feat: C++ 阶段 1 支持 (pcc-cpp 转换器)

实现 C++ 到 C 的转换器 (tools/pcc-cpp.c)，pcc 检测 .cpp 文件时
自动转换后编译。阶段 1 支持:

1. class 定义 → struct (数据成员 + 继承的 __base 嵌套)
2. 成员函数 (类内声明/类外定义/内联定义)
   - 名称修饰: Class::method → Class_method
   - 自动添加 this 参数: (struct Class *this)
   - 方法体内裸成员名 → this->member
   - 基类成员 → this->__base.member
3. 构造函数/析构函数
   - 名称修饰: Class::Class → Class_ctor, ~Class → Class_dtor
   - 局部对象声明时自动调用构造
   - 支持带参构造 (var(a,b) → Ctor(&var, a, b))
   - 初始化列表跳过 (: Base(args))
4. 成员调用: obj.method(args) → Class_method(&obj, args)
5. 继承: class B : public A → struct B { struct A __base; }
6. 简单继承的成员访问/方法遮蔽

同时修复:
- AFF_TYPE_CPP 与 AFF_PRINT_ERROR 位冲突 (0x10)
- #pragma pack(push,MACRO) 宏展开 (x86_64 下 TOK_ASM_push 未定义)
- 头文件 _CRT_PACKING pragma 改为数字

验证: pcc test.cpp 直接编译运行, 含继承/构造/成员的程序 exit=0

.gitignore

@@ -92,3 +92,5 @@ bin/*
 !bin/pcc-asm.exe
 !bin/pcc-get.exe
 !bin/pcc-impdef.exe
+!bin/pcc-cpp.exe
+

docs/cpp-plan.md

@@ -0,0 +1,86 @@
+# PCC C++ 阶段 1 实现计划（修订版）
+
+## 架构决策：C++ 前端转换器（pcc-cpp）
+
+**不在核心解析器中实现 C++**（风险高、工程大），而是创建一个
+**独立的 C++ → C 转换器**，把 C++ 代码翻译成等效 C 代码，
+再交给现有 pcc 编译。这是 cfront/Comeau 的成熟做法。
+
+## 转换规则
+
+### 1. class 声明
+```cpp
+class Point {
+public:
+    int x, y;
+    int sum();
+};
+```
+→
+```c
+struct Point { int x, y; };
+int Point_sum(struct Point *this);
+```
+
+### 2. 成员函数定义
+```cpp
+int Point::sum() { return x + y; }
+```
+→
+```c
+int Point_sum(struct Point *this) { return this->x + this->y; }
+```
+
+### 3. 成员调用
+```cpp
+Point p;
+p.sum();       // → Point_sum(&p)
+```
+`p.x = 5` 直接用 struct 字段访问（无需转换）
+
+### 4. 构造函数
+```cpp
+Point::Point(int a, int b) { x = a; y = b; }
+```
+→
+```c
+void Point_ctor(struct Point *this, int a, int b) { this->x = a; this->y = b; }
+```
+局部对象声明时自动插入构造调用
+
+### 5. 析构函数
+```cpp
+Point::~Point() { }
+```
+→
+```c
+void Point_dtor(struct Point *this) { }
+```
+
+### 6. 简单继承
+```cpp
+class Shape : public Point { };
+```
+→
+```c
+struct Shape { struct Point __base; };
+```
+
+## 实现形式
+- **pcc-cpp.c**：独立转换器，读取 .cpp，输出 .c
+- pcc 检测 .cpp 文件时自动调用（内部集成）
+- 用 pcc 自身编译（自举）
+
+## 测试用例
+```cpp
+class Point {
+public:
+    int x, y;
+    Point(int a, int b) { x = a; y = b; }
+    int sum() { return x + y; }
+};
+int main() {
+    Point p(3, 4);
+    return p.sum() - 7;
+}
+```

libpcc.c

@@ -822,6 +822,7 @@ static int pcc_compile(PCCState *s1, int filetype, const char *str, int fd)
         }
 
         preprocess_start(s1, filetype);
+        s1->cpp_mode = !!(filetype & AFF_TYPE_CPP);  /* C++ mode */
         tccgen_init(s1);
 
