This ! 425: requires the GNU assembler and linker in order to work. 1.1.1.2 root 426: 427: `-w' 428: Inhibit all warning messages. 429: 430: `-W' 431: Print extra warning messages for these events: 432: 1.1.1.4 ! root 433: * An automatic variable is used without first being ! 434: initialized. 1.1.1.2 root 435: 436: These warnings are possible only in optimizing compilation, 1.1.1.4 ! root 437: because they require data flow information that is computed ! 438: only when optimizing. They occur only for variables that ! 439: are candidates for register allocation. Therefore, they do ! 440: not occur for a variable that is declared `volatile', or ! 441: whose address is taken, or whose size is other than 1, 2, 4 ! 442: or 8 bytes. Also, they do not occur for structures, unions ! 443: or arrays, even when they are in registers. ! 444: ! 445: Note that there may be no warning about a variable that is ! 446: used only to compute a value that itself is never used, ! 447: because such computations may be deleted by the flow ! 448: analysis pass before the warnings are printed. ! 449: ! 450: These warnings are made optional because GNU CC is not ! 451: smart enough to see all the reasons why the code might be ! 452: correct despite appearing to have an error. Here is one ! 453: example of how this can happen: 1.1.1.2 root 454: 455: { 456: int x; 457: switch (y) 458: { 459: case 1: x = 1; 460: break; 461: case 2: x = 4; 462: break; 463: case 3: x = 5; 464: } 465: foo (x); 466: } 467: 468: If the value of `y' is always 1, 2 or 3, then `x' is always 469: initialized, but GNU CC doesn't know this. Here is another 470: common case: 471: 472: { 473: int save_y; 474: if (change_y) save_y = y, y = new_y; 475: ... 476: if (change_y) y = save_y; 477: } 478: 1.1.1.4 ! root 479: This has no bug because `save_y' is used only if it is set. 1.1.1.2 root 480: 1.1.1.4 ! root 481: * A nonvolatile automatic variable might be changed by a call ! 482: to `longjmp'. These warnings as well are possible only in 1.1.1.2 root 483: optimizing compilation. 484: 1.1.1.4 ! root 485: The compiler sees only the calls to `setjmp'. It cannot ! 486: know where `longjmp' will be called; in fact, a signal ! 487: handler could call it at any point in the code. As a ! 488: result, you may get a warning even when there is in fact no ! 489: problem because `longjmp' cannot in fact be called at the ! 490: place which would cause a problem. ! 491: ! 492: * A function can return either with or without a value. ! 493: (Falling off the end of the function body is considered ! 494: returning without a value.) For example, this function ! 495: would inspire such a warning: 1.1.1.2 root 496: 497: foo (a) 498: { 499: if (a > 0) 500: return a; 501: } 502: 1.1.1.4 ! root 503: Spurious warnings can occur because GNU CC does not realize ! 504: that certain functions (including `abort' and `longjmp') ! 505: will never return. 1.1.1.2 root 506: 1.1.1.4 ! root 507: In the future, other useful warnings may also be enabled by this ! 508: option. 1.1.1.2 root 509: 510: `-Wimplicit' 511: Warn whenever a function is implicitly declared. 512: 513: `-Wreturn-type' 1.1.1.4 ! root 514: Warn whenever a function is defined with a return-type that ! 515: defaults to `int'. Also warn about any `return' statement with ! 516: no return-value in a function whose return-type is not `void'. 1.1.1.2 root 517: 518: `-Wcomment' 519: Warn whenever a comment-start sequence `/*' appears in a comment. 520: 1.1.1.3 root 521: `-Wall' 522: All of the above `-W' options combined. 523: 1.1.1.4 ! root 524: `-Wwrite-strings' ! 525: Give string constants the type `const char[LENGTH]' so that ! 526: copying the address of one into a non-`const' `char *' pointer ! 527: will get a warning. These warnings will help you find at ! 528: compile time code that can try to write into a string constant, ! 529: but only if you have been very careful about using `const' in ! 530: declarations and prototypes. Otherwise, it will just be a ! 531: nuisance; this is why we did not make `-Wall' request these ! 532: warnings. ! 533: 1.1.1.2 root 534: `-p' 1.1.1.4 ! root 535: Generate extra code to write profile information suitable for ! 