CMake/Source/cmPolicies.cxx
Brad King b93f0318fe ENH: Support full-path libs w/out valid names.
This change introduces policy CMP0008 to decide how to treat full path
libraries that do not appear to be valid library file names.  Such
libraries worked by accident in the VS IDE and Xcode generators with
CMake 2.4 and below.  We support them in CMake 2.6 by introducing this
policy.  See policy documentation added by this change for details.
2008-07-23 12:59:14 -04:00

674 lines
26 KiB
C++

#include "cmPolicies.h"
#include "cmake.h"
#include "cmMakefile.h"
#include "cmSourceFile.h"
#include "cmVersion.h"
#include <map>
#include <set>
#include <queue>
#include <assert.h>
const char* cmPolicies::PolicyStatusNames[] = {
"OLD", "WARN", "NEW", "REQUIRED_IF_USED", "REQUIRED_ALWAYS"
};
class cmPolicy
{
public:
cmPolicy(cmPolicies::PolicyID iD,
const char *idString,
const char *shortDescription,
const char *longDescription,
unsigned int majorVersionIntroduced,
unsigned int minorVersionIntroduced,
unsigned int patchVersionIntroduced,
cmPolicies::PolicyStatus status)
{
if (!idString || !shortDescription || ! longDescription)
{
cmSystemTools::Error("Attempt to define a policy without "
"all parameters being specified!");
return;
}
this->ID = iD;
this->IDString = idString;
this->ShortDescription = shortDescription;
this->LongDescription = longDescription;
this->MajorVersionIntroduced = majorVersionIntroduced;
this->MinorVersionIntroduced = minorVersionIntroduced;
this->PatchVersionIntroduced = patchVersionIntroduced;
this->Status = status;
}
std::string GetVersionString()
{
cmOStringStream error;
error << this->MajorVersionIntroduced << "." <<
this->MinorVersionIntroduced << "." <<
this->PatchVersionIntroduced;
return error.str();
}
bool IsPolicyNewerThan(unsigned int majorV,
unsigned int minorV,
unsigned int patchV)
{
if (majorV < this->MajorVersionIntroduced)
{
return true;
}
if (majorV > this->MajorVersionIntroduced)
{
return false;
}
if (minorV < this->MinorVersionIntroduced)
{
return true;
}
if (minorV > this->MinorVersionIntroduced)
{
return false;
}
return (patchV < this->PatchVersionIntroduced);
}
cmPolicies::PolicyID ID;
std::string IDString;
std::string ShortDescription;
std::string LongDescription;
unsigned int MajorVersionIntroduced;
unsigned int MinorVersionIntroduced;
unsigned int PatchVersionIntroduced;
cmPolicies::PolicyStatus Status;
};
cmPolicies::cmPolicies()
{
// define all the policies
this->DefinePolicy(
CMP0000, "CMP0000",
"A minimum required CMake version must be specified.",
"CMake requires that projects specify the version of CMake to which "
"they have been written. "
"This policy has been put in place so users trying to build the project "
"may be told when they need to update their CMake. "
"Specifying a version also helps the project build with CMake versions "
"newer than that specified. "
"Use the cmake_minimum_required command at the top of your main "
" CMakeLists.txt file:\n"
" cmake_minimum_required(VERSION <major>.<minor>)\n"
"where \"<major>.<minor>\" is the version of CMake you want to support "
"(such as \"2.6\"). "
"The command will ensure that at least the given version of CMake is "
"running and help newer versions be compatible with the project. "
"See documentation of cmake_minimum_required for details.\n"
"Note that the command invocation must appear in the CMakeLists.txt "
"file itself; a call in an included file is not sufficient. "
"However, the cmake_policy command may be called to set policy "
"CMP0000 to OLD or NEW behavior explicitly. "
"The OLD behavior is to silently ignore the missing invocation. "
"The NEW behavior is to issue an error instead of a warning. "
"An included file may set CMP0000 explicitly to affect how this "
"policy is enforced for the main CMakeLists.txt file.",
2,6,0, cmPolicies::WARN
);
