Add some sanity to the clang detection code for qmake build

llvm-config can usually be found in PATH on systems which have standard
paths at all. There is no need to specify LLVM_INSTALL_DIR then.
Furthermore, llvm-config has an option --bindir which will tell us the
directory where clang can be found (if installed). No need to apply
strange heuristics based on LLVM_INSTALL_DIR. Finally, we can check
within each .pro file for the conditions to be met using qmake's
require() function. This way we don't need to fiddle with
LLVM_INSTALL_DIR in unrelated places.

Change-Id: I1a6ab092b06de40dfbfa4a9e7053451360fd24c8
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

README.md

@@ -31,7 +31,7 @@ The installed toolchains have to match the one Qt was compiled with.
 
 You can build Qt Creator with
 
-    # Optional, needed for the Clang Code Model:
+    # Optional, needed for the Clang Code Model if llvm-config is not in PATH:
     export LLVM_INSTALL_DIR=/path/to/llvm (or "set" on Windows)
     # Optional, needed to let the QbsProjectManager plugin use system Qbs:
     export QBS_INSTALL_DIR=/path/to/qbs
@@ -129,7 +129,7 @@ For detailed information on the supported compilers, see
        * Install LLVM/Clang - see the section "Get LLVM/Clang for the Clang
          Code Model".
        * Set the environment variable LLVM_INSTALL_DIR to the LLVM/Clang
-         installation directory.
+         installation directory if llvm-config is not in PATH.
        * When you launch Qt Creator, activate the Clang Code Model plugin as
          described in doc/src/editors/creator-clang-codemodel.qdoc.
 

src/plugins/clangcodemodel/clangcodemodel.pro

@@ -3,6 +3,8 @@ include(../../shared/clang/clang_installation.pri)
 
 include(../../shared/clang/clang_defines.pri)
 
+requires(!isEmpty(LLVM_VERSION))
+
 SOURCES += \
     clangactivationsequencecontextprocessor.cpp \
     clangactivationsequenceprocessor.cpp \

src/plugins/plugins.pro

@@ -96,21 +96,15 @@ exists(../shared/qbs/qbs.pro)|!isEmpty(QBS_INSTALL_DIR): \
     SUBDIRS += \
         qbsprojectmanager
 
-# prefer qmake variable set on command line over env var
-isEmpty(LLVM_INSTALL_DIR):LLVM_INSTALL_DIR=$$(LLVM_INSTALL_DIR)
-exists($$LLVM_INSTALL_DIR) {
-    SUBDIRS += clangcodemodel
+SUBDIRS += \
+    clangcodemodel
 
-    QTC_NO_CLANG_LIBTOOLING=$$(QTC_NO_CLANG_LIBTOOLING)
-    isEmpty(QTC_NO_CLANG_LIBTOOLING) {
+QTC_NO_CLANG_LIBTOOLING=$$(QTC_NO_CLANG_LIBTOOLING)
+isEmpty(QTC_NO_CLANG_LIBTOOLING) {
     SUBDIRS += clangrefactoring
     SUBDIRS += clangpchmanager
-    } else {
-        warning("Building the Clang refactoring and the pch manager plugins are disabled.")
-    }
 } else {
-    warning("Set LLVM_INSTALL_DIR to build the Clang Code Model. " \
-            "For details, see doc/src/editors/creator-clang-codemodel.qdoc.")
+    warning("Building the Clang refactoring and the pch manager plugins are disabled.")
 }
 
 isEmpty(IDE_PACKAGE_MODE) {

src/shared/clang/clang_installation.pri

@@ -1,7 +1,18 @@
 isEmpty(LLVM_INSTALL_DIR):LLVM_INSTALL_DIR=$$(LLVM_INSTALL_DIR)
 LLVM_INSTALL_DIR = $$clean_path($$LLVM_INSTALL_DIR)
-isEmpty(LLVM_INSTALL_DIR): error("No LLVM_INSTALL_DIR provided")
-!exists($$LLVM_INSTALL_DIR): error("LLVM_INSTALL_DIR does not exist: $$LLVM_INSTALL_DIR")
+
+!isEmpty(LLVM_INSTALL_DIR):!exists($$LLVM_INSTALL_DIR) {
+    error("Explicitly given LLVM_INSTALL_DIR does not exist: $$LLVM_INSTALL_DIR")
+}
+
+defineReplace(llvmWarningOrError) {
+    warningText = $$1
+    errorText = $$2
+    isEmpty(errorText): errorText = $$warningText
+    isEmpty(LLVM_INSTALL_DIR): warning($$warningText)
+    else: error($$errorText)
+    return(false)
+}
 
