Merge pull request swiftlang#410 from dmbryson/reldeps

[BuildSystem] Handle relative paths in 'shell' makefile-style dependencies

Author: dmbryson

lib/BuildSystem/BuildSystem.cpp

@@ -52,6 +52,7 @@
 #ifdef _WIN32
 #include <Shlwapi.h>
 #else
+#include <limits.h>
 #include <fnmatch.h>
 #include <unistd.h>
 #endif
@@ -2074,7 +2075,21 @@ class ShellCommand : public ExternalCommand {
       virtual void actOnRuleDependency(const char* dependency,
                                        uint64_t length,
                                        const StringRef unescapedWord) override {
-        bsci.taskDiscoveredDependency(task, BuildKey::makeNode(unescapedWord));
+        if (llvm::sys::path::is_absolute(unescapedWord)) {
+          bsci.taskDiscoveredDependency(task, BuildKey::makeNode(unescapedWord));
+          return;
+        }
+
+        // Generate absolute path
+        //
+        // NOTE: This is making the assumption that relative paths coming in a
+        // dependency file are in relation to the explictly set working
+        // directory, or the current working directory when it has not been set.
+        SmallString<PATH_MAX> absPath = StringRef(command->workingDirectory);
+        llvm::sys::path::append(absPath, unescapedWord);
+        llvm::sys::fs::make_absolute(absPath);
+
+        bsci.taskDiscoveredDependency(task, BuildKey::makeNode(absPath));
       }
 
       virtual void actOnRuleStart(const char* name, uint64_t length,
@@ -2191,7 +2206,12 @@ class ShellCommand : public ExternalCommand {
       inheritEnv = value == "true";
     } else if (name == "working-directory") {
 #if __APPLE__
-      workingDirectory = value;
+      // Ensure the working directory is absolute. This will make sure any
+      // relative directories are interpreted as relative to the CWD at the time
+      // the rule is defined.
+      SmallString<PATH_MAX> wd = value;
+      llvm::sys::fs::make_absolute(wd);
+      workingDirectory = StringRef(wd);
 #else
       ctx.error("working-directory unsupported on this platform");
       return false;

tests/BuildSystem/Build/discovered-makefile-deps-relative.llbuild

@@ -0,0 +1,58 @@
+# Check the handling of compiler-based discovered dependencies with relative
+# paths
+
+# We test with a simple command that just writes a fake .d file which lists an
+# input dependency on "header-1".
+
+# RUN: rm -rf %t.build
+# RUN: mkdir -p %t.build/wd
+# RUN: touch %t.build/wd/header-1 %t.build/wd/input-1
+# RUN: cp %s %t.build/build.llbuild
+
+
+# Check the first build.
+#
+# RUN: %{llbuild} buildsystem build --serial --chdir %t.build > %t1.out
+# RUN: %{FileCheck} --check-prefix=CHECK-INITIAL --input-file=%t1.out %s
+#
+# CHECK-INITIAL: CC output-1
+# CHECK-INITIAL: cat output-1 > ../output
+
+
+# Check a build that modifies the header.
+#
+# RUN: echo "mod" >> %t.build/header-1
+# RUN: %{llbuild} buildsystem build --serial --chdir %t.build &> %t2.out
+# RUN: %{FileCheck} --check-prefix=CHECK-AFTER-MOD --input-file=%t2.out %s
+#
+# CHECK-AFTER-MOD: CC output-1
+# CHECK-AFTER-MOD: cat output-1 > ../output
+#
+# REQUIRES: platform=Darwin
+
+
+client:
+  name: basic
+
+targets:
+  "": ["output"]
+
+commands:
+  output-1:
+    tool: shell
+    inputs: ["wd/input-1"]
+    outputs: ["wd/output-1"]
+    args: "echo \"output-1: input-1 header-1\" > output-1.d && cat input-1 header-1 > output-1"
+    description: CC output-1
+    deps: output-1.d
+    deps-style: makefile
+    working-directory: wd
+    
+  output:
+    tool: shell
+    inputs: ["wd/output-1"]
+    outputs: ["output"]
+    args: cat output-1 > ../output
+    working-directory: wd
+
+