Merge pull request #1099 from svaarala/fix-cygwin-math-issues

Fix a few math issues on Cygwin (MinGW)

Makefile

@@ -59,13 +59,20 @@ DUKTAPE_CMDLINE_SOURCES = \
 	examples/alloc-logging/duk_alloc_logging.c \
 	examples/alloc-torture/duk_alloc_torture.c \
 	examples/alloc-hybrid/duk_alloc_hybrid.c \
-	examples/debug-trans-socket/duk_trans_socket_unix.c \
 	extras/print-alert/duk_print_alert.c \
 	extras/console/duk_console.c \
 	extras/logging/duk_logging.c \
 	extras/module-duktape/duk_module_duktape.c
-LINENOISE_SOURCES = \
-	linenoise/linenoise.c
+ifdef SYSTEMROOT  # Windows
+DUKTAPE_CMDLINE_SOURCES += examples/debug-trans-socket/duk_trans_socket_windows.c
+else
+DUKTAPE_CMDLINE_SOURCES += examples/debug-trans-socket/duk_trans_socket_unix.c
+endif
+ifdef SYSTEMROOT  # Windows
+LINENOISE_SOURCES =
+else
+LINENOISE_SOURCES = linenoise/linenoise.c
+endif
 
 # Configure.py options for a few configuration profiles needed.
 CONFIGOPTS_NONDEBUG=--option-file util/makeduk_base.yaml
@@ -90,7 +97,11 @@ CCOPTS_SHARED += -DDUK_CMDLINE_PRINTALERT_SUPPORT
 CCOPTS_SHARED += -DDUK_CMDLINE_CONSOLE_SUPPORT
 CCOPTS_SHARED += -DDUK_CMDLINE_LOGGING_SUPPORT
 CCOPTS_SHARED += -DDUK_CMDLINE_MODULE_SUPPORT
+ifdef SYSTEMROOT  # Windows
+# Skip fancy (linenoise)
+else
 CCOPTS_SHARED += -DDUK_CMDLINE_FANCY
+endif
 CCOPTS_SHARED += -DDUK_CMDLINE_ALLOC_LOGGING
 CCOPTS_SHARED += -DDUK_CMDLINE_ALLOC_TORTURE
 CCOPTS_SHARED += -DDUK_CMDLINE_ALLOC_HYBRID
@@ -140,7 +151,11 @@ CCOPTS_AJDUK += -UDUK_CMDLINE_FANCY -DDUK_CMDLINE_AJSHEAP -D_POSIX_C_SOURCE=2008
 CCOPTS_AJDUK += -UDUK_CMDLINE_LOGGING_SUPPORT  # extras/logger init writes to Duktape.Logger, problem with ROM build
 CCOPTS_AJDUK += -UDUK_CMDLINE_MODULE_SUPPORT  # extras/module-duktape init writes to Duktape.Logger, problem with ROM build
 
+ifdef SYSTEMROOT  # Windows
+CCLIBS  = -lm -lws2_32
+else
 CCLIBS	= -lm
+endif
 
 # Emscripten options:
 #   - --memory-init-file 0 to avoid a separate memory init file (this is

RELEASES.rst

@@ -2033,6 +2033,9 @@ Planned
 
 * Fix Cygwin warning about shadowed 'accept' variable (GH-1098)
 
+* Fix Cygwin/MinGW math issues related to pow2() and atan2() semantics
+  (GH-1099)
+
 * Fix two-argument Math function (like Math.atan2()) argument coercion
   order; the order was not guaranteed but specification requires left-to-right
   ordering (GH-943)

config/config-options/DUK_USE_ATAN2_WORKAROUNDS.yaml

@@ -0,0 +1,8 @@
+define: DUK_USE_ATAN2_WORKAROUNDS
+introduced: 2.0.0
+default: false
+tags:
+  - portability
+description: >
+  Enable workarounds to common atan2() semantics issues.  At least Cygwin/MinGW
+  has such issues, see test-bug-mingw-math-issues.js.

config/config-options/DUK_USE_POW_NETBSD_WORKAROUND.yaml

@@ -1,5 +1,6 @@
 define: DUK_USE_POW_NETBSD_WORKAROUND
 introduced: 1.0.0
+removed: 2.0.0
 default: false
 tags:
   - portability

config/config-options/DUK_USE_POW_WORKAROUNDS.yaml

@@ -0,0 +1,9 @@
+define: DUK_USE_POW_WORKAROUNDS
+introduced: 2.0.0
+default: false
+tags:
+  - portability
+description: >
+  Enable workarounds to common pow() semantics issues.  At least NetBSD
+  6.0 x86 and Cygwin/MinGW have such issues, see test-bug-netbsd-math-pow.js
+  and test-bug-mingw-math-issues.js.

