TinyC upgrade (#6593)

1 files changed, 244 insertions, 0 deletions

diff --git a/tinyc/i386-link.c b/tinyc/i386-link.c
new file mode 100644
index 000000000..b44664404
--- /dev/null
+++ b/tinyc/i386-link.c
@@ -0,0 +1,244 @@
+#ifdef TARGET_DEFS_ONLY
+
+#define EM_TCC_TARGET EM_386
+
+/* relocation type for 32 bit data relocation */
+#define R_DATA_32   R_386_32
+#define R_DATA_PTR  R_386_32
+#define R_JMP_SLOT  R_386_JMP_SLOT
+#define R_GLOB_DAT  R_386_GLOB_DAT
+#define R_COPY      R_386_COPY
+#define R_RELATIVE  R_386_RELATIVE
+
+#define R_NUM       R_386_NUM
+
+#define ELF_START_ADDR 0x08048000
+#define ELF_PAGE_SIZE  0x1000
+
+#define PCRELATIVE_DLLPLT 0
+#define RELOCATE_DLLPLT 0
+
+#else /* !TARGET_DEFS_ONLY */
+
+#include "tcc.h"
+
+/* Returns 1 for a code relocation, 0 for a data relocation. For unknown
+   relocations, returns -1. */
+int code_reloc (int reloc_type)
+{
+    switch (reloc_type) {
+	case R_386_RELATIVE:
+	case R_386_16:
+        case R_386_32:
+	case R_386_GOTPC:
+	case R_386_GOTOFF:
+	case R_386_GOT32:
+	case R_386_GOT32X:
+	case R_386_GLOB_DAT:
+	case R_386_COPY:
+            return 0;
+
+	case R_386_PC16:
+	case R_386_PC32:
+	case R_386_PLT32:
+	case R_386_JMP_SLOT:
+            return 1;
+    }
+
+    tcc_error ("Unknown relocation type: %d", reloc_type);
+    return -1;
+}
+
+/* Returns an enumerator to describe whether and when the relocation needs a
+   GOT and/or PLT entry to be created. See tcc.h for a description of the
+   different values. */
+int gotplt_entry_type (int reloc_type)
+{
+    switch (reloc_type) {
+	case R_386_RELATIVE:
+	case R_386_16:
+	case R_386_GLOB_DAT:
+	case R_386_JMP_SLOT:
+	case R_386_COPY:
+            return NO_GOTPLT_ENTRY;
+
+        case R_386_32:
+	    /* This relocations shouldn't normally need GOT or PLT
+	       slots if it weren't for simplicity in the code generator.
+	       See our caller for comments.  */
+            return AUTO_GOTPLT_ENTRY;
+
+	case R_386_PC16:
+	case R_386_PC32:
+            return AUTO_GOTPLT_ENTRY;
+
+	case R_386_GOTPC:
+	case R_386_GOTOFF:
+            return BUILD_GOT_ONLY;
+
+	case R_386_GOT32:
+	case R_386_GOT32X:
+	case R_386_PLT32:
+            return ALWAYS_GOTPLT_ENTRY;
+    }
+
+    tcc_error ("Unknown relocation type: %d", reloc_type);
+    return -1;
+}
+
+ST_FUNC unsigned create_plt_entry(TCCState *s1, unsigned got_offset, struct sym_attr *attr)
+{
+    Section *plt = s1->plt;
+    uint8_t *p;
+    int modrm;
+    unsigned plt_offset, relofs;
+
+    /* on i386 if we build a DLL, we add a %ebx offset */
+    if (s1->output_type == TCC_OUTPUT_DLL)
+        modrm = 0xa3;
+    else
+        modrm = 0x25;
+
+    /* empty PLT: create PLT0 entry that pushes the library identifier
+       (GOT + PTR_SIZE) and jumps to ld.so resolution routine
+       (GOT + 2 * PTR_SIZE) */
+    if (plt->data_offset == 0) {
+        p = section_ptr_add(plt, 16);
+        p[0] = 0xff; /* pushl got + PTR_SIZE */
+        p[1] = modrm + 0x10;
+        write32le(p + 2, PTR_SIZE);
+        p[6] = 0xff; /* jmp *(got + PTR_SIZE * 2) */
+        p[7] = modrm;
+        write32le(p + 8, PTR_SIZE * 2);
+    }
+    plt_offset = plt->data_offset;
+
+    /* The PLT slot refers to the relocation entry it needs via offset.
+       The reloc entry is created below, so its offset is the current
+       data_offset */
+    relofs = s1->got->reloc ? s1->got->reloc->data_offset : 0;
+
+    /* Jump to GOT entry where ld.so initially put the address of ip + 4 */
+    p = section_ptr_add(plt, 16);
+    p[0] = 0xff; /* jmp *(got + x) */
+    p[1] = modrm;
+    write32le(p + 2, got_offset);
+    p[6] = 0x68; /* push $xxx */
+    write32le(p + 7, relofs);
+    p[11] = 0xe9; /* jmp plt_start */
+    write32le(p + 12, -(plt->data_offset));
+    return plt_offset;
+}
+
+/* relocate the PLT: compute addresses and offsets in the PLT now that final
+   address for PLT and GOT are known (see fill_program_header) */
+ST_FUNC void relocate_plt(TCCState *s1)
+{
+    uint8_t *p, *p_end;
+
+    if (!s1->plt)
+      return;
+
+    p = s1->plt->data;
+    p_end = p + s1->plt->data_offset;
+
+    if (p < p_end) {
+        add32le(p + 2, s1->got->sh_addr);
+        add32le(p + 8, s1->got->sh_addr);
+        p += 16;
+        while (p < p_end) {
+            add32le(p + 2, s1->got->sh_addr);
+            p += 16;
+        }
+    }
+}
+
+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, unsigned 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->sym_attrs[sym_index].dyn_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->sym_attrs[sym_index].dyn_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 relocation must copy initialized data from the library
+            to the program .bss segment. Currently made like for ARM
+            (to remove noise of default 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;
+    }
+}
+
+#endif /* !TARGET_DEFS_ONLY */