Add support for thread-local storage variables

5 files changed, 54 insertions, 14 deletions

diff --git a/elf.h b/elf.h
index 2983c75..039a697 100644
--- a/elf.h
+++ b/elf.h
@@ -447,6 +447,7 @@ typedef struct
 #define STT_SECTION     3               /* Symbol associated with a section */
 #define STT_FILE        4               /* Symbol's name is file name */
 #define STT_NUM         5               /* Number of defined types.  */
+#define STT_TLS         6               /* Symbol is a thread-local data object */
 #define STT_GNU_IFUNC   10              /* Symbol is a indirect code object */
 #define STT_LOOS        11              /* Start of OS-specific */
 #define STT_HIOS        12              /* End of OS-specific */
@@ -555,7 +556,8 @@ typedef struct
 #define PT_NOTE         4               /* Auxiliary information */
 #define PT_SHLIB        5               /* Reserved */
 #define PT_PHDR         6               /* Entry for header table itself */
-#define PT_NUM          7               /* Number of defined types.  */
+#define PT_TLS          7               /* Thread-local program segment */
+#define PT_NUM          8               /* Number of defined types.  */
 #define PT_LOOS         0x60000000      /* Start of OS-specific */
 #define PT_HIOS         0x6fffffff      /* End of OS-specific */
 #define PT_LOPROC       0x70000000      /* Start of processor-specific */
diff --git a/libtcc.c b/libtcc.c
index f841eb0..fbea50b 100644
--- a/libtcc.c
+++ b/libtcc.c
@@ -444,7 +444,10 @@ ST_FUNC void put_extern_sym2(Sym *sym, Section *section,
     } else if ((sym->type.t & VT_BTYPE) == VT_VOID) {
         sym_type = STT_NOTYPE;
     } else {
-        sym_type = STT_OBJECT;
+        if (section && section->sh_flags & SHF_TLS)
+            sym_type = STT_TLS;
+        else
+            sym_type = STT_OBJECT;
     }
 
     if (sym->type.t & VT_STATIC)
diff --git a/tccelf.c b/tccelf.c
index 8af4bb6..4602ce8 100644
--- a/tccelf.c
+++ b/tccelf.c
@@ -1543,6 +1543,7 @@ static int elf_output_file(TCCState *s1, const char *filename)
     int fd, mode, ret;
     int *section_order;
     int shnum, i, phnum, file_offset, offset, size, j, sh_order_index, k;
+    int have_tls_section = 0;
     long long tmp;
     addr_t addr;
     Section *strsec, *s;
@@ -1861,6 +1862,11 @@ static int elf_output_file(TCCState *s1, const char *filename)
             /* we output all sections if debug or object file */
             s->sh_size = s->data_offset;
         }
+        /* if tls section we'll need to add one segment */
+        if (s->sh_flags & SHF_TLS) {
+          have_tls_section = 1;
+          phnum++;
+        }
     }
 
     /* allocate program segment headers */
@@ -1904,12 +1910,16 @@ static int elf_output_file(TCCState *s1, const char *filename)
         if (interp)
             ph += 1 + HAVE_PHDR;
 
-        for(j = 0; j < 2; j++) {
-            ph->p_type = PT_LOAD;
-            if (j == 0)
-                ph->p_flags = PF_R | PF_X;
+        for(j = 0; j < 2 + have_tls_section; j++) {
+            if (j != 2)
+                ph->p_type = PT_LOAD;
             else
-                ph->p_flags = PF_R | PF_W;
+                ph->p_type = PT_TLS;
+            ph->p_flags = PF_R;
+            if (j == 0)
+                ph->p_flags |= PF_X;
+            else if (j == 1)
+                ph->p_flags |= PF_W;
             ph->p_align = s1->section_align;
             
             /* we do the following ordering: interp, symbol tables,
@@ -1920,13 +1930,16 @@ static int elf_output_file(TCCState *s1, const char *filename)
                     s = s1->sections[i];
                     /* compute if section should be included */
                     if (j == 0) {
-                        if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) != 
+                        if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE | SHF_TLS)) !=
                             SHF_ALLOC)
                             continue;
-                    } else {
-                        if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE)) != 
+                    } else if (j == 1) {
+                        if ((s->sh_flags & (SHF_ALLOC | SHF_WRITE | SHF_TLS)) !=
                             (SHF_ALLOC | SHF_WRITE))
                             continue;
+                    } else {
+                        if ((s->sh_flags & SHF_TLS) != SHF_TLS)
+                            continue;
                     }
                     if (s == interp) {
                         if (k != 0)
diff --git a/tccgen.c b/tccgen.c
index bab4f7c..bfe461f 100644
--- a/tccgen.c
+++ b/tccgen.c
@@ -31,6 +31,7 @@
 ST_DATA int rsym, anon_sym, ind, loc;
 
 ST_DATA Section *text_section, *data_section, *bss_section; /* predefined sections */
+ST_DATA Section *tdata_section, *tbss_section; /* thread-local storage sections */
 ST_DATA Section *cur_text_section; /* current section where function code is generated */
 #ifdef CONFIG_TCC_ASM
 ST_DATA Section *last_text_section; /* to handle .previous asm directive */
@@ -3092,6 +3093,10 @@ static int parse_btype(CType *type, AttributeDef *ad)
             t |= VT_INLINE;
             next();
             break;
+        case TOK_THREAD:
+            t |= VT_TLS;
+            next();
+            break;
 
             /* GNUC attribute */
         case TOK_ATTRIBUTE1:
@@ -5495,10 +5500,26 @@ static void decl_initializer_alloc(CType *type, AttributeDef *ad, int r,
         /* allocate symbol in corresponding section */
         sec = ad->section;
         if (!sec) {
-            if (has_init)
-                sec = data_section;
-            else if (tcc_state->nocommon)
-                sec = bss_section;
+            if (has_init) {
+                if (type->t & VT_TLS) {
+                    if (!tdata_section)
+                        tdata_section = new_section(tcc_state, ".tdata",
+                                               SHT_PROGBITS,
+                                               SHF_ALLOC | SHF_WRITE | SHF_TLS);
+                    sec = tdata_section;
+		} else
+                    sec = data_section;
+            }
+            else if (tcc_state->nocommon) {
+                if (type->t & VT_TLS) {
+                    if (!tbss_section)
+                        tbss_section = new_section(tcc_state, ".tbss",
+                                               SHT_NOBITS,
+                                               SHF_ALLOC | SHF_WRITE | SHF_TLS);
+                    sec = tbss_section;
+                } else
+                    sec = bss_section;
+            }
         }
         if (sec) {
             data_offset = sec->data_offset;
diff --git a/tcctok.h b/tcctok.h
index 9b47a60..d55c9d7 100644
--- a/tcctok.h
+++ b/tcctok.h
@@ -10,6 +10,7 @@
      DEF(TOK_FOR, "for")
      DEF(TOK_EXTERN, "extern")
      DEF(TOK_STATIC, "static")
+     DEF(TOK_THREAD, "__thread")
      DEF(TOK_UNSIGNED, "unsigned")
      DEF(TOK_GOTO, "goto")
      DEF(TOK_DO, "do")