g++ Compilation Summary

g++ Compilation Summary

First, build attention to detail

1. Use g++ to compile CPP files if you compile C + + source files with GCC, the following option is used:-lstdc++, otherwise, file compilation using C + + operations will fail.

2.gcc/g++ requires 4 steps to perform the compilation

① preprocessing, generating. i files [using the-e parameter]

② the preprocessed file is not converted to assembly language, generating the file. s[using the-s parameter]

③ has assembly changed to target code (machine code) to generate. o files [using the-C parameter]

④ Connect the target code, generate the executable program [using the-o parameter]

Second, GDB debugging

A list of DEBUG commands for 1.gdb.

Command	Explain	Shorthand
File	Load the executable file you want to debug	No
List	List part of the source code that generated the execution file	L
Next	Executes a line of source code but does not enter inside the function	N
Step	Executes a line of source code and goes inside the function	S
Run	Executing a program that is currently being debugged	R
Continue	Continue to execute the program	C
Quit	Terminate GDB	Q
Print	Outputs the value of the current set variable	P
Break	Set breakpoints in code	B
Info break	To view information about setting breakpoints	Ib
Delete	Delete a set breakpoint	D
Watch	Monitor the value of a variable, and the program stops once the value changes.	Wa
Help	GDB's help command	H

How to use:

Add the –g parameter when compiling the program, for example:

g++-g-o Hello Hello.cpp

The use of debugging in GDB to re-enter the command gdb+ executable file name, such as:

GDB Hello

View Source file List 1, enter repeat last instruction

Then, according to the parameter list, enter your own commands according to your own requirements.

Reference URL:

http://blog.csdn.net/wfdtxz/article/details/7368357

In addition, if you compile with makefile, pay special attention to the use of regular expressions, otherwise the compiled files will not be used for debugging.

such as Makefile1: (operating normally)

EXECUTEMAIN:MAIN.O COMMONFUN.O mytool.o        g++-o executemain main.o commonfun.o mytool.omain.o:main.cpp commonfun.h Mytool.h        g++-g-c main.cpp common.o:commonfun.h commonfun.cpp        g++-g-c commonfun.cppmytool.o:mytool.h mytool . cpp        g++-g-c mytool.cppclean:         rm-f executemain main.o commonfun.o MYTOOL.O

and Makefile2:

COMPILER=G++EXECUTEMAIN:MAIN.O COMMONFUN.O MYTOOL.O        $ (COMPILER)-o [email protected] $^. C.O:         $ (COMPILER)-g-c  $<clean:         rm-f *.o Executemain

The following error is indicated:

Third, g++ compilation options in detail:
For details, see annex: g++ Compilation Options table.
Attachment 1:g++ compilation Options table:

 
 

  
  
 
   
 
    
gcc/g++
 
    
Common options format for commands (option interpretation)
 
   
 
   
 
    
-O FILE
 
    
Specifies the output file name, which is not required when compiling to the target code. If file is not specified, the default file name is a.out.
 
   
 
   
 
    
-C
 
    
Compile only build target file, not link
 
   
 
   
 
    
-m486
 
    
Code optimization for 486.
 
   
 
   
 
    
-o0
 
    
No optimization processing is performed.
 
   
 
   
 
    
-O or-o1
 
    
Optimize the generated code.
 
   
 
   
 
    
-o2
 
    
Further optimization.
 
   
 
   
 
    
-o3
 
    
Further optimizations than-O2, including inline functions.
 
   
 
   
 
    
-W
 
    
Turn off all warnings and do not recommend using this item
 
   
 
   
 
    
-wall
 
    
Allows all useful warnings provided by GCC to be issued, or the specified warning can be marked with-W (warning)
 
   
 
   
 
    
-werror
 
    
Converts all warnings to errors to abort the compilation process when a warning occurs
 
   
 
   
 
    
-mm
 
    
Output a make-compatible related list
 
   
 
   
 
    
-V
 
    
Displays the commands used in each step of the compilation process
 
   
 
   
 
    
-E
 
    
Only the C pre-compiler is run.
 
   
 
   
 
    
-shared
 
    
Generate a shared destination file. Typically used when building a shared library.
 
   
 
   
 
    
-static
 
    
Link static libraries, i.e. perform static links
 
   
 
   
 
    
-lfoo
 
    
Link to a library of functions named Libfoo
 
   
 
   
 
    
-G
 
    
Include standard debugging information in an executable program
 
   
 
   
 
    
-ggdb
 
    
Include only GNU debugger in the executable program to make the other up to two is information
 
   
 
   
 
    
-O
 
    
Optimization of compiled code
 
   
 
   
 
    
-on
 
    
Specifies that the level of code optimization is n,o<=n<=3
 
   
 
   
 
    
-ansi
 
    
The standard syntax for Ansi/iso C is supported, and the part of the GNU syntax extension that conflicts with the standard (but this option does not guarantee the generation of ANSI-compatible code) will prohibit certain features of GNU C, such as ASM or typeof keywords.
 
   
 
   
 
    
-pedantic
 
    
Allow all warnings listed in the Ansi/iso C standard to be issued
 
   
 
   
 
    
-errors
 
    
Allow all errors listed in the Ansi/iso C standard to be issued
 
   
 
   
 
    
-traditional
 
    
Supports Kernighan & Ritchie C syntax (such as defining functions with legacy syntax); If you don't know what this option means, it doesn't matter.
 
   
 
   
 
    
-idirectory
 
    
Specifies additional header file search paths for directory.
 
   
 
   
 
    
-ldirectory
 
    
Specifies the additional library search path directory.
 
   
 
   
 
    
-dfoo=bar
 
    
Define the preprocessing macro foo at the command line with a value of bar
 
   
 
   
 
    
-idirname
 
    
Add dirname to the search directory list in the header file
 
   
 
   
 
    
-ldirname
 
    
Add dirname to the search directory list of the library file, by default GCC only links the shared library
 
   
 
   
 
    
-dmacro
 
    
The macro macro is defined with the string "1".
 
   
 
   
 
    
-dmacro=defn
 
    
The macro macro is defined as the string "DEFN".
 
   
 
   
 
    
-umacro
 
    
Cancels the definition of macro macros.
 
   
 
  
 
 
g++ Compilation Summary