Add module Exporter.qbs

This module generates qbs modules from products, providing an interface
to them for use by external projects.

[ChangeLog] Added new module "Exporter.qbs" for creating qbs modules
from products.

Task-number: QBS-1231
Change-Id: I9f0cf04b441aaf279cf19a84fd94d97a8cea9de8
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>

2 files changed, 346 insertions, 0 deletions

diff --git a/share/qbs/modules/Exporter/qbs/qbsexporter.js b/share/qbs/modules/Exporter/qbs/qbsexporter.js
new file mode 100644
index 000000000..e71622607
--- /dev/null
+++ b/share/qbs/modules/Exporter/qbs/qbsexporter.js
@@ -0,0 +1,268 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing
+**
+** This file is part of Qbs.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms and
+** conditions see http://www.qt.io/terms-conditions. For further information
+** use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file.  Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, The Qt Company gives you certain additional
+** rights.  These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+****************************************************************************/
+
+var FileInfo = require("qbs.FileInfo");
+var ModUtils = require("qbs.ModUtils");
+
+function tagListToString(tagList)
+{
+    return JSON.stringify(tagList);
+}
+
+function stringToTagList(tagListString)
+{
+    return JSON.parse(tagListString);
+}
+
+function writeTargetArtifactGroup(output, tagList, artifactList, moduleInstallDir, moduleFile)
+{
+    // Do not add our qbs module file itself.
+    if (tagListToString(tagList) === tagListToString(output.fileTags))
+        return;
+
+    moduleFile.writeLine("    Group {");
+    moduleFile.writeLine("        filesAreTargets: true");
+    var filteredTagList = tagList.filter(function(t) { return t !== "installable"; });
+    moduleFile.writeLine("        fileTags: " + JSON.stringify(filteredTagList));
+    moduleFile.writeLine("        files: [");
+    for (i = 0; i < artifactList.length; ++i) {
+        var artifact = artifactList[i];
+        var installedArtifactFilePath = ModUtils.artifactInstalledFilePath(artifact);
+
+        // Use relative file paths for relocatability.
+        var relativeInstalledArtifactFilePath = FileInfo.relativePath(moduleInstallDir,
+                                                                      installedArtifactFilePath);
+        moduleFile.writeLine("            " + JSON.stringify(relativeInstalledArtifactFilePath)
+                             + ",");
+    }
+    moduleFile.writeLine("        ]");
+    moduleFile.writeLine("    }");
+
+}
+
+function writeTargetArtifactGroups(product, output, moduleFile)
+{
+    var relevantArtifacts = [];
+    for (var i = 0; i < (product.Exporter.qbs._artifactTypes || []).length; ++i) {
+        var tag = product.Exporter.qbs._artifactTypes[i];
+        var artifactsForTag = product.artifacts[tag] || [];
+        for (var j = 0; j < artifactsForTag.length; ++j) {
+            if (!relevantArtifacts.contains(artifactsForTag[j]))
+                relevantArtifacts.push(artifactsForTag[j]);
+        }
+    }
+    var artifactsByTags = {};
+    var artifactCount = relevantArtifacts ? relevantArtifacts.length : 0;
+    for (i = 0; i < artifactCount; ++i) {
+        var artifact = relevantArtifacts[i];
+        if (!artifact.fileTags.contains("installable"))
+            continue;
+
+        // Put all artifacts with the same set of file tags into the same group, so we don't
+        // create more groups than necessary.
+        var key = tagListToString(artifact.fileTags);
+        var currentList = artifactsByTags[key];
+        if (currentList)
+            currentList.push(artifact);
+        else
+            currentList = [artifact];
+        artifactsByTags[key] = currentList;
+    }
+    var moduleInstallDir = FileInfo.path(ModUtils.artifactInstalledFilePath(output));
+    for (var tagListKey in artifactsByTags) {
+        writeTargetArtifactGroup(output, stringToTagList(tagListKey), artifactsByTags[tagListKey],
+                   moduleInstallDir, moduleFile);
+    }
+}
+
+function checkValuePrefix(name, value, forbiddenPrefix, prefixDescription)
+{
+    if (value.startsWith(forbiddenPrefix)) {
+        throw "Value '" + value + "' for exported property '" + name + "' in product '"
+                + product.name + "' points into " + prefixDescription + ".\n"
+                + "Did you forget to set the prefixMapping property in an Export item?";
+    }
+}
+
