WIP function pad min

src/coff/coff_obj_writer.c

@@ -283,6 +283,15 @@ coff_obj_writer_push_symbol_extern(COFF_ObjWriter *obj_writer, String8 name, U32
   return s;
 }
 
+internal COFF_ObjSymbol *
+coff_obj_writer_push_symbol_extern_func(COFF_ObjWriter *obj_writer, String8 name, U32 value, COFF_ObjSection *section)
+{
+  COFF_SymbolType      type = { .u.msb = COFF_SymDType_Func };
+  COFF_SymbolLocation  loc  = { .type = COFF_SymbolLocation_Section, .u.section = section };
+  COFF_ObjSymbol      *s    = coff_obj_writer_push_symbol(obj_writer, name, value, loc, type, COFF_SymStorageClass_External);
+  return s;
+}
+
 internal COFF_ObjSymbol *
 coff_obj_writer_push_symbol_static(COFF_ObjWriter *obj_writer, String8 name, U32 off, COFF_ObjSection *section)
 {

src/coff/coff_obj_writer.h

@@ -102,6 +102,7 @@ internal String8          coff_obj_writer_serialize(Arena *arena, COFF_ObjWriter
 internal COFF_ObjSection * coff_obj_writer_push_section(COFF_ObjWriter *obj_writer, String8 name, COFF_SectionFlags flags, String8 data);
 
 internal COFF_ObjSymbol*  coff_obj_writer_push_symbol(COFF_ObjWriter *obj_writer, String8 name, U32 value, COFF_SymbolLocation loc, COFF_SymbolType type, COFF_SymStorageClass storage_class);
+internal COFF_ObjSymbol * coff_obj_writer_push_symbol_extern_func(COFF_ObjWriter *obj_writer, String8 name, U32 value, COFF_ObjSection *section);
 internal COFF_ObjSymbol * coff_obj_writer_push_symbol_extern(COFF_ObjWriter *obj_writer, String8 name, U32 value, COFF_ObjSection *section);
 internal COFF_ObjSymbol * coff_obj_writer_push_symbol_static(COFF_ObjWriter *obj_writer, String8 name, U32 off, COFF_ObjSection *section);
 internal COFF_ObjSymbol * coff_obj_writer_push_symbol_secdef(COFF_ObjWriter *obj_writer, COFF_ObjSection *section, COFF_ComdatSelectType selection);

src/linker/lnk.c

@@ -179,7 +179,6 @@ lnk_config_from_argcv(Arena *arena, int argc, char **argv)
   lnk_cmd_line_push_option_if_not_presentf(scratch.arena, &cmd_line, LNK_CmdSwitch_HighEntropyVa,                 "");
   lnk_cmd_line_push_option_if_not_presentf(scratch.arena, &cmd_line, LNK_CmdSwitch_ManifestUac,                   "\"level='asInvoker' uiAccess='false'\"");
   lnk_cmd_line_push_option_if_not_presentf(scratch.arena, &cmd_line, LNK_CmdSwitch_NxCompat,                      "");
-  lnk_cmd_line_push_option_if_not_presentf(scratch.arena, &cmd_line, LNK_CmdSwitch_FunctionPadMin,                "0");
   lnk_cmd_line_push_option_if_not_presentf(scratch.arena, &cmd_line, LNK_CmdSwitch_LargeAddressAware,             "");
   lnk_cmd_line_push_option_if_not_presentf(scratch.arena, &cmd_line, LNK_CmdSwitch_PdbAltPath,                    "%%_RAD_PDB_PATH%%");
   lnk_cmd_line_push_option_if_not_presentf(scratch.arena, &cmd_line, LNK_CmdSwitch_PdbPageSize,                   "%u", KB(4));
@@ -1491,9 +1490,8 @@ lnk_build_link_context(TP_Context *tp, TP_Arena *tp_arena, LNK_Config *config)
             if (obj_node_arr.v[obj_idx].data.header.machine != COFF_MachineType_Unknown) {
               config->machine = obj_node_arr.v[obj_idx].data.header.machine;
 