536: the analysis program `prof'. 1.1.1.2 root 537: 538: `-pg' 1.1.1.4 ! root 539: Generate extra code to write profile information suitable for ! 540: the analysis program `gprof'. 1.1.1.2 root 541: 1.1.1.3 root 542: `-lLIBRARY' 1.1.1.4 ! root 543: Search a standard list of directories for a library named ! 544: LIBRARY, which is actually a file named `libLIBRARY.a'. The ! 545: linker uses this file as if it had been specified precisely by ! 546: name. ! 547: ! 548: The directories searched include several standard system ! 549: directories plus any that you specify with `-L'. ! 550: ! 551: Normally the files found this way are library files--archive ! 552: files whose members are object files. The linker handles an ! 553: archive file by scanning through it for members which define ! 554: symbols that have so far been referenced but not defined. But ! 555: if the file that is found is an ordinary object file, it is ! 556: linked in the usual fashion. The only difference between using ! 557: an `-l' option and specifying a file name is that `-l' searches ! 558: several directories. 1.1.1.2 root 559: 1.1.1.3 root 560: `-LDIR' 1.1.1.4 ! root 561: Add directory DIR to the list of directories to be searched for ! 562: `-l'. 1.1.1.3 root 563: 1.1.1.2 root 564: `-nostdlib' 565: Don't use the standard system libraries and startup files when 1.1.1.4 ! root 566: linking. Only the files you specify (plus `gnulib') will be ! 567: passed to the linker. 1.1.1.2 root 568: 569: `-mMACHINESPEC' 1.1.1.4 ! root 570: Machine-dependent option specifying something about the type of ! 571: target machine. These options are defined by the macro ! 572: `TARGET_SWITCHES' in the machine description. The default for ! 573: the options is also defined by that macro, which enables you to ! 574: change the defaults. ! 575: ! 576: These are the `-m' options defined in the 68000 machine ! 577: description: ! 578: ! 579: `-m68020' ! 580: `-mc68020' ! 581: Generate output for a 68020 (rather than a 68000). This is ! 582: the default if you use the unmodified sources. 1.1.1.2 root 583: 1.1.1.4 ! root 584: `-m68000' ! 585: `-mc68000' 1.1.1.2 root 586: Generate output for a 68000 (rather than a 68020). 587: 1.1.1.4 ! root 588: `-m68881' ! 589: Generate output containing 68881 instructions for floating ! 590: point. This is the default if you use the unmodified ! 591: sources. ! 592: ! 593: `-mfpa' ! 594: Generate output containing Sun FPA instructions for ! 595: floating point. 1.1.1.2 root 596: 1.1.1.4 ! root 597: `-msoft-float' 1.1.1.2 root 598: Generate output containing library calls for floating point. 599: 1.1.1.4 ! root 600: `-mshort' 1.1.1.2 root 601: Consider type `int' to be 16 bits wide, like `short int'. 602: 1.1.1.4 ! root 603: `-mnobitfield' 1.1.1.2 root 604: Do not use the bit-field instructions. `-m68000' implies 605: `-mnobitfield'. 606: 1.1.1.4 ! root 607: `-mbitfield' 1.1.1.2 root 608: Do use the bit-field instructions. `-m68020' implies 1.1.1.4 ! root 609: `-mbitfield'. This is the default if you use the ! 610: unmodified sources. 1.1.1.2 root 611: 1.1.1.4 ! root 612: `-mrtd' ! 613: Use a different function-calling convention, in which ! 614: functions that take a fixed number of arguments return with ! 615: the `rtd' instruction, which pops their arguments while ! 616: returning. This saves one instruction in the caller since ! 617: there is no need to pop the arguments there. ! 618: ! 619: This calling convention is incompatible with the one ! 620: normally used on Unix, so you cannot use it if you need to ! 621: call libraries compiled with the Unix compiler. ! 622: ! 623: Also, you must provide function prototypes for all ! 624: functions that take variable numbers of arguments ! 625: (including `printf'); otherwise incorrect code will be ! 626: generated for calls to those functions. ! 627: ! 628: In addition, seriously incorrect code will result if you ! 629: call a function with too many arguments. (Normally, extra ! 630: arguments are harmlessly ignored.) 1.1.1.2 root 631: 632: The `rtd' instruction is supported by the 68010 and 68020 633: processors, but not by the 68000. 