bugfix import linking

src/base/base_core.h

@@ -266,6 +266,7 @@
 #  define ins_atomic_u32_eval_cond_assign(x,k,c)  InterlockedCompareExchange((LONG *)(x),(k),(c))
 #  define ins_atomic_u32_add_eval(x,c)            InterlockedAdd((LONG *)(x), (c))
 #  define ins_atomic_u8_eval_assign(x,c)          InterlockedExchange8((CHAR *)(x), (c))
+#  define ins_atomic_u8_or(x,c)                   InterlockedOr8((char *)(x), (char)c)
 # else
 #  error Atomic intrinsics not defined for this compiler / architecture combination.
 # endif
@@ -284,6 +285,7 @@
 #  define ins_atomic_u32_eval_assign(x,c)         __atomic_exchange_n((x), (c), __ATOMIC_SEQ_CST)
 #  define ins_atomic_u32_eval_cond_assign(x,k,c)  ({ U32 _new = (c); __atomic_compare_exchange_n((U32 *)(x),&_new,(k),0,__ATOMIC_SEQ_CST,__ATOMIC_SEQ_CST); _new; })
 #  define ins_atomic_u8_eval_assign(x,c)          __atomic_exchange_n((x), (c), __ATOMIC_SEQ_CST)
+#  define ins_atomic_u8_or(x,c)                   __atomic_fetch_or((U8 *)(x), (U8)(c), __ATOMIC_SEQ_CST)
 #else
 #  error Atomic intrinsics not defined for this compiler / architecture.
 #endif

src/linker/lnk.c

@@ -1486,8 +1486,9 @@ lnk_queue_lib_member(Arena *arena, LNK_LibMemberRefList *queued_members, LNK_Sym
   B32 was_linked = lnk_lib_set_link_symbol(lib, member_idx, link_symbol);
   if (was_linked) {
     LNK_LibMemberRef *member_ref = push_array(arena, LNK_LibMemberRef, 1);
-    member_ref->lib        = lib;
+    member_ref->lib         = lib;
-    member_ref->member_idx = member_idx;
+    member_ref->member_idx  = member_idx;
+    member_ref->link_symbol = link_symbol;
     lnk_lib_member_ref_list_push_node(queued_members, member_ref);
   }
 }
@@ -1583,7 +1584,7 @@ lnk_link_inputs(TP_Context      *tp,
 
             LNK_LibMemberRef *member_ref  = member_refs[i];
             LNK_Lib          *lib         = member_ref->lib;
-            LNK_Symbol       *link_symbol = lib->member_links[member_ref->member_idx];
+            LNK_Symbol       *link_symbol = member_ref->link_symbol;
 
             COFF_ArchiveMember member_info = coff_archive_member_from_offset(lib->data, lib->member_offsets[member_ref->member_idx]);
             COFF_DataType      member_type = coff_data_type_from_data(member_info.data);
@@ -1612,35 +1613,21 @@ lnk_link_inputs(TP_Context      *tp,
 
           switch (member_type) {
           case COFF_DataType_Import: {
-            LNK_Symbol *link_symbol = lib->member_links[member_idx];
+            // find import stub
+            LNK_Symbol *import_stub = lnk_symbol_table_search(symtab, str8_lit(LNK_IMPORT_STUB));
 
-            LNK_Symbol *import_symbols[2] = {0};
+            // same import symbol must never be queued more than once, if it is, there is a bug in the link set logic
-            if (str8_starts_with(link_symbol->name, str8_lit("__imp_"))) {
+            AssertAlways(member_ref->link_symbol->refs != import_stub->refs);
-              import_symbols[0] = link_symbol;
-              import_symbols[1] = lnk_symbol_table_search(symtab, str8_skip(link_symbol->name, str8_lit("__imp_").size));
-            } else {
-              Temp temp = temp_begin(scratch.arena);
-              String8 imp_name = push_str8f(temp.arena, "__imp_%S", link_symbol->name);
-              import_symbols[0] = lnk_symbol_table_search(symtab, imp_name);
-              import_symbols[1] = link_symbol;
-              temp_end(temp);
-            }
 
-            for EachIndex(i, ArrayCount(import_symbols)) {
+            // replace the import symbol with a stub, which is later replaced with the real import symbol once import obj is ready
-              LNK_Symbol *import_symbol = import_symbols[i];
+            member_ref->link_symbol->refs = import_stub->refs;
-              if (import_symbol == 0) { continue; }
-
-              LNK_Symbol *import_stub = lnk_symbol_table_search(symtab, str8_lit(LNK_IMPORT_STUB));
-
-              // same import symbol must never be queued more than once, if it is, there is a bug in the link set logic
-              AssertAlways(import_symbol->refs != import_stub->refs);
-
-              // replace the import symbol with a stub, which is later replaced with the real import symbol once import obj is ready
-              import_symbol->refs = import_stub->refs;
-            }
 
