gcc详细文档说明

Short Contents Introduction 1 Programming Languages Supported by gCo 2 Language Standards Supported by gCc 1359 3 GCC Command Options 4 C Implementation-defined behavior ....267 5 C++ Implementation-defined behavior 6 Extensions to the C Language Family.......... 277 7 Extensions to the C++ language 59 8 GU Objective-C runtime features 571 g Binary compatibility 577 10 gcov-a Test Coverage Program .....581 11 Known Causes of Trouble with gcc 589 12 Reporting Bugs 605 13 How To Get Help with gCC .607 14 Contributing to GCC Development e·垂 609 Funding free software 611 The GNU Project and GNU/ Linux .,,,613 GNU General Public License ...,,,,,,,,615 GNU Free documentation license 627 contributors to gcc 635 Option Index 651 Keyword Index 667 Table of Contents Introduction 1 Programming Languages Supported by gCC 2 Language Standards Supported by GCC 2.1 C language 2.2 C++ language .6 2.3 Objective-C and Objective-C++ languages 7 3 GCC Command Options 3. 1 Option Summary 9 3.2 Options Controlling the Kind of Output 22 3.3 Compiling C++ Programs 28 3.4 Options Controlling C Dialect 28 3.5 Options Controlling C+- Dialect 33 3.6 Options Controlling Objective-C and Objective-C++ Dialects. 41 3.7 Options to Control Diagnostic Messages Formatting 45 3. 8 Options to Request or Suppress Warnings .46 3.9 Options for Debugging Your Program or GCC 67 3.10 Options That Control Optimization .85 3.11 Options Controlling the Preprocessor ...131 3. 12 Passing Options to the assembler 141 3.13 Options for Linking 141 3.14 Options for Directory Search 145 3.15 Specifying subprocesses and the switches to pass to them.. 147 3.16 Specifying Target Machine and Compiler Version ...... 154 17 Hardware Models and configurations 151 3.17.1 ARC Options .154 3.17.2 ARM Options 155 3. 17.3 AVR Options ....159 3.17. Blackfin options 160 3.17.5 CRIS Options 163 3.17.6CRX Options ..165 3. 17.7 Darwin Options 165 3. 8 DEC Alpha Options ..169 3.17.9 DEC Alpha/VMs Options 173 3. 17.10 FR30 Options 174 3. 17.11 FRV Options ...174 3.17. 12 GNU/Linux Options 177 3. 17.13 H8 300 Options ...178 3. 17.14 HPPA Options ..178 Using the GNU Compiler Collection(GCC) 3. 17.15 Intel 386 and AMD x86-64 Options .,181 3. 17.16 IA-64 Options 192 3.17.17 IA-64/VMS Options 196 3.17.18LM32Opti 196 3.17. 19 M32C Options .196 3.17.20 M32R/D Options 197 3. 17.21 M680x0 Options 198 3.17.22 M68hclx Options 203 3. 17.23 MCore Options 204 3.17. 24 MeP Options 205 3. 17.25 MIPS Options 207 3. 17.26 MMIX Options 218 3. 17.27 MN10300 Options 3. 17.28 PDP-11 Options ..,219 3. 17.29 pico Chip Options 220 3. 17.30 PowcrPC Options................... 221 3.17.31 IBM RS/6000 and PowerPC Options 221 3. 17.32 RX Options 234 3. 17.33 S/390 and zSeries Options 236 3.17.34 Score Options ...239 3.17.35 SH Options 239 3. 17.36 SPARC Options 243 3.17. 37 SPU Options 247 3. 17.38 Options for System V 3.17.39 V850 Options 249 3. 17.40 VAX Options ,.250 3.17. 41 VX Works Options 251 3.1742x86-64 Options.. 251 3.17.13 1386 and x86-64 Windows Options 251 3.17.44 Xstormv16 Options ...252 3.17.15 Xtensa Options 252 3. 17.46 ZSeries Options 254 3.18 Options for Code Generation Conventions..........254 3. 19 Environment variables a ffecting gcc 262 3.20 Using Prccompilcd Hcadcrs 265 4 C Implementation-defined behavior 267 4.1 Translation 267 4.2 Environment 267 4.3 Identifiers 267 4.4 Characters 268 1.5 Int 268 4.6 Floating point 269 4.7 Arrays and pointers 270 4.8 Hints 271 4.9 Structures. unions. enumerations. and bit-fields 271 4.10 Qualifiers 272 4.11 Declarate 4.12 Statements 72 4.13 Preprocessing directives ...272 4.14 Library functions ...273 4.15 Architecture 273 4.16 Locale-specific behavior ∴..273 5 C++Implementation-defined behavior.. 