MantisBT - CMake
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IDProjectCategoryView StatusDate SubmittedLast Update
0015807CMake(No Category)public2015-10-22 08:452016-03-07 09:12
Reportermaarten 
Assigned To 
PrioritynormalSeverityminorReproducibilityalways
StatusclosedResolutionno change required 
PlatformLinuxOSFedora LinuxOS Version22
Product VersionCMake 3.3.2 
Target VersionFixed in Version 
Summary0015807: Regex does not match last parenthesis if parenthesis is part of character set.
DescriptionThe aim is to extract the content between two parentheses.

Example:
from the string "FUNCTION(ARG1, ARG2, ARG3) //COMMENT",
I want to extract "ARG1, ARG2, ARG3".

The normal behavior of CMake is to return all the matched characters.
In the case of a paranthesis as matched character, it does not return the closing parenthesis.

For reference, I have added the expected behavior by replacing all parentheses with underscores.
Steps To Reproducecmake_minimum_required(VERSION 3.3)

#Do the match with parentheses
string(REGEX MATCH "FUNCTION\(([^\)]+)\)" ARGUMENT "FUNCTION(ARG1, ARG2, ARG3) //COMMENT")
message(STATUS "Result of regex match with parentheses: ${ARGUMENT}")

#Redo the match with the parentheses replaced with underscores
string(REGEX MATCH "FUNCTION_([^_]+)_" ARGUMENT "FUNCTION_ARG1, ARG2, ARG3_ //COMMENT")

message(STATUS "Result of regex match with underscores: ${ARGUMENT}")
Additional InformationOutput of the CMakeLists.txt:
-- The C compiler identification is GNU 5.1.1
-- The CXX compiler identification is GNU 5.1.1
-- Check for working C compiler: /usr/lib64/ccache/cc
-- Check for working C compiler: /usr/lib64/ccache/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/lib64/ccache/c++
-- Check for working CXX compiler: /usr/lib64/ccache/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Result of regex match with parentheses: FUNCTION(ARG1, ARG2, ARG3
-- Result of regex match with underscores: FUNCTION_ARG1, ARG2, ARG3_
-- Configuring done
-- Generating done
-- Build files have been written to: /tmp

The result of the regex match with parentheses should be
FUNCTION(ARG1, ARG2, ARG3)
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Issue History
Date ModifiedUsernameFieldChange
2015-10-22 08:45maartenNew Issue
2015-10-22 09:17maartenNote Added: 0039670
2015-10-22 09:19Brad KingNote Added: 0039671
2015-10-22 09:19Brad KingStatusnew => resolved
2015-10-22 09:19Brad KingResolutionopen => no change required
2016-03-07 09:12Robert MaynardNote Added: 0040625
2016-03-07 09:12Robert MaynardStatusresolved => closed

Notes
(0039670)
maarten   
2015-10-22 09:17   
I could get it working by double escaping the backslash.
Why is this?

cmake_minimum_required(VERSION 3.3)

#Do the match with parentheses
string(REGEX MATCH "FUNCTION\\(([^\\)]+)\\)" ARGUMENT "FUNCTION(ARG1, ARG2, ARG3) //COMMENT")
message(STATUS "Result of regex match with parenthesis: ${ARGUMENT}")

#Redo the match with the parentheses replaced with underscores
string(REGEX MATCH "FUNCTION_([^_]+)_" ARGUMENT "FUNCTION_ARG1, ARG2, ARG3_ //COMMENT")

message(STATUS "Result of regex match with underscores: ${ARGUMENT}")
(0039671)
Brad King   
2015-10-22 09:19   
You need another layer of backslashes to get through the CMake quoted argument syntax:

 string(REGEX MATCH "FUNCTION\\(([^)]+)\\)" ARGUMENT "FUNCTION(ARG1, ARG2, ARG3) //COMMENT")

Or you can use a bracket argument in CMake 3.0 and above:

 string(REGEX MATCH [[FUNCTION\(([^)]+)\)]] ARGUMENT "FUNCTION(ARG1, ARG2, ARG3) //COMMENT")
(0040625)
Robert Maynard   
2016-03-07 09:12   
Closing resolved issues that have not been updated in more than 4 months.