Clang: Fix code completion for connect()

Clang built with this patch properly handles
not only normal methods but also templated ones
which fixes code completion for QObject::connect.

Change-Id: If1c4c0f5fda29c1aff106d8ed7065ff502a26328
Reviewed-by: Marco Bubke <marco.bubke@qt.io>

2 files changed, 176 insertions, 0 deletions

diff --git a/dist/clang/patches/210_D43453_Fix-overloaded-static-functions-for-templates.patch b/dist/clang/patches/210_D43453_Fix-overloaded-static-functions-for-templates.patch
new file mode 100644
index 0000000000..2296904f7d
--- /dev/null
+++ b/dist/clang/patches/210_D43453_Fix-overloaded-static-functions-for-templates.patch
@@ -0,0 +1,168 @@
+diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
+index 1b07ec60ce..46ed08d1cf 100644
+--- a/lib/Sema/SemaOverload.cpp
++++ b/lib/Sema/SemaOverload.cpp
+@@ -6371,57 +6371,54 @@ void Sema::AddFunctionCandidates(const UnresolvedSetImpl &Fns,
+                                  bool FirstArgumentIsBase) {
+   for (UnresolvedSetIterator F = Fns.begin(), E = Fns.end(); F != E; ++F) {
+     NamedDecl *D = F.getDecl()->getUnderlyingDecl();
+-    if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) {
+-      ArrayRef<Expr *> FunctionArgs = Args;
+-      if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) {
+-        QualType ObjectType;
+-        Expr::Classification ObjectClassification;
+-        if (Args.size() > 0) {
+-          if (Expr *E = Args[0]) {
+-            // Use the explit base to restrict the lookup:
+-            ObjectType = E->getType();
+-            ObjectClassification = E->Classify(Context);
+-          } // .. else there is an implit base.
+-          FunctionArgs = Args.slice(1);
+-        }
+-        AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(),
+-                           cast<CXXMethodDecl>(FD)->getParent(), ObjectType,
+-                           ObjectClassification, FunctionArgs, CandidateSet,
+-                           SuppressUserConversions, PartialOverloading);
+-      } else {
+-        // Slice the first argument (which is the base) when we access
+-        // static method as non-static
+-        if (Args.size() > 0 && (!Args[0] || (FirstArgumentIsBase && isa<CXXMethodDecl>(FD) &&
+-                                             !isa<CXXConstructorDecl>(FD)))) {
+-          assert(cast<CXXMethodDecl>(FD)->isStatic());
+-          FunctionArgs = Args.slice(1);
+-        }
+-        AddOverloadCandidate(FD, F.getPair(), FunctionArgs, CandidateSet,
+-                             SuppressUserConversions, PartialOverloading);
+-      }
+-    } else {
+-      FunctionTemplateDecl *FunTmpl = cast<FunctionTemplateDecl>(D);
+-      if (isa<CXXMethodDecl>(FunTmpl->getTemplatedDecl()) &&
+-          !cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl())->isStatic()) {
+-        QualType ObjectType;
+-        Expr::Classification ObjectClassification;
++    ArrayRef<Expr *> FunctionArgs = Args;
++
++    FunctionTemplateDecl *FunTmpl = nullptr;
++    FunctionDecl *FD = dyn_cast<FunctionDecl>(D);
++
++    const bool IsTemplate = FD ? false : true;
++    if (IsTemplate) {
++      FunTmpl = cast<FunctionTemplateDecl>(D);
++      FD = FunTmpl->getTemplatedDecl();
++    }
++
++    if (isa<CXXMethodDecl>(FD) && !cast<CXXMethodDecl>(FD)->isStatic()) {
++      QualType ObjectType;
++      Expr::Classification ObjectClassification;