275 5. 1 Conditionally-supportcd behavior ..,,275 6 Extensions to the C Language Family 277 6.1 Statements and Declarations in Expressions 277 6.2 Locally Declared Labels 278 6.3 Labels as value 6. 4 Nested F 6.5 Constructing Function Calls 282 6.6 Relerring to a t Ith typeof 284 6.7 Conditionals with Omitted Operand ∴,285 6.8 Double-Word Integers 286 6.9 Complex Numbers 286 6.10 Additional Floating Types 287 6.11 Half- Precision Floating Point 287 6. 12 Decimal Floating Types 288 6.13 Hex Floats 6. 14 Fixed-Point Typ 288 6.15Named address spaces 9 6.16 Arrays of Length Zero 290 6.17 Structures With No Members 291 6.18 Arrays of Variable length 291 6. 19 Macros with a Variable Number of Arguments........ 292 6. 20 Slightly Looser Rules for Escaped Newlines 293 6.21 Non-Lvalue Arrays May Have Subscripts 293 6.22 Arithmetic on void- and Function-Pointers 294 6.23 Non-Constant Initializers · ..294 6.24 Compound literals 294 6.25 Designated Initializers 295 6.26 Case Ranges 96 6.27 Cast to a Union Type 296 6.28 Mixed Declarations and Code 297 6. 29 Declaring Attributes of functions 297 6.30 Attribute Syntax......................320 6.31 Prototypes and old-Style Function definitions ..323 6.32 C+ Style comments ..324 6.33 Dollar Signs in Identifier Names .324 6.34 The Character EsC in Constants ∴...324 6.35 Inquiring on Alignment of Types or variables 324 6.36 Specifying Attributes of Variables 325 6.36.1 Blackfin variable Attributes 329 6. 36.2 M32R/D Variable Attributes .330 Using the GNU Compiler Collection(GCC) 6.36.3 MeP Variable Attributes 330 6.36.4 1386 Variable Attributes 331 6.36.5 PowerPC variable Attributes 332 6.36.6 SPU Variable Attributes ....,333 6. 36.7 Stormy 16 Variable Attributes 333 6.36. 8 AVR Variable Attributes ..3:33 6.37 Specifying Attributes of Types 333 6.37.1 ARM Type Attributes 37 6. 37.2 MeP Type Attributes 338 6.37.3 1386 Type Attributes 338 6.37. 4 PowerPC Type Attributes 338 6.37.5 SPU Type Attributes 338 6.38 An inline function is as fast as a macro 39 6.39 Assembler Instructions with C Expression Operands.....340 6.39.1 Size of an asm 346 6.39.2 1386 floating point asm operands .346 6.40 Constraints for asm Operands 348 6.40. 1 Simple constraints .,348 6.40.2 Multiple Alternative Constraints 350 6.40.3 Constraint Modifier Characters ..350 6.40.4 Constraints for Particular Machines 351 6.41 Controlling Names Used in Assembler Code ..370 6.45 Function Names as String分∴∴Vb... 6.42 Variables in Specified registers ...370 6.42. 1 Defining Global Register V 371 6.42.2S1 g Registers for Lo Variable 372 6.43 Alternate Keywords.....................373 6.44 Incomplete enum Types 373 373 6.16 Getting the Return or Frame Address of a Function.....371 6.47 Using vector instructions through built-in functions.. 3 6.18 Offsetof 376 6.49 Built-in functions for atomic memory access 377 6.50 Object Size Checking Builtins .378 6.51 Other built-in functions provided by gcc .380 6.52 Built-in Functions Spccific to Particular Target Machines.. 389 6.52.1 Alpha Built-in Functions 389 6.52.2 ARM iWMMXt Built-in Functions 390 6.52. 3 ARM NEON Intrinsics .392 6.52.3.1 Addition.... ..,392 6.52.3.2 Multiplication 396 6.52.3. 3 Multiply-accumulate 398 6.52.3.4 Multiply-subtract 399 6.52.3.5 Subtraction 6.52.3.6 Comparison(equal-to 403 6.52.3.7 Comparison(greater-than-or-equal-to 404 6.52.3.8 Comparison (less-than-or-equal-to ·鲁 405 6.52. 3.9 Comparison(greater-than 406 6.52.3.10 Comparison(less-than 406 6.52. 3.11 Comparison(absolute greater-than-or-equal-to)..407 6.52.3. 12 Comparison(absolute less-than-or-equal-to)... 407 6.52.3. 13 Comparison (absolute greater-than) 407 6.52.3.14 Comparison(absolute less-than) ...408 6.52.3.15 Test bits 408 6.52.3.16 Absolute difference ..408 6.52.3. 