config/header-snippets/platform_fillins.h.in

@@ -279,12 +279,21 @@
 #endif  /* DUK_F_C99 */
 
 /* NetBSD 6.0 x86 (at least) has a few problems with pow() semantics,
- * see test-bug-netbsd-math-pow.js.  Use NetBSD specific workaround.
- * (This might be a wider problem; if so, generalize the define name.)
+ * see test-bug-netbsd-math-pow.js.  MinGW has similar (but different)
+ * issues, see test-bug-mingw-math-issues.js.  Enable pow() workarounds
+ * for these targets.
  */
-#undef DUK_USE_POW_NETBSD_WORKAROUND
-#if defined(DUK_F_NETBSD)
-#define DUK_USE_POW_NETBSD_WORKAROUND
+#undef DUK_USE_POW_WORKAROUNDS
+#if defined(DUK_F_NETBSD) || defined(DUK_F_MINGW)
+#define DUK_USE_POW_WORKAROUNDS
+#endif
+
+/* Similar workarounds for atan2() semantics issues.  MinGW issues are
+ * documented in test-bug-mingw-math-issues.js.
+ */
+#undef DUK_USE_ATAN2_WORKAROUNDS
+#if defined(DUK_F_MINGW)
+#define DUK_USE_ATAN2_WORKAROUNDS
 #endif
 
 /* Rely as little as possible on compiler behavior for NaN comparison,

doc/release-notes-v2-0.rst

@@ -1030,6 +1030,9 @@ Other incompatible changes
   is the same as "\u00078", "\8" and "\9" are accepted as literal "8" and "9"
   (even in strict mode).
 
+* The NetBSD pow() workaround option ``DUK_USE_POW_NETBSD_WORKAROUND`` has been
+  generalized and renamed to ``DUK_USE_POW_WORKAROUNDS``.
+
 Known issues
 ============
 

src-input/duk_bi_math.c

@@ -225,7 +225,34 @@ DUK_LOCAL double duk__sqrt(double x) {
 DUK_LOCAL double duk__tan(double x) {
 	return DUK_TAN(x);
 }
-DUK_LOCAL double duk__atan2(double x, double y) {
+DUK_LOCAL double duk__atan2_fixed(double x, double y) {
+#if defined(DUK_USE_ATAN2_WORKAROUNDS)
+	/* Specific fixes to common atan2() implementation issues:
+	 * - test-bug-mingw-math-issues.js
+	 */
+	if (DUK_ISINF(x) && DUK_ISINF(y)) {
+		if (DUK_SIGNBIT(x)) {
+			if (DUK_SIGNBIT(y)) {
+				return -2.356194490192345;
+			} else {
+				return -0.7853981633974483;
+			}
+		} else {
+			if (DUK_SIGNBIT(y)) {
+				return 2.356194490192345;
+			} else {
+				return 0.7853981633974483;
+			}
+		}
+	}
+#else
+	/* Some ISO C assumptions. */
+	DUK_ASSERT(DUK_ATAN2(DUK_DOUBLE_INFINITY, DUK_DOUBLE_INFINITY) == 0.7853981633974483);
+	DUK_ASSERT(DUK_ATAN2(-DUK_DOUBLE_INFINITY, DUK_DOUBLE_INFINITY) == -0.7853981633974483);
+	DUK_ASSERT(DUK_ATAN2(DUK_DOUBLE_INFINITY, -DUK_DOUBLE_INFINITY) == 2.356194490192345);
+	DUK_ASSERT(DUK_ATAN2(-DUK_DOUBLE_INFINITY, -DUK_DOUBLE_INFINITY) == -2.356194490192345);
+#endif
+
 	return DUK_ATAN2(x, y);
 }
 #endif  /* DUK_USE_AVOID_PLATFORM_FUNCPTRS */
@@ -278,10 +305,10 @@ DUK_LOCAL const duk__one_arg_func duk__one_arg_funcs[] = {
 /* order must match constants in genbuiltins.py */
 DUK_LOCAL const duk__two_arg_func duk__two_arg_funcs[] = {
 #if defined(DUK_USE_AVOID_PLATFORM_FUNCPTRS)
-	duk__atan2,
+	duk__atan2_fixed,
 	duk_js_arith_pow
 #else
-	DUK_ATAN2,
+	duk__atan2_fixed,
 	duk_js_arith_pow
 #endif
 };

src-input/duk_js.h

@@ -43,6 +43,7 @@ DUK_INTERNAL_DECL duk_small_uint_t duk_js_typeof_stridx(duk_tval *tv_x);
 
