Fixes #14921: Detect enums before simplifying platform types

[autoantwort]

No description provided.

[chrchr-github]

This issue has come up multiple times before, and is not restricted to enums or the Windows library, see e.g. https://trac.cppcheck.net/ticket/12589

Contributing factors:

• We have a single configuration file for huge libraries/APIs with dozens or hundreds of headers
• The --library option is usually set per project, not per file

I don't think the proposed change is the right way to address this. Maybe -UHANDLE can be used as a workaround?

[danmar]

is it OK to redefine HANDLE in the global scope? If I compile this code:

typedef void* HANDLE;
enum {HANDLE, X};

I get such gcc errors:

1.c:3:7: error: ‘HANDLE’ redeclared as different kind of symbol

I assume windows.h defines HANDLE using a typedef?

[danmar]

I feel there is some missing scope in the example code. HANDLE in the global scope should be simplified as a void * if --library=windows has been used .. and HANDLE in your inner scope should be handled as the enum constant. We need to distinguish which type to use in different scopes..

[autoantwort]

is it OK to redefine HANDLE in the global scope? If I compile this code:

typedef void* HANDLE;
enum {HANDLE, X};

I get such gcc errors:

If i compile this

typedef void* HANDLE;
enum class E {HANDLE, X};

it compiles without errors.

[autoantwort]

I don't think the proposed change is the right way to address this.

I guess the right fix would be introducing typedefs for the types instead of replacing them in the AST without context information.

[danmar]

trac ticket 11538 is about a syntax error

[danmar]

I guess the right fix would be introducing typedefs for the types instead of replacing them in the AST without context information.

I think I am thinking the same. However not by introducing some typedef .. tokens if that was what you meant.

To simplify platform types.. can we reuse the logic that simplifies typedefs in simplifyTypedef?

This code:

typedef void* HANDLE;
enum class E { HANDLE, X };
void foo(HANDLE h) { a = E::HANDLE; }

This --debug output looks correct as far as I see:

2: enum class E { HANDLE , X } ;
3: void foo ( void * h@var1 ) { a@exprUNIQUE =@exprUNIQUE E ::@exprUNIQUE HANDLE ; }

And ValueFlow determines the value for E::HANDLE properly.

my suggestion; we would break out code from Tokenizer::simplifyTypedefCpp into a function that we then call from simplifyPlatformType also.