634: 635: These `-m' options are defined in the Vax machine description: 636: 1.1.1.4 ! root 637: `-munix' ! 638: Do not output certain jump instructions (`aobleq' and so ! 639: on) that the Unix assembler for the Vax cannot handle ! 640: across long ranges. ! 641: ! 642: `-mgnu' ! 643: Do output those jump instructions, on the assumption that ! 644: you will assemble with the GNU assembler. 1.1.1.2 root 645: 1.1.1.4 ! root 646: `-mg' 1.1.1.3 root 647: Output code for g-format floating point numbers instead of 648: d-format. 649: 1.1.1.2 root 650: `-fFLAG' 651: Specify machine-independent flags. These are the flags: 652: 1.1.1.4 ! root 653: `-ffloat-store' 1.1.1.2 root 654: Do not store floating-point variables in registers. This 1.1.1.4 ! root 655: prevents undesirable excess precision on machines such as ! 656: the 68000 where the floating registers (of the 68881) keep ! 657: more precision than a `double' is supposed to have. ! 658: ! 659: For most programs, the excess precision does only good, but ! 660: a few programs rely on the precise definition of IEEE ! 661: floating point. Use `-ffloat-store' for such programs. ! 662: ! 663: `-fno-asm' ! 664: Do not recognize `asm', `inline' or `typeof' as a keyword. ! 665: These words may then be used as identifiers. ! 666: ! 667: `-fno-defer-pop' ! 668: Always pop the arguments to each function call as soon as ! 669: that function returns. Normally the compiler (when ! 670: optimizing) lets arguments accumulate on the stack for ! 671: several function calls and pops them all at once. ! 672: ! 673: `-fcombine-regs' ! 674: Allow the combine pass to combine an instruction that ! 675: copies one register into another. This might or might not ! 676: produce better code when used in addition to `-O'. I am ! 677: interested in hearing about the difference this makes. ! 678: ! 679: `-fforce-mem' ! 680: Force memory operands to be copied into registers before ! 681: doing arithmetic on them. This may produce better code by ! 682: making all memory references potential common ! 683: subexpressions. When they are not common subexpressions, ! 684: instruction combination should eliminate the separate ! 685: register-load. I am interested in hearing about the ! 686: difference this makes. 1.1.1.2 root 687: 1.1.1.4 ! root 688: `-fforce-addr' ! 689: Force memory address constants to be copied into registers ! 690: before doing arithmetic on them. This may produce better ! 691: code just as `-fforce-mem' may. I am interested in hearing 1.1.1.2 root 692: about the difference this makes. 693: 1.1.1.4 ! root 694: `-fomit-frame-pointer' ! 695: Don't keep the frame pointer in a register for functions ! 696: that don't need one. This avoids the instructions to save, ! 697: set up and restore frame pointers; it also makes an extra ! 698: register available in many functions. *It also makes ! 699: debugging impossible.* 1.1.1.2 root 700: 701: On some machines, such as the Vax, this flag has no effect, 1.1.1.4 ! root 702: because the standard calling sequence automatically handles ! 703: the frame pointer and nothing is saved by pretending it ! 704: doesn't exist. The machine-description macro ! 705: `FRAME_POINTER_REQUIRED' controls whether a target machine ! 706: supports this flag. *Note Registers::. ! 707: ! 708: `-finline-functions' ! 709: Integrate all simple functions into their callers. The ! 710: compiler heuristically decides which functions are simple ! 711: enough to be worth integrating in this way. ! 712: ! 713: If all calls to a given function are integrated, and the ! 714: function is declared `static', then the function is ! 715: normally not output as assembler code in its own right. ! 716: ! 717: `-fkeep-inline-functions' ! 718: Even if all calls to a given function are integrated, and ! 719: the function is declared `static', nevertheless output a ! 720: separate run-time callable version of the function. ! 721: ! 722: `-fwritable-strings' ! 723: Store string constants in the writable data segment and ! 724: don't uniquize them. This is for compatibility with old ! 725: programs which assume they can write into string constants. ! 