From bc98f4224b4ae2f4e0cc59ddca11972c203fdba6 Mon Sep 17 00:00:00 2001
From: datadiode <datadiode@users.noreply.github.com>
Date: Wed, 28 Aug 2024 07:34:10 +0200
Subject: [PATCH] Allow reexpansion of currently expanding macros during
 argument evaluation. This fixes #31 as reproduced in
 TEST_CASE(define_define_11) without breaking code from @ydamigos's comment to
 #225 as reproduced in TEST_CASE(define_define_11a).

---
 simplecpp.cpp | 33 ++++++---------------------------
 test.cpp      | 12 ++++++++++++
 2 files changed, 18 insertions(+), 27 deletions(-)

diff --git a/simplecpp.cpp b/simplecpp.cpp
index 3cce780..5a32740 100755
--- a/simplecpp.cpp
+++ b/simplecpp.cpp
@@ -102,8 +102,6 @@ static const simplecpp::TokenString ONCE("once");
 
 static const simplecpp::TokenString HAS_INCLUDE("__has_include");
 
-static const simplecpp::TokenString INNER_COMMA(",,");
-
 template<class T> static std::string toString(T t)
 {
     // NOLINTNEXTLINE(misc-const-correctness) - false positive
@@ -1622,10 +1620,6 @@ namespace simplecpp {
                 rawtok = rawtok2->next;
             }
             output->takeTokens(output2);
-            for (Token* tok = output->front(); tok; tok = tok->next) {
-                if (tok->str() == INNER_COMMA)
-                    tok->setstr(",");
-            }
             return rawtok;
         }
 
@@ -1795,25 +1789,9 @@ namespace simplecpp {
                     tok = expandHash(tokens, rawloc, tok, macros, expandedmacros, parametertokens);
                 } else {
                     if (!expandArg(tokens, tok, rawloc, macros, expandedmacros, parametertokens)) {
-                        bool expanded = false;
-                        const MacroMap::const_iterator it = macros.find(tok->str());
-                        if (it != macros.end() && expandedmacros.find(tok->str()) == expandedmacros.end()) {
-                            const Macro &m = it->second;
-                            if (!m.functionLike()) {
-                                Token* mtok = tokens->back();
-                                m.expand(tokens, rawloc, tok, macros, expandedmacros);
-                                for (mtok = mtok->next; mtok; mtok = mtok->next) {
-                                    if (mtok->op == ',')
-                                        mtok->setstr(INNER_COMMA);
-                                }
-                                expanded = true;
-                            }
-                        }
-                        if (!expanded) {
-                            tokens->push_back(new Token(*tok));
-                            if (tok->macro.empty() && (par > 0 || tok->str() != "("))
-                                tokens->back()->macro = name();
-                        }
+                        tokens->push_back(new Token(*tok));
+                        if (tok->macro.empty() && (par > 0 || tok->str() != "("))
+                            tokens->back()->macro = name();
                     }
 
                     if (tok->op == '(')
@@ -2138,9 +2116,10 @@ namespace simplecpp {
                 return true;
             for (const Token *partok = parametertokens[argnr]->next; partok != parametertokens[argnr + 1U];) {
                 const MacroMap::const_iterator it = macros.find(partok->str());
-                if (it != macros.end() && !partok->isExpandedFrom(&it->second) && (partok->str() == name() || expandedmacros.find(partok->str()) == expandedmacros.end()))
+                if (it != macros.end() && !partok->isExpandedFrom(&it->second) && (partok->str() == name() || expandedmacros.find(partok->str()) == expandedmacros.end())) {
+                    std::set<TokenString> expandedmacros; // temporary amnesia to allow reexpansion of currently expanding macros during argument evaluation
                     partok = it->second.expand(output, loc, partok, macros, expandedmacros);
-                else {
+                } else {
                     output->push_back(newMacroToken(partok->str(), loc, isReplaced(expandedmacros), partok));
                     output->back()->macro = partok->macro;
                     partok = partok->next;
diff --git a/test.cpp b/test.cpp
index d00658a..3e857b2 100644
--- a/test.cpp
+++ b/test.cpp
@@ -717,6 +717,17 @@ static void define_define_11()
     ASSERT_EQUALS("\n\n\n\nP2DIR ;", preprocess(code));
 }
 
+static void define_define_11a()
+{
+    const char code[] = "#define A_B_C              0x1\n"
+                        "#define A_ADDRESS          0x00001000U\n"
+                        "#define A                  ((uint32_t ) A_ADDRESS)\n"
+                        "#define CONCAT(x, y, z)    x ## _ ## y ## _ ## z\n"
+                        "#define TEST_MACRO         CONCAT(A, B, C)\n"
+                        "TEST_MACRO\n";
+    ASSERT_EQUALS("\n\n\n\n\n0x1", preprocess(code));
+}
+
 static void define_define_12()
 {
     const char code[] = "#define XY(Z)  Z\n"
@@ -2855,6 +2866,7 @@ int main(int argc, char **argv)
     TEST_CASE(define_define_9); // line break in nested macro call
     TEST_CASE(define_define_10);
     TEST_CASE(define_define_11);
+    TEST_CASE(define_define_11a);
     TEST_CASE(define_define_12); // expand result of ##
     TEST_CASE(define_define_13);
     TEST_CASE(define_define_14);