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Cleanup and doc updates

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Edward R. Gonzalez
2023-08-23 02:17:47 -04:00
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docs/Parsing.md
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@ -1,7 +1,9 @@
# Parsing
The library features a naive parser tailored for only what the library needs to construct the supported syntax of C++ into its AST.
This parser does not, and should not do the compiler's job. By only supporting this minimal set of features, the parser is kept (so far) under 5000 loc.
This parser does not, and should not do the compiler's job. By only supporting this minimal set of features, the parser is kept (so far) around 5000 loc.
You can think of this parser of a frontend parser vs a semantic parser. Its intuitively similar to WYSIWYG. What you precerive as the syntax from the user-side before the compiler gets a hold of it, is what you get.
The parsing implementation supports the following for the user:
@ -27,10 +29,12 @@ CodeUsing parse_using ( StrC using_def );
CodeVar parse_variable ( StrC var_def );
```
To parse file buffers, use the `parse_global_body` function.
***Parsing will aggregate any tokens within a function body or expression statement to an untyped Code AST.***
Everything is done in one pass for both the preprocessor directives and the rest of the language.
The parser performs no macro expansion as the scope of gencpp feature-set is to only support the preprocessor for the goal of having rudimentary awareness of preprocessor ***conditionals***, ***defines***, and ***includes***, and ***pragmas***.
The parser performs no macro expansion as the scope of gencpp feature-set is to only support the preprocessor for the goal of having rudimentary awareness of preprocessor ***conditionals***, ***defines***, ***includes***, and ***pragmas***.
The keywords supported for the preprocessor are:
@ -51,10 +55,17 @@ Any preprocessor definition abuse that changes the syntax of the core language i
Exceptions:
* function signatures are allowed for a preprocessed macro: `neverinline MACRO() { ... }`
* Disable with: `#define GEN_PARSER_DISABLE_MACRO_FUNCTION_SIGNATURES`
* typedefs allow for a preprocessed macro: `typedef MACRO();`
* Disable with: `#define GEN_PARSER_DISABLE_MACRO_TYPEDEF`
*(See functions `parse_operator_function_or_variable` and `parse_typedef` )*
Adding your own exceptions is possible by simply modifying the parser to allow for the syntax you need.
*Note: You could interpret this strictness as a feature. This would allow the user to see if their codebase or a third-party's codebase some some egregious preprocessor abuse.*
The lexing and parsing takes shortcuts from whats expected in the standard.
* Numeric literals are not checked for validity.
@ -69,3 +80,4 @@ The lexing and parsing takes shortcuts from whats expected in the standard.
* Parsing attributes can be extended to support user defined macros by defining `GEN_DEFINE_ATTRIBUTE_TOKENS` (see `gen.hpp` for the formatting)
Empty lines used throughout the file are preserved for formatting purposes during ast serialization.