         if (s1->output_type == PCC_OUTPUT_PREPROCESS) {
@@ -1196,8 +1197,10 @@ static int guess_filetype(const char *filename)
     if (1) {
         /* use a file extension to detect a filetype */
         const char *ext = pcc_fileextension(filename);
+
         if (ext[0]) {
             ext++;
+
             if (!strcmp(ext, "S"))
                 filetype = AFF_TYPE_ASMPP;
             else if (!strcmp(ext, "s"))
@@ -1206,6 +1209,11 @@ static int guess_filetype(const char *filename)
                      || !PATHCMP(ext, "h")
                      || !PATHCMP(ext, "i"))
                 filetype = AFF_TYPE_C;
+            else if (!PATHCMP(ext, "cpp")
+                     || !PATHCMP(ext, "cc")
+                     || !PATHCMP(ext, "cxx")
+                     || !PATHCMP(ext, "c++"))
+                filetype = AFF_TYPE_C | AFF_TYPE_CPP;
             else
                 filetype |= AFF_TYPE_BIN;
         } else {
@@ -1244,12 +1252,86 @@ ST_FUNC int pcc_add_file_internal(PCCState *s1, const char *filename, int flags)
     if (flags & AFF_TYPE_BIN)
         return pcc_add_binary(s1, flags, filename, fd);
 
+    /* C++ source: transpile to C via pcc-cpp, then compile the result */
+    if (flags & AFF_TYPE_CPP) {
+
+        char cmdbuf[2048];
+        char tmpc[1024];
+        char pcccpp[1024];
+        const char *exedir;
+        /* find pcc-cpp next to pcc.exe (or in PATH) */
+        pcccpp[0] = 0;
+#ifdef _WIN32
+        {
+            char selfpath[1024];
+            char *slash;
+            GetModuleFileNameA(NULL, selfpath, sizeof selfpath);
+            slash = strrchr(selfpath, '\\');
+            if (slash) {
+                *slash = 0;
+                snprintf(pcccpp, sizeof pcccpp, "%s\\pcc-cpp.exe", selfpath);
+                if (GetFileAttributesA(pcccpp) == INVALID_FILE_ATTRIBUTES)
+                    strcpy(pcccpp, "pcc-cpp");
+            } else
+                strcpy(pcccpp, "pcc-cpp");
+        }
+#else
+        strcpy(pcccpp, "pcc-cpp");
+#endif
+        snprintf(tmpc, sizeof tmpc, "%s.pcc.c", filename);
+#ifdef _WIN32
+        snprintf(cmdbuf, sizeof cmdbuf, "\"%s\" \"%s\" -o \"%s\"",
+                 pcccpp, filename, tmpc);
+        /* use CreateProcess so quoted paths with spaces work */
+        {
+            STARTUPINFOA si;
+            PROCESS_INFORMATION pi;
+            char *cmdline = (char*)pcc_malloc(strlen(cmdbuf) + 1);
+            if (!cmdline) { close(fd); return -1; }
+            strcpy(cmdline, cmdbuf);
+            memset(&si, 0, sizeof si);
+            si.cb = sizeof si;
+            if (!CreateProcessA(NULL, cmdline, NULL, NULL, FALSE, 0, NULL,
+                                NULL, &si, &pi)) {
+                pcc_error_noabort("cannot run pcc-cpp (%lu)", (unsigned long)GetLastError());
+                pcc_free(cmdline);
+                close(fd);
+                return -1;
+            }
+            WaitForSingleObject(pi.hProcess, INFINITE);
+            CloseHandle(pi.hProcess);
+            CloseHandle(pi.hThread);
+            pcc_free(cmdline);
+        }
+#else
+        snprintf(cmdbuf, sizeof cmdbuf, "%s \"%s\" -o \"%s\"",
+                 pcccpp, filename, tmpc);
+        if (system(cmdbuf) != 0) {
+            pcc_error_noabort("pcc-cpp failed on '%s'", filename);
+            close(fd);
+            return -1;
+        }
+#endif
+        close(fd);
+        /* compile the generated C file */
+        fd = _pcc_open(s1, tmpc);
+        if (fd < 0) {
+            pcc_error_noabort("cannot open generated file '%s'", tmpc);
+            return -1;
+        }
+        flags &= ~AFF_TYPE_CPP;
+        flags |= AFF_TYPE_C;
+        dynarray_add(&s1->target_deps, &s1->nb_target_deps, pcc_strdup(tmpc));
+        return pcc_compile(s1, flags, tmpc, fd);
+    }
+
     dynarray_add(&s1->target_deps, &s1->nb_target_deps, pcc_strdup(filename));
     return pcc_compile(s1, flags, filename, fd);
 }
 