             // push import member for import obj generation
-            lnk_lib_member_ref_list_push_node(&link->imports, member_ref);
+            LNK_LibMemberFlags member_flags  = lib->member_flags[member_ref->member_idx];
+            B32                is_first_link = member_flags != (LNK_LibMemberFlag_LinkedRegular | LNK_LibMemberFlag_LinkedImp);
+            if (is_first_link) {
+              lnk_lib_member_ref_list_push_node(&link->imports, member_ref);
+            }
           } break;
           case COFF_DataType_BigObj:
           case COFF_DataType_Obj: {

src/linker/lnk.h

@@ -7,8 +7,9 @@
 
 typedef struct LNK_LibMemberRef
 {
-  LNK_Lib *lib;
+  LNK_Lib    *lib;
-  U32      member_idx;
+  U32         member_idx;
+  LNK_Symbol *link_symbol;
   struct LNK_LibMemberRef *next;
 } LNK_LibMemberRef;
 
@@ -183,6 +184,7 @@ typedef struct
 {
   B32                   search_anti_deps;
   LNK_SymbolTable      *symtab;
+  LNK_Symbol           *import_stub;
   LNK_Lib              *lib;
   LNK_LibMemberRefList *member_ref_lists;
 } LNK_SearchLibTask;

src/linker/lnk_lib.c

@@ -142,6 +142,7 @@ lnk_lib_from_data(Arena *arena, String8 data, String8 path, U64 input_idx, LNK_L
   lib_out->member_offsets    = member_offsets;
   lib_out->symbol_indices    = symbol_indices;
   lib_out->member_links      = push_array(arena, LNK_Symbol *, member_count);
+  lib_out->member_flags      = push_array(arena, LNK_LibMemberFlags, member_count); 
   lib_out->symbol_names      = symbol_names;
   lib_out->long_names        = parse.long_names;
   lib_out->input_idx         = input_idx;
@@ -224,15 +225,21 @@ lnk_lib_list_push_parallel(TP_Context *tp, TP_Arena *arena, LNK_LibList *list, U
 internal B32
 lnk_lib_set_link_symbol(LNK_Lib *lib, U32 member_idx, LNK_Symbol *link_symbol)
 {
-  local_persist LNK_Symbol null_symbol;
+  B32 was_linked;
-
+  if (str8_starts_with(link_symbol->name, str8_lit("__imp_"))) {
-  LNK_Symbol *slot = ins_atomic_ptr_eval_assign(&lib->member_links[member_idx], &null_symbol);
+    U8 member_flags = ins_atomic_u8_or(&lib->member_flags[member_idx], LNK_LibMemberFlag_LinkedImp);
-
+    was_linked = !!(~member_flags & LNK_LibMemberFlag_LinkedImp);
-  B32 was_linked = (slot == 0);
+  } else {
+    U8 flag = LNK_LibMemberFlag_LinkedRegular;
+    U8 member_flags = ins_atomic_u8_or(&lib->member_flags[member_idx], LNK_LibMemberFlag_LinkedRegular);
+    was_linked = !!(~member_flags & LNK_LibMemberFlag_LinkedRegular);
+  }
 
   for (LNK_Symbol *leader = link_symbol;;) {
+    LNK_Symbol *slot = ins_atomic_ptr_eval_assign(&lib->member_links[member_idx], 0);
+
     // update slot symbol if it is empty or link symbol comes before symbol in the slot
-    if (slot && slot != &null_symbol) {
+    if (slot) {
       if (lnk_symbol_is_before(slot, leader)) {
         leader = slot;
       }
@@ -241,15 +248,12 @@ lnk_lib_set_link_symbol(LNK_Lib *lib, U32 member_idx, LNK_Symbol *link_symbol)
     }
 
     // try to insert back updated slot symbol
-    LNK_Symbol *swap = ins_atomic_ptr_eval_cond_assign(&lib->member_links[member_idx], leader, &null_symbol);
+    LNK_Symbol *swap = ins_atomic_ptr_eval_cond_assign(&lib->member_links[member_idx], leader, 0);
 
     // exit if slot symbol was null
-    if (swap == &null_symbol) {
+    if (swap == 0) {
       break;
     }
-
-    // reload slot symbol
-    slot = ins_atomic_ptr_eval_assign(&lib->member_links[member_idx], &null_symbol);
   }
 
   return was_linked;

src/linker/lnk_lib.h

@@ -3,6 +3,13 @@
 
 #pragma once
 
+typedef U8 LNK_LibMemberFlags;
+enum
+{
+  LNK_LibMemberFlag_LinkedRegular = (1 << 0),
+  LNK_LibMemberFlag_LinkedImp     = (1 << 1),
+};
+
 typedef struct LNK_Lib
 {
   String8              path;
@@ -13,6 +20,7 @@ typedef struct LNK_Lib
   U32                 *member_offsets;
   U16                 *symbol_indices;
   LNK_Symbol         **member_links;
+  LNK_LibMemberFlags  *member_flags;
   String8Array         symbol_names;
   String8              long_names;
   U64                  input_idx;