 # Expected input: "3.9.1", "5.0.0svn", "5.0.1git-81029f14223"
 defineReplace(extractVersion)      { return($$replace(1, ^(\\d+\\.\\d+\\.\\d+).*$, \\1)) }
@@ -69,20 +80,6 @@ defineReplace(findClangLibInLibDir) {
     }
 }
 
-defineReplace(findClangOnWindows) {
-    FILE_EXTS = a dll
-    msvc: FILE_EXTS = lib dll
-    for (suffix, $$list(lib bin)) {
-        for (libname, $$list(clang libclang)) {
-            for (ext, FILE_EXTS) {
-                exists("$${LLVM_INSTALL_DIR}/$${suffix}/$${libname}.$${ext}") {
-                    return($${LLVM_INSTALL_DIR}/$${suffix}/)
-                }
-            }
-        }
-    }
-}
-
 CLANGTOOLING_LIBS=-lclangTooling -lclangIndex -lclangFrontend -lclangParse -lclangSerialization \
                   -lclangSema -lclangEdit -lclangAnalysis -lclangDriver -lclangDynamicASTMatchers \
                   -lclangASTMatchers -lclangToolingCore -lclangAST -lclangLex -lclangBasic
@@ -91,33 +88,58 @@ win32:CLANGTOOLING_LIBS += -lversion
 BIN_EXTENSION =
 win32: BIN_EXTENSION = .exe
 
-llvm_config = $$system_quote($$LLVM_INSTALL_DIR/bin/llvm-config)
-requires(exists($$llvm_config$$BIN_EXTENSION))
-#message("llvm-config found, querying it for paths and version")
-LLVM_LIBDIR = $$quote($$system($$llvm_config --libdir, lines))
-LLVM_INCLUDEPATH = $$system($$llvm_config --includedir, lines)
+isEmpty(LLVM_INSTALL_DIR) {
+    llvm_config = llvm-config
+} else {
+    llvm_config = $$system_quote($$LLVM_INSTALL_DIR/bin/llvm-config)
+    requires(exists($$llvm_config$$BIN_EXTENSION))
+}
+
 output = $$system($$llvm_config --version, lines)
 LLVM_VERSION = $$extractVersion($$output)
-msvc {
-    LLVM_STATIC_LIBS_STRING += $$system($$llvm_config --libnames, lines)
+isEmpty(LLVM_VERSION) {
+    $$llvmWarningOrError(\
+        "Cannot determine clang version. Set LLVM_INSTALL_DIR to build the Clang Code Model",\
+        "LLVM_INSTALL_DIR does not contain a valid llvm-config, candidate: $$llvm_config")
+} else:!versionIsAtLeast($$LLVM_VERSION, 5, 0, 0): {
+    # CLANG-UPGRADE-CHECK: Adapt minimum version numbers.
+    $$llvmWarningOrError(\
+        "LLVM/Clang version >= 5.0.0 required, version provided: $$LLVM_VERSION")
+    LLVM_VERSION =
 } else {
+    LLVM_LIBDIR = $$quote($$system($$llvm_config --libdir, lines))
+    LLVM_BINDIR = $$quote($$system($$llvm_config --bindir, lines))
+    LLVM_INCLUDEPATH = $$system($$llvm_config --includedir, lines)
+    msvc {
+        LLVM_STATIC_LIBS_STRING += $$system($$llvm_config --libnames, lines)
+    } else {
         LLVM_STATIC_LIBS_STRING += $$system($$llvm_config --libs, lines)
-}
-LLVM_STATIC_LIBS_STRING += $$system($$llvm_config --system-libs, lines)
+    }
+    LLVM_STATIC_LIBS_STRING += $$system($$llvm_config --system-libs, lines)
 
