On 6/15/16, Matthew Fortune <Matthew.Fortune@xxxxxxxxxx> wrote: > Alastair Hughes <hobbitalastair@xxxxxxxxx> writes: >> I've cross compiled GCC 6.1.0 (target/build is mips, host is x86_64). > > This description does not match the log. The log is for: build=x86_64 > host/target=mips. The log shows the build system using a pre-installed > x86_64->mips cross compiler when building libgcc/libstdc++. My bad, I mixed that up... >> The resulting compiler will not run as it cannot find cc1, because the >> search dirs are incorrect; they are prefixed with "../lib" instead of >> "/usr/lib" (eg instead of /usr/lib/gcc/mips-linux-musl/6.1.0/ ..., the >> path is ../lib/gcc/mips-linux-musl/6.1.0/ ...). > > Can you show the full search paths that GCC tries? install: ../lib/gcc/mips-linux-musl/6.1.0/ programs: =../lib/gcc/mips-linux-musl/6.1.0/:../lib/gcc/:../mips-linux-musl/bin/mips-linux-musl/6.1.0/:../mips-linux-musl/bin/ libraries: =../lib/gcc/mips-linux-musl/6.1.0/:../lib/gcc/:../mips-linux-musl/lib/mips-linux-musl/6.1.0/:../mips-linux-musl/lib/:../lib/mips-linux-musl/6.1.0/:../lib/:/lib/mips-linux-musl/6.1.0/:/lib/:/usr/lib/mips-linux-musl/6.1.0/:/usr/lib/ >> If the problem is not a configuration mistake, where would I look to >> find out what could be the issue? Where does the GCC build process >> determine/set what the search dirs should be? > > The search paths are constructed out of the prefix in this case as well > as having a relative path as a fallback. > > The absolute path that you build GCC with (--prefix) will be searched > first with lib/gcc/xyz suffixed otherwise the directory containing the > GCC executable will be searched by suffixing ../ to get to the root of > the toolchain and then lib/gcc/xyz. > > The latter form of searching only works if you invoke the 'main' GCC > executable in <root>/bin/[mips-linux-musl-]gcc if you invoke the copy > at <root>/mips-linux-musl/bin/gcc then the relative path will fail as > that copy of gcc is 2 levels deep not 1 level. > > Hope that helps a bit, > Matthew Thanks Matthew! I continued looking based on your explanation and discovered that the issue appears to stem from running gcc with no PATH set (I was booting directly into a shell script to simplify debugging). Without investigating too deeply into gcc, it appears that gcc searches through PATH to find itself; as PATH is unset, it cannot locate itself. I can reproduce in my development environment by running unset $PATH; bash -c "gcc -print-search-dirs" It seems that gcc is not searching --prefix (set to /usr in this case); is that the intended behavior? Alastair Hughes
