If you use -march then GCC will be free to generate instructions that work on the specified CPU, but (typically) not on earlier CPUs in the architecture family. If you just use -mtune, then the compiler will generate code that works on any of them, but will favour instruction sequences that run fastest on the … Read more
As you noticed, these are Makefile {macros or variables}, not compiler options. They implement a set of conventions. (Macros is an old name for them, still used by some. GNU make doc calls them variables.) The only reason that the names matter is the default make rules, visible via make -p, which use some of … Read more
gcc being a compiler/linker, its -s option is something done while linking. It’s also not configurable – it has a set of information which it removes, no more no less. strip is something which can be run on an object file which is already compiled. It also has a variety of command-line options which you … Read more
What is the difference between the two, The g++ is a compiler driver. It knows how to invoke the actual compiler (cc1plus), assembler and linker. It does not know how to parse or compile the sources. and should I ever call cc1plus directly? No.
You must be reading some outdated copies of the manpages (emphasis added): -rpath=dir Add a directory to the runtime library search path. This is used when linking an ELF executable with shared objects. All -rpath arguments are concatenated and passed to the runtime linker, which uses them to locate shared objects at runtime. vs. -L … Read more
http://tldp.org/HOWTO/Program-Library-HOWTO/shared-libraries.html Use `-fPIC` or `-fpic` to generate position independent code. Whether to use `-fPIC` or `-fpic` to generate position independent code is target-dependent. The `-fPIC` choice always works, but may produce larger code than `-fpic` (mnemonic to remember this is that PIC is in a larger case, so it may produce larger amounts of code). … Read more
Update: Often people want the most recent version of gcc, and devtoolset is being kept up-to-date, so maybe you want devtoolset-N where N={4,5,6,7…}, check yum for the latest available on your system). Updated the cmds below for N=7. There is a package for gcc-7.2.1 for devtoolset-7 as an example. First you need to enable the … Read more
-g and -ggdb are similar with some slight differences, I read this here: -g produces debugging information in the OS¹s native format (stabs, COFF, XCOFF, or DWARF 2). -ggdb produces debugging information specifically intended for gdb. -ggdb3 produces extra debugging information, for example: including macro definitions. -ggdb by itself without specifying the level defaults to … Read more
EDIT Since not so recently by now, MinGW-w64 has “absorbed” one of the toolchain building projects. The downloads can be found here. The installer should work, and allow you to pick a version that you need. Note the Qt SDK comes with the same toolchain. So if you are developing in Qt and using the … Read more
gcc -lsome_dynamic_lib code.c some_static_lib.a