[LLDB] Add minimal support for the new Mojo language

[wallace]

Summary

Modular just announced a new language called Mojo. This patch adds an entry in the language list in LLDB for minimal support (e.g. being able to create a TypeSystem for this language). We will later add debug info entries when the language matures.

[bulbazord]

lldb/include/lldb/lldb-enumerations.h

493

These values correspond to DWARF5's official language codes and 0x0030 is technically already taken. LLDB just hasn't been updated yet. I don't think this should necessarily block this patch but this value will need to be changed at some point.

See: https://dwarfstd.org/languages.html

[aprantl]

lldb/include/lldb/lldb-enumerations.h

493

Registering a new language with the DWARF committee is a pretty quick process nowadays. Please do that before taking a constant in the reserved range.

[wallace]

lldb/include/lldb/lldb-enumerations.h

493

Thanks for the information. I'll do so then :)

[aprantl]

You can also use a constant in the Vendor extension space, which might be more appropriate until the languages sees adoption by a wider audience.

[wallace]

In D149702#4316747, @aprantl wrote:

You can also use a constant in the Vendor extension space, which might be more appropriate until the languages sees adoption by a wider audience.

That sounds like a better idea. Thanks! I'll give it a try

[wallace]

add the language as a vendor extension

[bulbazord]

Don't forget to come back and update it when you get an official designation!

[rriddle]

Nice!

lldb/docs/python_api_enums.rst

 .. py:data:: eLanguageTypeC11
 .. py:data:: eLanguageTypeSwift
 .. py:data:: eLanguageTypeJulia
 .. py:data:: eLanguageTypeDylan
 .. py:data:: eLanguageTypeC_plus_plus_14
 .. py:data:: eLanguageTypeFortran03
 .. py:data:: eLanguageTypeFortran08
 .. py:data:: eLanguageTypeMipsAssembler
+.. py:data:: eLanguageTypeMojo
 .. py:data:: eLanguageTypeExtRenderScript
 .. py:data:: eNumLanguageTypes
 
 
 .. _InstrumentationRuntimeType:
 
 InstrumentationRuntimeType
 --------------------------

lldb/include/lldb/lldb-enumerations.h

enum LanguageType {
   eLanguageTypeZig = 0x0027,
   eLanguageTypeCrystal = 0x0028,
   eLanguageTypeC_plus_plus_17 = 0x002a, ///< ISO C++:2017.
   eLanguageTypeC_plus_plus_20 = 0x002b, ///< ISO C++:2020.
   eLanguageTypeC17 = 0x002c,
   eLanguageTypeFortran18 = 0x002d,
   eLanguageTypeAda2005 = 0x002e,
   eLanguageTypeAda2012 = 0x002f,
 
   // Vendor Extensions
   // Note: Language::GetNameForLanguageType
   // assumes these can be used as indexes into array language_names, and
   // Language::SetLanguageFromCString and Language::AsCString assume these can
   // be used as indexes into array g_languages.
   eLanguageTypeMipsAssembler,           ///< Mips_Assembler.
+  // Mojo will move to the common list of languages once the DWARF committee
+  // creates a language code for it.
+  eLanguageTypeMojo,
   eNumLanguageTypes
 };
 
 enum InstrumentationRuntimeType {
   eInstrumentationRuntimeTypeAddressSanitizer = 0x0000,
   eInstrumentationRuntimeTypeThreadSanitizer = 0x0001,
   eInstrumentationRuntimeTypeUndefinedBehaviorSanitizer = 0x0002,
   eInstrumentationRuntimeTypeMainThreadChecker = 0x0003,

lldb/source/Target/Language.cpp

struct language_name_pair language_names[] = {
     {"c++17", eLanguageTypeC_plus_plus_17},
     {"c++20", eLanguageTypeC_plus_plus_20},
     {"c17", eLanguageTypeC17},
     {"fortran18", eLanguageTypeFortran18},
     {"ada2005", eLanguageTypeAda2005},
     {"ada2012", eLanguageTypeAda2012},
     // Vendor Extensions
     {"assembler", eLanguageTypeMipsAssembler},
+    {"mojo", eLanguageTypeMojo},
     // Now synonyms, in arbitrary order
     {"objc", eLanguageTypeObjC},
     {"objc++", eLanguageTypeObjC_plus_plus},
     {"pascal", eLanguageTypePascal83}};
 
 static uint32_t num_languages =
     sizeof(language_names) / sizeof(struct language_name_pair);