 /* arithmetic */
 DUK_INTERNAL_DECL double duk_js_arith_pow(double x, double y);
+DUK_INTERNAL_DECL double duk_js_arith_mod(double x, double y);
 
 #define duk_js_equals(thr,tv_x,tv_y) \
 	duk_js_equals_helper((thr), (tv_x), (tv_y), 0)

src-input/duk_js_arith.c

@@ -4,6 +4,58 @@
 
 #include "duk_internal.h"
 
+/* Ecmascript modulus ('%') does not match IEEE 754 "remainder" operation
+ * (implemented by remainder() in C99) but does seem to match ANSI C fmod().
+ * Compare E5 Section 11.5.3 and "man fmod".
+ */
+DUK_INTERNAL double duk_js_arith_mod(double d1, double d2) {
+#if defined(DUK_USE_POW_WORKAROUNDS)
+	/* Specific fixes to common fmod() implementation issues:
+	 * - test-bug-mingw-math-issues.js
+	 */
+	if (DUK_ISINF(d2)) {
+		if (DUK_ISINF(d1)) {
+			return DUK_DOUBLE_NAN;
+		} else {
+			return d1;
+		}
+	} else if (d1 == 0.0) {
+		/* d1 +/-0 is returned as is (preserving sign) except when
+		 * d2 is zero or NaN.
+		 */
+		if (d2 == 0.0 || DUK_ISNAN(d2)) {
+			return DUK_DOUBLE_NAN;
+		} else {
+			return d1;
+		}
+	}
+#else
+	/* Some ISO C assumptions. */
+	DUK_ASSERT(DUK_FMOD(1.0, DUK_DOUBLE_INFINITY) == 1.0);
+	DUK_ASSERT(DUK_FMOD(-1.0, DUK_DOUBLE_INFINITY) == -1.0);
+	DUK_ASSERT(DUK_FMOD(1.0, -DUK_DOUBLE_INFINITY) == 1.0);
+	DUK_ASSERT(DUK_FMOD(-1.0, -DUK_DOUBLE_INFINITY) == -1.0);
+	DUK_ASSERT(DUK_ISNAN(DUK_FMOD(DUK_DOUBLE_INFINITY, DUK_DOUBLE_INFINITY)));
+	DUK_ASSERT(DUK_ISNAN(DUK_FMOD(DUK_DOUBLE_INFINITY, -DUK_DOUBLE_INFINITY)));
+	DUK_ASSERT(DUK_ISNAN(DUK_FMOD(-DUK_DOUBLE_INFINITY, DUK_DOUBLE_INFINITY)));
+	DUK_ASSERT(DUK_ISNAN(DUK_FMOD(-DUK_DOUBLE_INFINITY, -DUK_DOUBLE_INFINITY)));
+	DUK_ASSERT(DUK_FMOD(0.0, 1.0) == 0.0 && DUK_SIGNBIT(DUK_FMOD(0.0, 1.0)) == 0);
+	DUK_ASSERT(DUK_FMOD(-0.0, 1.0) == 0.0 && DUK_SIGNBIT(DUK_FMOD(-0.0, 1.0)) != 0);
+	DUK_ASSERT(DUK_FMOD(0.0, DUK_DOUBLE_INFINITY) == 0.0 && DUK_SIGNBIT(DUK_FMOD(0.0, DUK_DOUBLE_INFINITY)) == 0);
+	DUK_ASSERT(DUK_FMOD(-0.0, DUK_DOUBLE_INFINITY) == 0.0 && DUK_SIGNBIT(DUK_FMOD(-0.0, DUK_DOUBLE_INFINITY)) != 0);
+	DUK_ASSERT(DUK_FMOD(0.0, -DUK_DOUBLE_INFINITY) == 0.0 && DUK_SIGNBIT(DUK_FMOD(0.0, DUK_DOUBLE_INFINITY)) == 0);
+	DUK_ASSERT(DUK_FMOD(-0.0, -DUK_DOUBLE_INFINITY) == 0.0 && DUK_SIGNBIT(DUK_FMOD(-0.0, -DUK_DOUBLE_INFINITY)) != 0);
+	DUK_ASSERT(DUK_ISNAN(DUK_FMOD(0.0, 0.0)));
+	DUK_ASSERT(DUK_ISNAN(DUK_FMOD(-0.0, 0.0)));
+	DUK_ASSERT(DUK_ISNAN(DUK_FMOD(0.0, -0.0)));
+	DUK_ASSERT(DUK_ISNAN(DUK_FMOD(-0.0, -0.0)));
+	DUK_ASSERT(DUK_ISNAN(DUK_FMOD(0.0, DUK_DOUBLE_NAN)));
+	DUK_ASSERT(DUK_ISNAN(DUK_FMOD(-0.0, DUK_DOUBLE_NAN)));
+#endif
+
