[flang][CMake] CYGWIN: Fix undefined references at link time. (llvm#67105)

carlo-bramini · mahesh-attarde · commit a5df1f115932 · 2025-07-28T04:22:24.000-07:00
While building the source of flang on CYGWIN, the process suddenly
stopped with lot of "Undefined reference" errors at link time.
According to the statement that a shared library can't have undefined
references on Windows, I applied the same fix to CYGWIN with this patch.
diff --git a/flang/test/CMakeLists.txt b/flang/test/CMakeLists.txt
@@ -65,6 +65,7 @@ set(FLANG_TEST_DEPENDS
   bbc
   FortranDecimal
 )
+
 if (NOT FLANG_STANDALONE_BUILD)
   list(APPEND FLANG_TEST_DEPENDS
     llvm-config
@@ -79,7 +80,7 @@ if (NOT FLANG_STANDALONE_BUILD)
   )
 endif ()
 
-if (LLVM_BUILD_EXAMPLES AND LLVM_ENABLE_PLUGINS AND NOT WIN32 AND NOT FLANG_STANDALONE_BUILD)
+if (LLVM_BUILD_EXAMPLES AND LLVM_ENABLE_PLUGINS AND NOT (WIN32 OR CYGWIN) AND NOT FLANG_STANDALONE_BUILD)
   list(APPEND FLANG_TEST_DEPENDS Bye)
 endif()
 

Original file line number	Diff line number	Diff line change
`@@ -65,6 +65,7 @@ set(FLANG_TEST_DEPENDS`
`65`	`65`	`bbc`
`66`	`66`	`FortranDecimal`
`67`	`67`	`)`
	`68`	`+`
`68`	`69`	`if (NOT FLANG_STANDALONE_BUILD)`
`69`	`70`	`list(APPEND FLANG_TEST_DEPENDS`
`70`	`71`	`llvm-config`
`@@ -79,7 +80,7 @@ if (NOT FLANG_STANDALONE_BUILD)`
`79`	`80`	`)`
`80`	`81`	`endif ()`
`81`	`82`
`82`		`-if (LLVM_BUILD_EXAMPLES AND LLVM_ENABLE_PLUGINS AND NOT WIN32 AND NOT FLANG_STANDALONE_BUILD)`
	`83`	`+if (LLVM_BUILD_EXAMPLES AND LLVM_ENABLE_PLUGINS AND NOT (WIN32 OR CYGWIN) AND NOT FLANG_STANDALONE_BUILD)`
`83`	`84`	`list(APPEND FLANG_TEST_DEPENDS Bye)`
`84`	`85`	`endif()`
`85`	`86`