this->DefinePolicy(
CMP0001, "CMP0001",
"CMAKE_BACKWARDS_COMPATIBILITY should no longer be used.",
"The OLD behavior is to check CMAKE_BACKWARDS_COMPATIBILITY and present "
"it to the user. "
"The NEW behavior is to ignore CMAKE_BACKWARDS_COMPATIBILITY "
"completely.\n"
"In CMake 2.4 and below the variable CMAKE_BACKWARDS_COMPATIBILITY was "
"used to request compatibility with earlier versions of CMake. "
"In CMake 2.6 and above all compatibility issues are handled by policies "
"and the cmake_policy command. "
"However, CMake must still check CMAKE_BACKWARDS_COMPATIBILITY for "
"projects written for CMake 2.4 and below.",
2,6,0, cmPolicies::WARN
);
this->DefinePolicy(
CMP0002, "CMP0002",
"Logical target names must be globally unique.",
"Targets names created with "
"add_executable, add_library, or add_custom_target "
"are logical build target names. "
"Logical target names must be globally unique because:\n"
" - Unique names may be referenced unambiguously both in CMake\n"
" code and on make tool command lines.\n"
" - Logical names are used by Xcode and VS IDE generators\n"
" to produce meaningful project names for the targets.\n"
"The logical name of executable and library targets does not "
"have to correspond to the physical file names built. "
"Consider using the OUTPUT_NAME target property to create two "
"targets with the same physical name while keeping logical "
"names distinct. "
"Custom targets must simply have globally unique names (unless one "
"uses the global property ALLOW_DUPLICATE_CUSTOM_TARGETS with a "
"Makefiles generator).",
2,6,0, cmPolicies::WARN
);
this->DefinePolicy(
CMP0003, "CMP0003",
"Libraries linked via full path no longer produce linker search paths.",
"This policy affects how libraries whose full paths are NOT known "
"are found at link time, but was created due to a change in how CMake "
"deals with libraries whose full paths are known. "
"Consider the code\n"
" target_link_libraries(myexe /path/to/libA.so)\n"
"CMake 2.4 and below implemented linking to libraries whose full paths "
"are known by splitting them on the link line into separate components "
"consisting of the linker search path and the library name. "
"The example code might have produced something like\n"
" ... -L/path/to -lA ...\n"
"in order to link to library A. "
"An analysis was performed to order multiple link directories such that "
"the linker would find library A in the desired location, but there "
"are cases in which this does not work. "
"CMake versions 2.6 and above use the more reliable approach of passing "
"the full path to libraries directly to the linker in most cases. "
"The example code now produces something like\n"
" ... /path/to/libA.so ....\n"
"Unfortunately this change can break code like\n"
" target_link_libraries(myexe /path/to/libA.so B)\n"
"where \"B\" is meant to find \"/path/to/libB.so\". "
"This code is wrong because the user is asking the linker to find "
"library B but has not provided a linker search path (which may be "
"added with the link_directories command). "
"However, with the old linking implementation the code would work "
"accidentally because the linker search path added for library A "
"allowed library B to be found."
"\n"
"In order to support projects depending on linker search paths "
"added by linking to libraries with known full paths, the OLD "
"behavior for this policy will add the linker search paths even "
"though they are not needed for their own libraries. "
"When this policy is set to OLD, CMake will produce a link line such as\n"
" ... -L/path/to /path/to/libA.so -lB ...\n"
"which will allow library B to be found as it was previously. "
"When this policy is set to NEW, CMake will produce a link line such as\n"
" ... /path/to/libA.so -lB ...\n"
"which more accurately matches what the project specified."