726: Writing into string constants is a very bad idea; ! 727: ``constants'' should be constant. ! 728: ! 729: `-fno-function-cse' ! 730: Do not put function addresses in registers; make each ! 731: instruction that calls a constant function contain the ! 732: function's address explicitly. ! 733: ! 734: This option results in less efficient code, but some ! 735: strange hacks that alter the assembler output may be ! 736: confused by the optimizations performed when this option is ! 737: not used. ! 738: ! 739: `-fvolatile' ! 740: Consider all memory references through pointers to be ! 741: volatile. 1.1.1.2 root 742: 1.1.1.4 ! root 743: `-funsigned-char' 1.1.1.2 root 744: Let the type `char' be the unsigned, like `unsigned char'. 745: 1.1.1.4 ! root 746: Each kind of machine has a default for what `char' should ! 747: be. It is either like `unsigned char' by default or like ! 748: `signed char' by default. (Actually, at present, the ! 749: default is always signed.) ! 750: ! 751: The type `char' is always a distinct type from either ! 752: `signed char' or `unsigned char', even though its behavior ! 753: is always just like one of those two. 1.1.1.2 root 754: 1.1.1.4 ! root 755: `-fsigned-char' 1.1.1.2 root 756: Let the type `char' be signed, like `signed char'. 757: 1.1.1.4 ! root 758: `-ffixed-REG' ! 759: Treat the register named REG as a fixed register; generated ! 760: code should never refer to it (except perhaps as a stack ! 761: pointer, frame pointer or in some other fixed role). ! 762: ! 763: REG must be the name of a register. The register names ! 764: accepted are machine-specific and are defined in the ! 765: `REGISTER_NAMES' macro in the machine description macro file. ! 766: ! 767: `-fcall-used-REG' ! 768: Treat the register named REG as an allocatable register ! 769: that is clobbered by function calls. It may be allocated ! 770: for temporaries or variables that do not live across a call. ! 771: Functions compiled this way will not save and restore the ! 772: register REG. ! 773: ! 774: Use of this flag for a register that has a fixed pervasive ! 775: role in the machine's execution model, such as the stack ! 776: pointer or frame pointer, will produce disastrous results. ! 777: ! 778: `-fcall-saved-REG' ! 779: Treat the register named REG as an allocatable register ! 780: saved by functions. It may be allocated even for ! 781: temporaries or variables that live across a call. ! 782: Functions compiled this way will save and restore the ! 783: register REG if they use it. ! 784: ! 785: Use of this flag for a register that has a fixed pervasive ! 786: role in the machine's execution model, such as the stack ! 787: pointer or frame pointer, will produce disastrous results. ! 788: ! 789: A different sort of disaster will result from the use of ! 790: this flag for a register in which function values are may ! 791: be returned. 1.1.1.2 root 792: 793: `-dLETTERS' 1.1.1.4 ! root 794: Says to make debugging dumps at times specified by LETTERS. ! 795: Here are the possible letters: 1.1.1.2 root 796: 1.1.1.4 ! root 797: `r' 1.1 root 798: Dump after RTL generation. 1.1.1.4 ! root 799: ! 800: `j' 1.1 root 801: Dump after first jump optimization. 1.1.1.4 ! root 802: ! 803: `J' 1.1.1.2 root 804: Dump after last jump optimization. 1.1.1.4 ! root 805: ! 806: `s' ! 807: Dump after CSE (including the jump optimization that ! 808: sometimes follows CSE). ! 809: ! 810: `L' 1.1 root 811: Dump after loop optimization. 1.1.1.4 ! root 812: ! 813: `f' 1.1 root 814: Dump after flow analysis. 1.1.1.4 ! root 815: ! 816: `c' 1.1 root 817: Dump after instruction combination. 1.1.1.4 ! root 818: ! 819: `l' 1.1 root 820: Dump after local register allocation. 1.1.1.4 ! root 821: ! 822: `g' 1.1 root 823: Dump after global register allocation. 1.1.1.4 ! root 824: ! 825: `m' 1.1.1.2 root 826: Print statistics on memory usage, at the end of the run. 827: 828: `-pedantic' 1.1.1.4 ! root 829: Issue all the warnings demanded by strict ANSI standard C; ! 830: reject all programs that use forbidden extensions. 1.1.1.2 root 831: 1.1.1.4 ! root 832: Valid ANSI standard C programs should compile properly with or ! 