(0014530)
Brad King (manager)
2009-01-12 08:59

Continuation characters in flags is not a supported use case. If the flags are generated by something else, use string(REGEX REPLACE) to remove them.

(0014596)
Jelle Geerts (reporter)
2009-01-17 08:43

It's not about the continuation characters, but it's about the newline characters. The command in link.txt may not have newline characters because cmake only executes the first line.

Might this be an issue to look into?

(0014597)
Brad King (manager)
2009-01-17 09:02

What is your use case for this? Why does the _link_ command line ever need a newline in it?

(0014598)
Jelle Geerts (reporter)
2009-01-17 09:04

Because having newlines inside the 'set( CMAKE_C_FLAGS' part improves the maintainability of the CMakeLists.txt file.

Example:
set( CMAKE_C_FLAGS "-ansi -Wall -Wextra -Werror -Wshadow -Wpointer-arith -Wcast-align -Wwrite-strings -Wmissing-prototypes -Wmissing-declarations -Wredundant-decls -Wnested-externs -Wstrict-prototypes -Wbad-function-cast -Wformat=2 -pedantic -Wa,--fatal-warnings" )
Versus:
set( CMAKE_C_FLAGS "-ansi -Wall -Wextra -Werror -Wshadow
-Wpointer-arith -Wcast-align -Wwrite-strings -Wmissing-prototypes
-Wmissing-declarations -Wredundant-decls -Wnested-externs
-Wstrict-prototypes -Wbad-function-cast -Wformat=2 -pedantic
-Wa,--fatal-warnings" )

(0014599)
Brad King (manager)
2009-01-17 11:07

I see. Unfortunately the flags were introduced _really_ early in CMake, before we had the convention of semi-colon separated lists. Otherwise you could just write the above code without the quotes. A while back I started working on a COMPILE_OPTIONS feature which is like flags but uses modern CMake conventions. I don't know when I'll get back to it.

Meanwhile, you can use the string(REPLACE) command to remove the newlines:

string(REPLACE "\n" " " CMAKE_C_FLAGS "
-ansi -Wall -Wextra -Werror -Wshadow
-Wpointer-arith -Wcast-align -Wwrite-strings -Wmissing-prototypes
-Wmissing-declarations -Wredundant-decls -Wnested-externs
-Wstrict-prototypes -Wbad-function-cast -Wformat=2 -pedantic
-Wa,--fatal-warnings
")

or create a macro to help you

macro(add_flags var)
  foreach(flag ${ARGN})
    set(${var} "${${var}} ${flag}")
  endforeach(flag)
endmacro(add_flags)

add_flags(CMAKE_C_FLAGS
  -ansi -Wall -Wextra -Werror -Wshadow
  -Wpointer-arith -Wcast-align -Wwrite-strings -Wmissing-prototypes
  -Wmissing-declarations -Wredundant-decls -Wnested-externs
  -Wstrict-prototypes -Wbad-function-cast -Wformat=2 -pedantic
  -Wa,--fatal-warnings
  )

The macro can be more efficient like this:

macro(add_flags var)
  string(REPLACE ";" " " _flags "${ARGN}")
  set(${var} "${${var}} ${_flags}")
endmacro(add_flags)

(0021205)
Göran Uddeborg (reporter)
2010-07-01 07:40

It would certainly be very nice if this could be fixed without extra local code like add_flags. Coming from Make previously, we hit this almost immediately. In our makefiles we always put the values of variables on several lines when there were many of them.

(0024860)
David Cole (manager)
2011-01-18 11:17

Looking at "older" "feedback" status bugs today... is this still an issue that we want to address moving forward? If so, please remove the "feedback" status and just set it to "assigned"... If not, please resolve it.

Thanks.

(0024875)
Brad King (manager)
2011-01-18 11:52

Closing as duplicate of 0006493 because the solution is the same: a future COMPILE_OPTIONS property. Please visit that issue and click the "Monitor" button to get further updates.