++      if (Args.size() > 0) {
+         if (Expr *E = Args[0]) {
+-          // Use the explit base to restrict the lookup:
++          // Use the explicit base to restrict the lookup:
+           ObjectType = E->getType();
+           ObjectClassification = E->Classify(Context);
+         } // .. else there is an implit base.
++        FunctionArgs = Args.slice(1);
++      }
++      if (IsTemplate)
+         AddMethodTemplateCandidate(
+-            FunTmpl, F.getPair(),
+-            cast<CXXRecordDecl>(FunTmpl->getDeclContext()),
+-            ExplicitTemplateArgs, ObjectType, ObjectClassification,
+-            Args.slice(1), CandidateSet, SuppressUserConversions,
+-            PartialOverloading);
+-      } else {
+-        AddTemplateOverloadCandidate(FunTmpl, F.getPair(),
+-                                     ExplicitTemplateArgs, Args,
+-                                     CandidateSet, SuppressUserConversions,
+-                                     PartialOverloading);
++            FunTmpl, F.getPair(), cast<CXXRecordDecl>(FD), ExplicitTemplateArgs,
++            ObjectType, ObjectClassification, FunctionArgs, CandidateSet,
++            SuppressUserConversions, PartialOverloading);
++      else
++        AddMethodCandidate(cast<CXXMethodDecl>(FD), F.getPair(),
++                           cast<CXXMethodDecl>(FD)->getParent(), ObjectType,
++                           ObjectClassification, FunctionArgs, CandidateSet,
++                           SuppressUserConversions, PartialOverloading);
++    } else {
++      // Slice the first argument (which is the base) when we access
++      // static method as non-static
++      if (Args.size() > 0 &&
++          (!Args[0] || (FirstArgumentIsBase && isa<CXXMethodDecl>(FD) &&
++                        !isa<CXXConstructorDecl>(FD)))) {
++        assert(cast<CXXMethodDecl>(FD)->isStatic());
++        FunctionArgs = Args.slice(1);
+       }
++      if (IsTemplate)
++        AddTemplateOverloadCandidate(
++            FunTmpl, F.getPair(), ExplicitTemplateArgs, FunctionArgs,
++            CandidateSet, SuppressUserConversions, PartialOverloading);
++      else
++        AddOverloadCandidate(FD, F.getPair(), FunctionArgs, CandidateSet,
++                             SuppressUserConversions, PartialOverloading);
+     }
+   }
+ }
+diff --git a/test/Index/complete-call.cpp b/test/Index/complete-call.cpp
+index ca116485ac..35f2009066 100644
+--- a/test/Index/complete-call.cpp
++++ b/test/Index/complete-call.cpp
+@@ -112,6 +112,33 @@ struct Bar2 : public Bar {
+   }
+ };
+ 
++struct BarTemplates {
++  static void foo_1() {}
++  void foo_1(float) {}
++  static void foo_1(int) {}
++
++  template<class T1, class T2>
++  static void foo_1(T1 a, T2 b) { a + b; }
++
++  template<class T1, class T2>
++  void foo_1(T1 a, T2 b, float c) { a + b + c; }
++
++  template<class T1, class T2>
++  static void foo_1(T2 a, int b, T1 c)  { a + b + c; }
++};
++
++void testTemplates() {
++  BarTemplates::foo_1();
++  BarTemplates b;
++  b.foo_1();
++}
++
++struct Bar2Template : public BarTemplates {
++  Bar2Template() {
++    BarTemplates::foo_1();
++  }
++};
++
+ // RUN: c-index-test -code-completion-at=%s:47:9 %s | FileCheck -check-prefix=CHECK-CC1 %s
+ // CHECK-CC1: OverloadCandidate:{ResultType void}{Text foo_1}{LeftParen (}{RightParen )} (1)
+ // CHECK-CC1: Completion contexts:
