[RFC] Add a minimal baremetal testsuite to Phobos

posix.mak

@@ -427,14 +427,42 @@ unittest/%.run : $(ROOT)/unittest/test_runner
 # Run separate -betterC tests
 ################################################################################
 
-test/betterC/%.run: test/betterC/%.d $(DMD) $(LIB)
+test/betterC/%.run: test/betterC/%.d $(DMD) $(DRUNTIME)
 	mkdir -p $(ROOT)/unittest/betterC
 	$(DMD) $(DFLAGS) -of$(ROOT)/unittest/betterC/$(notdir $(basename $<)) -betterC $(UDFLAGS) \
 		-defaultlib= -debuglib= $(LINKDL) $<
 	./$(ROOT)/unittest/betterC/$(notdir $(basename $<))
 
 betterC: $(subst .d,.run,$(wildcard test/betterC/*.d))
 
+################################################################################
+# Run separate baremetal tests (for now only on x86_64 Linux)
+################################################################################
+
+MINIMAL_RUNTIME=$(ROOT)/unittest/baremetal/runtime.a
+
+$(MINIMAL_RUNTIME): test/baremetal/runtime/runtime.d $(DMD) $(DRUNTIME)
+	mkdir -p $(ROOT)/unittest/baremetal
+	$(DMD) -betterC -c $(DFLAGS) -lib -of$@ $<
+
+test/baremetal/%.run: test/baremetal/%.d $(DMD) $(MINIMAL_RUNTIME)
+	mkdir -p $(ROOT)/unittest/baremetal
+	$(DMD) $(DFLAGS) -c -betterC -of$(ROOT)/unittest/baremetal/$(notdir $(basename $<)).o -betterC $(UDFLAGS) $<
+	ld $(ROOT)/unittest/baremetal/$(notdir $(basename $<)).o $(MINIMAL_RUNTIME) \
+		-o $(ROOT)/unittest/baremetal/$(notdir $(basename $<))
+	./$(ROOT)/unittest/baremetal/$(notdir $(basename $<))
+
+ifneq (linux, $(OS))
+baremetal:
+	@echo "Baremetal tests are currently only run on Linux x86_32 and x86_64"
+else
+ifeq (,$(findstring $(MODEL),64))
+baremetal:
+	@echo "Baremetal tests are currently only run on Linux x86_32 and x86_64"
+endif
+baremetal: $(subst .d,.run,$(wildcard test/baremetal/*.d))
+endif
+
 ################################################################################
 # More stuff
 ################################################################################
@@ -634,6 +662,6 @@ $(TESTS_EXTRACTOR): $(TOOLS_DIR)/tests_extractor.d | $(LIB)
 auto-tester-build: all checkwhitespace
 
 .PHONY : auto-tester-test
-auto-tester-test: unittest betterC
+auto-tester-test: unittest betterC baremetal
 
 .DELETE_ON_ERROR: # GNU Make directive (delete output files on error)

test/baremetal/hello.d

@@ -0,0 +1,6 @@
+extern(C) int main()
+{
+    import std.algorithm, std.range;
+    assert(100.iota.stride(2).take(10).sum == 90);
+    return 0;
+}

test/baremetal/runtime/runtime.d

@@ -0,0 +1,83 @@
+extern(C) void __d_sys_exit(size_t arg1)
+{
+    version(linux)
+    {
+        version(X86_64)
+        {
+            asm
+            {
+                mov RAX, 60;
+                mov RDI, arg1;
+                syscall;
+            }
+        }
+        else version(X86)
+        {
+            asm
+            {
+                mov EAX, 2;
+                mov EDI, arg1;
+                syscall;
+            }
+        }
+    }
+}
+
+extern(C) void __assert(const(char)* exp, const(char)* file, uint line)
+{
+    version(linux)
+        print("ASSERT ERROR\n");
+    assert(0);
+}
+
+extern extern(C) int main();
+private extern(C) void _start()
+{
+    __d_sys_exit(main());
+}
+
+void print(const char* c)
+{
+    print(c, c.strlen);
+}
+
+void print(const char* c, size_t len)
+{
+    version(linux)
+    {
+        version(X86_64)
+        {
+            asm
+            {
+                mov RDX, len;
+                mov RSI, c;
+                mov RAX, 1; // write
+                mov RDI, RAX;
+                syscall;
+            }
+        }
+        else version(X86)
+        {
+            asm
+            {
+                mov EDX, len;
+                mov ESI, c;
+                mov EAX, 1; // write
+                mov EDI, EAX;
+                syscall;
+            }
+        }
+    }
+}
+
+size_t strlen(const char* c)
+{
+    auto cptr = cast(char*) c;
+    size_t i;
+    while (*cptr != 0)
+    {
+        cptr++;
+        i++;
+    }
+    return i;
+}