-              if (config->do_function_pad_min == LNK_SwitchState_Yes && config->function_pad_min == 0) {
+              if (config->infer_function_pad_min) {
-                config->function_pad_min = push_array(tp_arena->v[0], U64, 1);
+                config->function_pad_min = lnk_get_default_function_pad_min(config->machine);
-                *config->function_pad_min = lnk_get_default_function_pad_min(config->machine);
               }
 
               break;
@@ -2350,13 +2348,15 @@ THREAD_POOL_TASK_FUNC(lnk_gather_section_contribs_task)
   for (U64 sect_idx = 0; sect_idx < obj->header.section_count_no_null; sect_idx += 1) {
     LNK_SectionContrib *sc          = &g_null_sc;
     COFF_SectionHeader *sect_header = &section_table[sect_idx];
-    if (~sect_header->flags & COFF_SectionFlag_LnkRemove) {
+    if (~sect_header->flags & COFF_SectionFlag_LnkRemove && sect_header->fsize > 0) {
+      LNK_SectionContribChunk *sc_chunk = 0;
+      {
         Temp temp = temp_begin(scratch.arena);
-
         String8 sect_name            = coff_name_from_section_header(string_table, sect_header);
         String8 sect_name_with_flags = lnk_make_name_with_flags(temp.arena, sect_name, sect_header->flags & ~COFF_SectionFlags_LnkFlags);
-      LNK_SectionContribChunk *sc_chunk             = 0;
         hash_table_search_string_raw(task->contribs_ht, sect_name_with_flags, &sc_chunk);
+        temp_end(temp);
+      }
 
       if (sc_chunk) {
         U16 sc_align = coff_align_size_from_section_flags(sect_header->flags);
@@ -2368,8 +2368,6 @@ THREAD_POOL_TASK_FUNC(lnk_gather_section_contribs_task)
         sc->u.obj_idx              = obj_idx;
         sc->u.obj_sect_idx         = sect_idx;
       }
-
-      temp_end(temp);
     }
     task->sect_map[obj_idx][sect_idx] = sc;
   }
@@ -2402,6 +2400,43 @@ THREAD_POOL_TASK_FUNC(lnk_set_comdat_leaders_task)
   ProfEnd();
 }
 
+internal
+THREAD_POOL_TASK_FUNC(lnk_patch_comdats_task)
+{
+  LNK_BuildImageTask *task    = raw_task;
+  U64                 obj_idx = task_id;
+  LNK_Obj            *obj     = task->objs[obj_idx];
+
+  ProfBeginV("Patch COMDATs [%S]", obj->path);
+  COFF_ParsedSymbol symbol;
+  for (U64 symbol_idx = 0; symbol_idx < obj->header.symbol_count; symbol_idx += (1 + symbol.aux_symbol_count)) {
+    symbol = lnk_parsed_symbol_from_coff_symbol_idx(obj, symbol_idx);
+    COFF_SymbolValueInterpType interp = coff_interp_symbol(symbol.section_number, symbol.value, symbol.storage_class);
+    if (interp == COFF_SymbolValueInterp_Regular && symbol.storage_class == COFF_SymStorageClass_External && symbol.value == 0) {
+      COFF_SectionHeader *sect_header = lnk_coff_section_header_from_section_number(obj, symbol.section_number);
+      if (sect_header->flags & COFF_SectionFlag_LnkCOMDAT) {
+        LNK_Symbol *defn = lnk_symbol_table_search(task->symtab, LNK_SymbolScope_Defined, symbol.name);
+
+        if (defn->u.defined.obj == obj && defn->u.defined.symbol_idx == symbol_idx) {
+          LNK_SectionContrib *sc = task->sect_map[obj_idx][symbol.section_number-1];
+          if (obj->header.is_big_obj) {
+            COFF_Symbol32 *symbol32 = symbol.raw_symbol;
+            symbol32->section_number = sc->u.sect_idx+1;
+            symbol32->value = safe_cast_u32(sc->u.off + symbol.value);
+          } else {
+            COFF_Symbol16 *symbol16 = symbol.raw_symbol;
+            symbol16->section_number = safe_cast_u16(sc->u.sect_idx+1);
+            symbol16->value = safe_cast_u32(sc->u.off + symbol.value);
+          }
+
+          task->u.patch_symtabs.was_symbol_patched[obj_idx][symbol_idx] = 1;
+        }
+      }
+    }
+  }
+  ProfEnd();
+}
+
 internal
 THREAD_POOL_TASK_FUNC(lnk_split_func_contribs_task)
 {
@@ -2414,6 +2449,7 @@ THREAD_POOL_TASK_FUNC(lnk_split_func_contribs_task)
 
