From d2115bfb27f18f56fea5ce506b6bbe838f2dfb1b Mon Sep 17 00:00:00 2001
From: bellard <bellard>
Date: Thu, 29 Aug 2002 23:05:59 +0000
Subject: [PATCH] added symbol + relocation handling

---
 i386-gen.c | 48 ++++++++++++++++++++++--------------------------
 tcc.c      | 53 ++++++++++++++++++++++++++++++++++-------------------
 2 files changed, 56 insertions(+), 45 deletions(-)

diff --git a/i386-gen.c b/i386-gen.c
index 85f101b..35cba2d 100644
--- a/i386-gen.c
+++ b/i386-gen.c
@@ -132,7 +132,7 @@ void gsym(int t)
 #define psym oad
 
 /* instruction + 4 bytes data. Return the address of the data */
-int oad(int c, int s)
+static int oad(int c, int s)
 {
     int ind1;
 
@@ -147,26 +147,22 @@ int oad(int c, int s)
 }
 
 /* output constant with relocation if 'r & VT_SYM' is true */
-void gen_addr32(int r, int c)
+static void gen_addr32(int r, Sym *sym, int c)
 {
-    if (!(r & VT_SYM)) {
-        gen_le32(c);
-    } else {
-        greloc(cur_text_section, 
-               (Sym *)c, ind, R_386_32);
-        gen_le32(0);
-    }
+    if (r & VT_SYM)
+        greloc(cur_text_section, sym, ind, R_386_32);
+    gen_le32(c);
 }
 
 /* generate a modrm reference. 'op_reg' contains the addtionnal 3
    opcode bits */
-void gen_modrm(int op_reg, int r, int c)
+static void gen_modrm(int op_reg, int r, Sym *sym, int c)
 {
     op_reg = op_reg << 3;
     if ((r & VT_VALMASK) == VT_CONST) {
         /* constant memory reference */
         o(0x05 | op_reg);
-        gen_addr32(r, c);
+        gen_addr32(r, sym, c);
     } else if ((r & VT_VALMASK) == VT_LOCAL) {
         /* currently, we use only ebp as base */
         if (c == (char)c) {
@@ -221,14 +217,14 @@ void load(int r, SValue *sv)
         } else {
             o(0x8b);     /* movl */
         }
-        gen_modrm(r, fr, fc);
+        gen_modrm(r, fr, sv->sym, fc);
     } else {
         if (v == VT_CONST) {
             o(0xb8 + r); /* mov $xx, r */
-            gen_addr32(fr, fc);
+            gen_addr32(fr, sv->sym, fc);
         } else if (v == VT_LOCAL) {
             o(0x8d); /* lea xxx(%ebp), r */
-            gen_modrm(r, VT_LOCAL, fc);
+            gen_modrm(r, VT_LOCAL, sv->sym, fc);
         } else if (v == VT_CMP) {
             oad(0xb8 + r, 0); /* mov $0, r */
             o(0x0f); /* setxx %br */
@@ -278,7 +274,7 @@ void store(int r, SValue *v)
     if (fr == VT_CONST ||
         fr == VT_LOCAL ||
         (v->r & VT_LVAL)) {
-        gen_modrm(r, v->r, fc);
+        gen_modrm(r, v->r, v->sym, fc);
     } else if (fr != r) {
         o(0xc0 + fr + r * 8); /* mov r, fr */
     }
@@ -362,9 +358,9 @@ void gfunc_call(GFuncContext *c)
         /* constant case */
         if (vtop->r & VT_SYM) {
             /* relocation case */
-            greloc(cur_text_section, vtop->c.sym, 
+            greloc(cur_text_section, vtop->sym, 
                    ind + 1, R_386_PC32);
-            oad(0xe8, -4);
+            oad(0xe8, vtop->c.ul - 4);
         } else {
             oad(0xe8, vtop->c.ul - ind - 5);
         }
@@ -443,7 +439,7 @@ void gfunc_epilog(void)
         greloc(cur_text_section, sym_data,
                ind + 1, R_386_32);
         oad(0xb8, 0); /* mov %eax, xxx */
-        sym = external_sym(TOK___bound_local_new, func_old_type, 0);
+        sym = external_global_sym(TOK___bound_local_new, func_old_type, 0);
         greloc(cur_text_section, sym, 
                ind + 1, R_386_PC32);
         oad(0xe8, -4);
@@ -453,7 +449,7 @@ void gfunc_epilog(void)
         greloc(cur_text_section, sym_data,
                ind + 1, R_386_32);
         oad(0xb8, 0); /* mov %eax, xxx */
-        sym = external_sym(TOK___bound_local_delete, func_old_type, 0);
+        sym = external_global_sym(TOK___bound_local_delete, func_old_type, 0);
         greloc(cur_text_section, sym, 
                ind + 1, R_386_PC32);
         oad(0xe8, -4);
@@ -766,7 +762,7 @@ void gen_opf(int op)
                 o(0xdc);
             else
                 o(0xd8);
-            gen_modrm(a, r, fc);
+            gen_modrm(a, r, vtop->sym, fc);
         }
         vtop--;
     }
@@ -816,8 +812,8 @@ void gen_cvt_ftoi(int t)
         size = 4;
     