-LLVM_STATIC_LIBS = $$split(LLVM_STATIC_LIBS_STRING, " ")
+    LLVM_STATIC_LIBS = $$split(LLVM_STATIC_LIBS_STRING, " ")
 
-LIBCLANG_MAIN_HEADER = $$LLVM_INCLUDEPATH/clang-c/Index.h
-!exists($$LIBCLANG_MAIN_HEADER): error("Cannot find libclang's main header file, candidate: $$LIBCLANG_MAIN_HEADER")
-!exists($$LLVM_LIBDIR): error("Cannot detect lib dir for clang, candidate: $$LLVM_LIBDIR")
-CLANG_LIB = $$findClangLibInLibDir($$LLVM_LIBDIR)
-isEmpty(CLANG_LIB): error("Cannot find Clang shared library in $$LLVM_LIBDIR")
+    LIBCLANG_MAIN_HEADER = $$LLVM_INCLUDEPATH/clang-c/Index.h
+    !exists($$LIBCLANG_MAIN_HEADER) {
+        $$llvmWarningOrError(\
+            "Cannot find libclang's main header file, candidate: $$LIBCLANG_MAIN_HEADER")
+    }
+    !exists($$LLVM_LIBDIR) {
+        $$llvmWarningOrError("Cannot detect lib dir for clang, candidate: $$LLVM_LIBDIR")
+    }
+    !exists($$LLVM_BINDIR) {
+        $$llvmWarningOrError("Cannot detect bin dir for clang, candidate: $$LLVM_BINDIR")
+    }
+    CLANG_LIB = $$findClangLibInLibDir($$LLVM_LIBDIR)
+    isEmpty(CLANG_LIB) {
+        $$llvmWarningOrError("Cannot find Clang shared library in $$LLVM_LIBDIR")
+    }
 
-!contains(QMAKE_DEFAULT_LIBDIRS, $$LLVM_LIBDIR): LIBCLANG_LIBS = -L$${LLVM_LIBDIR}
-LIBCLANG_LIBS += $${CLANG_LIB}
+    !contains(QMAKE_DEFAULT_LIBDIRS, $$LLVM_LIBDIR): LIBCLANG_LIBS = -L$${LLVM_LIBDIR}
+    LIBCLANG_LIBS += $${CLANG_LIB}
 