+function stringifyValue(project, product, moduleInstallDir, name, value)
+{
+    if (Array.isArray(value)) {
+        var repr = "[";
+        for (var i = 0; i < value.length; ++i) {
+            repr += stringifyValue(project, product, moduleInstallDir, name, value[i]) + ", ";
+        }
+        repr += "]";
+        return repr;
+    }
+    if (typeof(value) !== "string")
+        return JSON.stringify(value);
+
+    // Catch user oversights: Paths that point into the project source or build directories
+    // make no sense in the module.
+    if (!value.startsWith(product.qbs.installRoot)) {
+        checkValuePrefix(name, value, project.buildDirectory, "project build directory");
+        checkValuePrefix(name, value, project.sourceDirectory, "project source directory");
+    }
+
+    // Adapt file paths pointing into the install dir, that is, make them relative to the
+    // module file for relocatability. We accept them with or without the install root.
+    // The latter form will typically be a result of applying the prefixMapping property,
+    // while the first one could be an untransformed path, for instance if the project
+    // file is written in such a way that include paths are picked up from the installed
+    // location rather than the source directory.
+    var valuePrefixToStrip;
+    var fullInstallPrefix = FileInfo.joinPaths(product.qbs.installRoot, product.qbs.installPrefix);
+    if (fullInstallPrefix.length > 1 && value.startsWith(fullInstallPrefix)) {
+        valuePrefixToStrip = fullInstallPrefix;
+    } else {
+        var installPrefix = FileInfo.joinPaths("/", product.qbs.installPrefix);
+        if (installPrefix.length > 1 && value.startsWith(installPrefix))
+            valuePrefixToStrip = installPrefix;
+    }
+    if (valuePrefixToStrip) {
+        var deployedModuleInstallDir = moduleInstallDir.slice(fullInstallPrefix.length);
+        return "FileInfo.cleanPath(FileInfo.joinPaths(path, FileInfo.relativePath("
+                + JSON.stringify(deployedModuleInstallDir) + ", "
+                + JSON.stringify(value.slice(valuePrefixToStrip.length)) + ")))";
+    }
+
+    return JSON.stringify(value);
+}
+
+function writeProperty(project, product, moduleInstallDir, prop, indentation, considerValue,
+                       moduleFile)
+{
+    var line = indentation;
+    var separatorIndex = prop.name.lastIndexOf(".");
+    var isModuleProperty = separatorIndex !== -1;
+    var needsDeclaration = !prop.isBuiltin && !isModuleProperty;
+    if (needsDeclaration)
+        line += "property " + prop.type +  " ";
+    var moduleName;
+    if (isModuleProperty) {
+        moduleName = prop.name.slice(0, separatorIndex);
+        if ((product.Exporter.qbs.excludedDependencies || []).contains(moduleName))
+            return;
+    }
+    line += prop.name + ": ";
+
+    // We emit the literal value, unless the source code clearly refers to values from inside the
+    // original project, in which case the evaluated value is used.
+    if (considerValue && /(project|product)\./.test(prop.sourceCode)) {
+        var value;
+        if (isModuleProperty) {
+            var propertyName = prop.name.slice(separatorIndex + 1);
+            value = product.exports[moduleName][propertyName];
+        } else {
+            value = product.exports[prop.name];
+        }
+        line += stringifyValue(project, product, moduleInstallDir, prop.name, value);
+    } else {
+        line += prop.sourceCode.replace(/importingProduct\./g, "product.");
+    }
+    moduleFile.writeLine(line);
+}
+
+function writeProperties(project, product, moduleInstallDir, list, indentation, considerValue,
+                         moduleFile)
+{
+    for (var i = 0; i < list.length; ++i) {
+        writeProperty(project, product, moduleInstallDir, list[i], indentation, considerValue,
+                      moduleFile);
+    }
+}
+
+// This writes properties set on other modules in the Export item, i.e. property assignments
+// like "cpp.includePaths: '...'".
+function writeModuleProperties(project, product, output, moduleFile)
+{
+    var moduleInstallDir = FileInfo.path(ModUtils.artifactInstalledFilePath(output));
+    var filteredProps = product.exports.properties.filter(function(p) {
+        return p.name !== "name";
+    });
+
+    // The right-hand side can refer to values from the exporting product, in which case
+    // the evaluated value, rather than the source code, needs to go into the module file.
+    var considerValues = true;
+    writeProperties(project, product, moduleInstallDir, filteredProps, "    ", considerValues,
