"Cheng bin" <[EMAIL PROTECTED]> writes: > 1 : At the end of that makefile , There is a section noted as > "Regenerating top level configury". > It is clear what it do, but for what? Where is this piece of > code used in building procedure?
Those pieces of code are used by developers if and when they change the original source files Makefile.tpl, configure.ac, etc. > 2 : At lines around 462, There is a variable named "RECURSE_FLAGS", I > also puzzled > about its usage. It says that "When doing recursive invocations > of the top-level Makefile, > we don't want the outer make to evaluate them, so we pass these > variables down > unchanged. " Does it mean we will recall the top level makefile? > if so, Is "RECURSE_FLAGS" have any relations with the first > question. Maybe both > "Regenerating top level configury" and "RECURSE_FLAGS" is used > to compile gcc > several times in bootstrap. > Here I need a confirmation. If you look at the uses of RECURSE_FLAGS_TO_PASS you will see the cases where the top-level Makefile is reused in a recursive call to make. > 3 : For the cross compiler, I configured and compiled gcc twice, once > with just language C > supported, once with languages C/C++ supported. I compared the > two top level makefile > generated by configure and found the difference is that > libiberty and libstdc++-v3 is > compiled for target at the second time. So here is the question: > libstdc++v3 is compiled > for target as the c++ runtime library, but what libiberty for? I > can only infer that libstdc++v3 > needs it(otherwise why the first time which only supports c > language do not have it > compiled?). Unfortunately, I did not find any code in > libstdc++-v3 which calls functions > in libiberty. libstdc++-v3 uses the C++ demangler from libiberty. Ian