833: without this option (though a rare few will require `-ansi'). ! 834: However, without this option, certain GNU extensions and ! 835: traditional C features are supported as well. With this option, ! 836: they are rejected. There is no reason to use this option; it ! 837: exists only to satisfy pedants. ! 838: ! 839: These options control the C preprocessor, which is run on each C ! 840: source file before actual compilation. If you use the `-E' option, ! 841: nothing is done except C preprocessing. Some of these options make ! 842: sense only together with `-E' because they request preprocessor ! 843: output that is not suitable for actual compilation. 1.1.1.2 root 844: 845: `-C' 1.1.1.4 ! root 846: Tell the preprocessor not to discard comments. Used with the ! 847: `-E' option. 1.1.1.2 root 848: 849: `-IDIR' 1.1 root 850: Search directory DIR for include files. 1.1.1.2 root 851: 1.1.1.3 root 852: `-I-' 1.1.1.4 ! root 853: Any directories specified with `-I' options before the `-I-' ! 854: option are searched only for the case of `#include "FILE"'; they ! 855: are not searched for `#include <FILE>'. ! 856: ! 857: If additional directories are specified with `-I' options after ! 858: the `-I-', these directories are searched for all `#include' ! 859: directives. (Ordinarily *all* `-I' directories are used this ! 860: way.) 1.1.1.3 root 861: 862: In addition, the `-I-' option inhibits the use of the current 863: directory as the first search directory for `#include "FILE"'. 1.1.1.4 ! root 864: Therefore, the current directory is searched only if it is ! 865: requested explicitly with `-I.'. Specifying both `-I-' and ! 866: `-I.' allows you to control precisely which directories are ! 867: searched before the current one and which are searched after. 1.1.1.3 root 868: 869: `-nostdinc' 1.1.1.4 ! root 870: Do not search the standard system directories for header files. ! 871: Only the directories you have specified with `-I' options (and ! 872: the current directory, if appropriate) are searched. 1.1.1.3 root 873: 1.1.1.4 ! root 874: Between `-nostdinc' and `-I-', you can eliminate all directories ! 875: from the search path except those you specify. 1.1.1.3 root 876: 1.1.1.2 root 877: `-M' 1.1.1.4 ! root 878: Tell the preprocessor to output a rule suitable for `make' ! 879: describing the dependencies of each source file. For each ! 880: source file, the preprocessor outputs one `make'-rule whose ! 881: target is the object file name for that source file and whose ! 882: dependencies are all the files `#include'd in it. This rule may ! 883: be a single line or may be continued with `\'-newline if it is ! 884: long. 1.1.1.2 root 885: 886: `-M' implies `-E'. 887: 888: `-MM' 1.1.1.4 ! root 889: Like `-M' but the output mentions only the user-header files ! 890: included with `#include "FILE"'. System header files included ! 891: with `#include <FILE>' are omitted. 1.1.1.2 root 892: 893: `-MM' implies `-E'. 894: 895: `-DMACRO' 1.1 root 896: Define macro MACRO with the empty string as its definition. 1.1.1.2 root 897: 898: `-DMACRO=DEFN' 1.1 root 899: Define macro MACRO as DEFN. 1.1.1.2 root 900: 901: `-UMACRO' 1.1 root 902: Undefine macro MACRO. 1.1.1.2 root 903: 904: `-T' 905: Support ANSI C trigraphs. You don't want to know about this 906: brain-damage. The `-ansi' option also has this effect. 1.1 root 907: 1.1.1.4 ! root 908: 1.1 root 909: 1.1.1.3 root 910: File: internals, Node: Installation, Next: Trouble, Prev: Options, Up: Top 1.1 root 911: 912: Installing GNU CC 913: ***************** 914: 1.1.1.2 root 915: Here is the procedure for installing GNU CC on a Unix system. 916: 917: * Menu: 918: 919: * VMS Install:: See below for installation on VMS. 920: 1.1.1.4 ! root 921: 1. Edit `Makefile'. If you are using HPUX, or any form of system ! 922: V, you must make a few changes described in comments at the ! 923: beginning of the file. ! 924: ! 925: 2. On a Sequent system, go to the Berkeley universe. ! 926: ! 927: 3. Choose configuration files. ! 928: ! 929: * Make a symbolic link named `config.h' to the top-level ! 930: config file for the machine you are using (*note ! 931: Config::.). This file is responsible for defining ! 