+@@ -864,3 +891,25 @@ struct Bar2 : public Bar {
+ // CHECK-CC62-NEXT: Nested name specifier
+ // CHECK-CC62-NEXT: Objective-C interface
+ 
++// RUN: c-index-test -code-completion-at=%s:131:23 %s | FileCheck -check-prefix=CHECK-CC63 %s
++// CHECK-CC63: OverloadCandidate:{ResultType void}{Text foo_1}{LeftParen (}{RightParen )} (1)
++// CHECK-CC63: OverloadCandidate:{ResultType void}{Text foo_1}{LeftParen (}{CurrentParameter float}{RightParen )} (1)
++// CHECK-CC63: OverloadCandidate:{ResultType void}{Text foo_1}{LeftParen (}{CurrentParameter int}{RightParen )} (1)
++// CHECK-CC63: OverloadCandidate:{ResultType void}{Text foo_1}{LeftParen (}{CurrentParameter T1 a}{Comma , }{Placeholder T2 b}{RightParen )} (1)
++// CHECK-CC63: OverloadCandidate:{ResultType void}{Text foo_1}{LeftParen (}{CurrentParameter T1 a}{Comma , }{Placeholder T2 b}{Comma , }{Placeholder float c}{RightParen )} (1)
++// CHECK-CC63: OverloadCandidate:{ResultType void}{Text foo_1}{LeftParen (}{CurrentParameter T2 a}{Comma , }{Placeholder int b}{Comma , }{Placeholder T1 c}{RightParen )} (1)
++
++// RUN: c-index-test -code-completion-at=%s:133:11 %s | FileCheck -check-prefix=CHECK-CC64 %s
++// CHECK-CC64: OverloadCandidate:{ResultType void}{Text foo_1}{LeftParen (}{RightParen )} (1)
++// CHECK-CC64: OverloadCandidate:{ResultType void}{Text foo_1}{LeftParen (}{CurrentParameter float}{RightParen )} (1)
++// CHECK-CC64: OverloadCandidate:{ResultType void}{Text foo_1}{LeftParen (}{CurrentParameter int}{RightParen )} (1)
++// CHECK-CC64: OverloadCandidate:{ResultType void}{Text foo_1}{LeftParen (}{CurrentParameter T1 a}{Comma , }{Placeholder T2 b}{RightParen )} (1)
++// CHECK-CC64: OverloadCandidate:{ResultType void}{Text foo_1}{LeftParen (}{CurrentParameter T2 a}{Comma , }{Placeholder int b}{Comma , }{Placeholder T1 c}{RightParen )} (1)
++
++// RUN: c-index-test -code-completion-at=%s:138:25 %s | FileCheck -check-prefix=CHECK-CC65 %s
++// CHECK-CC65: OverloadCandidate:{ResultType void}{Text foo_1}{LeftParen (}{RightParen )} (1)
++// CHECK-CC65: OverloadCandidate:{ResultType void}{Text foo_1}{LeftParen (}{CurrentParameter float}{RightParen )} (1)
++// CHECK-CC65: OverloadCandidate:{ResultType void}{Text foo_1}{LeftParen (}{CurrentParameter int}{RightParen )} (1)
++// CHECK-CC65: OverloadCandidate:{ResultType void}{Text foo_1}{LeftParen (}{CurrentParameter T1 a}{Comma , }{Placeholder T2 b}{RightParen )} (1)
++// CHECK-CC65: OverloadCandidate:{ResultType void}{Text foo_1}{LeftParen (}{CurrentParameter T1 a}{Comma , }{Placeholder T2 b}{Comma , }{Placeholder float c}{RightParen )} (1)
++// CHECK-CC65: OverloadCandidate:{ResultType void}{Text foo_1}{LeftParen (}{CurrentParameter T2 a}{Comma , }{Placeholder int b}{Comma , }{Placeholder T1 c}{RightParen )} (1)
diff --git a/dist/clang/patches/README.md b/dist/clang/patches/README.md
index 7c5da42036..86e84e74de 100644
--- a/dist/clang/patches/README.md
+++ b/dist/clang/patches/README.md
@@ -121,3 +121,11 @@ Fix overloaded static functions in SemaCodeComplete
 
 Happens when static function is accessed via the class variable.
 That leads to incorrect overloads number because the variable is considered as the first argument.
+
+##### 210_D43453_Fix-overloaded-static-functions-for-templates.patch
+
+* <https://reviews.llvm.org/D43453>
+
+Fix overloaded static functions for templates
+
+Apply almost the same fix as D36390 but for templates