+	return (duk_double_t) DUK_FMOD((double) d1, (double) d2);
+}
+
 /* Shared helper for Math.pow() and exponentiation operator. */
 DUK_INTERNAL double duk_js_arith_pow(double x, double y) {
 	/* The ANSI C pow() semantics differ from Ecmascript.
@@ -24,10 +76,11 @@ DUK_INTERNAL double duk_js_arith_pow(double x, double y) {
 	if (DUK_FABS(x) == 1.0 && cy == DUK_FP_INFINITE) {
 		goto ret_nan;
 	}
-#if defined(DUK_USE_POW_NETBSD_WORKAROUND)
-	/* See test-bug-netbsd-math-pow.js: NetBSD 6.0 on x86 (at least) does not
-	 * correctly handle some cases where x=+/-0.  Specific fixes to these
-	 * here.
+
+#if defined(DUK_USE_POW_WORKAROUNDS)
+	/* Specific fixes to common pow() implementation issues:
+	 *   - test-bug-netbsd-math-pow.js: NetBSD 6.0 on x86 (at least)
+	 *   - test-bug-mingw-math-issues.js
 	 */
 	cx = (duk_small_int_t) DUK_FPCLASSIFY(x);
 	if (cx == DUK_FP_ZERO && y < 0.0) {
@@ -42,7 +95,7 @@ DUK_INTERNAL double duk_js_arith_pow(double x, double y) {
 		} else {
 			/* Math.pow(-0,y) where y<0 should be:
 			 *   - -Infinity if y<0 and an odd integer
-			 *   - Infinity otherwise
+			 *   - Infinity if y<0 but not an odd integer
 			 * NetBSD pow() returns -Infinity for all finite y<0.  The
 			 * if-clause also catches y == -Infinity (which works even
 			 * without the fix).
@@ -61,8 +114,22 @@ DUK_INTERNAL double duk_js_arith_pow(double x, double y) {
 				return DUK_DOUBLE_INFINITY;
 			}
 		}
+	} else if (cx == DUK_FP_NAN) {
+		if (y == 0.0) {
+			/* NaN ** +/- 0 should always be 1, but is NaN on
+			 * at least some Cygwin/MinGW versions.
+			 */
+			return 1.0;
+		}
 	}
+#else
+	/* Some ISO C assumptions. */
+	DUK_ASSERT(DUK_POW(DUK_DOUBLE_NAN, 0.0) == 1.0);
+	DUK_ASSERT(DUK_ISINF(DUK_POW(0.0, -1.0)) && DUK_SIGNBIT(DUK_POW(0.0, -1.0)) == 0);
+	DUK_ASSERT(DUK_ISINF(DUK_POW(-0.0, -2.0)) && DUK_SIGNBIT(DUK_POW(-0.0, -2.0)) == 0);
+	DUK_ASSERT(DUK_ISINF(DUK_POW(-0.0, -3.0)) && DUK_SIGNBIT(DUK_POW(-0.0, -3.0)) != 0);
 #endif
+
 	return DUK_POW(x, y);
 
  ret_nan:

src-input/duk_js_executor.c

@@ -73,15 +73,7 @@ DUK_LOCAL void duk__push_tvals_incref_only(duk_hthread *thr, duk_tval *tv_src, d
  */
 
 DUK_LOCAL DUK__INLINE_PERF duk_double_t duk__compute_mod(duk_double_t d1, duk_double_t d2) {
-	/*
-	 *  Ecmascript modulus ('%') does not match IEEE 754 "remainder"
-	 *  operation (implemented by remainder() in C99) but does seem
-	 *  to match ANSI C fmod().
-	 *
-	 *  Compare E5 Section 11.5.3 and "man fmod".
-	 */
-
-	return (duk_double_t) DUK_FMOD((double) d1, (double) d2);
+	return (duk_double_t) duk_js_arith_mod((double) d1, (double) d2);
 }
 