-QTC_NO_CLANG_LIBTOOLING=$$(QTC_NO_CLANG_LIBTOOLING)
-isEmpty(QTC_NO_CLANG_LIBTOOLING) {
+    QTC_NO_CLANG_LIBTOOLING=$$(QTC_NO_CLANG_LIBTOOLING)
+    isEmpty(QTC_NO_CLANG_LIBTOOLING) {
         QTC_FORCE_CLANG_LIBTOOLING = $$(QTC_FORCE_CLANG_LIBTOOLING)
         versionIsEqual($$LLVM_VERSION, 5, 0)|!isEmpty(QTC_FORCE_CLANG_LIBTOOLING) {
             !contains(QMAKE_DEFAULT_LIBDIRS, $$LLVM_LIBDIR): LIBTOOLING_LIBS = -L$${LLVM_LIBDIR}
@@ -126,30 +148,27 @@ isEmpty(QTC_NO_CLANG_LIBTOOLING) {
         } else {
             warning("Clang LibTooling is disabled because only version 5.0 is supported.")
         }
-} else {
+    } else {
         warning("Clang LibTooling is disabled.")
+    }
+
+    # Remove unwanted flags. It is a workaround for linking.
+    # It is not intended for cross compiler linking.
+    LLVM_CXXFLAGS = $$system($$llvm_config --cxxflags, lines)
+    LLVM_CXXFLAGS ~= s,-fno-exceptions,
+    LLVM_CXXFLAGS ~= s,-std=c++11,
+    LLVM_CXXFLAGS ~= s,-std=c++0x,
+    LLVM_CXXFLAGS ~= s,-O\S*,
+    LLVM_CXXFLAGS ~= s,/O\S*,
+    LLVM_CXXFLAGS ~= s,/W4,
+    LLVM_CXXFLAGS ~= s,/EH\S*,
+    LLVM_CXXFLAGS ~= s,-Werror=date-time,
+    LLVM_CXXFLAGS ~= s,-Wcovered-switch-default,
+    LLVM_CXXFLAGS ~= s,-fPIC,
+    LLVM_CXXFLAGS ~= s,-pedantic,
+    LLVM_CXXFLAGS ~= s,-Wstring-conversion,
+    # split-dwarf needs objcopy which does not work via icecc out-of-the-box
+    LLVM_CXXFLAGS ~= s,-gsplit-dwarf,
+
+    LLVM_IS_COMPILED_WITH_RTTI = $$system($$llvm_config --has-rtti, lines)
 }
-
-isEmpty(LLVM_VERSION): error("Cannot determine clang version at $$LLVM_INSTALL_DIR")
-!versionIsAtLeast($$LLVM_VERSION, 5, 0, 0): { # CLANG-UPGRADE-CHECK: Adapt minimum version numbers.
-    error("LLVM/Clang version >= 5.0.0 required, version provided: $$LLVM_VERSION")
-}
-
-# Remove unwanted flags. It is a workaround for linking. It is not intended for cross compiler linking.
-LLVM_CXXFLAGS = $$system($$llvm_config --cxxflags, lines)
-LLVM_CXXFLAGS ~= s,-fno-exceptions,
-LLVM_CXXFLAGS ~= s,-std=c++11,
-LLVM_CXXFLAGS ~= s,-std=c++0x,
-LLVM_CXXFLAGS ~= s,-O\S*,
-LLVM_CXXFLAGS ~= s,/O\S*,
-LLVM_CXXFLAGS ~= s,/W4,
-LLVM_CXXFLAGS ~= s,/EH\S*,
-LLVM_CXXFLAGS ~= s,-Werror=date-time,
-LLVM_CXXFLAGS ~= s,-Wcovered-switch-default,
-LLVM_CXXFLAGS ~= s,-fPIC,
-LLVM_CXXFLAGS ~= s,-pedantic,
-LLVM_CXXFLAGS ~= s,-Wstring-conversion,
-# split-dwarf needs objcopy which does not work via icecc out-of-the-box
-LLVM_CXXFLAGS ~= s,-gsplit-dwarf,
-
-LLVM_IS_COMPILED_WITH_RTTI = $$system($$llvm_config --has-rtti, lines)

src/tools/clangbackend/clangbackend.pro

@@ -6,6 +6,8 @@ include(../../qtcreatortool.pri)
 include(../../shared/clang/clang_installation.pri)
 include(source/clangbackendclangipc-source.pri)
 
+requires(!isEmpty(LLVM_VERSION))
+
 QT += core network
 QT -= gui
 

src/tools/clangpchmanagerbackend/clangpchmanagerbackend.pro

@@ -33,4 +33,4 @@ unix {
     !disable_external_rpath: QMAKE_LFLAGS += -Wl,-rpath,$$shell_quote($${LLVM_LIBDIR})
 }
 
-DEFINES += CLANG_COMPILER_PATH=\"R\\\"xxx($$LLVM_INSTALL_DIR/bin/clang)xxx\\\"\"
+DEFINES += CLANG_COMPILER_PATH=\"R\\\"xxx($${LLVM_BINDIR}/clang)xxx\\\"\"

src/tools/tools.pro

@@ -20,17 +20,14 @@ mac {
     SUBDIRS += iostool
 }
 
-isEmpty(LLVM_INSTALL_DIR):LLVM_INSTALL_DIR=$$(LLVM_INSTALL_DIR)
-exists($$LLVM_INSTALL_DIR) {
-    SUBDIRS += clangbackend
+SUBDIRS += clangbackend
 
