Merge pull request #198 from DrXiao/refine-elf-gen

Improve the ELF generation process

Author: jserv

src/arm-codegen.c

@@ -179,7 +179,7 @@ void cfg_flatten()
 
 void emit(int code)
 {
-    elf_write_code_int(code);
+    elf_write_int(elf_code, code);
 }
 
 void emit_ph2_ir(ph2_ir_t *ph2_ir)
@@ -271,16 +271,16 @@ void emit_ph2_ir(ph2_ir_t *ph2_ir)
         emit(__teq(rn));
         if (ph2_ir->is_branch_detached) {
             emit(__b(__NE, 8));
-            emit(__b(__AL, ph2_ir->else_bb->elf_offset - elf_code_idx));
+            emit(__b(__AL, ph2_ir->else_bb->elf_offset - elf_code->size));
         } else
-            emit(__b(__NE, ph2_ir->then_bb->elf_offset - elf_code_idx));
+            emit(__b(__NE, ph2_ir->then_bb->elf_offset - elf_code->size));
         return;
     case OP_jump:
-        emit(__b(__AL, ph2_ir->next_bb->elf_offset - elf_code_idx));
+        emit(__b(__AL, ph2_ir->next_bb->elf_offset - elf_code->size));
         return;
     case OP_call:
         func = find_func(ph2_ir->func_name);
-        emit(__bl(__AL, func->bbs->elf_offset - elf_code_idx));
+        emit(__bl(__AL, func->bbs->elf_offset - elf_code->size));
         return;
     case OP_load_data_address:
         emit(__movw(__AL, rd, ph2_ir->src0 + elf_data_start));
@@ -436,7 +436,7 @@ void code_generate()
     emit(__movt(__AL, __r8, GLOBAL_FUNC->stack_size));
     emit(__sub_r(__AL, __sp, __sp, __r8));
     emit(__mov_r(__AL, __r12, __sp));
-    emit(__bl(__AL, GLOBAL_FUNC->bbs->elf_offset - elf_code_idx));
+    emit(__bl(__AL, GLOBAL_FUNC->bbs->elf_offset - elf_code->size));
 
     /* exit */
     emit(__movw(__AL, __r8, GLOBAL_FUNC->stack_size));
@@ -468,7 +468,7 @@ void code_generate()
     emit(__add_r(__AL, __r8, __r12, __r8));
     emit(__lw(__AL, __r0, __r8, 0));
     emit(__add_i(__AL, __r1, __r8, 4));
-    emit(__b(__AL, MAIN_BB->elf_offset - elf_code_idx));
+    emit(__b(__AL, MAIN_BB->elf_offset - elf_code->size));
 
     for (int i = 0; i < ph2_ir_idx; i++) {
         ph2_ir = PH2_IR_FLATTEN[i];

src/defs.h

@@ -351,7 +351,7 @@ typedef struct {
 
 typedef struct basic_block basic_block_t;
 
-/* Definition of a dynamic array structure for sources in src/globals.c
+/* Definition of a growable buffer for a mutable null-terminated string
  * size:     Current number of elements in the array
  * capacity: Number of elements that can be stored without resizing
  * elements: Pointer to the array of characters
@@ -360,7 +360,7 @@ typedef struct {
     int size;
     int capacity;
     char *elements;
-} source_t;
+} strbuf_t;
 
 /* phase-2 IR definition */
 struct ph2_ir {
@@ -547,3 +547,48 @@ typedef struct {
     var_t *var;
     int polluted;
 } regfile_t;
+
+/* FIXME: replace char[2] with a short data type in ELF header structures */
+/* ELF header */
+typedef struct {
+    char e_ident[16];
+    char e_type[2];
+    char e_machine[2];
+    int e_version;
+    int e_entry;
+    int e_phoff;
+    int e_shoff;
+    int e_flags;
+    char e_ehsize[2];
+    char e_phentsize[2];
+    char e_phnum[2];
+    char e_shentsize[2];
+    char e_shnum[2];
+    char e_shstrndx[2];
+} elf32_hdr_t;
+
+/* ELF program header */
+typedef struct {
+    int p_type;
+    int p_offset;
+    int p_vaddr;
+    int p_paddr;
+    int p_filesz;
+    int p_memsz;
+    int p_flags;
+    int p_align;
+} elf32_phdr_t;
+
+/* ELF section header */
+typedef struct {
+    int sh_name;
+    int sh_type;
+    int sh_flags;
+    int sh_addr;
+    int sh_offset;
+    int sh_size;
+    int sh_link;
+    int sh_info;
+    int sh_addralign;
+    int sh_entsize;
+} elf32_shdr_t;