Allow the GccProbe to fail more gracefully

This lets error handling be deferred to a more appropriate venue
like module validate scripts rather than failing with an error
message like "could not find/execute g++".

Change-Id: I90223339a1b4ac4fa6674c8c2ddd95acc19d395e
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

2 files changed, 17 insertions, 0 deletions

diff --git a/share/qbs/imports/qbs/Probes/GccProbe.qbs b/share/qbs/imports/qbs/Probes/GccProbe.qbs
index c08ab7d9a..7214ffacb 100644
--- a/share/qbs/imports/qbs/Probes/GccProbe.qbs
+++ b/share/qbs/imports/qbs/Probes/GccProbe.qbs
@@ -29,6 +29,7 @@
 ****************************************************************************/
 
 import qbs
+import qbs.File
 import qbs.ModUtils
 import "../../../modules/cpp/gcc.js" as Gcc
 
@@ -53,6 +54,11 @@ PathProbe {
     property stringList frameworkPaths
 
     configure: {
+        if (!File.exists(compilerFilePath)) {
+            found = false;
+            return;
+        }
+
         var macros = Gcc.dumpMacros(environment, compilerFilePath, flags, _nullDevice);
         var defaultPaths = Gcc.dumpDefaultPaths(environment, compilerFilePath, flags, _nullDevice,
                                                 _pathListSeparator, _sysroot);
diff --git a/share/qbs/modules/cpp/GenericGCC.qbs b/share/qbs/modules/cpp/GenericGCC.qbs
index 5cad42578..d81fb15c8 100644
--- a/share/qbs/modules/cpp/GenericGCC.qbs
+++ b/share/qbs/modules/cpp/GenericGCC.qbs
@@ -242,6 +242,17 @@ CppModule {
     }
 
     validate: {
+        if (!File.exists(compilerPath)) {
+            var pathMessage = FileInfo.isAbsolutePath(compilerPath)
+                    ? "at '" + compilerPath + "'"
+                    : "'" + compilerPath + "' in PATH";
+            throw ModUtils.ModuleError("Could not find selected C++ compiler " + pathMessage + ". "
+                                       + "Ensure that the compiler is properly "
+                                       + "installed, or set cpp.toolchainInstallPath to a valid "
+                                       + "toolchain path, or consider whether you meant to set "
+                                       + "cpp.compilerName instead.");
+        }
+
         var validator = new ModUtils.PropertyValidator("cpp");
         validator.setRequiredProperty("architecture", architecture,
                                       "you might want to re-run 'qbs-setup-toolchains'");