932: information about the host machine. It includes `tm.h'. ! 933: ! 934: The file's name should be `config-MACHINE.h', with these ! 935: exceptions: ! 936: ! 937: `config-vms.h' ! 938: for vaxen running VMS. ! 939: ! 940: `config-vaxv.h' ! 941: for vaxen running system V. ! 942: ! 943: `config-i386v.h' ! 944: for Intel 80386's running system V. ! 945: ! 946: `config-sun4.h' ! 947: for Suns (model 3 or 4) running *operating system* ! 948: version 4. ! 949: ! 950: `config-hp9k3.h' ! 951: for the HP 9000 series 300. ! 952: ! 953: `config-gnx.h' ! 954: for the ns32000 running Genix ! 955: ! 956: If your system does not support symbolic links, you might ! 957: want to set up `config.h' to contain a `#include' command ! 958: which refers to the appropriate file. ! 959: ! 960: * Make a symbolic link named `tm.h' to the ! 961: machine-description macro file for your machine (its name ! 962: should be `tm-MACHINE.h'). 1.1.1.2 root 963: 1.1.1.4 ! root 964: If your system is a 68000, don't use the file `tm-m68k.h' ! 965: directly. Instead, use one of these files: 1.1.1.2 root 966: 1.1.1.4 ! root 967: `tm-sun3.h' ! 968: for Sun 3 machines. 1.1.1.2 root 969: 1.1.1.4 ! root 970: `tm-sun2.h' ! 971: for Sun 2 machines. 1.1.1.2 root 972: 1.1.1.4 ! root 973: `tm-3b1.h' ! 974: for AT&T 3b1 (aka 7300 Unix PC). ! 975: ! 976: `tm-isi68.h' ! 977: for Integrated Solutions systems. ! 978: ! 979: `tm-news800.h' ! 980: for SONY News systems. ! 981: ! 982: `tm-hp9k320.h' ! 983: for HPUX systems, if you are using GNU CC with the ! 984: system's assembler and linker. ! 985: ! 986: `tm-hp9k320g.h' ! 987: for HPUX systems, if you are using the GNU assembler, ! 988: linker and other utilities. Not all of the pieces of ! 989: GNU software needed for this mode of operation are as ! 990: yet in distribution; full instructions will appear ! 991: here in the future. ! 992: ! 993: For the vax, use `tm-vax.h' on BSD Unix, `tm-vaxv.h' on ! 994: system V, or `tm-vms.h' on VMS. ! 995: ! 996: For the SPARC (Sun 4), use `tm-sparc.h'. ! 997: ! 998: For the Motorola 88000, use `tm-m88k.h'. The support for ! 999: the 88000 has a few unfinished spots because there was no ! 1000: way to run the output. Bugs are suspected in handling of ! 1001: branch-tables and in the function prologue and epilogue. ! 1002: ! 1003: For the 80386, don't use `tm-i386.h' directly. Use ! 1004: `tm-i386v.h' if the target machine is running system V, ! 1005: `tm-seq386.h' for a Sequent 386 system, or `tm-compaq.h' ! 1006: for a Compaq. ! 1007: ! 1008: For the 32000, use `tm-sequent.h' if you are using a ! 1009: Sequent machine, or `tm-encore.h' for an Encore machine, or ! 1010: `tm-gnx.h' if you are using Genix version 3; otherwise, 1.1.1.3 root 1011: perhaps `tm-ns32k.h' will work for you. 1.1.1.2 root 1012: 1.1.1.4 ! root 1013: Note that Genix has bugs in `alloca' and `malloc'; you must ! 1014: get the compiled versions of these from GNU Emacs and edit ! 1015: GNU CC's `Makefile' to use them. ! 1016: ! 1017: Note that Encore systems are supported only under BSD. 1.1.1.2 root 1018: 1019: * Make a symbolic link named `md' to the machine description 1020: pattern file (its name should be `MACHINE.md'). 1021: 1022: * Make a symbolic link named `aux-output.c' to the output 1023: subroutine file for your machine (its name should be 1.1.1.4 ! root 1024: `output-MACHINE.c'). 1.1.1.2 root 1025: 1.1.1.4 ! root 1026: 4. Make sure the Bison parser generator is installed. (This is ! 1027: unnecessary if the Bison output files `c-parse.tab.c' and ! 1028: `cexp.c' are more recent than `c-parse.y' and `cexp.y' and you ! 1029: do not plan to change the `.y' files.) ! 1030: ! 1031: Note that if you have an old version of Bison you may get an ! 1032: error from the line with the `%expect' directive. If so, simply ! 1033: remove that line from `c-parse.y' and proceed. ! 1034: ! 1035: 5. If you are using a Sun, make sure the environment variable ! 1036: `FLOAT_OPTION' is not set. If this option were set to `f68881' ! 1037: when `gnulib' is compiled, the resulting code would demand to be ! 1038: linked with a special startup file and will not link properly ! 