From: Michael Urman <mu@tortall.net>
Date: Sat, 12 Mar 2005 05:06:50 +0000 (-0000)
Subject: Add `hidden' `internal' and `protected' symbol visibility types to
X-Git-Tag: v0.5.0rc1~172
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=3cc450d3ea88c4e22cd16b2459bef8c7b3f124ef;p=yasm
Add `hidden' `internal' and `protected' symbol visibility types to
global symbols in ELF. Search for STV_HIDDEN for explanations; these
don't seem to appear in the base ELF documentation.
Sample syntax:
global foo:hidden
Inspiration and base patch provided by Oskari Saarenmaa under our BSD
license. This checkin tweaks and extends Oskari's patch and adds tests.
svn path=/trunk/yasm/; revision=1202
---
diff --git a/modules/objfmts/elf/elf-objfmt.c b/modules/objfmts/elf/elf-objfmt.c
index 8b5c84ae..59bff2f3 100644
--- a/modules/objfmts/elf/elf-objfmt.c
+++ b/modules/objfmts/elf/elf-objfmt.c
@@ -86,8 +86,8 @@ yasm_objfmt_module yasm_elf_LTX_objfmt;
static elf_symtab_entry *
elf_objfmt_symtab_append(yasm_objfmt_elf *objfmt_elf, yasm_symrec *sym,
elf_section_index sectidx, elf_symbol_binding bind,
- elf_symbol_type type, yasm_expr *size,
- elf_address value)
+ elf_symbol_type type, elf_symbol_vis vis,
+ yasm_expr *size, elf_address value)
{
elf_strtab_entry *name = elf_strtab_append_str(objfmt_elf->strtab,
yasm_symrec_get_name(sym));
@@ -95,6 +95,7 @@ elf_objfmt_symtab_append(yasm_objfmt_elf *objfmt_elf, yasm_symrec *sym,
elf_symtab_append_entry(objfmt_elf->elf_symtab, entry);
elf_symtab_set_nonzero(entry, NULL, sectidx, bind, type, size, value);
+ elf_sym_set_visibility(entry, vis);
yasm_symrec_add_data(sym, &elf_symrec_data, entry);
return entry;
@@ -822,8 +823,16 @@ elf_objfmt_extern_declare(yasm_objfmt *objfmt, const char *name, /*@unused@*/
sym = yasm_symtab_declare(objfmt_elf->symtab, name, YASM_SYM_EXTERN, line);
elf_objfmt_symtab_append(objfmt_elf, sym, SHN_UNDEF, STB_GLOBAL,
- STT_NOTYPE, NULL, 0);
+ STT_NOTYPE, STV_DEFAULT, NULL, 0);
+ if (objext_valparams) {
+ yasm_valparam *vp = yasm_vps_first(objext_valparams);
+ for (; vp; vp = yasm_vps_next(vp))
+ {
+ if (vp->val)
+ yasm__error(line, N_("unrecognized symbol type `%s'"), vp->val);
+ }
+ }
return sym;
}
@@ -836,30 +845,50 @@ elf_objfmt_global_declare(yasm_objfmt *objfmt, const char *name,
yasm_symrec *sym;
elf_symbol_type type = STT_NOTYPE;
yasm_expr *size = NULL;
+ elf_symbol_vis vis = STV_DEFAULT;
+ unsigned int vis_overrides = 0;
sym = yasm_symtab_declare(objfmt_elf->symtab, name, YASM_SYM_GLOBAL, line);
if (objext_valparams) {
yasm_valparam *vp = yasm_vps_first(objext_valparams);
- if (vp && vp->val) {
- if (yasm__strcasecmp(vp->val, "function") == 0)
- type = STT_FUNC;
- else if (yasm__strcasecmp(vp->val, "data") == 0 ||
- yasm__strcasecmp(vp->val, "object") == 0)
- type = STT_OBJECT;
- else
- yasm__error(line, N_("unrecognized symbol type `%s'"),
- vp->val);
- vp = yasm_vps_next(vp);
- }
- if (vp && !vp->val && vp->param) {
- size = vp->param;
- vp->param = NULL; /* to avoid deleting the expr */
+ for (; vp; vp = yasm_vps_next(vp))
+ {
+ if (vp->val) {
+ if (yasm__strcasecmp(vp->val, "function") == 0)
+ type = STT_FUNC;
+ else if (yasm__strcasecmp(vp->val, "data") == 0 ||
+ yasm__strcasecmp(vp->val, "object") == 0)
+ type = STT_OBJECT;
+ else if (yasm__strcasecmp(vp->val, "internal") == 0) {
+ vis = STV_INTERNAL;
+ vis_overrides++;
+ }
+ else if (yasm__strcasecmp(vp->val, "hidden") == 0) {
+ vis = STV_HIDDEN;
+ vis_overrides++;
+ }
+ else if (yasm__strcasecmp(vp->val, "protected") == 0) {
+ vis = STV_PROTECTED;
+ vis_overrides++;
+ }
+ else
+ yasm__error(line, N_("unrecognized symbol type `%s'"),
