handle various possible namings for an implicitly named entry

2 files changed, 35 insertions, 1 deletions

diff --git a/src/analyzer.js b/src/analyzer.js
index 3feaff92..3f4df5ba 100644
--- a/src/analyzer.js
+++ b/src/analyzer.js
@@ -8,6 +8,8 @@ var VAR_NATIVE = 'native';
 var VAR_NATIVIZED = 'nativized';
 var VAR_EMULATED = 'emulated';
 
+var ENTRY_IDENT = toNiceIdent('%0');
+
 function cleanFunc(func) {
   func.lines = func.lines.filter(function(line) { return line.intertype !== null });
   func.labels.forEach(function(label) {
@@ -72,7 +74,7 @@ function analyzer(data, sidePass) {
           if (item.items[i+1].intertype !== 'label') {
             item.items.splice(i+1, 0, {
               intertype: 'label',
-              ident: toNiceIdent('%1'),
+              ident: ENTRY_IDENT,
               lineNum: subItem.lineNum + '.5'
             });
           }
@@ -706,6 +708,8 @@ function analyzer(data, sidePass) {
           // MICRO_OPTS == 1: Properly implement phis, by pushing them back into the branch
           // that leads to here. We will only have the |var| definition in this location.
 
+          var unknownEntry = null;
+
           // First, push phis back
           func.labels.forEach(function(label) {
             label.lines.forEach(function(line) {
@@ -715,6 +719,15 @@ function analyzer(data, sidePass) {
                   var param = phi.params[i];
                   var sourceLabelId = param.label;
                   var sourceLabel = func.labelsDict[sourceLabelId];
+                  if (!sourceLabel) {
+                    // The entry might not have an explicit label, and there is no consistent naming convention for it.
+                    // So we need to handle that in a special way here.
+                    assert(!unknownEntry, 'More than one unknown label in phi, so both cannot be an unlabelled entry, in ' + func.ident);
+                    unknownEntry = sourceLabelId;
+                    sourceLabelId = ENTRY_IDENT;
+                    sourceLabel = func.labelsDict[sourceLabelId];
+                    assert(sourceLabel, 'Cannot find entry label when looking for it after seeing an unknown label in a phi');
+                  }
                   var lastLine = sourceLabel.lines.slice(-1)[0];
                   if (lastLine.intertype == 'assign') lastLine = lastLine.value;
                   assert(lastLine.intertype in LLVM.PHI_REACHERS, 'Only some can lead to labels with phis:' + [func.ident, label.ident, lastLine.intertype]);
diff --git a/tests/cases/phientryimplicit.ll b/tests/cases/phientryimplicit.ll
index 5b3b0b31..8a510f43 100644
--- a/tests/cases/phientryimplicit.ll
+++ b/tests/cases/phientryimplicit.ll
@@ -2,6 +2,8 @@
 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"
 
+; Phi nodes can refer to the entry. And the entry might be unnamed, and doesn't even have a consistent implicit name!
+
 @.str = private unnamed_addr constant [15 x i8] c"hello, world!\0A\00", align 1 ; [#uses=1 type=[15 x i8]*]
 
 ; [#uses=0]
@@ -12,11 +14,30 @@ define i32 @main() {
 
 ; <label>:17                                      ; preds = %1
   %25 = trunc i32 1 to i1
+  br label %26
 
 ; <label>:26                                      ; preds = %17, %1
   %27 = phi i1 [ false, %1 ], [ %25, %17 ]        ; [#uses=1 type=i1]
   store i32 0, i32* %retval
   %call = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([15 x i8]* @.str, i32 0, i32 0)) ; [#uses=0 type=i32]
+  %cal2 = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([15 x i8]* @.str, i32 0, i32 0), i32 %27) ; make sure %27 is used
+  ret i32 1
+}
+
+define i32 @main0() {
+  %retval = alloca i32, align 4                   ; [#uses=1 type=i32*]
+  %16 = trunc i32 1 to i1
+  br i1 %16, label %17, label %26, !dbg !1269853  ; [debug line = 3920:5]
+
+; <label>:17                                      ; preds = %1
+  %25 = trunc i32 1 to i1
+  br label %26
+
+; <label>:26                                      ; preds = %17, %1
+  %27 = phi i1 [ false, %0 ], [ %25, %17 ]        ; [#uses=1 type=i1]
+  store i32 0, i32* %retval
+  %call = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([15 x i8]* @.str, i32 0, i32 0)) ; [#uses=0 type=i32]
+  %cal2 = call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([15 x i8]* @.str, i32 0, i32 0), i32 %27) ; make sure %27 is used
   ret i32 1
 }