-    QTC_NO_CLANG_LIBTOOLING=$$(QTC_NO_CLANG_LIBTOOLING)
-    isEmpty(QTC_NO_CLANG_LIBTOOLING) {
+QTC_NO_CLANG_LIBTOOLING=$$(QTC_NO_CLANG_LIBTOOLING)
+isEmpty(QTC_NO_CLANG_LIBTOOLING) {
     SUBDIRS += clangrefactoringbackend
     SUBDIRS += clangpchmanagerbackend
-    } else {
+} else {
     warning("Building the Clang refactoring back end and the pch manager plugins are disabled.")
-    }
 }
 
 isEmpty(BUILD_CPLUSPLUS_TOOLS):BUILD_CPLUSPLUS_TOOLS=$$(BUILD_CPLUSPLUS_TOOLS)

tests/tests.pro

@@ -1,4 +1,2 @@
 TEMPLATE=subdirs
-SUBDIRS += auto manual tools
-isEmpty(LLVM_INSTALL_DIR):LLVM_INSTALL_DIR=$$(LLVM_INSTALL_DIR)
-exists($$LLVM_INSTALL_DIR):SUBDIRS += unit
+SUBDIRS += auto manual tools unit

tests/unit/unittest/clang_dependency.pri

@@ -1,27 +1,26 @@
-isEmpty(LLVM_INSTALL_DIR):LLVM_INSTALL_DIR=$$(LLVM_INSTALL_DIR)
-!isEmpty(LLVM_INSTALL_DIR) {
 include(../../../src/shared/clang/clang_installation.pri)
-requires(!isEmpty(LIBCLANG_LIBS))
-equals(LLVM_IS_COMPILED_WITH_RTTI, "NO") : message("LLVM needs to be compiled with RTTI!")
-requires(equals(LLVM_IS_COMPILED_WITH_RTTI, "YES"))
+!isEmpty(LLVM_VERSION) {
+    requires(!isEmpty(LIBCLANG_LIBS))
+    equals(LLVM_IS_COMPILED_WITH_RTTI, "NO") : message("LLVM needs to be compiled with RTTI!")
+    requires(equals(LLVM_IS_COMPILED_WITH_RTTI, "YES"))
 
-DEFINES += CLANG_UNIT_TESTS
-INCLUDEPATH += $$LLVM_INCLUDEPATH
-win32 {
+    DEFINES += CLANG_UNIT_TESTS
+    INCLUDEPATH += $$LLVM_INCLUDEPATH
+    win32 {
         LIBS += -lVersion
 
         # set run path for clang.dll dependency
-    bin_path = $$LLVM_INSTALL_DIR/bin
+        bin_path = $$LLVM_BINDIR
         bin_path ~= s,/,\\,g
         # the below gets added to later by testcase.prf
         check.commands = cd . & set PATH=$$bin_path;%PATH%& cmd /c
+    }
+
+    LIBS += $$LIBTOOLING_LIBS $$LIBCLANG_LIBS
+    QMAKE_RPATHDIR += $$LLVM_LIBDIR
+
+    LLVM_CXXFLAGS ~= s,-g\d?,
+    QMAKE_CXXFLAGS += $$LLVM_CXXFLAGS
+
+    DEFINES += CLANG_COMPILER_PATH=\"R\\\"xxx($$LLVM_BINDIR/clang)xxx\\\"\"
 }
-
-LIBS += $$LIBTOOLING_LIBS $$LIBCLANG_LIBS
-QMAKE_RPATHDIR += $$LLVM_LIBDIR
-
-LLVM_CXXFLAGS ~= s,-g\d?,
-QMAKE_CXXFLAGS += $$LLVM_CXXFLAGS
-}
-
-DEFINES += CLANG_COMPILER_PATH=\"R\\\"xxx($$LLVM_INSTALL_DIR/bin/clang)xxx\\\"\"

tests/unit/unittest/creator_dependency.pri

@@ -14,7 +14,7 @@ include($$PWD/../../../src/plugins/clangrefactoring/clangrefactoring-source.pri)
 include($$PWD/../../../src/plugins/clangpchmanager/clangpchmanager-source.pri)
 include($$PWD/../../../src/plugins/cpptools/cpptoolsunittestfiles.pri)
 include(cplusplus.pri)
-!isEmpty(LLVM_INSTALL_DIR) {
+!isEmpty(LLVM_VERSION) {
 include($$PWD/../../../src/shared/clang/clang_defines.pri)
 include($$PWD/../../../src/tools/clangbackend/source/clangbackendclangipc-source.pri)
 include($$PWD/../../../src/plugins/clangcodemodel/clangcodemodelunittestfiles.pri)