diff options
| -rw-r--r-- | build2/cc/compile.cxx | 55 |
1 files changed, 46 insertions, 9 deletions
diff --git a/build2/cc/compile.cxx b/build2/cc/compile.cxx index bfc79c9..5f48492 100644 --- a/build2/cc/compile.cxx +++ b/build2/cc/compile.cxx @@ -1412,11 +1412,30 @@ namespace build2 // So this is how we are going to work around this problem: we first run // with -E but without -MG. If there are any errors (maybe because of // generated headers maybe not), we restart with -MG and without -E. If - // this fixes the error (so it was a generate header after all), then we - // have to restart at which point we go back to -E and no -MG. And we + // this fixes the error (so it was a generated header after all), then + // we have to restart at which point we go back to -E and no -MG. And we // keep yo-yoing like this. Missing generated headers will probably be // fairly rare occurrence so this shouldn't be too expensive. // + // Actually, there is another error case we would like to handle: an + // outdated generated header that is now causing an error (e.g., because + // of a check that is now triggering #error or some such). So there are + // actually three error cases: outdated generated header, missing + // generated header, and some other error. To handle the outdated case + // we need the compiler to produce the dependency information even in + // case of an error. Clang does it, for VC we parse diagnostics + // ourselves, but GCC does not (but a patch has been submitted). + // + // So the final plan is then as follows: + // + // 1. Start wothout -MG and with suppressed diagnostics. + // 2. If error but we've updated a header, then repeat step 1. + // 3. Otherwise, restart with -MG and diagnostics. + // + // Note that below we don't even check if the compiler supports the + // dependency info on error. We just try to use it and if it's not + // there we ignore the io error since the compiler has failed. + // bool args_gen; // Current state of args. size_t args_i; // Start of the -M/-MD "tail". @@ -2304,9 +2323,9 @@ namespace build2 bool good_error (false), bad_error (false); size_t skip (skip_count); + string l; // Reuse. for (bool first (true), second (false); !(restart || is.eof ());) { - string l; getline (is, l); if (is.fail ()) @@ -2505,18 +2524,36 @@ namespace build2 // if (e.normal ()) { - // If this run was without the generated header support, force - // it and restart. + // If this run was with the generated header support then we + // have issued diagnostics and it's time to give up. + // + if (gen) + throw failed (); + + // Just to recap, being here means something is wrong with the + // source: it can be a missing generated header, it can be an + // outdated generated header (e.g., some check triggered #error + // which will go away if only we updated the generated header), + // or it can be a real error that is not going away. // - if (!gen) + // So this is what we are going to do here: if anything got + // updated on this run (i.e., the compiler has produced valid + // dependency information even though there were errors and we + // managed to find and update a header based on this + // informaion), then we restart in the same mode hoping that + // this fixes things. Otherwise, we force the generated header + // support which will either uncover a missing generated header + // or will issue diagnostics. + // + if (restart) + l6 ([&]{trace << "trying again without generated headers";}); + else { restart = true; force_gen = true; l6 ([&]{trace << "restarting with forced generated headers";}); - continue; } - - throw failed (); + continue; } else fail << args[0] << " terminated abnormally: " << e.description (); |