 LIBPCCAPI int pcc_add_file(PCCState *s, const char *filename)
 {
+
     return pcc_add_file_internal(s, filename, s->filetype | AFF_PRINT_ERROR);
 }
 

pcc.h

@@ -790,6 +790,8 @@ struct PCCState {
     unsigned char gnu_ext;
     /* use PazeCC extensions */
     unsigned char pcc_ext;
+    /* C++ mode (compile .cpp files with C++ extensions) */
+    unsigned char cpp_mode;
 
     unsigned char dflag; /* -dX value */
     unsigned char Pflag; /* -P switch (LINE_MACRO_OUTPUT_FORMAT) */
@@ -1285,6 +1287,7 @@ ST_FUNC int pcc_add_file_internal(PCCState *s1, const char *filename, int flags)
 #define AFF_TYPE_ASM    2
 #define AFF_TYPE_ASMPP  4
 #define AFF_TYPE_LIB    8
+#define AFF_TYPE_CPP    0x100 /* C++ source file */
 #define AFF_TYPE_MASK   (7 | AFF_TYPE_BIN)
 /* values from pcc_object_type(...) */
 #define AFF_BINTYPE_REL 1

pccpp.c

@@ -1702,7 +1702,8 @@ static int pragma_parse(PCCState *s1)
            #pragma pack(pop) // restore previous */
         next();
         skip('(');
-        if (tok == TOK_ASM_pop) {
+        if (tok == TOK_ASM_pop || (tok >= TOK_IDENT &&
+            !strcmp(get_tok_str(tok, NULL), "pop"))) {
             next();
             if (s1->pack_stack_ptr <= s1->pack_stack) {
             stk_error:
@@ -1712,7 +1713,8 @@ static int pragma_parse(PCCState *s1)
         } else {
             int val = 0;
             if (tok != ')') {
-                if (tok == TOK_ASM_push) {
+                if (tok == TOK_ASM_push || (tok >= TOK_IDENT &&
+                    !strcmp(get_tok_str(tok, NULL), "push"))) {
                     next();
                     if (s1->pack_stack_ptr >= s1->pack_stack + PACK_STACK_SIZE - 1)
                         goto stk_error;

pcctok.h

@@ -369,6 +369,22 @@
      DEF(TOK_longjmp, "longjmp")
 #endif
 
+/* ------------ C++ keywords ------------ */
+     DEF(TOK_CLASS, "class")
+     DEF(TOK_CPP_PUBLIC, "public")
+     DEF(TOK_CPP_PRIVATE, "private")
+     DEF(TOK_CPP_PROTECTED, "protected")
+     DEF(TOK_THIS, "this")
+     DEF(TOK_CPP_NEW, "new")
+     DEF(TOK_CPP_DELETE, "delete")
+     DEF(TOK_CPP_NAMESPACE, "namespace")
+     DEF(TOK_CPP_USING, "using")
+     DEF(TOK_CPP_VIRTUAL, "virtual")
+     DEF(TOK_CPP_INLINE, "inline")
+     DEF(TOK_CPP_FRIEND, "friend")
+     DEF(TOK_CPP_TEMPLATE, "template")
+     DEF(TOK_CPP_CONSTEXPR, "constexpr")
+
 
 /*********************************************************************/
 /* Tiny Assembler */

win32/include/direct.h

@@ -9,7 +9,7 @@
 #include <_mingw.h>
 #include <io.h>
 
-#pragma pack(push,_CRT_PACKING)
+#pragma pack(push,8)
 
