cppparser: Support #elifdef, #elifndef, #warning directives (C++23)

Author: rdb

src/cppparser/cppPreprocessor.cxx

@@ -1662,7 +1662,7 @@ process_directive(int c) {
     handle_ifndef_directive(args, loc);
   } else if (command == "if") {
     handle_if_directive(args, loc);
-  } else if (command == "else" || command == "elif") {
+  } else if (command == "else" || command == "elif" || command == "elifdef" || command == "elifndef") {
     // Presumably this follows some #if or #ifdef.  We don't bother to check
     // this, however.
     skip_false_if_block(false);
@@ -1677,6 +1677,8 @@ process_directive(int c) {
     // Quietly ignore idents.
   } else if (command == "error") {
     handle_error_directive(args, loc);
+  } else if (command == "warning") {
+    handle_warning_directive(args, loc);
   } else {
     loc.first_line = begin_line;
     loc.first_column = begin_column;
@@ -1979,6 +1981,14 @@ handle_error_directive(const string &args, const YYLTYPE &loc) {
   error(args, loc);
 }
 
+/**
+ *
+ */
+void CPPPreprocessor::
+handle_warning_directive(const string &args, const YYLTYPE &loc) {
+  warning(args, loc);
+}
+
 /**
  * We come here when we fail an #if or an #ifdef test, or when we reach the
  * #else clause to something we didn't fail.  This function skips all text up
@@ -2021,6 +2031,18 @@ skip_false_if_block(bool consider_elifs) {
           handle_if_directive(args, loc);
           return;
         }
+      } else if (command == "elifdef") {
+        if (level == 0 && consider_elifs) {
+          _save_comments = true;
+          handle_ifdef_directive(args, loc);
+          return;
+        }
+      } else if (command == "elifndef") {
+        if (level == 0 && consider_elifs) {
+          _save_comments = true;
+          handle_ifndef_directive(args, loc);
+          return;
+        }
       } else if (command == "endif") {
         // Skip any args.
         if (level == 0) {

src/cppparser/cppPreprocessor.h

@@ -146,6 +146,7 @@ class CPPPreprocessor {
   void handle_include_directive(const std::string &args, const YYLTYPE &loc);
   void handle_pragma_directive(const std::string &args, const YYLTYPE &loc);
   void handle_error_directive(const std::string &args, const YYLTYPE &loc);
+  void handle_warning_directive(const std::string &args, const YYLTYPE &loc);
 
   void skip_false_if_block(bool consider_elifs);
   bool is_manifest_defined(const std::string &manifest_name) const;

tests/cppparser/CMakeLists.txt

@@ -7,6 +7,7 @@ function(parse_test file)
   add_test(NAME ${name} COMMAND parse_file -T ${extra_args} "-S${PROJECT_SOURCE_DIR}/parser-inc" "${CMAKE_CURRENT_SOURCE_DIR}/${file}")
 endfunction()
 
+parse_test(conditional.c)
 parse_test(literals.c)
 parse_test(recursive_macros.c)
 parse_test(stat.c)

tests/cppparser/conditional.c

@@ -0,0 +1,71 @@
+#define TRUE 1
+
+#ifdef TRUE
+#else
+#error Should not reach
+#endif
+
+#if TRUE
+#else
+#error Should not reach
+#endif
+
+#if TRUE
+#elif FALSE
+#error Should not reach
+#endif
+
+#if TRUE
+#elifdef FALSE
+#error Should not reach
+#endif
+
+#if TRUE
+#elifndef FALSE
+#error Should not reach
+#endif
+
+#if TRUE
+#elif TRUE
+#error Should not reach
+#endif
+
+#if TRUE
+#elifdef TRUE
+#error Should not reach
+#endif
+
+#ifndef TRUE
+#error Should not reach
+#else
+#endif
+
+#ifndef TRUE
+#error Should not reach
+#elif TRUE
+#else
+#error Should not reach
+#endif
+
+#ifndef TRUE
+#error Should not reach
+#elifdef TRUE
+#else
+#error Should not reach
+#endif
+
+#ifndef TRUE
+#error Should not reach
+#elif FALSE
+#error Should not reach
+#else
+#endif
+
+#ifdef FALSE
+#error Should not reach
+#elifdef FALSE
+#error Should not reach
+#elifndef TRUE
+#error Should not reach
+#endif
+