   ProfBeginV("%S", obj->path);
 
+  U64List func_list = {0};
   COFF_ParsedSymbol symbol;
   for (U64 symbol_idx = 0; symbol_idx < obj->header.symbol_count; symbol_idx += (1 + symbol.aux_symbol_count)) {
     symbol = lnk_parsed_symbol_from_coff_symbol_idx(obj, symbol_idx);
@@ -2471,24 +2507,22 @@ THREAD_POOL_TASK_FUNC(lnk_split_func_contribs_task)
           }
         }
       }
+
+      u64_list_push(scratch.arena, &func_list, symbol_idx);
     }
   }
 
+  U64      *sect_offset_map_counts = push_array(scratch.arena, U64, obj->header.section_count_no_null);
+  PairU64 **sect_offset_map        = push_array(scratch.arena, PairU64 *, obj->header.section_count_no_null);
   for (U64 sect_idx = 0; sect_idx < obj->header.section_count_no_null; sect_idx += 1) {
-    COFF_SectionHeader *section_header = lnk_coff_section_header_from_section_number(obj, sect_idx+1);
-    if (~section_header->flags & COFF_SectionFlag_CntCode) { continue; }
-    COFF_RelocInfo      reloc_info     = coff_reloc_info_from_section_header(obj->data, section_header);
-    COFF_Reloc         *relocs         = (COFF_Reloc *)(obj->data.str + reloc_info.array_off);
     LNK_SectionContrib *sc = task->sect_map[obj_idx][sect_idx];
 
     U64 offset_map_count = 0;
     for (String8Node *data_n = &sc->first_data_node; data_n != 0; data_n = data_n->next) {
       offset_map_count += 1;
     }
-    if (offset_map_count <= 1) { continue; }
 
-    Temp temp = temp_begin(scratch.arena);
+    PairU64 *offset_map         = push_array(scratch.arena, PairU64, offset_map_count);
-    PairU64 *offset_map         = push_array(temp.arena, PairU64, offset_map_count);
     U64      data_node_idx      = 0;
     U64      prev_cursor_offset = 0;
     U64      new_cursor_offset  = 0;
@@ -2499,6 +2533,19 @@ THREAD_POOL_TASK_FUNC(lnk_split_func_contribs_task)
       new_cursor_offset += Max(task->function_pad_min, data_n->string.size);
     }
 
+    sect_offset_map_counts[sect_idx] = offset_map_count;
+    sect_offset_map[sect_idx]        = offset_map;
+  }
+
+  for (U64 sect_idx = 0; sect_idx < obj->header.section_count_no_null; sect_idx += 1) {
+    COFF_SectionHeader *section_header = lnk_coff_section_header_from_section_number(obj, sect_idx+1);
+    if (section_header->flags & COFF_SectionFlag_CntCode) {
+      COFF_RelocInfo      reloc_info       = coff_reloc_info_from_section_header(obj->data, section_header);
+      COFF_Reloc         *relocs           = (COFF_Reloc *)(obj->data.str + reloc_info.array_off);
+      LNK_SectionContrib *sc               = task->sect_map[obj_idx][sect_idx];
+      U64                 offset_map_count = sect_offset_map_counts[sect_idx];
+      PairU64            *offset_map       = sect_offset_map[sect_idx];
+      if (offset_map_count > 0) {
         for (U64 reloc_idx = 0; reloc_idx < reloc_info.count; reloc_idx += 1) {
           COFF_Reloc *reloc = &relocs[reloc_idx];
           U64 offset_idx = pair_u64_nearest_v0(offset_map, offset_map_count, reloc->apply_off);
@@ -2508,10 +2555,21 @@ THREAD_POOL_TASK_FUNC(lnk_split_func_contribs_task)
             InvalidPath;
           }
         }
-    temp_end(temp);
+      }
+    }
   }
 