"\n"
"The setting for this policy used when generating the link line is that "
"in effect when the target is created by an add_executable or "
"add_library command. For the example described above, the code\n"
" cmake_policy(SET CMP0003 OLD) # or cmake_policy(VERSION 2.4)\n"
" add_executable(myexe myexe.c)\n"
" target_link_libraries(myexe /path/to/libA.so B)\n"
"will work and suppress the warning for this policy. "
"It may also be updated to work with the corrected linking approach:\n"
" cmake_policy(SET CMP0003 NEW) # or cmake_policy(VERSION 2.6)\n"
" link_directories(/path/to) # needed to find library B\n"
" add_executable(myexe myexe.c)\n"
" target_link_libraries(myexe /path/to/libA.so B)\n"
"Even better, library B may be specified with a full path:\n"
" add_executable(myexe myexe.c)\n"
" target_link_libraries(myexe /path/to/libA.so /path/to/libB.so)\n"
"When all items on the link line have known paths CMake does not check "
"this policy so it has no effect.\n"
"Note that the warning for this policy will be issued for at most "
"one target. This avoids flooding users with messages for every "
"target when setting the policy once will probably fix all targets.",
2,6,0, cmPolicies::WARN);
this->DefinePolicy(
CMP0004, "CMP0004",
"Libraries linked may not have leading or trailing whitespace.",
"CMake versions 2.4 and below silently removed leading and trailing "
"whitespace from libraries linked with code like\n"
" target_link_libraries(myexe \" A \")\n"
"This could lead to subtle errors in user projects.\n"
"The OLD behavior for this policy is to silently remove leading and "
"trailing whitespace. "
"The NEW behavior for this policy is to diagnose the existence of "
"such whitespace as an error. "
"The setting for this policy used when checking the library names is "
"that in effect when the target is created by an add_executable or "
"add_library command.",
2,6,0, cmPolicies::WARN);
this->DefinePolicy(
CMP0005, "CMP0005",
"Preprocessor definition values are now escaped automatically.",
"This policy determines whether or not CMake should generate escaped "
"preprocessor definition values added via add_definitions. "
"CMake versions 2.4 and below assumed that only trivial values would "
"be given for macros in add_definitions calls. "
"It did not attempt to escape non-trivial values such as string "
"literals in generated build rules. "
"CMake versions 2.6 and above support escaping of most values, but "
"cannot assume the user has not added escapes already in an attempt to "
"work around limitations in earlier versions.\n"
"The OLD behavior for this policy is to place definition values given "
"to add_definitions directly in the generated build rules without "
"attempting to escape anything. "
"The NEW behavior for this policy is to generate correct escapes "
"for all native build tools automatically. "
"See documentation of the COMPILE_DEFINITIONS target property for "
"limitations of the escaping implementation.",
2,6,0, cmPolicies::WARN);
this->DefinePolicy(
CMP0006, "CMP0006",
"Installing MACOSX_BUNDLE targets requires a BUNDLE DESTINATION.",
"This policy determines whether the install(TARGETS) command must be "
"given a BUNDLE DESTINATION when asked to install a target with the "
"MACOSX_BUNDLE property set. "
"CMake 2.4 and below did not distinguish application bundles from "
"normal executables when installing targets. "
"CMake 2.6 provides a BUNDLE option to the install(TARGETS) command "
"that specifies rules specific to application bundles on the Mac. "
"Projects should use this option when installing a target with the "
"MACOSX_BUNDLE property set.\n"
"The OLD behavior for this policy is to fall back to the RUNTIME "
"DESTINATION if a BUNDLE DESTINATION is not given. "
"The NEW behavior for this policy is to produce an error if a bundle "
"target is installed without a BUNDLE DESTINATION.",
2,6,0, cmPolicies::WARN);
this->DefinePolicy(
CMP0007, "CMP0007",
"list command no longer ignores empty elements.",
"This policy determines whether the list command will "
"ignore empty elements in the list. "
"CMake 2.4 and below list commands ignored all empty elements"
" in the list. For example, a;b;;c would have length 3 and not 4. "
"The OLD behavior for this policy is to ignore empty list elements. "
"The NEW behavior for this policy is to correctly count empty "
"elements in a list. ",
2,6,0, cmPolicies::WARN);
this->DefinePolicy(
CMP0008, "CMP0008",
"Libraries linked by full-path must have a valid library file name.",
"In CMake 2.4 and below it is possible to write code like\n"
" target_link_libraries(myexe /full/path/to/somelib)\n"
"where \"somelib\" is supposed to be a valid library file name "
"such as \"libsomelib.a\" or \"somelib.lib\". "
"For Makefile generators this produces an error at build time "
"because the dependency on the full path cannot be found. "
"For VS IDE and Xcode generators this used to work by accident because "
"CMake would always split off the library directory and ask the "
"linker to search for the library by name (-lsomelib or somelib.lib). "
"Despite the failure with Makefiles, some projects have code like this "
"and build only with VS and/or Xcode. "
"This version of CMake prefers to pass the full path directly to the "
"native build tool, which will fail in this case because it does "
"not name a valid library file."
