ENH: Add SKIP_RULE_DEPENDS option for add_custom_command()

- Allows make rules to be created with no dependencies.
  - Such rules will not re-run even if the commands themselves change.
  - Useful to create rules that run only if the output is missing.
This commit is contained in:
Brad King 2008-05-14 11:38:47 -04:00
parent 3fb5602e54
commit 600e5e274e
8 changed files with 61 additions and 10 deletions

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@ -40,6 +40,7 @@ bool cmAddCustomCommandCommand
std::vector<std::string> depends, outputs, output;
bool verbatim = false;
bool append = false;
bool skip_rule_depends = false;
std::string implicit_depends_lang;
cmCustomCommand::ImplicitDependsList implicit_depends;
@ -103,6 +104,11 @@ bool cmAddCustomCommandCommand
{
verbatim = true;
}
else if(copy == "SKIP_RULE_DEPENDS")
{
doing = doing_nothing;
skip_rule_depends = true;
}
else if(copy == "APPEND")
{
append = true;
@ -310,8 +316,8 @@ bool cmAddCustomCommandCommand
working.c_str(), false,
escapeOldStyle);
// Add implicit dependency scanning requests if any were given.
if(!implicit_depends.empty())
// Get the rule object to add some extra information.
if(!implicit_depends.empty() || skip_rule_depends)
{
bool okay = false;
if(cmSourceFile* sf =
@ -320,7 +326,16 @@ bool cmAddCustomCommandCommand
if(cmCustomCommand* cc = sf->GetCustomCommand())
{
okay = true;
cc->SetImplicitDepends(implicit_depends);
// Add implicit dependency scanning requests if any were
// given.
if(!implicit_depends.empty())
{
cc->SetImplicitDepends(implicit_depends);
}
// Set the rule dependency state.
cc->SetSkipRuleDepends(skip_rule_depends);
}
}
if(!okay)

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@ -71,7 +71,7 @@ public:
" COMMAND command1 [ARGS] [args1...]\n"
" [COMMAND command2 [ARGS] [args2...] ...]\n"
" [MAIN_DEPENDENCY depend]\n"
" [DEPENDS [depends...]]\n"
" [DEPENDS [depends...]] [SKIP_RULE_DEPENDS]\n"
" [IMPLICIT_DEPENDS <lang1> depend1 ...]\n"
" [WORKING_DIRECTORY dir]\n"
" [COMMENT comment] [VERBATIM] [APPEND])\n"
@ -134,6 +134,12 @@ public:
"created as a file on disk it should be marked as SYMBOLIC with "
"SET_SOURCE_FILES_PROPERTIES.\n"
"The SKIP_RULE_DEPENDS option prevents the custom build rule from "
"having a dependency on itself. This prevents the rule from running "
"again just because the command changed but is useful to create "
"rules that have absolutely no dependencies. Such rules run only "
"when the output file is missing.\n"
"The IMPLICIT_DEPENDS option requests scanning of implicit "
"dependencies of an input file. The language given specifies the "
"programming language whose corresponding dependency scanner should "

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@ -22,6 +22,7 @@ cmCustomCommand::cmCustomCommand()
this->HaveComment = false;
this->EscapeOldStyle = true;
this->EscapeAllowMakeVars = false;
this->SkipRuleDepends = false;
}
//----------------------------------------------------------------------------
@ -50,10 +51,9 @@ cmCustomCommand::cmCustomCommand(const std::vector<std::string>& outputs,
Comment(comment?comment:""),
WorkingDirectory(workingDirectory?workingDirectory:""),
EscapeAllowMakeVars(false),
EscapeOldStyle(true)
EscapeOldStyle(true),
SkipRuleDepends(false)
{
this->EscapeOldStyle = true;
this->EscapeAllowMakeVars = false;
}
//----------------------------------------------------------------------------
@ -135,6 +135,18 @@ void cmCustomCommand::SetEscapeAllowMakeVars(bool b)
this->EscapeAllowMakeVars = b;
}
//----------------------------------------------------------------------------
bool cmCustomCommand::GetSkipRuleDepends() const
{
return this->SkipRuleDepends;
}
//----------------------------------------------------------------------------
void cmCustomCommand::SetSkipRuleDepends(bool b)
{
this->SkipRuleDepends = b;
}
//----------------------------------------------------------------------------
cmCustomCommand::ImplicitDependsList const&
cmCustomCommand::GetImplicitDepends() const

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@ -68,6 +68,10 @@ public:
bool GetEscapeAllowMakeVars() const;
void SetEscapeAllowMakeVars(bool b);
/** Set/Get whether to skip the dependency on the rule itself. */
bool GetSkipRuleDepends() const;
void SetSkipRuleDepends(bool b);
typedef std::pair<cmStdString, cmStdString> ImplicitDependsPair;
class ImplicitDependsList: public std::vector<ImplicitDependsPair> {};
void SetImplicitDepends(ImplicitDependsList const&);
@ -83,6 +87,7 @@ private:
std::string WorkingDirectory;
bool EscapeAllowMakeVars;
bool EscapeOldStyle;
bool SkipRuleDepends;
ImplicitDependsList ImplicitDepends;
};

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@ -1122,8 +1122,11 @@ void cmMakefileTargetGenerator
this->LocalGenerator->AppendCustomDepend(depends, cc);
// Add a dependency on the rule file itself.
this->LocalGenerator->AppendRuleDepend(depends,
this->BuildFileNameFull.c_str());
if(!cc.GetSkipRuleDepends())
{
this->LocalGenerator->AppendRuleDepend(depends,
this->BuildFileNameFull.c_str());
}
// Check whether we need to bother checking for a symbolic output.
bool need_symbolic = this->GlobalGenerator->GetNeedSymbolicMark();

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@ -151,6 +151,14 @@ ADD_EXECUTABLE(CustomCommand
${PROJECT_BINARY_DIR}/generated.c
${PROJECT_BINARY_DIR}/not_included.h
gen_redirect.c # default location for custom commands is in build tree
gen_once.c
)
# Add a rule with no dependencies.
ADD_CUSTOM_COMMAND(
OUTPUT gen_once.c
COMMAND ${CMAKE_COMMAND} -E copy ${PROJECT_SOURCE_DIR}/gen_once.c.in ${PROJECT_BINARY_DIR}/gen_once.c
SKIP_RULE_DEPENDS
)
# Add the rule to create generated.c at build time. This is placed

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@ -6,10 +6,11 @@
int generated();
int wrapped();
int gen_once(void);
int main ()
{
if (generated()*wrapped()*doc() == 3*5*7)
if (generated()*wrapped()*doc()*gen_once() == 3*5*7*11)
{
FILE* fin = fopen(PROJECT_BINARY_DIR "/not_included.h", "r");
if(fin)

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@ -0,0 +1 @@
int gen_once(void) { return 11; }