Update ab.

Author: davidgiven

build/ab.py

@@ -501,11 +501,17 @@ def emit_rule(self, ins, outs, cmds=[], label=None):
 
         emit(f"OUTS_{outsn}", "=", *fouts, into=lines)
         emit(f"INS_{insn}", "=", *fins, into=lines)
-        emit(name, ":", f"$(OUTS_{outsn})")
-        emit(hashfile, ":")
-        emit(f"\t@mkdir -p {self.dir}")
-        emit(f"\t@touch {hashfile}")
-        emit(f"$(OUTS_{outsn})", "&:",f"$(INS_{insn})", hashfile, into=lines)
+        emit(name, ":", f"$(OUTS_{outsn})", into=lines)
+        emit(hashfile, ":", into=lines)
+        emit(f"\t@mkdir -p {self.dir}", into=lines)
+        emit(f"\t@touch {hashfile}", into=lines)
+        emit(
+            f"$(OUTS_{outsn})",
+            "&:" if len(fouts) > 1 else ":",
+            f"$(INS_{insn})",
+            hashfile,
+            into=lines,
+        )
 
         if label:
             emit("\t$(hide)", "$(ECHO) $(PROGRESSINFO)" + label, into=lines)

build/c.py

@@ -444,7 +444,7 @@ def programimpl(
     simplerule(
         replaces=self,
         ins=cfiles + libs,
-        outs=[f"={self.localname}$(EXT)"],
+        outs=[f"={self.localname}{toolchain.EXE}"],
         deps=deps,
         label=label,
         commands=commands,

build/toolchain.py

@@ -1,5 +1,10 @@
+import platform
+
+_is_windows = (platform.system() == "Windows")
+
 class Toolchain:
     PREFIX = ""
+    EXE = ".exe" if _is_windows else ""
 
 
 class HostToolchain(Toolchain):