MSVC: Support cLanguageVersion

It is supported since MSVC 16.8[1] and clang-cl 13[2].

[1] https://devblogs.microsoft.com/cppblog/c11-and-c17-standard-support-arriving-in-msvc/
[2] https://github.com/llvm/llvm-project/commit/d087d805acb664e885e9c31a916f6cfa5dbc2186

Change-Id: I858beadf20c357d8a4c369ab7bc32f69ef956ebb
Reviewed-by: Ivan Komissarov <ABBAPOH@gmail.com>

4 files changed, 42 insertions, 8 deletions

diff --git a/changelogs/changes-1.23.1.md b/changelogs/changes-1.23.1.md
index 430a33bfe..dc4a23535 100644
--- a/changelogs/changes-1.23.1.md
+++ b/changelogs/changes-1.23.1.md
@@ -4,6 +4,7 @@
 # Other modules
 * Fixed protobuf linking on macOS 11.
 * Added support for c17 and c2x values in cpp.cLanguageVersion
+* Added support for cpp.cLanguageVersion for the MSVC toolchain
 
 # Contributors
 * Christian Kandeler
diff --git a/share/qbs/modules/cpp/msvc.js b/share/qbs/modules/cpp/msvc.js
index b206bd4ba..1b70904c0 100644
--- a/share/qbs/modules/cpp/msvc.js
+++ b/share/qbs/modules/cpp/msvc.js
@@ -102,6 +102,12 @@ function hasCxx20Option(input)
             || (input.qbs.toolchain.contains("clang-cl") && input.cpp.compilerVersionMajor >= 13);
 }
 
+function hasCVerOption(input)
+{
+    return Utilities.versionCompare(input.cpp.compilerVersion, "19.29.30138.0") >= 0
+            || (input.qbs.toolchain.contains("clang-cl") && input.cpp.compilerVersionMajor >= 13);
+}
+
 function supportsExternalIncludesOption(input) {
     if (input.qbs.toolchain.contains("clang-cl"))
         return false; // Exclude clang-cl.
@@ -112,7 +118,7 @@ function supportsExternalIncludesOption(input) {
     return Utilities.versionCompare(input.cpp.compilerVersion, "19.16") >= 0;
 }
 
-function addLanguageVersionFlag(input, args) {
+function addCxxLanguageVersionFlag(input, args) {
     var cxxVersion = Cpp.languageVersion(input.cpp.cxxLanguageVersion,
             ["c++23", "c++20", "c++17", "c++14", "c++11", "c++98"], "C++");
     if (!cxxVersion)
@@ -138,6 +144,25 @@ function addLanguageVersionFlag(input, args) {
         args.push(flag);
 }
 
+function addCLanguageVersionFlag(input, args) {
+    var cVersion = Cpp.languageVersion(input.cpp.cLanguageVersion,
+            ["c17", "c11"], "C");
+    if (!cVersion)
+        return;
+
+    var hasStdOption = hasCVerOption(input);
+    if (!hasStdOption)
+        return;
+
+    var flag;
+    if (cVersion === "c17")
+        flag = "/std:c17";
+    else if (cVersion === "c11")
+        flag = "/std:c11";
+    if (flag)
+        args.push(flag);
+}
+
 function handleClangClArchitectureFlags(product, architecture, flags) {
     if (product.qbs.toolchain.contains("clang-cl")) {
         if (architecture === "x86")
@@ -277,9 +302,10 @@ function prepareCompiler(project, product, inputs, outputs, input, output, expli
     // Language
     if (tag === "cpp") {
         args.push("/TP");
-        addLanguageVersionFlag(input, args);
+        addCxxLanguageVersionFlag(input, args);
     } else if (tag === "c") {
         args.push("/TC");
+        addCLanguageVersionFlag(input, args);
     }
 
     // Whether we're compiling a precompiled header or normal source file
diff --git a/tests/auto/blackbox/testdata/maximum-c-language-version/maximum-c-language-version.qbs b/tests/auto/blackbox/testdata/maximum-c-language-version/maximum-c-language-version.qbs
index 320494d00..9f41570f8 100644
--- a/tests/auto/blackbox/testdata/maximum-c-language-version/maximum-c-language-version.qbs
+++ b/tests/auto/blackbox/testdata/maximum-c-language-version/maximum-c-language-version.qbs
@@ -4,10 +4,13 @@ CppApplication {
 
     Probe {
         id: osProbe
-        property stringList toolchain: qbs.toolchain
+        property string toolchainType: qbs.toolchainType
+        property string compilerVersion: cpp.compilerVersion
         configure: {
-            if (toolchain.contains("msvc"))
-                console.info("is msvc");
+            console.info("is msvc: " + (toolchainType === "msvc" || toolchainType === "clang-cl"));
+            var isOld = (toolchainType === "msvc" && compilerVersion < "19.29.30138")
+                || (toolchainType === "clang-cl" && compilerVersion < "13");
+            console.info("is old msvc: " + isOld);
             found = true;
         }
     }
diff --git a/tests/auto/blackbox/tst_blackbox.cpp b/tests/auto/blackbox/tst_blackbox.cpp
index bfec09344..20d85d543 100644
--- a/tests/auto/blackbox/tst_blackbox.cpp
+++ b/tests/auto/blackbox/tst_blackbox.cpp
@@ -7916,14 +7916,18 @@ void TestBlackbox::maximumCLanguageVersion()
     QDir::setCurrent(testDataDir + "/maximum-c-language-version");
     QCOMPARE(runQbs(QbsRunParameters("resolve",
                                      QStringList("products.app.enableNewestModule:true"))), 0);
-    if (m_qbsStdout.contains("is msvc"))
-        QSKIP("MSVC has no support for setting the C language version.");
+    const bool isMsvc = m_qbsStdout.contains("is msvc: true");
+    if (isMsvc && m_qbsStdout.contains("is old msvc: true"))
+        QSKIP("MSVC supports setting the C language version only from version 16.8, and Clang from version 13.");
     QCOMPARE(runQbs(QStringList({"--command-echo-mode", "command-line", "-n"})), 0);
     QVERIFY2(m_qbsStdout.contains("c11") || m_qbsStdout.contains("c1x"), m_qbsStdout.constData());
     QCOMPARE(runQbs(QbsRunParameters("resolve",
                                      QStringList("products.app.enableNewestModule:false"))), 0);
     QCOMPARE(runQbs(QStringList({"--command-echo-mode", "command-line", "-n"})), 0);
-    QVERIFY2(m_qbsStdout.contains("c99"), m_qbsStdout.constData());
+    if (isMsvc)
+        QVERIFY2(!m_qbsStdout.contains("c11"), m_qbsStdout.constData());
+    else
+        QVERIFY2(m_qbsStdout.contains("c99"), m_qbsStdout.constData());
 }
 
 void TestBlackbox::maximumCxxLanguageVersion()