Handle issue #20395

[Emmankoko]

for typedefs with ids that are D type keywords, maybe avoid aliasing them.

this ensures D semantics are not broken.

There's a need for new check keyword functions because of the inability for the one already implemented in D work well for C code. because the C ids are not parsed as tokens but identifiers.

@dkorpel @thewilsonator

has been discussed in forum: https://forum.dlang.org/post/[email protected]

[Emmankoko]

I am a little skeptical about this. I would need to expand this for all D keywords in all type of code. but I don't think skipping them is the right call. maybe prepending a _ to them so they get parsed. and we make a loud noise to the D community that any D keyword used in C code variably should be used in with _ prepended when imported into D.

@dkorpel @thewilsonator

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[thewilsonator]

diff --git a/home/circleci/dmd/compiler/src/dmd/frontend.h b/home/circleci/dmd/generated/linux/release/64/frontend.h
index d0063f09f..8bb76e554 100644
--- a/home/circleci/dmd/compiler/src/dmd/frontend.h
+++ b/home/circleci/dmd/generated/linux/release/64/frontend.h
@@ -9018,10 +9018,10 @@ struct Token final
         };
         Identifier* ident;
     };
+    void checkKeyword();
     void setString(const char* ptr, size_t length);
     void setString(const OutBuffer& buf);
     void setString();
-    void checkKeyword();
     const char* toChars() const;
     static const char* toChars(TOK value);
     Token() :

[Emmankoko]

diff --git a/home/circleci/dmd/compiler/src/dmd/frontend.h b/home/circleci/dmd/generated/linux/release/64/frontend.h
index d0063f09f..8bb76e554 100644
--- a/home/circleci/dmd/compiler/src/dmd/frontend.h
+++ b/home/circleci/dmd/generated/linux/release/64/frontend.h
@@ -9018,10 +9018,10 @@ struct Token final
         };
         Identifier* ident;
     };
+    void checkKeyword();
     void setString(const char* ptr, size_t length);
     void setString(const OutBuffer& buf);
     void setString();
-    void checkKeyword();
     const char* toChars() const;
     static const char* toChars(TOK value);
     Token() :

I just updated the header as well. but I don't know yet if that's a key factor too. or what am I doing wrong with the frontend.h file.

[dkorpel]

This is a good start but I have doubts about patching up identifiers in the C parser, it looks fragile and slow having to find and replace keywords in so many places. It also creates unexpected changes in the mangling of function symbols. Could you try creating aliases like alias version_ = version for global variables, struct fields and functions instead? Local variables don't need to change since they are not accessible from D.

[Emmankoko]

This is a good start but I have doubts about patching up identifiers in the C parser, it looks fragile and slow having to find and replace keywords in so many places. It also creates unexpected changes in the mangling of function symbols. Could you try creating aliases like alias version_ = version for global variables, struct fields and functions instead? Local variables don't need to change since they are not accessible from D.

my only concern is that, if I create an alias and we have

int version;
alias version_ = version;

in the end, int version is still emitted. and even, doesn't alias version_ = version break D semantics ? aliasing version

[dkorpel]

in the end, int version is still emitted

Which matches C behavior, which I think is good

Doesn't alias version_ = version break D semantics ? aliasing version

This is not expressible in D code obviously, but internally, ImportC already allows creating identifiers that are D keywords in the AST so I assume it handles it just fine. If you encounter any trouble you can get back to me.

[Emmankoko]

in the end, int version is still emitted

Which matches C behavior, which I think is good

Doesn't alias version_ = version break D semantics ? aliasing version

This is not expressible in D code obviously, but internally, ImportC already allows creating identifiers that are D keywords in the AST so I assume it handles it just fine. If you encounter any trouble you can get back to me.

Okay right! that's valid.

[ibuclaw]

I'm sceptical about this. What are you going to do with the libm function creal? Suffix an underscore? That'll cause a linker error if anyone tries to call it.

Likewise it potentially introduces symbol conflicts where none existed in C - struct { int byte; int byte_; } boom;

I don't think ImportC should try to be smart. It only needs to parse C code, from the D user code interface anything less than WYSIWYG only seeks to cause confusion.