+ vp->val);
+ }
+ else if (vp->param && !size) {
+ size = vp->param;
+ vp->param = NULL; /* to avoid deleting the expr */
+ }
}
+ if (vis_overrides > 1) {
+ yasm__warning(YASM_WARN_GENERAL, line,
+ N_("More than one symbol visibility provided; using last"));
+ }
}
elf_objfmt_symtab_append(objfmt_elf, sym, SHN_UNDEF, STB_GLOBAL,
- type, size, 0);
+ type, vis, size, 0);
return sym;
}
@@ -878,30 +907,32 @@ elf_objfmt_common_declare(yasm_objfmt *objfmt, const char *name,
if (objext_valparams) {
yasm_valparam *vp = yasm_vps_first(objext_valparams);
- if (vp && !vp->val && vp->param) {
- /*@dependent@*/ /*@null@*/ const yasm_intnum *align_expr;
-
- align_expr = yasm_expr_get_intnum(&vp->param, NULL);
- if (!align_expr) {
- yasm__error(line,
- N_("alignment constraint is not a power of two"));
- return sym;
- }
- addralign = yasm_intnum_get_uint(align_expr);
-
- /* Alignments must be a power of two. */
- if ((addralign & (addralign - 1)) != 0) {
- yasm__error(line,
- N_("alignment constraint is not a power of two"));
- return sym;
- }
- } else if (vp && vp->val)
- yasm__warning(YASM_WARN_GENERAL, line,
- N_("Unrecognized qualifier `%s'"), vp->val);
+ for (; vp; vp = yasm_vps_next(vp)) {
+ if (!vp->val && vp->param) {
+ /*@dependent@*/ /*@null@*/ const yasm_intnum *align_expr;
+
+ align_expr = yasm_expr_get_intnum(&vp->param, NULL);
+ if (!align_expr) {
+ yasm__error(line,
+ N_("alignment constraint is not a power of two"));
+ return sym;
+ }
+ addralign = yasm_intnum_get_uint(align_expr);
+
+ /* Alignments must be a power of two. */
+ if ((addralign & (addralign - 1)) != 0) {
+ yasm__error(line,
+ N_("alignment constraint is not a power of two"));
+ return sym;
+ }
+ } else if (vp->val)
+ yasm__warning(YASM_WARN_GENERAL, line,
+ N_("Unrecognized qualifier `%s'"), vp->val);
+ }
}
elf_objfmt_symtab_append(objfmt_elf, sym, SHN_COMMON, STB_GLOBAL,
- STT_NOTYPE, size, addralign);
+ STT_NOTYPE, STV_DEFAULT, size, addralign);
return sym;
}
diff --git a/modules/objfmts/elf/elf-x86-amd64.c b/modules/objfmts/elf/elf-x86-amd64.c
index 29542f92..27bfb1c3 100644
--- a/modules/objfmts/elf/elf-x86-amd64.c
+++ b/modules/objfmts/elf/elf-x86-amd64.c
@@ -63,7 +63,7 @@ elf_x86_amd64_write_symtab_entry(unsigned char *bufp,
{
YASM_WRITE_32_L(bufp, entry->name ? entry->name->index : 0);
YASM_WRITE_8(bufp, ELF64_ST_INFO(entry->bind, entry->type));
- YASM_WRITE_8(bufp, 0);
+ YASM_WRITE_8(bufp, ELF64_ST_OTHER(entry->vis));
if (entry->sect) {
if (yasm_section_is_absolute(entry->sect)) {
YASM_WRITE_16_L(bufp, SHN_ABS);
diff --git a/modules/objfmts/elf/elf-x86-x86.c b/modules/objfmts/elf/elf-x86-x86.c
index e20150ea..d585a398 100644
--- a/modules/objfmts/elf/elf-x86-x86.c
+++ b/modules/objfmts/elf/elf-x86-x86.c
@@ -68,7 +68,7 @@ elf_x86_x86_write_symtab_entry(unsigned char *bufp,
YASM_WRITE_32I_L(bufp, size_intn);
YASM_WRITE_8(bufp, ELF32_ST_INFO(entry->bind, entry->type));
- YASM_WRITE_8(bufp, 0);
+ YASM_WRITE_8(bufp, ELF32_ST_OTHER(entry->vis));
if (entry->sect) {
if (yasm_section_is_absolute(entry->sect)) {
YASM_WRITE_16_L(bufp, SHN_ABS);
diff --git a/modules/objfmts/elf/elf.c b/modules/objfmts/elf/elf.c
index 1af53597..3cfa772d 100644
--- a/modules/objfmts/elf/elf.c
+++ b/modules/objfmts/elf/elf.c
@@ -252,6 +252,7 @@ elf_symtab_entry_create(elf_strtab_entry *name,
entry->index = 0;
entry->bind = 0;
entry->type = STT_NOTYPE;
+ entry->vis = STV_DEFAULT;
return entry;
}
@@ -324,6 +325,7 @@ elf_symtab_create()
entry->index = SHN_UNDEF;
entry->bind = 0;
entry->type = 0;
+ entry->vis = STV_DEFAULT;
entry->symindex = 0;
