refactor: mingw config

.gnfiles/build/toolchain/common/BUILD.gn

@@ -119,6 +119,11 @@ config("allow_undefined") {
       "dynamic_lookup",
     ]
   }
+  # Although MinGW linker (ld) does actually silently accept the
+  # --allow-shlib-undefined option, but it can't do anything on PE targets.
+  # On Windows platform we have to allow undefined symbols in another way.
+  # (e.g. change ten_runtime_go to static library)
+  # Ref: https://github.com/llvm/llvm-project/issues/55245
 }
 
 config("disallow_undefined") {

.gnfiles/build/toolchain/mingw/BUILD.gn

@@ -45,16 +45,16 @@ config("debug") {
   defines = [ "_DEBUG" ]
   cflags = [ "-g" ]
   cflags_cc = []
-  ldflags = [
-    # Note: Do NOT use -static here, as it prevents linking with .dll.a import libraries
-    # (ten_runtime and ten_utils)
-    # Instead, use -Wl,-Bstatic/-Bdynamic to selectively static link libraries
-    "-Wl,-Bstatic",
-    "-lgcc",             # Static link libgcc (avoids libgcc_s_seh-1.dll)
-    "-lstdc++",          # Static link libstdc++ (avoids libstdc++-6.dll)
-    "-lpthread",         # Static link pthread (avoids libwinpthread-1.dll)
-    "-Wl,-Bdynamic",     # Switch back to dynamic linking for other libraries
-  ]
+
+  # Note: Static linking of libgcc/libstdc++/pthread is handled in mingw.gni
+  # at the END of the link command (in rspfile_content) but not here. Because
+  # GNU ld is a single-pass linker and libraries must appear AFTER object files
+  # that reference them.
+  # Ref: https://sourceware.org/binutils/docs/ld/Options.html
+  # "...an undefined symbol in an object appearing later on the command line
+  # will not cause the linker to search the archive again."
+  ldflags = []
+
   libs = default_libs
 }
 
@@ -65,17 +65,15 @@ config("release") {
     "-g",  # Keep debug info for backtraces even in release
   ]
   cflags_cc = []
-  ldflags = [
-    "-Wl,-O2",
-    # Note: Do NOT use -static here, as it prevents linking with .dll.a import libraries
-    # (ten_runtime and ten_utils)
-    # Instead, use -Wl,-Bstatic/-Bdynamic to selectively static link libraries
-    "-Wl,-Bstatic",
-    "-lgcc",             # Static link libgcc (avoids libgcc_s_seh-1.dll)
-    "-lstdc++",          # Static link libstdc++ (avoids libstdc++-6.dll)
-    "-lpthread",         # Static link pthread (avoids libwinpthread-1.dll)
-    "-Wl,-Bdynamic",     # Switch back to dynamic linking for other libraries
-  ]
+
+  # Note: Static linking of libgcc/libstdc++/pthread is handled in mingw.gni
+  # at the END of the link command (in rspfile_content) but not here. Because
+  # GNU ld is a single-pass linker and libraries must appear AFTER object files
+  # that reference them.
+  # Ref: https://sourceware.org/binutils/docs/ld/Options.html
+  # "...an undefined symbol in an object appearing later on the command line
+  # will not cause the linker to search the archive again."
+  ldflags = [ "-Wl,-O2" ]
   libs = default_libs
 }
 

.gnfiles/build/toolchain/mingw/mingw.gni

@@ -131,8 +131,17 @@ template("mingw_toolchain") {
       rspfile = sofile + ".rsp"
       pool = "//.gnfiles/build/toolchain:link_pool"
 
+      # Note: Static linking flags (-Wl,-Bstatic -lgcc -lstdc++ -lpthread -Wl,-Bdynamic)
+      # are placed at the END of rspfile_content, after all other libs. Or else dynamic
+      # libs (e.g. simple_http_server_cpp.dll) that depends on libgcc_s_seh-1.dll and
+      # libstdc++-6.dll will not be correctly loaded.
+      # This is critical because GNU ld is a single-pass linker - libraries must
+      # appear AFTER the object files that reference them.
+      # Ref: https://sourceware.org/binutils/docs/ld/Options.html
+      # "...an undefined symbol in an object appearing later on the command line
+      # will not cause the linker to search the archive again."
       command = "cmd /c del /f /q \"$sofile\" \"$implibfile\" 2>nul & $ld -shared {{ldflags}} -Wl,--allow-multiple-definition -o \"$sofile\" -Wl,--out-implib=\"$implibfile\" -Wl,--start-group @\"$rspfile\" -Wl,--end-group"
-      rspfile_content = "-Wl,--whole-archive {{inputs}} {{solibs}} -Wl,--no-whole-archive $solink_libs_section_prefix {{libs}} $solink_libs_section_postfix"
+      rspfile_content = "-Wl,--whole-archive {{inputs}} {{solibs}} -Wl,--no-whole-archive $solink_libs_section_prefix {{libs}} $solink_libs_section_postfix -Wl,-Bstatic -lgcc -lstdc++ -lpthread -Wl,-Bdynamic"
 
       description = "LD  $sofile $implibfile"
       default_output_extension = ".dll"
@@ -158,8 +167,9 @@ template("mingw_toolchain") {
       rspfile = sofile + ".rsp"
       pool = "//.gnfiles/build/toolchain:link_pool"
 
+      # Note: Static linking flags are placed at the END of rspfile_content.
       command = "cmd /c del /f /q \"{{output}}\" 2>nul & $ld -shared {{ldflags}} -Wl,--allow-multiple-definition -o \"{{output}}\" -Wl,--start-group @\"$rspfile\" -Wl,--end-group"
-      rspfile_content = "-Wl,--whole-archive {{inputs}} {{solibs}} -Wl,--no-whole-archive $solink_libs_section_prefix {{libs}} $solink_libs_section_postfix"
+      rspfile_content = "-Wl,--whole-archive {{inputs}} {{solibs}} -Wl,--no-whole-archive $solink_libs_section_prefix {{libs}} $solink_libs_section_postfix -Wl,-Bstatic -lgcc -lstdc++ -lpthread -Wl,-Bdynamic"
 
       description = "LD  {{output}}"
       default_output_extension = ".dll"
@@ -179,8 +189,9 @@ template("mingw_toolchain") {
       default_output_extension = ".exe"
       default_output_dir = "{{root_out_dir}}"
 
+      # Note: Static linking flags are placed at the END of rspfile_content.
       command = "cmd /c del /f /q \"{{output}}\" 2>nul & $ld {{ldflags}} -Wl,--allow-multiple-definition -o \"{{output}}\" -Wl,--start-group @\"$rspfile\" -Wl,--end-group"
-      rspfile_content = "-Wl,--no-whole-archive $inputs_section_prefix {{inputs}} {{solibs}} $libs_section_prefix {{libs}} $libs_section_postfix"
+      rspfile_content = "-Wl,--no-whole-archive $inputs_section_prefix {{inputs}} {{solibs}} $libs_section_prefix {{libs}} $libs_section_postfix -Wl,-Bstatic -lgcc -lstdc++ -lpthread -Wl,-Bdynamic"
 
       description = "LD  {{output}}"
       outputs = [ outfile ]