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Diffstat (limited to 'math/plplot/files/patch-git_db396b')
| -rw-r--r-- | math/plplot/files/patch-git_db396b | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/math/plplot/files/patch-git_db396b b/math/plplot/files/patch-git_db396b new file mode 100644 index 00000000000..231130d68bd --- /dev/null +++ b/math/plplot/files/patch-git_db396b @@ -0,0 +1,119 @@ +From db396b9fbdc9cd54fb8545ea655185ca73a2a07e Mon Sep 17 00:00:00 2001 +From: "Alan W. Irwin" <airwin@users.sourceforge.net> +Date: Sat, 19 Nov 2016 16:04:28 -0800 +Subject: [PATCH] Build system: Fix if argument dereferencing issue that occurs + for CMake-3.7.0 + +My thanks to Tom Schoonjans for reporting this issue. + +CMake-3.1 and beyond implements policy CMP0054. The OLD behaviour of +this policy (which we are forced to adopt because we currently support +CMake-3.0.2, ugh) is that quoted strings in if arguments are +dereferenced if there is a variable of the same name that has been +defined. + +For example in the following if statement + +if(BINDING STREQUAL "c") + +CMake looks for a variable called c that has been defined and uses the +value of that variable (which is really a nasty bug in the older +versions of CMake such as 3.0.2 since it is a huge surprise that that +dereferencing occurs instead of just using the string as is for the +comparison). But we are stuck with that bug (because we support 3.0.2 +which implies the OLD behaviour of CMP0054). + +However, modern versions of CMake such as 3.1.x through 3.7.0 do warn +when this bug shows up. We got no such warning up to 3.6.x, but +evidentally for CMake-3.7.0, the c variable has been set somewhere in +the official CMake code (e.g., in the find modules) so for that versin +we got warnings for the above if statement each time our build system +code executes the function (pkg_config_file) that contains the above +statement, and the result was the above if statement failed when +BINDING derefenced to c, and the pkg-config files that are configured +by that function were screwed up as a result as noticed by Tom +Schoonjans. + +I have worked around the problem by replacing the above logic with + +if("X${BINDING}X" STREQUAL "XcX") + +on the assumption that no CMake variable in our own build system logic +and also the CMake code provided by CMake itself is going to have the name +XcX, but I have also commented the result with "CMP0054" so it will +be easy to find and remove this commit once we no longer have to +support CMake-3.0.2 so that we can use the rational CMP0054 NEW behaviour +which is that quoted strings such as "c" are not dereferenced in "if" +statements! + +Meanwhile, we rely on sharp-eyed users like Tom to tell us whenever +there is a message concerning CMP0054 for any CMake version of 3.1 or +higher since that is a signal that in virtually every case our CMake +logic will go wrong (as in this 4.7.0 case) do to this OLD CMP0054 +behaviour. + +Tested by: Alan W. Irwin <airwin@users.sourceforge.net> on Linux +(Debian Jessie) by comparing pkg-config files we configure in +pkgcfg/*.pc with equivalent good *.pc results that were derived with a +previous version of CMake that did not define the "c" variable that +triggered this bug. In all cases for CMake-3.7.0, the file names and +contents of those files are now identical to the good past results. +Also, because of this fix all CMP0054 warnings now no longer occur +with cmake-3.7.0. +--- + cmake/modules/pkg-config.cmake | 21 +++++++++++++-------- + 1 file changed, 13 insertions(+), 8 deletions(-) + +diff --git a/cmake/modules/pkg-config.cmake b/cmake/modules/pkg-config.cmake +index 6674efa..05a4a53 100644 +--- cmake/modules/pkg-config.cmake ++++ cmake/modules/pkg-config.cmake +@@ -1,6 +1,6 @@ + # cmake/modules/pkg-config.cmake + # +-# Copyright (C) 2006-2015 Alan W. Irwin ++# Copyright (C) 2006-2016 Alan W. Irwin + # + # This file is part of PLplot. + # +@@ -415,25 +415,30 @@ function(pkg_config_file BINDING PC_SHORT_NAME PC_LONG_NAME PC_LIBRARY_NAME PC_C + message(FATAL_ERROR "pkg_config_file called with wrong number of arguments") + endif(ARGC EQUAL 7) + +- if(BINDING STREQUAL "c") ++ # N.B. all the tests on "X${BINDING}X" below rather than BINDING ++ # are to beat a potential dereferencing problem for strings in if statements. ++ # This problem only occurs with old CMake versions that don't ++ # have CMP0054 set to NEW. ++ ++ if("X${BINDING}X" STREQUAL "XcX") + set(PC_FILE_SUFFIX "") + set(PC_REQUIRES "") +- elseif(BINDING STREQUAL "wxwidgets") ++ elseif("X${BINDING}X" STREQUAL "XwxwidgetsX") + set(PC_FILE_SUFFIX "-${BINDING}") + set(PC_REQUIRES "plplot-c++") +- else(BINDING STREQUAL "c") ++ else("X${BINDING}X" STREQUAL "XcX") + set(PC_FILE_SUFFIX "-${BINDING}") + set(PC_REQUIRES "plplot") +- endif(BINDING STREQUAL "c") ++ endif("X${BINDING}X" STREQUAL "XcX") + + if(NON_TRANSITIVE) +- if(BINDING STREQUAL "ocaml") ++ if("X${BINDING}X" STREQUAL "XocamlX") + # Don't know how to do non-transitive linking for + # Ocaml binding of PLplot. + set(PC_REQUIRES_TAG "Requires") +- else(BINDING STREQUAL "ocaml") ++ else("X${BINDING}X" STREQUAL "XocamlX") + set(PC_REQUIRES_TAG "Requires.private") +- endif(BINDING STREQUAL "ocaml") ++ endif("X${BINDING}X" STREQUAL "XocamlX") + else(NON_TRANSITIVE) + set(PC_REQUIRES_TAG "Requires") + endif(NON_TRANSITIVE) +-- +2.10.1 + |