+                    moduleFile);
+}
+
+function writeItem(product, item, indentation, moduleFile)
+{
+    moduleFile.writeLine(indentation + item.name + " {");
+    var newIndentation = indentation + "    ";
+
+    // These are sub-items of the Export item, whose properties entirely live in the context
+    // of the importing product. Therefore, they must never use pre-evaluated values.
+    var considerValues = false;
+    writeProperties(undefined, product, undefined, item.properties, newIndentation, considerValues,
+                    moduleFile)
+
+    for (var i = 0; i < item.childItems.length; ++i)
+        writeItem(product, item.childItems[i], newIndentation, moduleFile);
+    moduleFile.writeLine(indentation + "}");
+}
+
+function isExcludedDependency(product, childItem)
+{
+    if ((product.Exporter.qbs.excludedDependencies || []).length === 0)
+        return false;
+    if (childItem.name !== "Depends")
+        return false;
+    for (var i = 0; i < childItem.properties.length; ++i) {
+        var prop = childItem.properties[i];
+        var unquotedRhs = prop.sourceCode.slice(1, -1);
+        if (prop.name === "name" && product.Exporter.qbs.excludedDependencies.contains(unquotedRhs))
+            return true;
+    }
+    return false;
+}
+
+function writeChildItems(product, moduleFile)
+{
+    for (var i = 0; i < product.exports.childItems.length; ++i) {
+        var item = product.exports.childItems[i];
+        if (!isExcludedDependency(product, item))
+            writeItem(product, item, "    ", moduleFile);
+    }
+}
+
+function writeImportStatements(product, moduleFile)
+{
+    var imports = product.exports.imports;
+
+    // We potentially use FileInfo ourselves when transforming paths in stringifyValue().
+    if (!imports.contains("import qbs.FileInfo"))
+        imports.push("import qbs.FileInfo");
+
+    for (var i = 0; i < product.exports.imports.length; ++i)
+        moduleFile.writeLine(product.exports.imports[i]);
+}
diff --git a/share/qbs/modules/Exporter/qbs/qbsexporter.qbs b/share/qbs/modules/Exporter/qbs/qbsexporter.qbs
new file mode 100644
index 000000000..6cdc55891
--- /dev/null
+++ b/share/qbs/modules/Exporter/qbs/qbsexporter.qbs
@@ -0,0 +1,78 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing
+**
+** This file is part of Qbs.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms and
+** conditions see http://www.qt.io/terms-conditions. For further information
+** use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file.  Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, The Qt Company gives you certain additional
+** rights.  These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+****************************************************************************/
+
+import qbs
+import qbs.FileInfo
+import qbs.TextFile
+
+import "qbsexporter.js" as HelperFunctions
+
+Module {
+    property stringList artifactTypes
+    property string fileName: product.targetName + ".qbs"
+    property stringList excludedDependencies
+    property string additionalContent
+
+    property stringList _artifactTypes: artifactTypes ? artifactTypes : ["installable"]
+
+    additionalProductTypes: ["Exporter.qbs.module"]
+
+    Rule {
+        multiplex: true
+        requiresInputs: false
+
+        // Make sure we only run when all other artifacts are already present.
+        inputs: product.type.filter(function(t) { return t !== "Exporter.qbs.module"; })
+
+        Artifact {
+            filePath: product.Exporter.qbs.fileName
+            fileTags: ["Exporter.qbs.module"]
+            qbs.install: true
+        }
+        prepare: {
+            var cmd = new JavaScriptCommand();
+            cmd.description = "Creating " + output.fileName;
+            cmd.sourceCode = function() {
+                var f = new TextFile(output.filePath, TextFile.WriteOnly);
+                f.writeLine("import qbs");
+                HelperFunctions.writeImportStatements(product, f);
+                f.writeLine("\nModule {");
+                HelperFunctions.writeModuleProperties(project, product, output, f);
+                HelperFunctions.writeTargetArtifactGroups(product, output, f);
+                HelperFunctions.writeChildItems(product, f);
+                if (product.Exporter.qbs.additionalContent)
+                    f.writeLine(product.Exporter.qbs.additionalContent);
+                f.writeLine("}");
+                f.close();
+            };
+            return [cmd];
+        }
+    }
+}