base default output on filename instead of "a.out"

Also choose a target-appropriate default extension for dlls and exes.

ChangeLog.txt

@@ -100,6 +100,9 @@ Compiler frontend changes:
   in the current compilation unit.
 * External entry points for the main module are also now always compiled; "-shared"
   now only affects the type of file output by the compiler.
+* The default output filename for executables and dynamic libraries is now the
+  basename of the input file instead of "a.out". For instance, "clay hello.clay" will
+  output an executable named "hello" (or "hello.exe" if compiling for a Windows target).
 
 Planned changes
 ---------------

compiler/src/main.cpp

@@ -21,12 +21,8 @@
 #include <cstring>
 
 #ifdef WIN32
-#define DEFAULT_EXE "a.exe"
-#define DEFAULT_DLL "a.dll"
 #define PATH_SEPARATORS "/\\"
 #else
-#define DEFAULT_EXE "a.out"
-#define DEFAULT_DLL "a.out"
 #define PATH_SEPARATORS "/"
 #endif
 
@@ -305,6 +301,28 @@ static string basename(const string &fullname)
     return fullname.substr(from, length);
 }
 
+static string sharedExtensionForTarget(llvm::Triple const &triple) {
+    if (triple.getOS() == llvm::Triple::Win32
+        || triple.getOS() == llvm::Triple::MinGW32
+        || triple.getOS() == llvm::Triple::Cygwin) {
+        return ".dll";
+    } else if (triple.getOS() == llvm::Triple::Darwin) {
+        return ".dylib";
+    } else {
+        return ".so";
+    }
+}
+
+static string exeExtensionForTarget(llvm::Triple const &triple) {
+    if (triple.getOS() == llvm::Triple::Win32
+        || triple.getOS() == llvm::Triple::MinGW32
+        || triple.getOS() == llvm::Triple::Cygwin) {
+        return ".exe";
+    } else {
+        return "";
+    }
+}
+
 int main(int argc, char **argv) {
     if (argc == 1) {
         usage(argv[0]);
@@ -711,9 +729,9 @@ int main(int argc, char **argv) {
         else if (emitObject)
             outputFile = clayFileBasename + ".o";
         else if (sharedLib)
-            outputFile = DEFAULT_DLL;
+            outputFile = clayFileBasename + sharedExtensionForTarget(llvmTriple);
         else
-            outputFile = DEFAULT_EXE;
+            outputFile = clayFileBasename + exeExtensionForTarget(llvmTriple);
     }
     llvm::sys::Path outputFilePath(outputFile);
     llvm::sys::RemoveFileOnSignal(outputFilePath);

test/runtests.py

@@ -116,7 +116,7 @@ def loadTest(self, testfile):
         self.testfile = testfile
 
     def cmdline(self, clay) :
-        return [clay, "-I" + self.path] + self.buildflags + [self.testfile]
+        return [clay, "-I" + self.path, "-o", "test.exe"] + self.buildflags + [self.testfile]
 
     def pre_build(self) :
         pass
@@ -177,7 +177,7 @@ def name(self):
         return os.path.relpath(self.path, testRoot)
 
     def runtest(self):
-        outfilename = "a.exe" if sys.platform == "win32" else "a.out"
+        outfilename = "test.exe"
         outfilename = os.path.join(".", outfilename)
         process = Popen(self.cmdline(compiler), stdout=PIPE, stderr=PIPE)
         compilerout, compilererr = process.communicate()