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authorpommicket <pommicket@gmail.com>2022-02-18 12:36:57 -0500
committerpommicket <pommicket@gmail.com>2022-02-18 12:36:57 -0500
commit826d1afd58c2e064a9c8fdb09eda1b08469de1a8 (patch)
treeb4fedc589a1944f6cf3f451a9db976b431e89b25 /05/tcc-0.9.27/i386-link.c
parentc42c5d94b8944e19cd17a5b540e4c70013c62b92 (diff)
newer version of tcc almost working
Diffstat (limited to '05/tcc-0.9.27/i386-link.c')
-rw-r--r--05/tcc-0.9.27/i386-link.c247
1 files changed, 247 insertions, 0 deletions
diff --git a/05/tcc-0.9.27/i386-link.c b/05/tcc-0.9.27/i386-link.c
new file mode 100644
index 0000000..aea3c21
--- /dev/null
+++ b/05/tcc-0.9.27/i386-link.c
@@ -0,0 +1,247 @@
+#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:
+#ifdef TCC_TARGET_PE
+ add32le(ptr, val - s1->pe_imagebase);
+#endif
+ /* 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 */