properly handle invoke of setjmp, by lowering to a call, which fixes phis that refer to it. fixes #1942

3 files changed, 61 insertions, 1 deletions

diff --git a/src/analyzer.js b/src/analyzer.js
index 17582ea3..e8ca6cf6 100644
--- a/src/analyzer.js
+++ b/src/analyzer.js
@@ -1570,7 +1570,17 @@ function analyzer(data, sidePass) {
         for (var j = 0; j < label.lines.length; j++) {
           var line = label.lines[j];
           if ((line.intertype == 'call' || line.intertype == 'invoke') && line.ident == setjmp) {
-            // Add a new label
+            if (line.intertype == 'invoke') {
+              // setjmp cannot trigger unwinding, so just reduce the invoke to a call + branch
+              line.intertype = 'call';
+              label.lines.push({
+                intertype: 'branch',
+                label: line.toLabel,
+                lineNum: line.lineNum + 0.01, // XXX legalizing might confuse this
+              });
+              line.toLabel = line.unwindLabel = -2;
+            }
+            // split this label into up to the setjmp (including), then a new label for the rest. longjmp will reach the rest
             var oldLabel = label.ident;
             var newLabel = func.labelIdCounter++;
             if (!func.setjmpTable) func.setjmpTable = [];
diff --git a/tests/cases/longjmp_tiny_invoke_phi.ll b/tests/cases/longjmp_tiny_invoke_phi.ll
new file mode 100644
index 00000000..30c43339
--- /dev/null
+++ b/tests/cases/longjmp_tiny_invoke_phi.ll
@@ -0,0 +1,46 @@
+; ModuleID = '/tmp/emscripten_temp/src.cpp.o'
+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"
+
+@_ZL3buf = internal global [20 x i16] zeroinitializer, align 2
+@.str = private unnamed_addr constant [13 x i8] c"hello world\0A\00", align 1
+@.str1 = private unnamed_addr constant [6 x i8] c"more\0A\00", align 1
+@.str2 = private unnamed_addr constant [6 x i8] c"fair\0A\00", align 1
+
+define i32 @main() {
+entry:
+  %retval = alloca i32, align 4
+  store i32 0, i32* %retval
+  %call = invoke i32 @setjmp(i16* getelementptr inbounds ([20 x i16]* @_ZL3buf, i32 0, i32 0)) returns_twice
+          to label %allgood unwind label %awful
+
+allgood:
+  %p = phi i32 [0, %entry], [1, %if.else]
+  %calll = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([6 x i8]* @.str2, i32 0, i32 0))
+  %total = add i32 %p, %call
+  %tobool = icmp ne i32 %total, 10
+  br i1 %tobool, label %if.then, label %if.else
+
+if.then:                                          ; preds = %entry
+  %call1 = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([13 x i8]* @.str, i32 0, i32 0))
+  call void @longjmp(i16* getelementptr inbounds ([20 x i16]* @_ZL3buf, i32 0, i32 0), i32 10)
+  br label %if.end
+
+if.else:                                          ; preds = %entry
+  %call2 = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([6 x i8]* @.str1, i32 0, i32 0))
+  %chak = icmp ne i32 %call2, 1337
+  br i1 %chak, label %if.end, label %allgood
+
+if.end:                                           ; preds = %if.else, %if.then
+  ret i32 0
+
+awful:
+  ret i32 1
+}
+
+declare i32 @setjmp(i16*) returns_twice
+
+declare i32 @printf(i8*, ...)
+
+declare void @longjmp(i16*, i32)
+
diff --git a/tests/cases/longjmp_tiny_invoke_phi.txt b/tests/cases/longjmp_tiny_invoke_phi.txt
new file mode 100644
index 00000000..aaa41d11
--- /dev/null
+++ b/tests/cases/longjmp_tiny_invoke_phi.txt
@@ -0,0 +1,4 @@
+fair
+hello world
+fair
+more