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authorMichael Forney <mforney@mforney.org>2019-02-19 12:43:29 -0800
committerMichael Forney <mforney@mforney.org>2019-02-19 13:25:27 -0800
commit07ead54177dbbc28ce0665f0091f6be0940f5763 (patch)
treeab5c47e87a85c9ed05fb39006f0c9ae59eec7ef2
parentd13019290ee2e7f41369f1d31ce903efd26cfd05 (diff)
Add missing lvalue conversions
typeintpromote and typeargpromote assume they are dealing with an unqualified type, and return an incorrect result if they are given a qualified one. So, add an assert here. This was causing const integer types to get promoted to themselves due to missing lvalue conversions. Thanks to Andrew Chambers for the bug report and test case.
-rw-r--r--expr.c4
-rw-r--r--tests/lvalue-conversion.c6
-rw-r--r--tests/lvalue-conversion.qbe14
-rw-r--r--type.c2
4 files changed, 26 insertions, 0 deletions
diff --git a/expr.c b/expr.c
index aad7cbc..46d81e8 100644
--- a/expr.c
+++ b/expr.c
@@ -473,6 +473,7 @@ postfixexpr(struct scope *s, struct expression *r)
if (!p && !t->func.isvararg && t->func.paraminfo)
error(&tok.loc, "too many arguments for function call");
*end = assignexpr(s);
+ lvalueconvert(*end);
if (!t->func.isprototype || (t->func.isvararg && !p))
*end = exprconvert(*end, typeargpromote((*end)->type));
else
@@ -585,17 +586,20 @@ unaryexpr(struct scope *s)
case TADD:
next();
e = castexpr(s);
+ lvalueconvert(e);
e = exprconvert(e, typeintpromote(e->type));
break;
case TSUB:
next();
e = castexpr(s);
+ lvalueconvert(e);
e = exprconvert(e, typeintpromote(e->type));
e = mkbinaryexpr(&tok.loc, TSUB, mkconstexpr(&typeint, 0), e);
break;
case TBNOT:
next();
e = castexpr(s);
+ lvalueconvert(e);
e = exprconvert(e, typeintpromote(e->type));
e = mkbinaryexpr(&tok.loc, TXOR, e, mkconstexpr(e->type, -1));
break;
diff --git a/tests/lvalue-conversion.c b/tests/lvalue-conversion.c
new file mode 100644
index 0000000..6bbc326
--- /dev/null
+++ b/tests/lvalue-conversion.c
@@ -0,0 +1,6 @@
+void g();
+void f(void) {
+ static const unsigned char c = 0;
+ g(c);
+ g(~c);
+}
diff --git a/tests/lvalue-conversion.qbe b/tests/lvalue-conversion.qbe
new file mode 100644
index 0000000..ac5fbc3
--- /dev/null
+++ b/tests/lvalue-conversion.qbe
@@ -0,0 +1,14 @@
+data $.Lc.2 = align 1 { b 0, }
+export
+function $f() {
+@start.1
+@body.2
+ %.1 =w loadub $.Lc.2
+ %.2 =w extub %.1
+ call $g(w %.2)
+ %.3 =w loadub $.Lc.2
+ %.4 =w extub %.3
+ %.5 =w xor %.4, 18446744073709551615
+ call $g(w %.5)
+ ret
+}
diff --git a/type.c b/type.c
index 97def21..d5550d3 100644
--- a/type.c
+++ b/type.c
@@ -237,6 +237,7 @@ typeunqual(struct type *t, enum typequalifier *tq)
struct type *
typeintpromote(struct type *t)
{
+ assert(t->kind != TYPEQUALIFIED);
if (typeprop(t) & PROPINT && typerank(t) <= typerank(&typeint))
return t->size < typeint.size || t->basic.issigned ? &typeint : &typeuint;
return t;
@@ -245,6 +246,7 @@ typeintpromote(struct type *t)
struct type *
typeargpromote(struct type *t)
{
+ assert(t->kind != TYPEQUALIFIED);
if (t == &typefloat)
return &typedouble;
return typeintpromote(t);