"\n"
"This policy determines what to do with full paths that do not appear "
"to name a valid library file. "
"The OLD behavior for this policy is to split the library name from the "
"path and ask the linker to search for it. "
"The NEW behavior for this policy is to trust the given path and "
"pass it directly to the native build tool unchanged.",
2,6,1, cmPolicies::WARN);
}
cmPolicies::~cmPolicies()
{
// free the policies
std::map<cmPolicies::PolicyID,cmPolicy *>::iterator i
= this->Policies.begin();
for (;i != this->Policies.end(); ++i)
{
delete i->second;
}
}
void cmPolicies::DefinePolicy(cmPolicies::PolicyID iD,
const char *idString,
const char *shortDescription,
const char *longDescription,
unsigned int majorVersionIntroduced,
unsigned int minorVersionIntroduced,
unsigned int patchVersionIntroduced,
cmPolicies::PolicyStatus status)
{
// a policy must be unique and can only be defined once
if (this->Policies.find(iD) != this->Policies.end())
{
cmSystemTools::Error("Attempt to redefine a CMake policy for policy "
"ID ", this->GetPolicyIDString(iD).c_str());
return;
}
this->Policies[iD] = new cmPolicy(iD, idString,
shortDescription,
longDescription,
majorVersionIntroduced,
minorVersionIntroduced,
patchVersionIntroduced,
status);
this->PolicyStringMap[idString] = iD;
}
bool cmPolicies::ApplyPolicyVersion(cmMakefile *mf,
const char *version)
{
std::string ver = "2.4.0";
if (version && strlen(version) > 0)
{
ver = version;
}
unsigned int majorVer = 2;
unsigned int minorVer = 0;
unsigned int patchVer = 0;
// parse the string
if(sscanf(ver.c_str(), "%u.%u.%u",
&majorVer, &minorVer, &patchVer) < 2)
{
cmOStringStream e;
e << "Invalid policy version value \"" << ver << "\". "
<< "A numeric major.minor[.patch] must be given.";
mf->IssueMessage(cmake::FATAL_ERROR, e.str());
return false;
}
// it is an error if the policy version is less than 2.4
if (majorVer < 2 || majorVer == 2 && minorVer < 4)
{
mf->IssueMessage(cmake::FATAL_ERROR,
"An attempt was made to set the policy version of CMake to something "
"earlier than \"2.4\". "
"In CMake 2.4 and below backwards compatibility was handled with the "
"CMAKE_BACKWARDS_COMPATIBILITY variable. "
"In order to get compatibility features supporting versions earlier "
"than 2.4 set policy CMP0001 to OLD to tell CMake to check the "
"CMAKE_BACKWARDS_COMPATIBILITY variable. "
"One way to so this is to set the policy version to 2.4 exactly."
);
return false;
}
// It is an error if the policy version is greater than the running
// CMake.
if (majorVer > cmVersion::GetMajorVersion() ||
(majorVer == cmVersion::GetMajorVersion() &&
minorVer > cmVersion::GetMinorVersion()) ||
(majorVer == cmVersion::GetMajorVersion() &&
minorVer == cmVersion::GetMinorVersion() &&
patchVer > cmVersion::GetPatchVersion()))
{
cmOStringStream e;
e << "An attempt was made to set the policy version of CMake to \""
<< version << "\" which is greater than this version of CMake. "
<< "This is not allowed because the greater version may have new "
<< "policies not known to this CMake. "
<< "You may need a newer CMake version to build this project.";
mf->IssueMessage(cmake::FATAL_ERROR, e.str());
return false;
}
// now loop over all the policies and set them as appropriate
std::map<cmPolicies::PolicyID,cmPolicy *>::iterator i
= this->Policies.begin();
for (;i != this->Policies.end(); ++i)
{
if (i->second->IsPolicyNewerThan(majorVer,minorVer,patchVer))
{
if (!mf->SetPolicy(i->second->ID, cmPolicies::WARN))
{
return false;
}
}
else
{
if (!mf->SetPolicy(i->second->ID, cmPolicies::NEW))
{
return false;
}
}
}
return true;
}
// is this a valid status the listfile can set this policy to?