 #if defined(DUK_USE_ES7_EXP_OPERATOR)

tests/ecmascript/test-bug-mingw-math-issues.js

@@ -0,0 +1,75 @@
+/*
+ *  Some MinGW math issues
+ *
+ *  https://github.com/svaarala/duktape/pull/1099
+ */
+
+/*@include util-number.js@*/
+
+/*===
+1
+1
+-1e+100
+-1e+100
+NaN
+NaN
+NaN
+NaN
+0
+-0
+0
+-0
+0
+-0
+0
+-0
+NaN
+NaN
+NaN
+NaN
+NaN
+NaN
+0.7853981633974483
+2.356194490192345
+-0.7853981633974483
+-2.356194490192345
+1
+1
+===*/
+
+function test() {
+    printExact((0/0) ** 0);
+    printExact((0/0) ** -0);
+    printExact((-1e100) % (1/0));  // return 1st arg if modulus is +/- inf
+    printExact((-1e100) % (-1/0));
+    printExact((1/0) % (1/0));     // but if 1st arg is +/- inf (and modulus +/- inf), return NaN
+    printExact((1/0) % (-1/0));
+    printExact((-1/0) % (1/0));
+    printExact((-1/0) % (-1/0));
+    printExact(0 % 1);  // preserve zero and its sign, even for inf
+    printExact(-0 % 1);
+    printExact(0 % -1);
+    printExact(-0 % -1);
+    printExact(0 % (1/0));
+    printExact(-0 % (1/0));
+    printExact(0 % (-1/0));
+    printExact(-0 % (-1/0));
+    printExact(0 % (0/0));    // ... but if modulus is NaN or 0, result is NaN
+    printExact(-0 % (0/0));
+    printExact(0 % 0);
+    printExact(-0 % 0);
+    printExact(0 % -0);
+    printExact(-0 % -0);
+    printExact(Math.atan2(1/0, 1/0));
+    printExact(Math.atan2(1/0, -1/0));
+    printExact(Math.atan2(-1/0, 1/0));
+    printExact(Math.atan2(-1/0, -1/0));
+    printExact(Math.pow(0/0, 0));
+    printExact(Math.pow(0/0, -0));
+}
+
+try {
+    test();
+} catch (e) {
+    print(e.stack || e);
+}

util/makeduk_base.yaml

@@ -8,7 +8,7 @@
 DUK_USE_TARGET_INFO: "\"duk command built from Duktape repo\""
 
 DUK_USE_FATAL_HANDLER:
-  verbatim: "#define DUK_USE_FATAL_HANDLER(udata,msg) do { const char *fatal_msg = (msg); fprintf(stderr, \"*** FATAL ERROR: %s\\n\", fatal_msg ? fatal_msg : \"no message\"); *((volatile unsigned int *) 0) = (unsigned int) 0xdeadbeefUL; abort(); } while(0)"
+  verbatim: "#define DUK_USE_FATAL_HANDLER(udata,msg) do { const char *fatal_msg = (msg); fprintf(stderr, \"*** FATAL ERROR: %s\\n\", fatal_msg ? fatal_msg : \"no message\"); fflush(stderr); *((volatile unsigned int *) 0) = (unsigned int) 0xdeadbeefUL; abort(); } while(0)"
 DUK_USE_SELF_TESTS: true
 
 #DUK_USE_ASSERTIONS: true

util/makeduk_debug.yaml

@@ -5,5 +5,5 @@ DUK_USE_DEBUG: true
 DUK_USE_DEBUG_LEVEL: 0
 #DUK_USE_DEBUG_LEVEL: 1
 DUK_USE_DEBUG_WRITE:
-  verbatim: "#define DUK_USE_DEBUG_WRITE(level,file,line,func,msg) do {fprintf(stderr, \"D%ld %s:%ld (%s): %s\\n\", (long) (level), (file), (long) (line), (func), (msg));} while(0)"
+  verbatim: "#define DUK_USE_DEBUG_WRITE(level,file,line,func,msg) do {fprintf(stderr, \"D%ld %s:%ld (%s): %s\\n\", (long) (level), (file), (long) (line), (func), (msg)); fflush(stderr);} while(0)"
 DUK_USE_ASSERTIONS: true