fix for getFastValue with subtracting a negative

3 files changed, 20 insertions, 1 deletions

diff --git a/src/parseTools.js b/src/parseTools.js
index 4f2f7142..86e3c643 100644
--- a/src/parseTools.js
+++ b/src/parseTools.js
@@ -1171,7 +1171,7 @@ function getFastValue(a, op, b, type) {
     if (op == 'pow') {
       return Math.pow(a, b).toString();
     } else {
-      return eval(a + op + b).toString();
+      return eval(a + op + '(' + b + ')').toString(); // parens protect us from "5 - -12" being seen as "5--12" which is "(5--)12"
     }
   }
   if (op == 'pow') {
diff --git a/tests/cases/subnums.ll b/tests/cases/subnums.ll
new file mode 100644
index 00000000..981a1592
--- /dev/null
+++ b/tests/cases/subnums.ll
@@ -0,0 +1,18 @@
+; ModuleID = 'tests/hello_world.bc'
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32-S128"
+target triple = "i386-pc-linux-gnu"
+
+@.str = private unnamed_addr constant [15 x i8] c"hello, world! %d\0A\00", align 1 ; [#uses=1 type=[18 x i8]*]
+
+; [#uses=0]
+define i32 @main() {
+entry:
+  %retval = alloca i32, align 4                   ; [#uses=1 type=i32*]
+  %sub = sub nsw i32 0, -2147483648
+  store i32 %sub, i32* %retval
+  %call = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([18 x i8]* @.str, i32 0, i32 0), i32 %sub) ; [#uses=0 type=i32]
+  ret i32 1
+}
+
+; [#uses=1]
+declare i32 @printf(i8*, ...)
diff --git a/tests/cases/subnums.txt b/tests/cases/subnums.txt
new file mode 100644
index 00000000..e8831e0b
--- /dev/null
+++ b/tests/cases/subnums.txt
@@ -0,0 +1 @@
+hello, world! -2147483648