Hi
I'm reading about GNU CPP(GNU C preprocessor). In the CPP manual -> 1.1 Character sets:
I think "under control of the user" means to use the option -fexec-charset=, right? And in the above part, it says pretty clear: "After preprocessing is complete", so the job -- "string and character constants are converted again, into the execution character set" -- should be done by the C compiler(compilation proper), not GNU CPP. Then the option -fexec-charset= should be an option controlling the C compiler, not the preprocessor. But in the GCC manual, this option is listed in the "3.11 Options Controlling the Preprocessor". I don't understand this, If this option is an option controlling the preprocessor, it conflicts with the CPP manual. How to understand this?

THANKS!!

Yes.

The GNU compiler does not use a separate preprocessor, but the preprocessor is integrated into the compiler. In GCC, the translation takes part in the preprocessor component (from a source tree perspective), but as part of the compilation process.

I don't get it. I knew that a rough definition of compilation started from preprocessing and ended after linking. GCC manual says "Compilation can involve up to four stages: preprocessing, compilation proper, assembly and linking, always in that order." The manual distinguished preprocessing and compilation proper conceptually, so when it says "options controlling the preprocessor" it means the option is used for preprocessing (first of the four stages). That's what I don't understand because I think -fexec-charset= should be "options controlling the compilation proper". You can say compilation in a rough definition, but the manual doesn't seem to mean that.

Yes,that is true. Logically, Gcc distinguishes 4 phases, but preprocessing and compilationq proper are merged into a single phase. The c standard doesn't clearly say where the conversion belongs to. The wording in the Gcc docu might be misleading and - I don't think it is important - but the whole conversion stuff in Gcc is implemented in libcpp (preprocessing library). But the conversion only takes place during compilation prop. So the docu lists this option under preprocessing because this is implemented in the preprocessor.

I hope it's clearer now?

Andi

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I see. The conversion code is in the cpp library but is invoked during compilation proper phase. Then I think maybe GCC manual should put it in other section like "options controlling compilaton proper", alternatively, the writers should put your reply into the manual as a footnote. Can save me days...