bool cmPolicies::IsValidPolicyStatus(cmPolicies::PolicyID id,
cmPolicies::PolicyStatus status)
{
// if they are setting a feature to anything other than OLD or WARN and the
// feature is not known about then that is an error
if (this->Policies.find(id) == this->Policies.end())
{
if (status == cmPolicies::WARN ||
status == cmPolicies::OLD)
{
return true;
}
cmOStringStream error;
error <<
"Error: an attempt was made to enable the new behavior for " <<
"a new feature that is in a later version of CMake than "
"what you are runing, please upgrade to a newer version "
"of CMake.";
cmSystemTools::Error(error.str().c_str());
return false;
}
// now we know the feature is defined, so the only issue is if someone is
// setting it to WARN or OLD when the feature is REQUIRED_ALWAYS
if ((status == cmPolicies::WARN ||
status == cmPolicies::OLD) &&
this->Policies[id]->Status == cmPolicies::REQUIRED_ALWAYS)
{
cmOStringStream error;
error <<
"Error: an attempt was made to enable the old behavior for " <<
"a feature that is no longer supported. The feature in " <<
"question is feature " <<
id <<
" which had new behavior introduced in CMake version " <<
this->Policies[id]->GetVersionString() <<
" please either update your CMakeLists files to conform to " <<
"the new behavior " <<
"or use an older version of CMake that still supports " <<
"the old behavior. Run cmake --help-policies " <<
id << " for more information.";
cmSystemTools::Error(error.str().c_str());
return false;
}
return true;
}
// is this a valid status the listfile can set this policy to?
bool cmPolicies::IsValidUsedPolicyStatus(cmPolicies::PolicyID id,
cmPolicies::PolicyStatus status)
{
// if they are setting a feature to anything other than OLD or WARN and the
// feature is not known about then that is an error
if (this->Policies.find(id) == this->Policies.end())
{
if (status == cmPolicies::WARN ||
status == cmPolicies::OLD)
{
return true;
}
cmOStringStream error;
error <<
"Error: an attempt was made to enable the new behavior for " <<
"a new feature that is in a later version of CMake than "
"what you are runing, please upgrade to a newer version "
"of CMake.";
cmSystemTools::Error(error.str().c_str());
return false;
}
// now we know the feature is defined, so the only issue is if someone is
// setting it to WARN or OLD when the feature is REQUIRED_ALWAYS
if ((status == cmPolicies::WARN ||
status == cmPolicies::OLD) &&
(this->Policies[id]->Status == cmPolicies::REQUIRED_ALWAYS ||
this->Policies[id]->Status == cmPolicies::REQUIRED_IF_USED))
{
cmOStringStream error;
error <<
"Error: an attempt was made to enable the old behavior for " <<
"a feature that is no longer supported. The feature in " <<
"question is feature " <<
id <<
" which had new behavior introduced in CMake version " <<
this->Policies[id]->GetVersionString() <<
" please either update your CMakeLists files to conform to " <<
"the new behavior " <<
"or use an older version of CMake that still supports " <<
"the old behavior. Run cmake --help-policies " <<
id << " for more information.";
cmSystemTools::Error(error.str().c_str());
return false;
}
return true;
}
bool cmPolicies::GetPolicyID(const char *id, cmPolicies::PolicyID &pid)
{
if (!id || strlen(id) < 1)
{
return false;
}
std::map<std::string,cmPolicies::PolicyID>::iterator pos =
this->PolicyStringMap.find(id);
if (pos == this->PolicyStringMap.end())
{
return false;
}
pid = pos->second;
return true;
}
std::string cmPolicies::GetPolicyIDString(cmPolicies::PolicyID pid)
{
std::map<cmPolicies::PolicyID,cmPolicy *>::iterator pos =
