4 ms·

What??? How would that happen? Are modules always compiled with zero flags because in non-module c++ how the dependent module gets compiled is defined in the bu

What??? How would that happen? Are modules always compiled with zero flags because in non-module c++ how the dependent module gets compiled is defined in the build system so in order for the compiler to build a missing .bmi it would have to ask the build system how to build it . The build system just figures out how to invoke the compiler. The compiler does the actual building. When the compiler runs, it has all the flags. Remember, headers in C / C++ are basically a file level construct. They happen before you even split the file into tokens. #include just means "do the equivalent of opening that file in a text editor and copy and paste it in place of this #include line." The compiler is already compiling header files, as part of compiling cpp files.

tokyodude 8y ago
But we're not talking about header files, we're talking about modules. Modules are a new concept so how they work is up for definition. To say that if bar.cpp uses module foo that foo.bmi must already exist is not an unreasonable rule. modules work with the import statement (new) not the #include statement. They are not the same as include at all. In fact this is spelled out in the article in the first goal > The “importer” of a module cannot affect the content of the module being imported. The state of the compiler (preprocessor) in the importing source has no bearing on the processing of the imported code. In other words, the flags passed in when compiling bar.cpp have no effect on foo.bmi. foo.bmi is the result of the flags passed in when foo.cpp was compiled and those flags can only be gotten from the build system if foo.bmi does not exist.