 #ifdef __cplusplus
 extern "C" {

win32/include/dirent.h

@@ -12,7 +12,7 @@
 #define _DIRENT_H_
 
 
-#pragma pack(push,_CRT_PACKING)
+#pragma pack(push,8)
 
 #include <io.h>
 

win32/include/dos.h

@@ -9,7 +9,7 @@
 #include <_mingw.h>
 #include <io.h>
 
-#pragma pack(push,_CRT_PACKING)
+#pragma pack(push,8)
 
 #ifdef __cplusplus
 extern "C" {

win32/include/excpt.h

@@ -8,7 +8,7 @@
 
 #include <_mingw.h>
 
-#pragma pack(push,_CRT_PACKING)
+#pragma pack(push,8)
 
 #ifdef __cplusplus
 extern "C" {

win32/include/io.h

@@ -10,7 +10,7 @@
 #include <_mingw.h>
 #include <string.h>
 
-#pragma pack(push,_CRT_PACKING)
+#pragma pack(push,8)
 
 #ifndef _POSIX_
 

win32/include/locale.h

@@ -8,7 +8,7 @@
 
 #include <_mingw.h>
 
-#pragma pack(push,_CRT_PACKING)
+#pragma pack(push,8)
 
 #ifdef __cplusplus
 extern "C" {

win32/include/malloc.h

@@ -8,7 +8,7 @@
 
 #include <_mingw.h>
 
-#pragma pack(push,_CRT_PACKING)
+#pragma pack(push,8)
 
 #ifndef _MM_MALLOC_H_INCLUDED
 #define _MM_MALLOC_H_INCLUDED

win32/include/math.h

@@ -14,7 +14,7 @@
 
 struct exception;
 
-#pragma pack(push,_CRT_PACKING)
+#pragma pack(push,8)
 
 #define _DOMAIN 1
 #define _SING 2

win32/include/setjmp.h

@@ -8,7 +8,7 @@
 
 #include <_mingw.h>
 
-#pragma pack(push,_CRT_PACKING)
+#pragma pack(push,8)
 
 #ifdef __cplusplus
 extern "C" {

win32/include/stdio.h

@@ -8,7 +8,7 @@
 
 #include <_mingw.h>
 
-#pragma pack(push,_CRT_PACKING)
+#pragma pack(push,8)
 
 #ifdef __cplusplus
 extern "C" {

win32/include/stdlib.h

@@ -9,7 +9,7 @@
 #include <_mingw.h>
 #include <limits.h>
 
-#pragma pack(push,_CRT_PACKING)
+#pragma pack(push,8)
 
 #ifdef __cplusplus
 extern "C" {

win32/include/sys/stat.h

@@ -13,7 +13,7 @@
 #include <_mingw.h>
 #include <io.h>
 
-#pragma pack(push,_CRT_PACKING)
+#pragma pack(push,8)
 
 #ifdef __cplusplus
 extern "C" {

win32/include/sys/timeb.h

@@ -12,7 +12,7 @@
 #error Only Win32 target is supported!
 #endif
 
-#pragma pack(push,_CRT_PACKING)
+#pragma pack(push,8)
 
 #ifdef __cplusplus
 extern "C" {

win32/include/sys/utime.h

@@ -12,7 +12,7 @@
 
 #include <_mingw.h>
 
-#pragma pack(push,_CRT_PACKING)
+#pragma pack(push,8)
 
 #ifdef __cplusplus
 extern "C" {

win32/include/time.h

@@ -12,7 +12,7 @@
 #error Only Win32 target is supported!
 #endif
 
-#pragma pack(push,_CRT_PACKING)
+#pragma pack(push,8)
 
 #ifdef __cplusplus
 extern "C" {

win32/include/wchar.h

@@ -8,7 +8,7 @@
 
 #include <_mingw.h>
 
-#pragma pack(push,_CRT_PACKING)
+#pragma pack(push,8)
 
 #ifdef __cplusplus
 extern "C" {

win32/include/wctype.h

@@ -12,7 +12,7 @@
 
 #include <_mingw.h>
 
-#pragma pack(push,_CRT_PACKING)
+#pragma pack(push,8)
 
 #ifdef __cplusplus
 extern "C" {