[lit] Fix internal env calling other internal commands

Without this patch, when using lit's internal shell, if `env` on a lit
RUN line calls `cd`, `mkdir`, or any of the other in-process shell
builtins that lit implements, lit accidentally searches for the latter
as an external executable.

This patch puts such builtins in a map so that boilerplate for them
need be implemented only once.  This patch moves that handling after
processing of `env` so that `env` calling such a builtin can be
detected.  Finally, because such calls appear to be useless, this
patch takes the safe approach of diagnosing them rather than
supporting them.

Reviewed By: probinson, mgorny, rnk

Differential Revision: https://reviews.llvm.org/D66506

7 files changed, 41 insertions, 2 deletions

diff --git a/llvm/utils/lit/tests/Inputs/shtest-env/env-calls-cd.txt b/llvm/utils/lit/tests/Inputs/shtest-env/env-calls-cd.txt
new file mode 100644
index 00000000000..b045506ba31
--- /dev/null
+++ b/llvm/utils/lit/tests/Inputs/shtest-env/env-calls-cd.txt
@@ -0,0 +1 @@
+# RUN: env -u FOO BAR=3 cd foobar
diff --git a/llvm/utils/lit/tests/Inputs/shtest-env/env-calls-colon.txt b/llvm/utils/lit/tests/Inputs/shtest-env/env-calls-colon.txt
new file mode 100644
index 00000000000..f2566c43b2d
--- /dev/null
+++ b/llvm/utils/lit/tests/Inputs/shtest-env/env-calls-colon.txt
@@ -0,0 +1 @@
+# RUN: env -u FOO BAR=3 :
diff --git a/llvm/utils/lit/tests/Inputs/shtest-env/env-calls-echo.txt b/llvm/utils/lit/tests/Inputs/shtest-env/env-calls-echo.txt
new file mode 100644
index 00000000000..b4591ee5f23
--- /dev/null
+++ b/llvm/utils/lit/tests/Inputs/shtest-env/env-calls-echo.txt
@@ -0,0 +1 @@
+# RUN: env -u FOO BAR=3 echo hello world
diff --git a/llvm/utils/lit/tests/Inputs/shtest-env/env-calls-export.txt b/llvm/utils/lit/tests/Inputs/shtest-env/env-calls-export.txt
new file mode 100644
index 00000000000..9712e42f202
--- /dev/null
+++ b/llvm/utils/lit/tests/Inputs/shtest-env/env-calls-export.txt
@@ -0,0 +1 @@
+# RUN: env -u FOO BAR=3 export BAZ=3
diff --git a/llvm/utils/lit/tests/Inputs/shtest-env/env-calls-mkdir.txt b/llvm/utils/lit/tests/Inputs/shtest-env/env-calls-mkdir.txt
new file mode 100644
index 00000000000..6116a25c94f
--- /dev/null
+++ b/llvm/utils/lit/tests/Inputs/shtest-env/env-calls-mkdir.txt
@@ -0,0 +1 @@
+# RUN: env -u FOO BAR=3 mkdir foobar
diff --git a/llvm/utils/lit/tests/Inputs/shtest-env/env-calls-rm.txt b/llvm/utils/lit/tests/Inputs/shtest-env/env-calls-rm.txt
new file mode 100644
index 00000000000..6c5e8e87391
--- /dev/null
+++ b/llvm/utils/lit/tests/Inputs/shtest-env/env-calls-rm.txt
@@ -0,0 +1 @@
+# RUN: env -u FOO BAR=3 rm foobar
diff --git a/llvm/utils/lit/tests/shtest-env.py b/llvm/utils/lit/tests/shtest-env.py
index e89bfd6156b..3b547dff85e 100644
--- a/llvm/utils/lit/tests/shtest-env.py
+++ b/llvm/utils/lit/tests/shtest-env.py
@@ -7,7 +7,7 @@
 
