r369281 - Implement P1668R1

[Erich Keane via cfe-commits]

Author: erichkeane
Date: Mon Aug 19 10:39:59 2019
New Revision: 369281

URL: http://llvm.org/viewvc/llvm-project?rev=369281&view=rev
Log:
Implement P1668R1

Allow inline assembly statements in unexecuted branches of constexpr
functions.

Modified:
    cfe/trunk/lib/Frontend/InitPreprocessor.cpp
    cfe/trunk/lib/Sema/SemaDeclCXX.cpp
    cfe/trunk/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p3.cpp
    cfe/trunk/test/Lexer/cxx-features.cpp
    cfe/trunk/test/SemaCXX/cxx1z-constexpr-lambdas.cpp

Modified: cfe/trunk/lib/Frontend/InitPreprocessor.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Frontend/InitPreprocessor.cpp?rev=369281&r1=369280&r2=369281&view=diff
==============================================================================
--- cfe/trunk/lib/Frontend/InitPreprocessor.cpp (original)
+++ cfe/trunk/lib/Frontend/InitPreprocessor.cpp Mon Aug 19 10:39:59 2019
@@ -480,6 +480,7 @@ static void InitializeCPlusPlusFeatureTe
     Builder.defineMacro("__cpp_user_defined_literals", "200809L");
     Builder.defineMacro("__cpp_lambdas", "200907L");
     Builder.defineMacro("__cpp_constexpr",
+                        LangOpts.CPlusPlus2a ? "201907L" :
                         LangOpts.CPlusPlus17 ? "201603L" :
                         LangOpts.CPlusPlus14 ? "201304L" : "200704");
     Builder.defineMacro("__cpp_range_based_for",

Modified: cfe/trunk/lib/Sema/SemaDeclCXX.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclCXX.cpp?rev=369281&r1=369280&r2=369281&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDeclCXX.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDeclCXX.cpp Mon Aug 19 10:39:59 2019
@@ -1995,6 +1995,9 @@ CheckConstexprFunctionStmt(Sema &SemaRef
         return false;
     return true;
 
+  case Stmt::GCCAsmStmtClass:
+  case Stmt::MSAsmStmtClass:
+    // C++2a allows inline assembly statements.
   case Stmt::CXXTryStmtClass:
     if (Cxx2aLoc.isInvalid())
       Cxx2aLoc = S->getBeginLoc();

Modified: cfe/trunk/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p3.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p3.cpp?rev=369281&r1=369280&r2=369281&view=diff
==============================================================================
--- cfe/trunk/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p3.cpp (original)
+++ cfe/trunk/test/CXX/dcl.dcl/dcl.spec/dcl.constexpr/p3.cpp Mon Aug 19 10:39:59 2019
@@ -136,9 +136,13 @@ constexpr int AllowedStmtsCXX11() {
 }
 
 //  or a compound-statement that does not contain [CXX1Y]
-constexpr int DisallowedStmtsCXX1Y_1() {
+constexpr int DisallowedStmtsCXX1Y_1(bool b) {
   //  - an asm-definition
-  asm("int3"); // expected-error {{statement not allowed in constexpr function}}
+  if (b)
+    asm("int3");
+#if !defined(CXX2A)
+  // expected-error at -2 {{use of this statement in a constexpr function is a C++2a extension}}
+#endif
   return 0;
 }
 constexpr int DisallowedStmtsCXX1Y_2() {

Modified: cfe/trunk/test/Lexer/cxx-features.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Lexer/cxx-features.cpp?rev=369281&r1=369280&r2=369281&view=diff
==============================================================================
--- cfe/trunk/test/Lexer/cxx-features.cpp (original)
+++ cfe/trunk/test/Lexer/cxx-features.cpp Mon Aug 19 10:39:59 2019
@@ -203,7 +203,7 @@
 #error "wrong value for __cpp_lambdas"
 #endif
 
-#if check(constexpr, 0, 200704, 201304, 201603, 201603)
+#if check(constexpr, 0, 200704, 201304, 201603, 201907)
 #error "wrong value for __cpp_constexpr"
 #endif
 

Modified: cfe/trunk/test/SemaCXX/cxx1z-constexpr-lambdas.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaCXX/cxx1z-constexpr-lambdas.cpp?rev=369281&r1=369280&r2=369281&view=diff
==============================================================================
--- cfe/trunk/test/SemaCXX/cxx1z-constexpr-lambdas.cpp (original)
+++ cfe/trunk/test/SemaCXX/cxx1z-constexpr-lambdas.cpp Mon Aug 19 10:39:59 2019
@@ -23,7 +23,10 @@ namespace ns1 {
 } // end ns1
 
 namespace ns2 {
-  auto L = [](int I) constexpr { asm("non-constexpr");  }; //expected-error{{not allowed in constexpr function}}
+  auto L = [](int I) constexpr { if (I == 5) asm("non-constexpr");  };
+#if __cpp_constexpr < 201907L
+  //expected-error at -2{{use of this statement in a constexpr function is a C++2a extension}}
+#endif
 } // end ns1
 
 // This is not constexpr until C++20, as the requirements on constexpr