address PR comments

Author: jeanPerier

flang/lib/Optimizer/Analysis/AliasAnalysis.cpp

@@ -371,8 +371,8 @@ static ModRefResult getCallModRef(fir::CallOp call, mlir::Value var) {
   // Fortran semantics apply (e.g., a bare alloca/allocmem result may very well
   // be placed in an allocatable/pointer descriptor and escape).
 
-  // All the logic bellows are based on Fortran semantics and only holds if this
-  // is a call to a procedure form the Fortran source and this is a variable
+  // All the logic below is based on Fortran semantics and only holds if this
+  // is a call to a procedure from the Fortran source and this is a variable
   // from the Fortran source. Compiler generated temporaries or functions may
   // not adhere to this semantic.
   // TODO: add some opt-in or op-out mechanism for compiler generated temps.

flang/test/Analysis/AliasAnalysis/gen_mod_ref_test.py

@@ -3,7 +3,7 @@
 """
  Add attributes hook in an HLFIR code to test fir.call ModRef effects
  with the test-fir-alias-analysis-modref pass.
- 
+
  This will insert mod ref test hook:
    - to any fir.call to a function which name starts with "test_effect_"
    - to any hlfir.declare for variable which name starts with "test_var_"
@@ -13,6 +13,14 @@
 import re
 
 for line in sys.stdin:
-  line = re.sub(r'(fir.call @_\w*P)(test_effect_\w*)(\(.*) : ', r'\1\2\3 {test.ptr ="\2"} : ', line)
-  line = re.sub(r'(hlfir.declare .*uniq_name =.*E)(test_var_\w*)"', r'\1\2", test.ptr ="\2"', line)
-  sys.stdout.write(line)
+    line = re.sub(
+        r"(fir.call @_\w*P)(test_effect_\w*)(\(.*) : ",
+        r'\1\2\3 {test.ptr ="\2"} : ',
+        line,
+    )
+    line = re.sub(
+        r'(hlfir.declare .*uniq_name =.*E)(test_var_\w*)"',
+        r'\1\2", test.ptr ="\2"',
+        line,
+    )
+    sys.stdout.write(line)

flang/test/Analysis/AliasAnalysis/modref-call-globals.f90

@@ -45,6 +45,20 @@ subroutine test_saved_target
 ! CHECK-LABEL: Testing : "_QPtest_saved_target"
 ! CHECK: test_effect_external -> test_var_target_xsaved#0: ModRef
 
+subroutine test_saved_target_2
+  use somemod, only : may_capture
+  implicit none
+  real, save, target :: test_var_target_xsaved
+  ! Pointer associations made to SAVE variables remain valid after the
+  ! procedure exit, so it cannot be ruled out that the variable has been
+  ! captured in a previous call to `test_var_target_xsaved` even though the
+  ! call to `test_effect_external` appears first here.
+  call test_effect_external()
+  call may_capture(test_var_target_xsaved)
+end subroutine
+! CHECK-LABEL: Testing : "_QPtest_saved_target_2"
+! CHECK: test_effect_external -> test_var_target_xsaved#0: ModRef
+
 subroutine test_saved_used_in_internal
   implicit none
   real, save :: test_var_saved_captured

flang/test/Analysis/AliasAnalysis/modref-call-internal-proc.f90

@@ -33,9 +33,9 @@ subroutine test_effect_internal()
 
 subroutine test_associate()
   implicit none
-  real :: test_var_x(10)
+  real :: test_var_x(10), test_var_a(10)
   associate (test_var_y=>test_var_x)
-    test_var_y = test_effect_internal()
+     test_var_a = test_effect_internal()
   end associate
 contains
   function test_effect_internal() result(res)
@@ -44,6 +44,7 @@ function test_effect_internal() result(res)
   end function
 end subroutine
 ! CHECK-LABEL: Testing : "_QPtest_associate"
+! CHECK: test_effect_internal -> test_var_a#0: NoModRef
 ! CHECK: test_effect_internal -> test_var_x#0: ModRef
 ! CHECK: test_effect_internal -> test_var_y#0: ModRef
 
@@ -55,7 +56,8 @@ subroutine effect_inside_internal()
   call internal_sub()
 contains
   subroutine internal_sub
-    test_var_x = test_effect_internal_func()
+    real :: test_var_y(10)
+    test_var_y = test_effect_internal_func()
   end subroutine
   function test_effect_internal_func() result(res)
     real :: res(10)
@@ -64,6 +66,7 @@ function test_effect_internal_func() result(res)
 end subroutine
 ! CHECK-LABEL: Testing : "_QFeffect_inside_internalPinternal_sub"
 ! CHECK: test_effect_internal_func -> test_var_x#0: ModRef
+! CHECK: test_effect_internal_func -> test_var_y#0: NoModRef
 
 ! Test that captured variables are considered to be affected when calling
 ! any procedure