 # Make sure env commands are included in printed commands.
 
-# CHECK: -- Testing: 7 tests{{.*}}
+# CHECK: -- Testing: 13 tests{{.*}}
 
 # CHECK: FAIL: shtest-env :: env-args-last-is-assign.txt ({{[^)]*}})
 # CHECK: Error: 'env' requires a subcommand
@@ -25,19 +25,52 @@
 # CHECK: Error: 'env' requires a subcommand
 # CHECK: error: command failed with exit status: {{.*}}
 
+# CHECK: FAIL: shtest-env :: env-calls-cd.txt ({{[^)]*}})
+# CHECK: $ "env" "-u" "FOO" "BAR=3" "cd" "foobar"
+# CHECK: Error: 'env' cannot call 'cd'
+# CHECK: error: command failed with exit status: {{.*}}
+
+# CHECK: FAIL: shtest-env :: env-calls-colon.txt ({{[^)]*}})
+# CHECK: $ "env" "-u" "FOO" "BAR=3" ":"
+# CHECK: Error: 'env' cannot call ':'
+# CHECK: error: command failed with exit status: {{.*}}
+
+# CHECK: FAIL: shtest-env :: env-calls-echo.txt ({{[^)]*}})
+# CHECK: $ "env" "-u" "FOO" "BAR=3" "echo" "hello" "world"
+# CHECK: Error: 'env' cannot call 'echo'
+# CHECK: error: command failed with exit status: {{.*}}
+
+# CHECK: FAIL: shtest-env :: env-calls-export.txt ({{[^)]*}})
+# CHECK: $ "env" "-u" "FOO" "BAR=3" "export" "BAZ=3"
+# CHECK: Error: 'env' cannot call 'export'
+# CHECK: error: command failed with exit status: {{.*}}
+
+# CHECK: FAIL: shtest-env :: env-calls-mkdir.txt ({{[^)]*}})
+# CHECK: $ "env" "-u" "FOO" "BAR=3" "mkdir" "foobar"
+# CHECK: Error: 'env' cannot call 'mkdir'
+# CHECK: error: command failed with exit status: {{.*}}
+
+# CHECK: FAIL: shtest-env :: env-calls-rm.txt ({{[^)]*}})
+# CHECK: $ "env" "-u" "FOO" "BAR=3" "rm" "foobar"
+# CHECK: Error: 'env' cannot call 'rm'
+# CHECK: error: command failed with exit status: {{.*}}
+
 # CHECK: PASS: shtest-env :: env-u.txt ({{[^)]*}})
 # CHECK: $ "{{[^"]*}}" "print_environment.py"
 # CHECK: $ "env" "-u" "FOO" "{{[^"]*}}" "print_environment.py"
 # CHECK: $ "env" "-u" "FOO" "-u" "BAR" "{{[^"]*}}" "print_environment.py"
+# CHECK-NOT: ${{.*}}print_environment.py
 
 # CHECK: PASS: shtest-env :: env.txt ({{[^)]*}})
 # CHECK: $ "env" "A_FOO=999" "{{[^"]*}}" "print_environment.py"
 # CHECK: $ "env" "A_FOO=1" "B_BAR=2" "C_OOF=3" "{{[^"]*}}" "print_environment.py"
+# CHECK-NOT: ${{.*}}print_environment.py
 
 # CHECK: PASS: shtest-env :: mixed.txt ({{[^)]*}})
 # CHECK: $ "env" "A_FOO=999" "-u" "FOO" "{{[^"]*}}" "print_environment.py"
 # CHECK: $ "env" "A_FOO=1" "-u" "FOO" "B_BAR=2" "-u" "BAR" "C_OOF=3" "{{[^"]*}}" "print_environment.py"
+# CHECK-NOT: ${{.*}}print_environment.py
 
 # CHECK: Expected Passes : 3
-# CHECK: Unexpected Failures: 4
+# CHECK: Unexpected Failures: 10
 # CHECK-NOT: {{.}}