this->Policies.find(pid);
if (pos == this->Policies.end())
{
return "";
}
return pos->second->IDString;
}
///! return a warning string for a given policy
std::string cmPolicies::GetPolicyWarning(cmPolicies::PolicyID id)
{
std::map<cmPolicies::PolicyID,cmPolicy *>::iterator pos =
this->Policies.find(id);
if (pos == this->Policies.end())
{
cmSystemTools::Error(
"Request for warning text for undefined policy!");
return "Request for warning text for undefined policy!";
}
cmOStringStream msg;
msg <<
"Policy " << pos->second->IDString << " is not set: "
"" << pos->second->ShortDescription << " "
"Run \"cmake --help-policy " << pos->second->IDString << "\" for "
"policy details. "
"Use the cmake_policy command to set the policy "
"and suppress this warning.";
return msg.str();
}
///! return an error string for when a required policy is unspecified
std::string cmPolicies::GetRequiredPolicyError(cmPolicies::PolicyID id)
{
std::map<cmPolicies::PolicyID,cmPolicy *>::iterator pos =
this->Policies.find(id);
if (pos == this->Policies.end())
{
cmSystemTools::Error(
"Request for error text for undefined policy!");
return "Request for warning text for undefined policy!";
}
cmOStringStream error;
error <<
"Policy " << pos->second->IDString << " is not set to NEW: "
"" << pos->second->ShortDescription << " "
"Run \"cmake --help-policy " << pos->second->IDString << "\" for "
"policy details. "
"CMake now requires this policy to be set to NEW by the project. "
"The policy may be set explicitly using the code\n"
" cmake_policy(SET " << pos->second->IDString << " NEW)\n"
"or by upgrading all policies with the code\n"
" cmake_policy(VERSION " << pos->second->GetVersionString() <<
") # or later\n"
"Run \"cmake --help-command cmake_policy\" for more information.";
return error.str();
}
///! Get the default status for a policy
cmPolicies::PolicyStatus
cmPolicies::GetPolicyStatus(cmPolicies::PolicyID id)
{
// if the policy is not know then what?
std::map<cmPolicies::PolicyID,cmPolicy *>::iterator pos =
this->Policies.find(id);
if (pos == this->Policies.end())
{
// TODO is this right?
return cmPolicies::WARN;
}
return pos->second->Status;
}
void cmPolicies::GetDocumentation(std::vector<cmDocumentationEntry>& v)
{
// now loop over all the policies and set them as appropriate
std::map<cmPolicies::PolicyID,cmPolicy *>::iterator i
= this->Policies.begin();
for (;i != this->Policies.end(); ++i)
{
cmOStringStream full;
full << i->second->LongDescription;
full << "\nThis policy was introduced in CMake version ";
full << i->second->GetVersionString() << ".";
if(i->first != cmPolicies::CMP0000)
{
full << " "
<< "CMake version " << cmVersion::GetMajorVersion()
<< "." << cmVersion::GetMinorVersion() << " ";
// add in some more text here based on status
switch (i->second->Status)
{
case cmPolicies::WARN:
full << "warns when the policy is not set and uses OLD behavior. "
<< "Use the cmake_policy command to set it to OLD or NEW "
<< "explicitly.";
break;
case cmPolicies::OLD:
full << "defaults to the OLD behavior for this policy.";
break;
case cmPolicies::NEW:
full << "defaults to the NEW behavior for this policy.";
break;
case cmPolicies::REQUIRED_IF_USED:
full << "requires the policy to be set to NEW if you use it. "
<< "Use the cmake_policy command to set it to NEW.";
break;
case cmPolicies::REQUIRED_ALWAYS:
full << "requires the policy to be set to NEW. "
<< "Use the cmake_policy command to set it to NEW.";
break;
}
}
cmDocumentationEntry e(i->second->IDString.c_str(),
i->second->ShortDescription.c_str(),
full.str().c_str());
v.push_back(e);
}
}