instead of put the first 6 arguments in registers just to move them onto the stack in the function prologue? I was looking at some code that gcc generated and that’s what it always did. Then you forgot to enable optimization. gcc -O0 spills everything to memory so you can modify them with a debugger … Read more
From the GCC manual: Many options have long names starting with -f or with -W—for example, -fforce-mem, -fstrength-reduce, -Wformat and so on. Most of these have both positive and negative forms; the negative form of -ffoo would be -fno-foo. This manual documents only one of these two forms, whichever one is not the default. But … Read more
Because This Question was marked as Duplicate, even if doesn’t have to do with it, because there is about Linker Flag and here is about Compiler Flags, I will post My answer HERE. You will have to go to Settings -> Compiler… and next you’ll have to click on Linker Settings TAB. On the right … Read more
It is normally stored in the comment section strings -a <binary/library> |grep “GCC: (” returns GCC: (GNU) X.X.X strip -R .comment <binary> strings -a <binary/library> |grep “GCC: (” returns no output It is not uncommon to strip the .comment (as well as .note) section out to reduce size via strip –strip-all -R .note -R .comment … Read more
Use -masm=intel and don’t use any .att_syntax directives in your inline asm. This works with GCC and I think ICC, and with any constraints you use. Other methods don’t. (See Can I use Intel syntax of x86 assembly with GCC? for a simple answer saying that; this answer explores exactly what goes wrong, including with … Read more
Debian / Ubuntu The problem is you likely only have the gcc for your current architecture and that’s 64bit. You need the 32bit support files. For that, you need to install them sudo apt install gcc-multilib
TL:DR different object file formats / easier portability to new Unix platforms (historically) is one of the main reasons for gcc keeping the assembler separate from the compiler, I think. Outside of gcc, the mainstream x86 C and C++ compilers (clang/LLVM, MSVC, ICC) go straight to machine code, with the option of printing asm text … Read more
You must be reading some outdated copies of the manpages (emphasis added): -rpath=dir Add a directory to the runtime library search path.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
By compiler: GCC: -Wa,-mbranches-within-32B-boundaries clang (10+): -mbranches-within-32B-boundaries compiler option directly, not -Wa. MSVC: /QIntel-jcc-erratum See Intel JCC Erratum – what is the effect of prefixes used for mitigation? ICC: TODO, look for docs. The GNU toolchain does mitigation in the assembler, with as -mbranches-within-32B-boundaries, which enables (GAS manual: x86 options): -malign-branch-boundary=32 (care about 32-byte boundaries). … Read more
In addition to considering the directory to contain “system headers”, -isystem alters the header search list, putting the directory argument at the top of the system header directories. If the directory already exists in the search list, it is removed from its current location. As of (at least) GCC 6.1.1, some C++ headers such as … Read more