1039: without special pains. 1.1.1.2 root 1040: 1.1.1.4 ! root 1041: 6. Build the compiler. Just type `make' in the compiler directory. 1.1.1.2 root 1042: 1.1.1.4 ! root 1043: 7. Move the first-stage object files and executables into a ! 1044: subdirectory with this command: 1.1.1.2 root 1045: 1046: make stage1 1047: 1048: The files are moved into a subdirectory named `stage1'. Once 1.1.1.4 ! root 1049: installation is complete, you may wish to delete these files ! 1050: with `rm -r stage1'. 1.1.1.2 root 1051: 1.1.1.4 ! root 1052: 8. Recompile the compiler with itself, with this command: 1.1.1.2 root 1053: 1054: make CC=stage1/gcc CFLAGS="-g -O -Bstage1/" 1055: 1.1.1.4 ! root 1056: On a 68000 or 68020 system lacking floating point hardware, ! 1057: unless you have selected a `tm.h' file that expects by default ! 1058: that there is no such hardware, do this instead: 1.1.1.2 root 1059: 1060: make CC=stage1/gcc CFLAGS="-g -O -Bstage1/ -msoft-float" 1061: 1.1.1.4 ! root 1062: 9. If you wish to test the compiler by compiling it with itself one ! 1063: more time, do this: 1.1.1.2 root 1064: 1065: make stage2 1.1.1.4 ! root 1066: Make CC=stage2/gcc CFLAGS="-g -O -Bstage2/" 1.1.1.2 root 1067: foreach file (*.o) 1068: cmp $file stage2/$file 1069: end 1070: 1.1.1.4 ! root 1071: This will notify you if any of these stage 3 object files ! 1072: differs from those of stage 2. Any difference, no matter how ! 1073: innocuous, indicates that the stage 2 compiler has compiled GNU ! 1074: CC incorrectly, and is therefore a potentially serious bug which ! 1075: you should investigate and report (*note Bugs::.). ! 1076: ! 1077: Aside from the `-B' option, the options should be the same as ! 1078: when you made stage 2. 1.1.1.2 root 1079: 1.1.1.4 ! root 1080: 10. Install the compiler driver, the compiler's passes and run-time ! 1081: support. You can use the following command: 1.1.1.2 root 1082: 1083: make install 1084: 1.1.1.4 ! root 1085: This copies the files `cc1', `cpp' and `gnulib' to files ! 1086: `gcc-cc1', `gcc-cpp' and `gcc-gnulib' in directory ! 1087: `/usr/local/lib', which is where the compiler driver program ! 1088: looks for them. It also copies the driver program `gcc' into ! 1089: the directory `/usr/local', so that it appears in typical ! 1090: execution search paths. ! 1091: ! 1092: *Warning: there is a bug in `alloca' in the Sun library. To ! 1093: avoid this bug, install the binaries of GNU CC that were ! 1094: compiled by GNU CC. They use `alloca' as a built-in function ! 1095: and never the one in the library.* ! 1096: ! 1097: *Warning: the GNU CPP may not work for `ioctl.h', `ttychars.h' ! 1098: and other system header files unless the `-traditional' option ! 1099: is used.* The bug is in the header files: at least on some ! 1100: machines, they rely on behavior that is incompatible with ANSI ! 1101: C. This behavior consists of substituting for macro argument ! 1102: names when they appear inside of character constants. The ! 1103: `-traditional' option tells GNU CC to behave the way these ! 1104: headers expect. 1.1.1.2 root 1105: 1.1.1.4 ! root 1106: Because of this problem, you might prefer to configure GNU CC to ! 1107: use the system's own C preprocessor. To do so, make the file 1.1.1.2 root 1108: `/usr/local/lib/gcc-cpp' a link to `/lib/cpp'. 1109: 1.1.1.4 ! root 1110: Alternatively, on Sun systems and 4.3BSD at least, you can ! 1111: correct the include files by running the shell script ! 1112: `fixincludes'. This installs modified, corrected copies of the ! 1113: files `ioctl.h', `ttychars.h' and many others, in a special ! 1114: directory where only GNU CC will normally look for them. 1.1.1.2 root 1115: 1.1.1.4 ! root 1116: See the file `fixincludes' for a list of all the files we know ! 1117: to require correction. 1.1.1.2 root 1118: 1119: If you cannot install the compiler's passes and run-time support in 1.1.1.4 ! root 1120: `/usr/local/lib', you can alternatively use the `-B' option to ! 1121: specify a prefix by which they may be found. The compiler ! 1122: concatenates the prefix with the names `cpp', `cc1' and `gnulib'. ! 1123: Thus, you can put the files in a directory `/usr/foo/gcc' and specify ! 