     o(0x2dd9); /* ldcw xxx */
-    sym = external_sym(TOK___tcc_int_fpu_control, 
-                       VT_SHORT | VT_UNSIGNED, VT_LVAL);
+    sym = external_global_sym(TOK___tcc_int_fpu_control, 
+                              VT_SHORT | VT_UNSIGNED, VT_LVAL);
     greloc(cur_text_section, sym, 
            ind, R_386_32);
     gen_le32(0);
@@ -829,8 +825,8 @@ void gen_cvt_ftoi(int t)
         o(0x3cdf); /* fistpll */
     o(0x24);
     o(0x2dd9); /* ldcw xxx */
-    sym = external_sym(TOK___tcc_fpu_control, 
-                       VT_SHORT | VT_UNSIGNED, VT_LVAL);
+    sym = external_global_sym(TOK___tcc_fpu_control, 
+                              VT_SHORT | VT_UNSIGNED, VT_LVAL);
     greloc(cur_text_section, sym, 
            ind, R_386_32);
     gen_le32(0);
@@ -871,7 +867,7 @@ void gen_bounded_ptr_add(void)
     vtop -= 2;
     save_regs(0);
     /* do a fast function call */
-    sym = external_sym(TOK___bound_ptr_add, func_old_type, 0);
+    sym = external_global_sym(TOK___bound_ptr_add, func_old_type, 0);
     greloc(cur_text_section, sym, 
            ind + 1, R_386_PC32);
     oad(0xe8, -4);
@@ -917,7 +913,7 @@ void gen_bounded_ptr_deref(void)
     /* patch relocation */
     /* XXX: find a better solution ? */
     rel = (Elf32_Rel *)(cur_text_section->reloc->data + vtop->c.ul);
-    sym = external_sym(func, func_old_type, 0);
+    sym = external_global_sym(func, func_old_type, 0);
     if (!sym->c)
         put_extern_sym(sym, NULL, 0, 0);
     rel->r_info = ELF32_R_INFO(sym->c, ELF32_R_TYPE(rel->r_info));
diff --git a/tcc.c b/tcc.c
index 017b248..1babd27 100644
--- a/tcc.c
+++ b/tcc.c
@@ -100,7 +100,6 @@ typedef union CValue {
     long long ll;
     unsigned long long ull;
     struct CString *cstr;
-    struct Sym *sym;
     void *ptr;
     int tab[1];
 } CValue;
@@ -112,6 +111,7 @@ typedef struct SValue {
     unsigned short r2;     /* second register, used for 'long long'
                               type. If not used, set to VT_CONST */
     CValue c;              /* constant, if VT_CONST */
+    struct Sym *sym;       /* symbol, if (VT_SYM | VT_CONST) */
 } SValue;
 
 /* symbol management */
@@ -548,7 +548,7 @@ static char *pstrcat(char *buf, int buf_size, const char *s);
 void sum(int l);
 void next(void);
 void next_nomacro(void);
-int expr_const(void);
+static int expr_const(void);
 void expr_eq(void);
 void gexpr(void);
 void decl(int l);
@@ -2895,8 +2895,9 @@ static void vpush_ref(int t, Section *sec, unsigned long offset, unsigned long s
 {
     CValue cval;
 
-    cval.sym = get_sym_ref(t, sec, offset, size);
+    cval.ul = 0;
     vsetc(t, VT_CONST | VT_SYM, &cval);
+    vtop->sym = get_sym_ref(t, sec, offset, size);
 }
 
