[PATCH] D45927: [clang-tidy] [modernize-use-auto] Correct way to calculate a type name length for multi-token types

[Alexander Kornienko via Phabricator via cfe-commits]

alexfh added inline comments.


================
Comment at: clang-tidy/modernize-use-auto-min-type-name-length.cpp:61-83
+    long int li = static_cast<long int>(foo<long int>());
+    // CHECK-FIXES-0-0: auto li = {{.*}}
+    // CHECK-FIXES-0-5: auto li = {{.*}}
+    // CHECK-FIXES-1-0: auto  li = {{.*}}
+    // CHECK-FIXES-1-5: auto  li = {{.*}}
+    long int *pli = static_cast<long int *>(foo<long int*>());
+    // CHECK-FIXES-0-0: auto *pli = {{.*}}
----------------
zinovy.nis wrote:
> zinovy.nis wrote:
> > zinovy.nis wrote:
> > > alexfh wrote:
> > > > These tests could be more useful, if they verified boundary values of the MinTypeNameLength, e.g. that `long int` is replaced with `auto` when the option is set to 8 and it stays `long int`with the option set to 9.
> > > > 
> > > > Please also add tests with template typenames: e.g. the lenght of `T <  int  >` should be considered 6 and the length of `T  <  const int >` is 12. I guess, the algorithm I proposed will be incorrect for pointer type arguments of templates (the length of `T<int*>` should be 7 regardless of `RemoveStars`), but this can be fixed by conditionally (on RemoveStars) trimming `*`s from the right of the type name and then treating them as punctuation. So instead of
> > > > 
> > > > ```
> > > >   for (const unsigned char C : tooling::fixit::getText(SR, Context)) {
> > > >     const CharType NextChar =
> > > >         std::isalnum(C)
> > > >             ? Alpha
> > > >             : (std::isspace(C) || (!RemoveStars && C == '*')) ? Space
> > > >                                                               : Punctuation;
> > > > ```
> > > > 
> > > > you could use something similar to
> > > > 
> > > > ```
> > > >   StringRef Text = tooling::fixit::getText(SR, Context);
> > > >   if (RemoveStars)
> > > >     Text = Text.rtrim(" \t\v\n\r*");
> > > >   for (const unsigned char C : Text) {
> > > >     const CharType NextChar =
> > > >         std::isalnum(C) ? Alpha : std::isspace(C) ? Space : Punctuation;
> > > > ```
> > > > These tests could be more useful, if they verified boundary values of the MinTypeNameLength, e.g. that long int is replaced with auto when the option is set to 8 and it stays long intwith the option set to 9.
> > > > 
> > > 
> > > `int`-test is just for that :-)
> > > 
> > > ```
> > > int a = static_cast<int>(foo());                 // ---> int  a = ...
> > > ```
> > I measured lengths for template cases:
> > 
> > 
> > ```
> > S=std::string *   len=12
> > S=std::vector<std::string> *   len=25
> > S=std::vector<const std::string> *   len=31
> > S=std::string        *   len=12
> > S=std::vector<std::string>       *   len=25
> > S=std::vector<const std::string>    *   len=31
> > ```
> > 
> > 
> RemoveStars==1 here.
> S=std::string *   len=12

With RemoveStars this should be 11?

> S=std::vector<std::string> *   len=25

24?

> S=std::vector<const std::string> *   len=31

30?

The point of my comment was that stars should be treated specially only at the end of the type, not inside template parameters, e.g. `T<int****>` should have length 10 regardless of RemoveStars. All your examples are with trailing stars.


================
Comment at: clang-tidy/modernize-use-auto-min-type-name-length.cpp:61-83
+    long int li = static_cast<long int>(foo<long int>());
+    // CHECK-FIXES-0-0: auto li = {{.*}}
+    // CHECK-FIXES-0-5: auto li = {{.*}}
+    // CHECK-FIXES-1-0: auto  li = {{.*}}
+    // CHECK-FIXES-1-5: auto  li = {{.*}}
+    long int *pli = static_cast<long int *>(foo<long int*>());
+    // CHECK-FIXES-0-0: auto *pli = {{.*}}
----------------
alexfh wrote:
> zinovy.nis wrote:
> > zinovy.nis wrote:
> > > zinovy.nis wrote:
> > > > alexfh wrote:
> > > > > These tests could be more useful, if they verified boundary values of the MinTypeNameLength, e.g. that `long int` is replaced with `auto` when the option is set to 8 and it stays `long int`with the option set to 9.
> > > > > 
> > > > > Please also add tests with template typenames: e.g. the lenght of `T <  int  >` should be considered 6 and the length of `T  <  const int >` is 12. I guess, the algorithm I proposed will be incorrect for pointer type arguments of templates (the length of `T<int*>` should be 7 regardless of `RemoveStars`), but this can be fixed by conditionally (on RemoveStars) trimming `*`s from the right of the type name and then treating them as punctuation. So instead of
> > > > > 
> > > > > ```
> > > > >   for (const unsigned char C : tooling::fixit::getText(SR, Context)) {
> > > > >     const CharType NextChar =
> > > > >         std::isalnum(C)
> > > > >             ? Alpha
> > > > >             : (std::isspace(C) || (!RemoveStars && C == '*')) ? Space
> > > > >                                                               : Punctuation;
> > > > > ```
> > > > > 
> > > > > you could use something similar to
> > > > > 
> > > > > ```
> > > > >   StringRef Text = tooling::fixit::getText(SR, Context);
> > > > >   if (RemoveStars)
> > > > >     Text = Text.rtrim(" \t\v\n\r*");
> > > > >   for (const unsigned char C : Text) {
> > > > >     const CharType NextChar =
> > > > >         std::isalnum(C) ? Alpha : std::isspace(C) ? Space : Punctuation;
> > > > > ```
> > > > > These tests could be more useful, if they verified boundary values of the MinTypeNameLength, e.g. that long int is replaced with auto when the option is set to 8 and it stays long intwith the option set to 9.
> > > > > 
> > > > 
> > > > `int`-test is just for that :-)
> > > > 
> > > > ```
> > > > int a = static_cast<int>(foo());                 // ---> int  a = ...
> > > > ```
> > > I measured lengths for template cases:
> > > 
> > > 
> > > ```
> > > S=std::string *   len=12
> > > S=std::vector<std::string> *   len=25
> > > S=std::vector<const std::string> *   len=31
> > > S=std::string        *   len=12
> > > S=std::vector<std::string>       *   len=25
> > > S=std::vector<const std::string>    *   len=31
> > > ```
> > > 
> > > 
> > RemoveStars==1 here.
> > S=std::string *   len=12
> 
> With RemoveStars this should be 11?
> 
> > S=std::vector<std::string> *   len=25
> 
> 24?
> 
> > S=std::vector<const std::string> *   len=31
> 
> 30?
> 
> The point of my comment was that stars should be treated specially only at the end of the type, not inside template parameters, e.g. `T<int****>` should have length 10 regardless of RemoveStars. All your examples are with trailing stars.
> int-test is just for that :-)

Nope, the point is to verify that the length of multi-token type names is calculated correctly. `int` is a single token.


https://reviews.llvm.org/D45927