1124: `-B/usr/foo/gcc/' when you run GNU CC. ! 1125: ! 1126: Also, you can specify an alternative default directory for these ! 1127: files by setting the Make variable `libdir' when you make GNU CC. ! 1128: 1.1.1.2 root 1129: 1130: 1131: File: internals, Node: VMS Install, Prev: Installation, Up: Installation 1132: 1133: Installing GNU CC on VMS 1134: ======================== 1135: 1.1.1.4 ! root 1136: The VMS version of GNU CC is distributed in an unusual tape format ! 1137: which consists of several tape files. The first is a command file; ! 1138: the second is an executable program which reads Unix tar format; the ! 1139: third is another command file which uses this program to read the ! 1140: remainder of the tape. ! 1141: ! 1142: To load the tape, it suffices to mount it `/foreign' and then do ! 1143: `@mta0:' to execute the command file at the beginning of the tape. ! 1144: ! 1145: The tape contains executables and object files as well as sources, so ! 1146: no compilation is necessary unless you change the sources. (This is ! 1147: a good thing, since you probably don't have any other C compiler.) ! 1148: If you must recompile, here is how: ! 1149: ! 1150: 1. Copy the file `tm-vms.h' to `tm.h', `config-vms.h' to ! 1151: `config.h', `vax.md' to `md.' and `output-vax.c' to ! 1152: `aux-output.c'. 1.1.1.2 root 1153: 1154: 2. Type `@make' to do recompile everything. 1155: 1.1.1.4 ! root 1156: To install the `GCC' command so you can use the compiler easily, in ! 1157: the same manner as you use the VMS C compiler, you must install the ! 1158: VMS CLD file for GNU CC as follows: ! 1159: ! 1160: 1. Define the VMS logical names `GNU_CC' and `GNU_CC_INCLUDE' to ! 1161: point to the directories where the GNU CC executables ! 1162: (`gcc-cpp', `gcc-cc1', etc.) and the C include files are kept. ! 1163: This should be done with the commands: 1.1.1.3 root 1164: 1165: $ assign /super /system disk:[gcc] gnu_cc 1166: $ assign /super /system disk:[gcc.include] gnu_cc_include 1167: 1.1.1.4 ! root 1168: with the appropriate disk and directory names. These commands ! 1169: can be placed in your system startup file so they will be ! 1170: executed whenever the machine is rebooted. 1.1.1.3 root 1171: 1172: 2. Install the `GCC' command with the command line: 1173: 1174: $ set command /table=sys$library:dcltables gnu_cc:gcc 1175: 1.1.1.4 ! root 1176: Now you can invoke the compiler with a command like `gcc ! 1177: /verbose file.c', which is equivalent to the command `gcc -v -c ! 1178: file.c' in Unix. ! 1179: 1.1.1.3 root 1180: 1.1.1.2 root 1181: 1.1.1.3 root 1182: File: internals, Node: Trouble, Next: Incompatibilities, Prev: Installation, Up: Top 1183: 1184: Trouble in Installation 1185: *********************** 1186: 1.1.1.4 ! root 1187: Here are some of the things that have caused trouble for people ! 1188: installing GNU CC. 1.1.1.2 root 1189: 1.1.1.4 ! root 1190: * On certain systems, defining certain environment variables such ! 1191: as `CC' can interfere with the functioning of `make'. 1.1.1.2 root 1192: 1.1.1.4 ! root 1193: * Cross compilation can run into trouble for certain machines ! 1194: because some target machines' assemblers require floating point ! 1195: numbers to be written as *integer* constants in certain contexts. ! 1196: ! 1197: The compiler writes these integer constants by examining the ! 1198: floating point value as an integer and printing that integer, ! 1199: because this is simple to write and independent of the details ! 1200: of the floating point representation. But this does not work if ! 1201: the compiler is running on a different machine with an ! 1202: incompatible floating point format, or even a different ! 1203: byte-ordering. ! 1204: ! 1205: It is possible to fix this by writing machine-independent code ! 1206: which understands the floating point representation of the ! 1207: target machine. I am not interested in doing that much work to ! 1208: compensate for bugs in assemblers. 1.1 root 1209: 1210:
This archive runs on limited infrastructure. Preserving old code on modern bandwidth. Automated agents are requested to crawl responsibly.