[Coverage] The coverage region for switch covers the code after the switch.

This patch fixes a regression introduced in r262697 that changed the way the
coverage regions for switches are constructed. The PGO instrumentation counter
for a switch statement refers to the counter at the exit of the switch.
Therefore, the coverage region for the switch statement should cover the code
that comes after the switch, and not the switch statement itself.

rdar://28480997

Differential Revision: https://reviews.llvm.org/D24981

llvm-svn: 282554

3 files changed, 18 insertions, 14 deletions

diff --git a/clang/lib/CodeGen/CoverageMappingGen.cpp b/clang/lib/CodeGen/CoverageMappingGen.cpp
index e008f44fc6f..0e51658e4b5 100644
--- a/clang/lib/CodeGen/CoverageMappingGen.cpp
+++ b/clang/lib/CodeGen/CoverageMappingGen.cpp
@@ -842,7 +842,11 @@ struct CounterCoverageMappingBuilder
 
     Counter ExitCount = getRegionCounter(S);
     SourceLocation ExitLoc = getEnd(S);
-    pushRegion(ExitCount, getStart(S), ExitLoc);
+    pushRegion(ExitCount);
+
+    // Ensure that handleFileExit recognizes when the end location is located
+    // in a different file.
+    MostRecentLocation = getStart(S);
     handleFileExit(ExitLoc);
   }
 
diff --git a/clang/test/CoverageMapping/switch.c b/clang/test/CoverageMapping/switch.c
index 6aa2b31426f..9463eb3ee36 100644
--- a/clang/test/CoverageMapping/switch.c
+++ b/clang/test/CoverageMapping/switch.c
@@ -1,44 +1,44 @@
 // RUN: %clang_cc1 -fprofile-instrument=clang -fcoverage-mapping -dump-coverage-mapping -emit-llvm-only -main-file-name switch.c %s | FileCheck %s
                     // CHECK: foo
 void foo(int i) {   // CHECK-NEXT: File 0, [[@LINE]]:17 -> [[@LINE+8]]:2 = #0
-  switch(i) {       // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+5]]:4 = #1
+  switch(i) {
   case 1:           // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+3]]:10 = #2
     return;
   case 2:           // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+1]]:10 = #3
     break;
   }
-  int x = 0;
+  int x = 0;        // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+1]]:2 = #1
 }
 
 void nop() {}
 
                     // CHECK: bar
 void bar(int i) {   // CHECK-NEXT: File 0, [[@LINE]]:17 -> [[@LINE+20]]:2 = #0
-  switch (i)        // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+1]]:6 = #1
+  switch (i)
     ;               // CHECK-NEXT: File 0, [[@LINE]]:5 -> [[@LINE]]:6 = 0
 
-  switch (i) {      // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+1]]:4 = #2
+  switch (i) {      // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+16]]:2 = #1
   }
 
-  switch (i)        // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+1]]:10 = #3
+  switch (i)        // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+13]]:2 = #2
     nop();          // CHECK-NEXT: File 0, [[@LINE]]:5 -> [[@LINE]]:10 = 0
 
-  switch (i)        // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+2]]:10 = #4
+  switch (i)        // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+10]]:2 = #3
   case 1:           // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+1]]:10 = #5
     nop();
 
-  switch (i) {      // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+4]]:4 = #6
+  switch (i) {      // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+6]]:2 = #4
     nop();          // CHECK-NEXT: File 0, [[@LINE]]:5 -> [[@LINE+2]]:10 = 0
   case 1:           // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+1]]:10 = #7
     nop();
   }
-  nop();
+  nop();            // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+1]]:2 = #6
 }
 
                     // CHECK-NEXT: main
 int main() {        // CHECK-NEXT: File 0, [[@LINE]]:12 -> [[@LINE+34]]:2 = #0
   int i = 0;
-  switch(i) {       // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+9]]:4 = #1
+  switch(i) {
   case 0:           // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+7]]:10 = #2
     i = 1;
     break;
@@ -48,7 +48,7 @@ int main() {        // CHECK-NEXT: File 0, [[@LINE]]:12 -> [[@LINE+34]]:2 = #0
   default:          // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+1]]:10 = #4
     break;
   }
-  switch(i) {       // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+8]]:4 = #5
+  switch(i) {       // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+22]]:2 = #1
   case 0:           // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+6]]:10 = #6
     i = 1;
     break;
@@ -58,7 +58,7 @@ int main() {        // CHECK-NEXT: File 0, [[@LINE]]:12 -> [[@LINE+34]]:2 = #0
     break;
   }
 
-  switch(i) {       // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+7]]:4 = #9
+  switch(i) {       // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+12]]:2 = #5
   case 1:           // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+5]]:11 = #10
   case 2:           // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+4]]:11 = (#10 + #11)
     i = 11;
@@ -67,7 +67,7 @@ int main() {        // CHECK-NEXT: File 0, [[@LINE]]:12 -> [[@LINE+34]]:2 = #0
     i = 99;
   }
 
-  foo(1);
+  foo(1);           // CHECK-NEXT: File 0, [[@LINE]]:3 -> [[@LINE+2]]:11 = #9
   bar(1);
   return 0;
 }
diff --git a/clang/test/CoverageMapping/switchmacro.c b/clang/test/CoverageMapping/switchmacro.c
index f83d26fd168..55f93d8f60c 100644
--- a/clang/test/CoverageMapping/switchmacro.c
+++ b/clang/test/CoverageMapping/switchmacro.c
@@ -4,7 +4,7 @@
 
 // CHECK: foo
 int foo(int i) { // CHECK-NEXT: File 0, [[@LINE]]:16 -> {{[0-9]+}}:2 = #0
-  switch (i) {   // CHECK-NEXT: File 0, [[@LINE]]:3 -> {{[0-9]+}}:4 = #1
+  switch (i) {
   default:       // CHECK-NEXT: File 0, [[@LINE]]:3 -> {{[0-9]+}}:11 = #2
     if (i == 1)  // CHECK-NEXT: File 0, [[@LINE]]:9 -> [[@LINE]]:15 = #2
       return 0;  // CHECK-NEXT: File 0, [[@LINE]]:7 -> [[@LINE]]:15 = #3