[cmake] Don't export `LLVM_TOOLS_INSTALL_DIR` anymore

First of all, `LLVM_TOOLS_INSTALL_DIR` put there breaks our NixOS
builds, because `LLVM_TOOLS_INSTALL_DIR` defined the same as
`CMAKE_INSTALL_BINDIR` becomes an *absolute* path, and then when
downstream projects try to install there too this breaks because our
builds always install to fresh directories for isolation's sake.

Second of all, note that `LLVM_TOOLS_INSTALL_DIR` stands out against the
other specially crafted `LLVM_CONFIG_*` variables substituted in
`llvm/cmake/modules/LLVMConfig.cmake.in`.

@beanz added it in d0e1c2a550ef348aae036d0fe78cab6f038c420c to fix a
dangling reference in `AddLLVM`, but I am suspicious of how this
variable doesn't follow the pattern.

Those other ones are carefully made to be build-time vs install-time
variables depending on which `LLVMConfig.cmake` is being generated, are
carefully made relative as appropriate, etc. etc. For my NixOS use-case
they are also fine because they are never used as downstream install
variables, only for reading not writing.

To avoid the problems I face, and restore symmetry, I deleted the
exported and arranged to have many `${project}_TOOLS_INSTALL_DIR`s.
`AddLLVM` now instead expects each project to define its own, and they
do so based on `CMAKE_INSTALL_BINDIR`. `LLVMConfig` still exports
`LLVM_TOOLS_BINARY_DIR` which is the location for the tools defined in
the usual way, matching the other remaining exported variables.

For the `AddLLVM` changes, I tried to copy the existing pattern of
internal vs non-internal or for LLVM vs for downstream function/macro
names, but it would good to confirm I did that correctly.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D117977

4 files changed, 19 insertions, 5 deletions

diff --git a/bolt/tools/CMakeLists.txt b/bolt/tools/CMakeLists.txt
index 1fe85145d79a..91b00a5438af 100644
--- a/bolt/tools/CMakeLists.txt
+++ b/bolt/tools/CMakeLists.txt
@@ -1,3 +1,17 @@
+set(BOLT_TOOLS_INSTALL_DIR "${CMAKE_INSTALL_BINDIR}" CACHE PATH
+    "Path for binary subdirectory (defaults to '${CMAKE_INSTALL_BINDIR}')")
+mark_as_advanced(BOLT_TOOLS_INSTALL_DIR)
+
+# Move these macros to AddBolt if such a CMake module is ever created.
+
+macro(add_bolt_tool name)
+  llvm_add_tool(BOLT ${ARGV})
+endmacro()
+
+macro(add_bolt_tool_symlink name)
+  llvm_add_tool_symlink(BOLT ${ARGV})
+endmacro()
+
 add_subdirectory(driver)
 add_subdirectory(llvm-bolt-fuzzer)
 add_subdirectory(merge-fdata)
diff --git a/bolt/tools/driver/CMakeLists.txt b/bolt/tools/driver/CMakeLists.txt
index 2338ccec11d2..e56be15dbcff 100644
--- a/bolt/tools/driver/CMakeLists.txt
+++ b/bolt/tools/driver/CMakeLists.txt
@@ -11,7 +11,7 @@ else()
   set(BOLT_DRIVER_DEPS "")
 endif()
 
-add_llvm_tool(llvm-bolt
+add_bolt_tool(llvm-bolt
   llvm-bolt.cpp
 
   DEPENDS
@@ -25,8 +25,8 @@ target_link_libraries(llvm-bolt
   LLVMBOLTUtils
   )
 
-add_llvm_tool_symlink(perf2bolt llvm-bolt)
-add_llvm_tool_symlink(llvm-boltdiff llvm-bolt)
+add_bolt_tool_symlink(perf2bolt llvm-bolt)
+add_bolt_tool_symlink(llvm-boltdiff llvm-bolt)
 
 set(BOLT_DEPENDS
   llvm-bolt
diff --git a/bolt/tools/heatmap/CMakeLists.txt b/bolt/tools/heatmap/CMakeLists.txt
index 820b268125e8..cb8e7ee2605c 100644
--- a/bolt/tools/heatmap/CMakeLists.txt
+++ b/bolt/tools/heatmap/CMakeLists.txt
@@ -5,7 +5,7 @@ set(LLVM_LINK_COMPONENTS
   Support
   )
 
-add_llvm_tool(llvm-bolt-heatmap
+add_bolt_tool(llvm-bolt-heatmap
   heatmap.cpp
   )
 
diff --git a/bolt/tools/merge-fdata/CMakeLists.txt b/bolt/tools/merge-fdata/CMakeLists.txt
index 2de2ede8f2b5..08b2e65b1bce 100644
--- a/bolt/tools/merge-fdata/CMakeLists.txt
+++ b/bolt/tools/merge-fdata/CMakeLists.txt
@@ -1,6 +1,6 @@
 set(LLVM_LINK_COMPONENTS Support)
 
-add_llvm_tool(merge-fdata
+add_bolt_tool(merge-fdata
   merge-fdata.cpp
 
   DEPENDS