 /* define a new external reference to a symbol 'v' of type 'u' */
@@ -2934,8 +2935,9 @@ static void vpush_global_sym(int t, int v)
     CValue cval;
 
     sym = external_global_sym(v, t, 0);
-    cval.sym = sym;
+    cval.ul = 0;
     vsetc(t, VT_CONST | VT_SYM, &cval);
+    vtop->sym = sym;
 }
 
 void vset(int t, int r, int v)
@@ -3160,7 +3162,8 @@ int gv(int rc)
                 ptr[i] = vtop->c.tab[i];
             sym = get_sym_ref(vtop->t, data_section, offset, size << 2);
             vtop->r |= VT_LVAL | VT_SYM;
-            vtop->c.sym = sym;
+            vtop->sym = sym;
+            vtop->c.ul = 0;
         }
 #ifdef CONFIG_TCC_BCHECK
         if (vtop->r & VT_MUSTBOUND) 
@@ -3675,6 +3678,14 @@ void gen_opic(int op)
                     op = TOK_SHR;
             }
             goto general_case;
+        } else if (c2 && (op == '+' || op == '-') &&
+                   (vtop[-1].r & (VT_VALMASK | VT_LVAL | VT_SYM)) == 
+                   (VT_CONST | VT_SYM)) {
+            /* symbol + constant case */
+            if (op == '-')
+                fc = -fc;
+            vtop--;
+            vtop->c.i += fc;
         } else {
         general_case:
             /* call low level op generator */
@@ -5189,8 +5200,10 @@ void unary(void)
             }
             vset(s->t, s->r, s->c);
             /* if forward reference, we must point to s */
-            if (vtop->r & VT_SYM)
-                vtop->c.sym = s;
+            if (vtop->r & VT_SYM) {
+                vtop->sym = s;
+                vtop->c.ul = 0;
+            }
         }
     }
     
@@ -5273,7 +5286,7 @@ void unary(void)
                         tok_str_new(&str);
                         parlevel = 0;
                         while ((parlevel > 0 || (tok != ')' && tok != ',')) && 
-                               tok != -1) {
+                               tok != TOK_EOF) {
                             if (tok == '(')
                                 parlevel++;
                             else if (tok == ')')
@@ -5509,23 +5522,23 @@ void gexpr(void)
     }
 }
 
-/* parse a constant expression and return value in vtop */
-void expr_const1(void)
+/* parse a constant expression and return value in vtop.  */
+static void expr_const1(void)
 {
     int a;
     a = const_wanted;
     const_wanted = 1;
     expr_eq();
-    if ((vtop->r & (VT_VALMASK | VT_LVAL)) != VT_CONST)
-        expect("constant");
     const_wanted = a;
 }
 
-/* parse an integer constant and return its value */
-int expr_const(void)
+/* parse an integer constant and return its value. */
+static int expr_const(void)
 {
     int c;
     expr_const1();
+    if ((vtop->r & (VT_VALMASK | VT_LVAL | VT_SYM)) != VT_CONST)
+        expect("constant expression");
     c = vtop->c.i;
     vpop();
     return c;
@@ -5899,6 +5912,9 @@ static void init_putv(int t, Section *sec, unsigned long c,
         global_expr = 1;
         expr_const1();
         global_expr = saved_global_expr;
+        /* NOTE: symbols are accepted */
+        if ((vtop->r & (VT_VALMASK | VT_LVAL)) != VT_CONST)
+            error("initializer element is not constant");
         break;
     case EXPR_ANY:
         expr_eq();
@@ -5936,11 +5952,9 @@ static void init_putv(int t, Section *sec, unsigned long c,
             break;
         default:
             if (vtop->r & VT_SYM) {
-                greloc(sec, vtop->c.sym, c, R_DATA_32);
-                *(int *)ptr = 0;
-            } else {
-                *(int *)ptr = vtop->c.i;
+                greloc(sec, vtop->sym, c, R_DATA_32);
             }
+            *(int *)ptr = vtop->c.i;
             break;
         }
         vtop--;
@@ -6284,8 +6298,9 @@ static void decl_initializer_alloc(int t, AttributeDef *ad, int r,
 
             /* push global reference */
             sym = get_sym_ref(t, sec, addr, size);
-            cval.sym = sym;
+            cval.ul = 0;
             vsetc(t, VT_CONST | VT_SYM, &cval);
+            vtop->sym = sym;
         }
 
         /* handles bounds now because the symbol must be defined