STAILQ_INSERT_TAIL(symtab, entry, qlink);
return symtab;
@@ -489,6 +491,12 @@ void elf_symtab_set_nonzero(elf_symtab_entry *entry,
if (value) entry->value = value;
}
+void
+elf_sym_set_visibility(elf_symtab_entry *entry,
+ elf_symbol_vis vis)
+{
+ entry->vis = ELF_ST_VISIBILITY(vis);
+}
elf_secthead *
elf_secthead_create(elf_strtab_entry *name,
diff --git a/modules/objfmts/elf/elf.h b/modules/objfmts/elf/elf.h
index 10208c5c..5c579138 100644
--- a/modules/objfmts/elf/elf.h
+++ b/modules/objfmts/elf/elf.h
@@ -196,15 +196,28 @@ typedef enum {
STN_UNDEF = 0
} elf_symbol_index;
+/* elf symbol visibility - lower two bits of OTHER field */
+typedef enum {
+ STV_DEFAULT = 0, /* Default symbol visibility rules */
+ STV_INTERNAL = 1, /* Processor specific hidden class */
+ STV_HIDDEN = 2, /* Sym unavailable in other modules */
+ STV_PROTECTED = 3 /* Not preemptable, not exported */
+} elf_symbol_vis;
+
/* internal only object definitions */
#ifdef YASM_OBJFMT_ELF_INTERNAL
+#define ELF_VISIBILITY_MASK 0x03
+#define ELF_ST_VISIBILITY(v) ((v) & ELF_VISIBILITY_MASK)
+
#define ELF32_ST_INFO(bind, type) (((bind) << 4) + ((type) & 0xf))
#define ELF32_R_INFO(s,t) (((s)<<8)+(unsigned char)(t))
+#define ELF32_ST_OTHER(vis) ELF_ST_VISIBILITY(vis)
#define ELF64_ST_INFO(bind, type) (((bind) << 4) + ((type) & 0xf))
#define ELF64_R_INFO(s,t) (((s)<<32) + ((t) & 0xffffffffL))
+#define ELF64_ST_OTHER(vis) ELF_ST_VISIBILITY(vis)
#define EHDR32_SIZE 52
#define EHDR64_SIZE 64
@@ -376,6 +389,7 @@ struct elf_symtab_entry {
elf_section_index index;
elf_symbol_binding bind;
elf_symbol_type type;
+ elf_symbol_vis vis;
elf_symbol_index symindex;
};
@@ -422,7 +436,8 @@ void elf_symtab_set_nonzero(elf_symtab_entry *entry,
elf_symbol_type type,
struct yasm_expr *size,
elf_address value);
-
+void elf_sym_set_visibility(elf_symtab_entry *entry,
+ elf_symbol_vis vis);
/* section header functions */
elf_secthead *elf_secthead_create(elf_strtab_entry *name,
diff --git a/modules/objfmts/elf/tests/Makefile.inc b/modules/objfmts/elf/tests/Makefile.inc
index dee1cb8a..51d51b06 100644
--- a/modules/objfmts/elf/tests/Makefile.inc
+++ b/modules/objfmts/elf/tests/Makefile.inc
@@ -34,6 +34,9 @@ EXTRA_DIST += modules/objfmts/elf/tests/elfreloc-ext.hex
EXTRA_DIST += modules/objfmts/elf/tests/elfabssect.asm
EXTRA_DIST += modules/objfmts/elf/tests/elfabssect.errwarn
EXTRA_DIST += modules/objfmts/elf/tests/elfabssect.hex
+EXTRA_DIST += modules/objfmts/elf/tests/elfvisibility.asm
+EXTRA_DIST += modules/objfmts/elf/tests/elfvisibility.errwarn
+EXTRA_DIST += modules/objfmts/elf/tests/elfvisibility.hex
EXTRA_DIST += modules/objfmts/elf/tests/amd64/Makefile.inc
diff --git a/modules/objfmts/elf/tests/elfvisibility.asm b/modules/objfmts/elf/tests/elfvisibility.asm
new file mode 100644
index 00000000..13203106
--- /dev/null
+++ b/modules/objfmts/elf/tests/elfvisibility.asm
@@ -0,0 +1,6 @@
+[section .text]
+
+global ghidden:hidden
+global ginternal:internal
+global gprotected:protected
+global gtoomany:hidden internal
diff --git a/modules/objfmts/elf/tests/elfvisibility.errwarn b/modules/objfmts/elf/tests/elfvisibility.errwarn
new file mode 100644
index 00000000..968dc9bb
--- /dev/null
+++ b/modules/objfmts/elf/tests/elfvisibility.errwarn
@@ -0,0 +1 @@
+-:6: warning: More than one symbol visibility provided; using last
diff --git a/modules/objfmts/elf/tests/elfvisibility.hex b/modules/objfmts/elf/tests/elfvisibility.hex
new file mode 100644
index 00000000..8b2d2cb0
--- /dev/null
+++ b/modules/objfmts/elf/tests/elfvisibility.hex
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