17 Absolute difference and accumulate 409 6.52.3.18 Maximun..,,, ....110 6.52.3.19 Minimum 411 6.52.3.20 Pairwise add .,,,.,412 6.52.3.21 Pairwise add, single_opcode widen and accumulate 413 6.52.3.22 Folding maximum ..413 6.52.3. 23 Folding minimum 414 6.52.3.24 Reciprocal step 414 6.52.3.25 Vcctor shift lcft................. 414 6.52.3.26 Vector shift left by constant ........417 6.52.3.27 Vector shift right by constant.......... 420 6.52.3.28 Vector shift right by constant and accumulate 423 6.52.3. 29 Vector shift right and insert 424 6.52.3.30 Vector shift left and insert 425 6.52.3.31 Absolute value 426 6.52.3.32 Negation 427 6.52.3.33 Bitwise not 427 6.52.3.34 Count leading sign bits 428 6.52.3.35 Count leading zeros ,普 428 6.52.3.36 Count number of set bits 429 6.52.3.37 Reciprocal estimate .429 6.52.3.38 Reciprocal square-root estimate 6.52.3.39 Get lanes from a vector ..430 6.52.3.10 Set lanes in a vector ..,131 6.52.3.41 Create vector from literal bit pattern ,,,432 6.52.3.42 Set all lanes to the same value ∴..432 6.52.3.43 Combining vectors ...436 6.52.3.44 Splitting vectors 436 6.52.3.45 Conversions .....437 6.52.3.46 MovC, singlc-opcodc narrowing .437 6.52.3.47 Move, single_opcode long 438 6.52.3.48 Table lookup .,439 6.52.3.49 Extended table lookup 439 6.52.3.50 Multiply, lane ..440 6.52.3.51 Long multiply, lane 440 6.52.3.52 Saturating doubling long multiply, lane 440 6.52.3.53 Saturating doubling multiply high, lane ...441 6.52.3.54 Multiply-accumulate, lane 441 6.52.3.55 Multiply-subtract, lane 442 6.52.3.56 Secte alar 443 6.52.3.57 Vector long multiply by scalar ..443 Using the GNU Compiler Collection(GCC) 6.52.3.58 Vector saturating doubling long multiply by scalar 443 6.52.3.59 Vector saturating doubling multiply high by scalar 444 6.52.3.60 Vector multiply-accumulate by scalar 444 6.52.3.61 Vector multiply-subtract by scalar 445 6.52.3. 62 Vector extract 446 6.52.3.63 Reverse elements ...,117 6.52.3.64 Bit selection 448 6.52.3.65 Transpose elements 450 6.52.3.66 Zip elements 451 6.52.3.67 Unzip elements 452 6.52.3.68 Flement /structure loads, VLD1 variants 453 6.52. 3.69 Elcmont/structurc stores, VSTI variants..... 456 6.52.3. 70 Element / structure loads, VLD2 variants 458 6.52.3.71 Elcment/structurc stores, VST2 variants.....460 6.52.3.72 Element/structure loads, VLD3 variants 462 6.52.3. 73 Element/structure stores, VST3 variants..... 464 6.52.3. 74 Element /structure loads, VLD4 variants 466 6.52.3.75 Element /structure stores, VST4 variants 468 6.52. 3.76 Logical operations(AND) 470 6.52.3.77 Logical operations ( OR) 471 6.52. 3.78 Logical operations(exclusive OR) 6.523.79 Logical operations( AND-NO1)......,... 471 472 6.52.3. 80 Logical operations(OR-NOT ∴...473 6.52.3.81 Reinterpret casts 474 6.52.4 Blackfin Built-in Functions 480 6.52.5 FR-V Built-in Funct 480 6.52.5.1 Argument Types 180 6.52.5.2 Directly-mapped Integer Functions........ 480 6.52.5.3 Directly-mapped Media Functions 481 6. 52.5.4 Raw read /write Functions 483 6.52.5.5 Other Built-in Functions 483 6.52.6 X86 Built-in Functions ...484 6.52.7 MIPS dsP Built-in Functions 499 6.52.8 MIPS Paired-Single Support 504 6.52. 9 MIPS Loongson Built-in Functions ..504 6.52.9.1 Paired-Single Arit 506 6.52.9.2 Paired-Single Built-in Functions 507 6.52.9.3 MPS-3D Built-in Functions 508 6.52. 10 pico Chip Built-in Functions ..510 6.52. 11 Other mips Built -in Functions ....5l1 6.52. 12 PowerPC AltiVec Built-in Functions 511 6.52.13 RX Built-in Functions ..544 6.52.14 SPARC ViS Built-in Functions .546 6.52.15 SPu Built-in Functions 547 6.53 Format Checks Specific to Particular Target Machines 547 6.53. 1 Solaris format checks 547