CXX: add "consteval" to "properties:" field

Close #3539.

Signed-off-by: Masatake YAMATO <[email protected]>

Author: masatake

Units/parser-cxx.r/properties-consteval.d/args.ctags

@@ -0,0 +1,4 @@
+--sort=no
+--kinds-c++=*-{parameter}
+--fields=+x
+--fields-c++=+{properties}

Units/parser-cxx.r/properties-consteval.d/expected.tags

@@ -0,0 +1,9 @@
+sqr	input.cc	/^consteval int sqr(int n)$/;"	f	typeref:typename:int	properties:consteval
+r	input.cc	/^constexpr int r = sqr(100); \/\/ OK$/;"	v	typeref:typename:int	properties:constexpr
+x	input.cc	/^int x = 100;$/;"	v	typeref:typename:int
+r2	input.cc	/^int r2 = sqr(x);            \/\/ Error: Call does not produce a constant$/;"	v	typeref:typename:int
+sqrsqr	input.cc	/^consteval int sqrsqr(int n)$/;"	f	typeref:typename:int	properties:consteval
+dblsqr	input.cc	/^constexpr int dblsqr(int n)$/;"	f	typeref:typename:int	properties:constexpr
+f	input.cc	/^consteval int f() { return 42; }$/;"	f	typeref:typename:int	properties:consteval
+g	input.cc	/^consteval auto g() { return &f; }$/;"	f	typeref:typename:auto	properties:consteval
+h	input.cc	/^consteval int h(int (*p)() = g()) { return p(); }$/;"	f	typeref:typename:int	properties:consteval

Units/parser-cxx.r/properties-consteval.d/input.cc

@@ -0,0 +1,25 @@
+// Taken from https://en.cppreference.com/w/cpp/language/consteval
+consteval int sqr(int n)
+{
+    return n*n;
+}
+constexpr int r = sqr(100); // OK
+ 
+int x = 100;
+int r2 = sqr(x);            // Error: Call does not produce a constant
+ 
+consteval int sqrsqr(int n)
+{
+    return sqr(sqr(n));     // Not a constant expression at this point, but OK
+}
+ 
+constexpr int dblsqr(int n)
+{
+    return 2 * sqr(n);      // Error: Enclosing function is not consteval
+                            // and sqr(n) is not a constant
+}
+
+consteval int f() { return 42; }
+consteval auto g() { return &f; }
+consteval int h(int (*p)() = g()) { return p(); }
+

parsers/cxx/cxx_keyword.c

@@ -212,6 +212,11 @@ static CXXKeywordDescriptor g_aCXXKeywordTable[] = {
 		CXXLanguageC | CXXLanguageCPP | CXXLanguageCUDA,
 		CXXKeywordMayAppearInVariableDeclaration | CXXKeywordFlagMayBePartOfTypeName
 	},
+	{
+		"consteval",
+		CXXLanguageCPP,
+		CXXKeywordExcludeFromTypeNames
+	},
 	{
 		"constexpr",
 		CXXLanguageCPP,

parsers/cxx/cxx_keyword.h

@@ -52,6 +52,7 @@ typedef enum _CXXKeyword
 	//CXXKeywordCOMPL,
 	CXXKeywordCONCEPT, // Concepts TS
 	CXXKeywordCONST,
+	CXXKeywordCONSTEVAL, // (since C++20)
 	CXXKeywordCONSTEXPR, // (since C++11)
 	CXXKeywordCONST_CAST,
 	CXXKeywordCONTINUE,
@@ -175,4 +176,4 @@ void cxxKeywordEnableFinal(bool bEnableIt);
 bool cxxKeywordIsDisabled(CXXKeyword eKeywordId);
 
 
-#endif //!ctags_cxx_keyword_h_
+#endif //!ctags_cxx_keyword_h_

parsers/cxx/cxx_parser_block.c

@@ -640,6 +640,9 @@ static bool cxxParserParseBlockInternal(bool bExpectClosingBracket)
 					case CXXKeywordCONSTEXPR:
 						g_cxx.uKeywordState |= CXXParserKeywordStateSeenConstexpr;
 					break;
+					case CXXKeywordCONSTEVAL:
+						g_cxx.uKeywordState |= CXXParserKeywordStateSeenConsteval;
+					break;
 					default:
 						if(g_cxx.uKeywordState & CXXParserKeywordStateSeenTypedef)
 						{

parsers/cxx/cxx_parser_function.c

@@ -1732,6 +1732,8 @@ int cxxParserEmitFunctionTags(
 				uProperties |= CXXTagPropertyDeprecated;
 			if(g_cxx.uKeywordState & CXXParserKeywordStateSeenConstexpr)
 				uProperties |= CXXTagPropertyConstexpr;
+			if(g_cxx.uKeywordState & CXXParserKeywordStateSeenConsteval)
+				uProperties |= CXXTagPropertyConsteval;
 			if(pInfo->pSignatureConst)
 				uProperties |= CXXTagPropertyConst;
 			if(pInfo->uFlags & CXXFunctionSignatureInfoPure)

parsers/cxx/cxx_parser_internal.h

@@ -286,6 +286,8 @@ typedef enum _CXXParserKeywordState
 	CXXParserKeywordStateSeenFriend = (1 << 12),
 	// "constexpr" has been seen
 	CXXParserKeywordStateSeenConstexpr = (1 << 13),
+	// "consteval" has been seen
+	CXXParserKeywordStateSeenConsteval = (1 << 14),
 } CXXParserKeywordState;
 
 #define CXX_PARSER_MAXIMUM_NESTING_LEVELS 1024

parsers/cxx/cxx_parser_variable.c

@@ -759,6 +759,7 @@ bool cxxParserExtractVariableDeclarations(CXXTokenChain * pChain,unsigned int uF
 				//	uProperties |= CXXTagPropertyVolatile;
 				if(g_cxx.uKeywordState & CXXParserKeywordStateSeenConstexpr)
 					uProperties |= CXXTagPropertyConstexpr;
+				// consteval is not here; it is for functions.
 
 				pszProperties = cxxTagSetProperties(uProperties);
 			}

parsers/cxx/cxx_tag.c

@@ -372,6 +372,8 @@ vString * cxxTagSetProperties(unsigned int uProperties)
 		ADD_PROPERTY("fntryblock");
 	if (uProperties & CXXTagPropertyConstexpr)
 		ADD_PROPERTY("constexpr");
+	if (uProperties & CXXTagPropertyConsteval)
+		ADD_PROPERTY("consteval");
 
 	cxxTagSetField(CXXTagFieldProperties,vStringValue(pszProperties),false);