Do section relocation in architecture backend

2016-11-12 23:16:06 +08:00
parent 60374d01ae
commit cb273fdad8
9 changed files with 552 additions and 490 deletions
--- a/i386-link.c
+++ b/i386-link.c
@ -0,0 +1,90 @@
+#include "tcc.h"
+#define HAVE_SECTION_RELOC
+
+static ElfW_Rel *qrel; /* ptr to next reloc entry reused */
+
+void relocate_init(Section *sr)
+{
+    qrel = (ElfW_Rel *) sr->data;
+}
+
+void relocate(TCCState *s1, ElfW_Rel *rel, int type, char *ptr, addr_t addr, addr_t val)
+{
+    int sym_index, esym_index;
+
+    sym_index = ELFW(R_SYM)(rel->r_info);
+
+    switch (type) {
+        case R_386_32:
+            if (s1->output_type == TCC_OUTPUT_DLL) {
+                esym_index = s1->symtab_to_dynsym[sym_index];
+                qrel->r_offset = rel->r_offset;
+                if (esym_index) {
+                    qrel->r_info = ELFW(R_INFO)(esym_index, R_386_32);
+                    qrel++;
+                    return;
+                } else {
+                    qrel->r_info = ELFW(R_INFO)(0, R_386_RELATIVE);
+                    qrel++;
+                }
+            }
+            add32le(ptr, val);
+            return;
+        case R_386_PC32:
+            if (s1->output_type == TCC_OUTPUT_DLL) {
+                /* DLL relocation */
+                esym_index = s1->symtab_to_dynsym[sym_index];
+                if (esym_index) {
+                    qrel->r_offset = rel->r_offset;
+                    qrel->r_info = ELFW(R_INFO)(esym_index, R_386_PC32);
+                    qrel++;
+                    return;
+                }
+            }
+            add32le(ptr, val - addr);
+            return;
+        case R_386_PLT32:
+            add32le(ptr, val - addr);
+            return;
+        case R_386_GLOB_DAT:
+        case R_386_JMP_SLOT:
+            write32le(ptr, val);
+            return;
+        case R_386_GOTPC:
+            add32le(ptr, s1->got->sh_addr - addr);
+            return;
+        case R_386_GOTOFF:
+            add32le(ptr, val - s1->got->sh_addr);
+            return;
+        case R_386_GOT32:
+        case R_386_GOT32X:
+            /* we load the got offset */
+            add32le(ptr, s1->sym_attrs[sym_index].got_offset);
+            return;
+        case R_386_16:
+            if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY) {
+            output_file:
+                tcc_error("can only produce 16-bit binary files");
+            }
+            write16le(ptr, read16le(ptr) + val);
+            return;
+        case R_386_PC16:
+            if (s1->output_format != TCC_OUTPUT_FORMAT_BINARY)
+                goto output_file;
+            write16le(ptr, read16le(ptr) + val - addr);
+            return;
+        case R_386_RELATIVE:
+            /* do nothing */
+            return;
+        case R_386_COPY:
+            /* This reloction must copy initialized data from the library
+            to the program .bss segment. Currently made like for ARM
+            (to remove noise of defaukt case). Is this true? 
+            */
+            return;
+        default:
+            fprintf(stderr,"FIXME: handle reloc type %d at %x [%p] to %x\n",
+                type, (unsigned)addr, ptr, (unsigned)val);
+            return;
+    }
+}