Issue History
Date Modified	Username	Field	Change
2009-01-11 07:04	Jelle Geerts	New Issue
2009-01-11 20:29	Bill Hoffman	Status	new => assigned
2009-01-11 20:29	Bill Hoffman	Assigned To	=> Brad King
2009-01-12 08:59	Brad King	Note Added: 0014530
2009-01-12 08:59	Brad King	Status	assigned => closed
2009-01-12 08:59	Brad King	Resolution	open => won't fix
2009-01-17 08:43	Jelle Geerts	Note Added: 0014596
2009-01-17 08:43	Jelle Geerts	Status	closed => feedback
2009-01-17 08:43	Jelle Geerts	Resolution	won't fix => reopened
2009-01-17 09:02	Brad King	Note Added: 0014597
2009-01-17 09:04	Jelle Geerts	Note Added: 0014598
2009-01-17 11:07	Brad King	Note Added: 0014599
2010-07-01 07:40	Göran Uddeborg	Note Added: 0021205
2011-01-18 11:17	David Cole	Note Added: 0024860
2011-01-18 11:51	Brad King	Relationship added	duplicate of 0006493
2011-01-18 11:52	Brad King	Note Added: 0024875
2011-01-18 11:52	Brad King	Status	feedback => closed
2011-01-18 11:52	Brad King	Resolution	reopened => duplicate

Notes
(0014530) Brad King (manager) 2009-01-12 08:59	Continuation characters in flags is not a supported use case. If the flags are generated by something else, use string(REGEX REPLACE) to remove them.

(0014596) Jelle Geerts (reporter) 2009-01-17 08:43	It's not about the continuation characters, but it's about the newline characters. The command in link.txt may not have newline characters because cmake only executes the first line. Might this be an issue to look into?

(0014597) Brad King (manager) 2009-01-17 09:02	What is your use case for this? Why does the _link_ command line ever need a newline in it?

(0014598) Jelle Geerts (reporter) 2009-01-17 09:04	Because having newlines inside the 'set( CMAKE_C_FLAGS' part improves the maintainability of the CMakeLists.txt file. Example: set( CMAKE_C_FLAGS "-ansi -Wall -Wextra -Werror -Wshadow -Wpointer-arith -Wcast-align -Wwrite-strings -Wmissing-prototypes -Wmissing-declarations -Wredundant-decls -Wnested-externs -Wstrict-prototypes -Wbad-function-cast -Wformat=2 -pedantic -Wa,--fatal-warnings" ) Versus: set( CMAKE_C_FLAGS "-ansi -Wall -Wextra -Werror -Wshadow -Wpointer-arith -Wcast-align -Wwrite-strings -Wmissing-prototypes -Wmissing-declarations -Wredundant-decls -Wnested-externs -Wstrict-prototypes -Wbad-function-cast -Wformat=2 -pedantic -Wa,--fatal-warnings" )

(0014599) Brad King (manager) 2009-01-17 11:07	I see. Unfortunately the flags were introduced _really_ early in CMake, before we had the convention of semi-colon separated lists. Otherwise you could just write the above code without the quotes. A while back I started working on a COMPILE_OPTIONS feature which is like flags but uses modern CMake conventions. I don't know when I'll get back to it. Meanwhile, you can use the string(REPLACE) command to remove the newlines: string(REPLACE "\n" " " CMAKE_C_FLAGS " -ansi -Wall -Wextra -Werror -Wshadow -Wpointer-arith -Wcast-align -Wwrite-strings -Wmissing-prototypes -Wmissing-declarations -Wredundant-decls -Wnested-externs -Wstrict-prototypes -Wbad-function-cast -Wformat=2 -pedantic -Wa,--fatal-warnings ") or create a macro to help you macro(add_flags var) foreach(flag ${ARGN}) set(${var} "${${var}} ${flag}") endforeach(flag) endmacro(add_flags) add_flags(CMAKE_C_FLAGS -ansi -Wall -Wextra -Werror -Wshadow -Wpointer-arith -Wcast-align -Wwrite-strings -Wmissing-prototypes -Wmissing-declarations -Wredundant-decls -Wnested-externs -Wstrict-prototypes -Wbad-function-cast -Wformat=2 -pedantic -Wa,--fatal-warnings ) The macro can be more efficient like this: macro(add_flags var) string(REPLACE ";" " " _flags "${ARGN}") set(${var} "${${var}} ${_flags}") endmacro(add_flags)

(0021205) Göran Uddeborg (reporter) 2010-07-01 07:40	It would certainly be very nice if this could be fixed without extra local code like add_flags. Coming from Make previously, we hit this almost immediately. In our makefiles we always put the values of variables on several lines when there were many of them.

(0024860) David Cole (manager) 2011-01-18 11:17	Looking at "older" "feedback" status bugs today... is this still an issue that we want to address moving forward? If so, please remove the "feedback" status and just set it to "assigned"... If not, please resolve it. Thanks.

(0024875) Brad King (manager) 2011-01-18 11:52	Closing as duplicate of 0006493 because the solution is the same: a future COMPILE_OPTIONS property. Please visit that issue and click the "Monitor" button to get further updates.