-  // TODO: update symbols with new offsets
+  for (U64Node *func_n = func_list.first; func_n != 0; func_n = func_n->next) {
+    COFF_ParsedSymbol symbol = lnk_parsed_symbol_from_coff_symbol_idx(obj, func_n->data);
+
+    U64      offset_map_count = sect_offset_map_counts[symbol.section_number-1];
+    PairU64 *offset_map       = sect_offset_map[symbol.section_number-1];
+    U64      offset_idx       = pair_u64_nearest_v0(offset_map, offset_map_count, symbol.value);
+    AssertAlways(offset_idx < offset_map_count);
+
+    U32 *value_ptr = obj->header.is_big_obj ? &((COFF_Symbol32 *)symbol.raw_symbol)->value : &((COFF_Symbol16 *)symbol.raw_symbol)->value;
+    *value_ptr = offset_map[offset_idx].v1 + (*value_ptr - offset_map[offset_idx].v0);
+  }
 
   ProfEnd();
 
@@ -2608,16 +2666,18 @@ THREAD_POOL_TASK_FUNC(lnk_patch_regular_symbols_task)
 
     COFF_SymbolValueInterpType interp = coff_interp_symbol(symbol.section_number, symbol.value, symbol.storage_class);
     if (interp == COFF_SymbolValueInterp_Regular) {
-      U32 section_number = 0;
-      U32 value = 0;
-      {
       COFF_SectionHeader *sect_header = lnk_coff_section_header_from_section_number(obj, symbol.section_number);
-        if (~sect_header->flags & COFF_SectionFlag_LnkRemove) {
+
       LNK_SectionContrib *sc = task->sect_map[obj_idx][symbol.section_number-1];
+      U16 section_number;
+      U32 value;
+      if (sc == &g_null_sc) {
+        section_number = LNK_REMOVED_SECTION_NUMBER;
+        value          = max_U32;
+      } else {
         section_number = safe_cast_u32(sc->u.sect_idx + 1);
         value          = sc->u.off + symbol.value;
       }
-      }
 
       if (obj->header.is_big_obj) {
         COFF_Symbol32 *symbol32  = symbol.raw_symbol;
@@ -3013,15 +3073,17 @@ THREAD_POOL_TASK_FUNC(lnk_obj_reloc_patcher)
       U32 symbol_secoff = 0;
       S64 symbol_voff   = 0;
       {
-        COFF_ParsedSymbol symbol;
+        COFF_ParsedSymbol          symbol = lnk_parsed_symbol_from_coff_symbol_idx(obj, reloc->isymbol);
-        if (obj_header.is_big_obj) {
-          symbol = coff_parse_symbol32(string_table, (COFF_Symbol32 *)symbol_table.str + reloc->isymbol);
-        } else {
-          symbol = coff_parse_symbol16(string_table, (COFF_Symbol16 *)symbol_table.str + reloc->isymbol);
-        }
-
         COFF_SymbolValueInterpType interp = coff_interp_symbol(symbol.section_number, symbol.value, symbol.storage_class);
         if (interp == COFF_SymbolValueInterp_Regular) {
+          if (symbol.section_number == LNK_REMOVED_SECTION_NUMBER) {
+            if (!lnk_is_coff_section_debug(obj, sect_idx)) {
+              String8 sect_name = coff_name_from_section_header(string_table, &section_table[sect_idx]);
+              lnk_error_obj(LNK_Error_RelocationAgainstRemovedSection, obj, "relocating against symbol that is in a removed section (symbol: %S, reloc-section: %S 0x%llx, reloc: 0x%llx)", symbol.name, sect_name, sect_idx+1, reloc_idx);
+            }
+            continue;
+          }
+
           symbol_secnum = symbol.section_number;
           symbol_secoff = symbol.value;
           symbol_voff   = safe_cast_u32((U64)task->image_section_table[symbol.section_number]->voff + (U64)symbol_secoff);
@@ -4007,7 +4069,7 @@ lnk_build_image(TP_Arena *arena, TP_Context *tp, LNK_Config *config, LNK_SymbolT
   LNK_BuildImageTask task = {0};
   task.symtab           = symtab;
   task.sectab           = sectab;
-  task.function_pad_min = *config->function_pad_min;
+  task.function_pad_min = config->function_pad_min;
   task.default_align    = coff_default_align_from_machine(config->machine);
   task.objs_count       = objs_count;
   task.objs             = objs;
@@ -4153,10 +4215,6 @@ lnk_build_image(TP_Arena *arena, TP_Context *tp, LNK_Config *config, LNK_SymbolT
       ProfEnd();
     }
 
