Signed overflow Was: Re: GNU poke 2.0.92 with ubsan

[Jose E. Marchesi]

Hi Bruno.
So I tried with ubsan with your patch, plus these changes:

diff --git a/libpoke/pkl-fold.c b/libpoke/pkl-fold.c
index 71656d75..2c96bfb4 100644
--- a/libpoke/pkl-fold.c
+++ b/libpoke/pkl-fold.c
@@ -227,8 +227,8 @@ EMUL_UU (bnoto) { return ~op; }
               /* Check for overflow in several signed */                \
               /* arithmetic operations.  */                             \
               size_t size = PKL_AST_TYPE_I_SIZE (type);                 \
-              int64_t op_val = ((int64_t) PKL_AST_INTEGER_VALUE (op)    \
-                                << (64 - size));                        \
+              int64_t op_val = ((uint64_t) (int64_t) PKL_AST_INTEGER_VALUE 
(op)) \
+                                << (64 - size);                         \
                                                                         \
               switch (PKL_AST_EXP_CODE (PKL_PASS_NODE))                 \
                 {                                                       \
@@ -583,10 +583,10 @@ EMUL_UU (bnoto) { return ~op; }
               /* Check for overflow in several signed */                \
               /* arithmetic operations.  */                             \
               size_t size = PKL_AST_TYPE_I_SIZE (type);                 \
-              int64_t op1_val = ((int64_t) PKL_AST_INTEGER_VALUE (op1)  \
-                                 << (64 - size));                       \
-              int64_t op2_val = ((int64_t) PKL_AST_INTEGER_VALUE (op2)  \
-                                 << (64 - size));                       \
+              int64_t op1_val = ((uint64_t)(int64_t) PKL_AST_INTEGER_VALUE 
(op1)) \
+                                 << (64 - size);                       \
+              int64_t op2_val = ((uint64_t)(int64_t) PKL_AST_INTEGER_VALUE 
(op2)) \
+                                 << (64 - size);                       \
                                                                         \
               switch (PKL_AST_EXP_CODE (PKL_PASS_NODE))                 \
                 {                                                       \
diff --git a/libpoke/pvm-val.h b/libpoke/pvm-val.h
index 9489bf4a..1954e40e 100644
--- a/libpoke/pvm-val.h
+++ b/libpoke/pvm-val.h
@@ -64,7 +64,7 @@
                         << (32 - PVM_VAL_INT_SIZE ((V)))       \
                         >> (32 - PVM_VAL_INT_SIZE ((V))))
 #define PVM_MAKE_INT(V,S)                       \
-  (((((int64_t) (V)) & 0xffffffff) << 32)       \
+  (((((uint64_t)(int64_t) (V)) & 0xffffffff) << 32)     \
    | ((((S) - 1) & 0x1f) << 3)                  \
    | PVM_VAL_TAG_INT)
 
diff --git a/libpoke/pvm.jitter b/libpoke/pvm.jitter
index 80fc58df..495eaa29 100644
--- a/libpoke/pvm.jitter
+++ b/libpoke/pvm.jitter
@@ -323,7 +323,7 @@ late-header-c
   {                                                                          \
     CTYPE a = PVM_VAL_##TYPE (JITTER_TOP_STACK ());                          \
     int size = PVM_VAL_##TYPE##_SIZE (JITTER_TOP_STACK ());                  \
-    int64_t a64 = ((int64_t) a << (64 - size));                              \
+    int64_t a64 = ((uint64_t)(int64_t) a) << (64 - size);                    \
                                                                              \
     if (INT_NEGATE_OVERFLOW (a64))                                           \
       PVM_RAISE_DFL (PVM_E_OVERFLOW);                                        \
@@ -404,7 +404,7 @@ late-header-c
     CTYPE a = PVM_VAL_##TYPE (JITTER_UNDER_TOP_STACK ());                    \
     CTYPE b = PVM_VAL_##TYPE (JITTER_TOP_STACK ());                          \
     int size = PVM_VAL_##TYPE##_SIZE (JITTER_TOP_STACK ());                  \
-    int64_t a64 = ((int64_t) a << (64 - size));                              \
+    int64_t a64 = ((uint64_t)(int64_t) a) << (64 - size);                    \
                                                                              \
     if (INT_DIVIDE_OVERFLOW (a64, b))                                        \
       PVM_RAISE_DFL (PVM_E_OVERFLOW);                                        \
@@ -422,7 +422,7 @@ late-header-c
     CTYPE a = PVM_VAL_##TYPE (JITTER_UNDER_TOP_STACK ());                    \
     CTYPE b = PVM_VAL_##TYPE (JITTER_TOP_STACK ());                          \
     int size = PVM_VAL_##TYPE##_SIZE (JITTER_TOP_STACK ());                  \
-    int64_t a64 = ((int64_t) a << (64 - size));                              \
+    int64_t a64 = ((uint64_t) (int64_t) a) << (64 - size);                   \
                                                                              \
     if (INT_DIVIDE_OVERFLOW (a64, b))                                        \
       PVM_RAISE_DFL (PVM_E_OVERFLOW);                                        \

The testsuite now passes without failures and without UBSAN warnings.
However, the changes in pkl-fold.c trigger a compile-time warning
(-Woverflow) in the gnulib macros INT_*_OVERFLOW.

This is one of these warnings:

In file included from ../../gl-libpoke/xalloc.h:27:0,
                 from ../../libpoke/pkl-fold.c:28:
../../libpoke/pkl-fold.c: In function 'pkl_fold_or':
../../gl-libpoke/intprops.h:310:65: warning: integer overflow in expression 
[-Woverflow]
        : (a) % (_GL_INT_CONVERT (a, _GL_SIGNED_INT_MAXIMUM (b)) + 1))   \
                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~
../../gl-libpoke/intprops.h:300:19: note: in expansion of macro 
'_GL_UNSIGNED_NEG_MULTIPLE'
    : (b) < 0 && ! _GL_UNSIGNED_NEG_MULTIPLE (a, b, max))
                   ^~~~~~~~~~~~~~~~~~~~~~~~~
../../gl-libpoke/intprops.h:388:3: note: in expansion of macro 
'_GL_REMAINDER_OVERFLOW'
   op_result_overflow (a, b,                                     \
   ^~~~~~~~~~~~~~~~~~
../../gl-libpoke/intprops.h:378:3: note: in expansion of macro 
'_GL_BINARY_OP_OVERFLOW'
   _GL_BINARY_OP_OVERFLOW (a, b, _GL_REMAINDER_OVERFLOW)
   ^~~~~~~~~~~~~~~~~~~~~~
../../libpoke/pkl-fold.c:613:23: note: in expansion of macro 
'INT_REMAINDER_OVERFLOW'
                   if (INT_REMAINDER_OVERFLOW (op1_val,                  \