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I can't tell if you're being sarcastic. Generally, compiling GCC to target another architecture involves not only recreating most of the root directory structu

I can't tell if you're being sarcastic. Generally, compiling GCC to target another architecture involves not only recreating most of the root directory structure (notably include files) of the target on the host, but also compiling libc, bintools, and a few other more obscure libraries. And this all needs to be done in the correct order (which involves something like compiling half of libc before compiling GCC, and compiling the rest of libc afterward). Maybe in 3.x and MIPS it "just worked". My experience is 4.x and Tilera. Myself and another engineer dumped a week into that sinkhole before giving up. Clang/LLVM on the other hand… ./configure && make && make install. No other wacky dependencies or build steps. And it generates better code in many cases (particularly when dealing with structures).

microcolonel 12y ago
There are scripts that do this for you, but yeah it's still a bit wonky. Also, unless you're talking about some completely unexplored target architecture, there are entire root filesystems available already for cross compilation.
fla 12y ago
Have you tried to use buildroot ? http://buildroot.uclibc.org/ http://buildroot.uclibc.org/
- colanderman 12y ago
  Unfortunately this had to cooperate with an existing root environment on the target, so buildroot (as fantastic as it is) was not an option.
zvrba 12y ago
> I can't tell if you're being sarcastic. I'm not. The process is well described, it tells you exactly prerequisites, in which order to build them, and how to configure the directory structure for building gcc itself. It worked for me the very first time I tried it. Though I needed only a freestanding implementation, so I didn't bother with compiling libc. I believe that cross-compiling libc can be painful.
drdaeman 12y ago
Depends on the approach. In some distributions, say, Debian, there are readily available cross-compiler packages (like g++-4.4-arm-linux-gnueabi). I haven't rebuilt gcc, but the approach must be to pull package's source, add a patch and run the build - then debian/rules and myriad of various helper scripts will take the hassle of doing everything. Just can't be the other way since package builds are automated. And there are other tools, like buildcross that also automate the job.

microcolonel 12y ago

There are scripts that do this for you, but yeah it's still a bit wonky. Also, unless you're talking about some completely unexplored target architecture, there are entire root filesystems available already for cross compilation.

fla 12y ago

Have you tried to use buildroot ? http://buildroot.uclibc.org/ http://buildroot.uclibc.org/

colanderman 12y ago
Unfortunately this had to cooperate with an existing root environment on the target, so buildroot (as fantastic as it is) was not an option.

zvrba 12y ago

> I can't tell if you're being sarcastic. I'm not. The process is well described, it tells you exactly prerequisites, in which order to build them, and how to configure the directory structure for building gcc itself. It worked for me the very first time I tried it. Though I needed only a freestanding implementation, so I didn't bother with compiling libc. I believe that cross-compiling libc can be painful.

drdaeman 12y ago

Depends on the approach. In some distributions, say, Debian, there are readily available cross-compiler packages (like g++-4.4-arm-linux-gnueabi). I haven't rebuilt gcc, but the approach must be to pull package's source, add a patch and run the build - then debian/rules and myriad of various helper scripts will take the hassle of doing everything. Just can't be the other way since package builds are automated. And there are other tools, like buildcross that also automate the job.