-    ProfBegin("Set COMDAT Leaders");
-    tp_for_parallel(tp, 0, objs_count, lnk_set_comdat_leaders_task, &task);
-    ProfEnd();
-
     // build common block
     //
     // TODO: build common block in .bss and merge with .data
@@ -4213,7 +4271,7 @@ lnk_build_image(TP_Arena *arena, TP_Context *tp, LNK_Config *config, LNK_SymbolT
         radsort(common_block_contribs, common_block_contribs_count, lnk_common_block_contrib_is_before);
 
         // compute .bss virtual size - this marks start of the common block
-        lnk_finalize_section_layout(common_block_sect, config->file_align, *config->function_pad_min);
+        lnk_finalize_section_layout(common_block_sect, config->file_align, config->function_pad_min);
         U64 common_block_cursor = common_block_sect->vsize;
 
         // compute and assign offsets into the common block
@@ -4253,7 +4311,7 @@ lnk_build_image(TP_Arena *arena, TP_Context *tp, LNK_Config *config, LNK_SymbolT
 
       // assign contribs offsets, sizes, and section indices
       for (LNK_SectionNode *sect_n = sectab->list.first; sect_n != 0; sect_n = sect_n->next) {
-        lnk_finalize_section_layout(&sect_n->data, config->file_align, *config->function_pad_min);
+        lnk_finalize_section_layout(&sect_n->data, config->file_align, config->function_pad_min);
       }
 
       // remove empty sections
@@ -4278,15 +4336,14 @@ lnk_build_image(TP_Arena *arena, TP_Context *tp, LNK_Config *config, LNK_SymbolT
       // assing layout offsets and sizes to merged sections
       for (LNK_SectionNode *sect_n = sectab->merge_list.first; sect_n != 0; sect_n = sect_n->next) {
         LNK_Section        *sect         = &sect_n->data;
-        LNK_Section *final_sect = sect->merge_dst;
         LNK_SectionContrib *first_sc     = lnk_get_first_section_contrib(sect);
         LNK_SectionContrib *last_sc      = lnk_get_last_section_contrib(sect);
         U64                 last_sc_size = lnk_size_from_section_contrib(last_sc);
-        sect->voff     = final_sect->voff + first_sc->u.off;
+        sect->voff  = sect->merge_dst->voff + first_sc->u.off;
         sect->vsize = (last_sc->u.off - first_sc->u.off) + last_sc_size;
-        sect->foff     = final_sect->foff + first_sc->u.off;
+        sect->foff  = sect->merge_dst->foff + first_sc->u.off;
         sect->fsize = (last_sc->u.off - first_sc->u.off) + last_sc_size;
-        sect->sect_idx = final_sect->sect_idx;
+        lnk_assign_section_index(sect, sect->merge_dst->sect_idx);
       }
 
       ProfEnd();
@@ -4309,6 +4366,14 @@ lnk_build_image(TP_Arena *arena, TP_Context *tp, LNK_Config *config, LNK_SymbolT
       task.u.patch_symtabs.common_block_contribs = common_block_contribs;
       ProfEnd();
 
