[clang] Issue #19 and #20 - Describe auto (C++11) type inferences (PR #86474)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Nisarga V (nisarga3)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/86474.diff


7 Files Affected:

- (modified) clang/include/clang/Basic/DiagnosticSemaKinds.td (+2) 
- (modified) clang/include/clang/Basic/LangOptions.def (+1) 
- (modified) clang/include/clang/Driver/Options.td (+6) 
- (modified) clang/include/clang/Frontend/FrontendOptions.h (+6) 
- (modified) clang/lib/Frontend/CompilerInvocation.cpp (+7) 
- (modified) clang/lib/Sema/SemaDecl.cpp (+8) 
- (modified) clang/tools/driver/cc1_main.cpp (+4) 


``````````diff
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 9b5245695153ec..c1c8e2a58d1701 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -2496,6 +2496,8 @@ def err_auto_init_list_from_c : Error<
   "%select{initializer list|array}1 in C">;
 def err_auto_bitfield : Error<
   "cannot pass bit-field as __auto_type initializer in C">;
+def note_deduced_auto_type : Note<
+    "deduced type of %0 is %1">;
 
 // C++1y decltype(auto) type
 def err_decltype_auto_invalid : Error<
diff --git a/clang/include/clang/Basic/LangOptions.def b/clang/include/clang/Basic/LangOptions.def
index 472fd9f093a718..6cb262c845af8b 100644
--- a/clang/include/clang/Basic/LangOptions.def
+++ b/clang/include/clang/Basic/LangOptions.def
@@ -100,6 +100,7 @@ LANGOPT(CPlusPlus20       , 1, 0, "C++20")
 LANGOPT(CPlusPlus23       , 1, 0, "C++23")
 LANGOPT(CPlusPlus26       , 1, 0, "C++26")
 LANGOPT(ObjC              , 1, 0, "Objective-C")
+LANGOPT(DumpAutoTypeInference , 1, 0, "Dump auto type inference information")
 BENIGN_LANGOPT(ObjCDefaultSynthProperties , 1, 0,
                "Objective-C auto-synthesized properties")
 BENIGN_LANGOPT(EncodeExtendedBlockSig , 1, 0,
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index aca8c9b0d5487a..542065be3c8811 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -7474,6 +7474,12 @@ def stats_file : Joined<["-"], "stats-file=">,
 def stats_file_append : Flag<["-"], "stats-file-append">,
   HelpText<"If stats should be appended to stats-file instead of overwriting it">,
   MarshallingInfoFlag<FrontendOpts<"AppendStats">>;
+
+def fdump_auto_type_inference : Flag<["-"], "fdump-auto-type-inference">, Group<f_Group>,
+    HelpText<"Enable dumping of auto type inference information">;
+def fno_dump_auto_type_inference : Flag<["-"], "fno-dump-auto-type-inference">,Group<f_Group>,
+    HelpText<"Disable dumping of auto type inference information">;
+
 def fdump_record_layouts_simple : Flag<["-"], "fdump-record-layouts-simple">,
   HelpText<"Dump record layout information in a simple form used for testing">,
   MarshallingInfoFlag<LangOpts<"DumpRecordLayoutsSimple">>;
diff --git a/clang/include/clang/Frontend/FrontendOptions.h b/clang/include/clang/Frontend/FrontendOptions.h
index 8085dbcbf671a6..fac6ff18ecae69 100644
--- a/clang/include/clang/Frontend/FrontendOptions.h
+++ b/clang/include/clang/Frontend/FrontendOptions.h
@@ -134,6 +134,9 @@ enum ActionKind {
   /// Run one or more source code analyses.
   RunAnalysis,
 
+  /// for dumping auto type inference
+  DumpAutoTypeInference,
+
   /// Dump template instantiations
   TemplightDump,
 
@@ -274,6 +277,9 @@ class FrontendInputFile {
 /// FrontendOptions - Options for controlling the behavior of the frontend.
 class FrontendOptions {
 public:
+bool DumpAutoTypeInference=false;
+bool shouldDumpAutoTypeInference() const { return DumpAutoTypeInference; }
+void setDumpAutoTypeInference(bool Value) { DumpAutoTypeInference = Value; }
   /// Disable memory freeing on exit.
   LLVM_PREFERRED_TYPE(bool)
   unsigned DisableFree : 1;
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 451bdb9386f587..17d100f8ba2aa7 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -2576,6 +2576,7 @@ static const auto &getFrontendActionTable() {
       {frontend::RunPreprocessorOnly, OPT_Eonly},
       {frontend::PrintDependencyDirectivesSourceMinimizerOutput,
        OPT_print_dependency_directives_minimized_source},
+      {frontend::DumpAutoTypeInference, OPT_fdump_auto_type_inference},
   };
 
   return Table;
@@ -2842,6 +2843,11 @@ static bool ParseFrontendArgs(FrontendOptions &Opts, ArgList &Args,
   for (const auto *AA : Args.filtered(OPT_plugin_arg))
     Opts.PluginArgs[AA->getValue(0)].emplace_back(AA->getValue(1));
 
+    // Add custom flag handling for -fdump-auto-type-inference
+  if (Args.hasArg(OPT_fdump_auto_type_inference)) {
+    Opts.setDumpAutoTypeInference(true);
+  }
+
   for (const std::string &Arg :
          Args.getAllArgValues(OPT_ftest_module_file_extension_EQ)) {
     std::string BlockName;
@@ -4295,6 +4301,7 @@ static bool isStrictlyPreprocessorAction(frontend::ActionKind Action) {
   case frontend::RunAnalysis:
   case frontend::TemplightDump:
   case frontend::MigrateSource:
+  case frontend::DumpAutoTypeInference:
     return false;
 
   case frontend::DumpCompilerOptions:
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 1f4a041e88dfff..9afa30fab19639 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -13200,6 +13200,14 @@ bool Sema::DeduceVariableDeclarationType(VarDecl *VDecl, bool DirectInit,
   VDecl->setType(DeducedType);
   assert(VDecl->isLinkageValid());
 
+    // Check if the variable declaration is in the compiled file
+  SourceManager &SM = getSourceManager();
+  SourceLocation Loc = VDecl->getLocation();
+  if (SM.isWrittenInMainFile(Loc)) {
+    // Print the deduced type for diagnostic purposes
+    llvm::outs() << "Deduced type for '" << VDecl->getNameAsString() << "': " << DeducedType.getAsString() << "\n";
+  }
+
   // In ARC, infer lifetime.
   if (getLangOpts().ObjCAutoRefCount && inferObjCARCLifetime(VDecl))
     VDecl->setInvalidDecl();
diff --git a/clang/tools/driver/cc1_main.cpp b/clang/tools/driver/cc1_main.cpp
index b5c6be3c557bb3..065c8b8689e979 100644
--- a/clang/tools/driver/cc1_main.cpp
+++ b/clang/tools/driver/cc1_main.cpp
@@ -191,6 +191,10 @@ int cc1_main(ArrayRef<const char *> Argv, const char *Argv0, void *MainAddr) {
 
   bool Success = CompilerInvocation::CreateFromArgs(Clang->getInvocation(),
                                                     Argv, Diags, Argv0);
+   // Check if the '-fdump-type-auto-reference' flag is present
+  if (Success && Clang->getFrontendOpts().DumpAutoTypeInference) {
+    llvm::outs() << "Dumping type auto reference...✔\n";
+  }
 
   if (!Clang->getFrontendOpts().TimeTracePath.empty()) {
     llvm::timeTraceProfilerInitialize(

``````````

</details>


https://github.com/llvm/llvm-project/pull/86474