+      ProfBegin("Set COMDAT Leaders");
+      tp_for_parallel(tp, 0, objs_count, lnk_set_comdat_leaders_task, &task);
+      ProfEnd();
+
+      ProfBegin("Patch COMDAT Leaders");
+      tp_for_parallel(tp, 0, objs_count, lnk_patch_comdats_task, &task);
+      ProfEnd();
+
       ProfBegin("Patch Common Block Leaders");
       tp_for_parallel(tp, 0, tp->worker_count, lnk_patch_common_block_leaders_task, &task);
       ProfEnd();
@@ -4372,7 +4437,7 @@ lnk_build_image(TP_Arena *arena, TP_Context *tp, LNK_Config *config, LNK_SymbolT
         sc->align           = 1;
         sc->u.obj_idx       = max_U32;
 
-        lnk_finalize_section_layout(reloc, config->file_align, *config->function_pad_min);
+        lnk_finalize_section_layout(reloc, config->file_align, config->function_pad_min);
         lnk_assign_section_virtual_space(reloc, config->sect_align, &voff_cursor);
         lnk_assign_section_index(reloc, sectab->next_sect_idx++);
 
@@ -4404,7 +4469,7 @@ lnk_build_image(TP_Arena *arena, TP_Context *tp, LNK_Config *config, LNK_SymbolT
     image_header_sc->first_data_node = *image_header_data.first;
     image_header_sc->last_data_node  = image_header_data.last;
 
-    lnk_finalize_section_layout(image_header_sect, config->file_align, *config->function_pad_min);
+    lnk_finalize_section_layout(image_header_sect, config->file_align, config->function_pad_min);
   }
 
   ProfBegin("Patch Section Symbols");

src/linker/lnk.h

@@ -16,6 +16,8 @@ typedef struct LNK_LinkContext
 
 // -- Image --------------------------------------------------------------------
 
+#define LNK_REMOVED_SECTION_NUMBER (U16)-3
+
 typedef struct LNK_ImageContext
 {
   String8           image_data;

src/linker/lnk_config.c

@@ -1203,9 +1203,9 @@ lnk_apply_cmd_option_to_config(Arena *arena, LNK_Config *config, String8 cmd_nam
   case LNK_CmdSwitch_FunctionPadMin: {
     if (value_strings.node_count == 0) {
       config->function_pad_min       = 0;
+      config->infer_function_pad_min = 1;
     } else {
-      config->function_pad_min = push_array(arena, U64, 1);
+      lnk_cmd_switch_parse_u64(obj_path, lib_path, cmd_switch, value_strings, &config->function_pad_min, LNK_ParseU64Flag_CheckUnder32bit);
-      lnk_cmd_switch_parse_u64(obj_path, lib_path, cmd_switch, value_strings, config->function_pad_min, LNK_ParseU64Flag_CheckUnder32bit);
     }
     config->do_function_pad_min = LNK_SwitchState_Yes;
   } break;

src/linker/lnk_config.h

@@ -325,7 +325,8 @@ typedef struct LNK_Config
   U64                         max_worker_count;
   String8                     shared_thread_pool_name;
   LNK_SwitchState             do_function_pad_min;
-  U64                        *function_pad_min;
+  B32                         infer_function_pad_min;
+  U64                         function_pad_min;
   U64                        *manifest_resource_id;
   B32                         no_default_libs;
   Version                     link_ver;

src/linker/lnk_error.h

@@ -40,6 +40,7 @@ typedef enum
   LNK_Error_UnresolvedSymbol,
   LNK_Error_AssociativeLoop,
   LNK_Error_AlternateNameConflict,
+  LNK_Error_RelocationAgainstRemovedSection,
   LNK_Error_StopLast,
   
   LNK_Error_First,

src/linker/lnk_obj.c

@@ -299,6 +299,10 @@ THREAD_POOL_TASK_FUNC(lnk_input_coff_symbol_table)
     switch (interp) {
     case COFF_SymbolValueInterp_Regular: {
       if (symbol.storage_class == COFF_SymStorageClass_External) {
+        COFF_SectionHeader *sect_header = lnk_coff_section_header_from_section_number(obj, symbol.section_number);
+        if (sect_header->flags & COFF_SectionFlag_LnkRemove) {
+          break;
+        }
         LNK_Symbol *defn = lnk_make_defined_symbol(arena, symbol.name, obj, symbol_idx);
         U64         hash = lnk_symbol_hash(symbol.name);
         lnk_symbol_table_push_(task->symtab, arena, worker_id, LNK_SymbolScope_Defined, hash, defn);

src/linker/lnk_section_table.c

@@ -347,7 +347,7 @@ lnk_finalize_section_layout(LNK_Section *sect, U64 file_align, U64 function_pad_
     for (U64 sc_idx = 0; sc_idx < sc_chunk->count; sc_idx += 1) {
       LNK_SectionContrib *sc = sc_chunk->v[sc_idx];
 
-      // assign offset and size
+      // assign offset
       cursor = AlignPow2(cursor, sc->align);
       sc->u.off = cursor;
 

src/torture/torture.c

@@ -3352,6 +3352,48 @@ exit:;
   return result;
 }
 
+internal T_Result
+t_function_pad_min(void)
+{
+  Temp scratch = scratch_begin(0,0);
+  T_Result result = T_Result_Fail;
+
+  {
+    COFF_ObjWriter *obj_writer = coff_obj_writer_alloc(0, COFF_MachineType_X64);
+    U8 ret[] = { 0xc3, 0xc3, 0xc3 };
+    COFF_ObjSection *text_sect = t_push_text_section(obj_writer, str8_array_fixed(ret));
+    coff_obj_writer_push_symbol_extern_func(obj_writer, str8_lit("A"), 0, text_sect);
+    coff_obj_writer_push_symbol_extern_func(obj_writer, str8_lit("B"), 1, text_sect);
+    coff_obj_writer_push_symbol_extern_func(obj_writer, str8_lit("C"), 2, text_sect);
+    String8 obj = coff_obj_writer_serialize(scratch.arena, obj_writer);
+    coff_obj_writer_release(&obj_writer);
+    if (!t_write_file(str8_lit("funcs.obj"), obj)) { goto exit; }
+  }
+
+  int linker_exit_code = t_invoke_linkerf("/subsystem:console /entry:A /functionpadmin:8 /out:a.exe funcs.obj");
+  if (linker_exit_code != 0) { goto exit; }
+
+  String8             exe           = t_read_file(scratch.arena, str8_lit("a.exe"));
+  PE_BinInfo          pe            = pe_bin_info_from_data(scratch.arena, exe);
+  COFF_SectionHeader *section_table = (COFF_SectionHeader *)str8_substr(exe, pe.section_table_range).str;
+  String8             string_table  = str8_substr(exe, pe.string_table_range);
+  COFF_SectionHeader *text_sect     = t_coff_section_header_from_name(string_table, section_table, pe.section_count, str8_lit(".text"));
+  if (text_sect == 0) { goto exit; }
+  String8             text_data     = str8_substr(exe, rng_1u64(text_sect->foff, text_sect->foff + text_sect->vsize));
+
+  U8 expected_text[] = {
+    0xc3, 0xcc, 0xcc, 0xcc, 0xcc, 0xcc, 0xcc, 0xcc,
+    0xc3, 0xcc, 0xcc, 0xcc, 0xcc, 0xcc, 0xcc, 0xcc,
+    0xc3, 0xcc, 0xcc, 0xcc, 0xcc, 0xcc, 0xcc, 0xcc
+  };
+  if (!str8_match(text_data, str8_array_fixed(expected_text), 0)) { goto exit; }
+
+  result = T_Result_Pass;
+exit:;
+  scratch_end(scratch);
+  return result;
+}
+
 ////////////////////////////////////////////////////////////////
 
 internal void
@@ -3405,6 +3447,7 @@ entry_point(CmdLine *cmdline)
     { "delay_import_user32",              t_delay_import_user32              },
     { "empty_section",                    t_empty_section                    },
     { "removed_section",                  t_removed_section                  },
+    { "function_pad_min",                 t_function_pad_min                 },
     //{ "import_export",        t_import_export        },
   };