Generating PDB files on Windows

1. Add /Z7 as compiler flag in CROSSTOOL, this causes full debugging
   infomation built into object files, no PDB file is generated.

2. Add /DEBUG as linker flag so that a PDB file will be generated for
   executable or dll.
     * /DEBUG:FULL for dbg mode. the full PDB can be used to debug the
       executable when no other build products are available, such as
       when the executable is deployed.
     * /DEBUG:FASTLINK for fastbuild mode. object files are still needed
       when debugging the executable, but linking speed can be two to four
       times faster that full PDB generation.
     * No option is added for opt mode.
     More detailed info: https://msdn.microsoft.com/en-us/library/xe4t6fc1.aspx

3. Add an empty feature in MSVC CROSSTOOL to tell Bazel we need PDB file

4. Add PDB file artifact in an output named pdb_file of cc_binary,
   then you can build the pdb file by bazel build //foo/bar:bin --output_groups=pdb_file

5. Add test for PDB file generation

Change-Id: Ia5096470187ebca72f2c804f32d5b723f40c0b85
PiperOrigin-RevId: 153449059

2 files changed, 19 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcBinary.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcBinary.java
index 9b9ae3118f..ca98d7bf61 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CcBinary.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CcBinary.java
@@ -297,6 +297,14 @@ public abstract class CcBinary implements RuleConfiguredTargetFactory {
       linkActionBuilder.setLTOIndexing(false);
     }
 
+    // On Windows, if GENERATE_PDB_FILE feature is enabled
+    // then a pdb file will be built along with the executable.
+    Artifact pdbFile = null;
+    if (featureConfiguration.isEnabled(CppRuleClasses.GENERATE_PDB_FILE)) {
+      pdbFile = ruleContext.getRelatedArtifact(binary.getRootRelativePath(), ".pdb");
+      linkActionBuilder.addActionOutput(pdbFile);
+    }
+
     CppLinkAction linkAction = linkActionBuilder.build();
     ruleContext.registerAction(linkAction);
     LibraryToLink outputLibrary = linkAction.getOutputLibrary();
@@ -412,6 +420,11 @@ public abstract class CcBinary implements RuleConfiguredTargetFactory {
           new ExecutionInfoProvider(ImmutableMap.of(ExecutionRequirements.REQUIRES_DARWIN, "")));
     }
 
+    // If PDB file is generated by the link action, we add it to pdb_file output group
+    if (pdbFile != null) {
+      ruleBuilder.addOutputGroup("pdb_file", pdbFile);
+    }
+
     return ruleBuilder
         .addProvider(RunfilesProvider.class, RunfilesProvider.simple(runfiles))
         .addProvider(
diff --git a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppRuleClasses.java b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppRuleClasses.java
index 698353a105..6cad3decee 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/cpp/CppRuleClasses.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/cpp/CppRuleClasses.java
@@ -283,6 +283,12 @@ public class CppRuleClasses {
    */
   public static final String THIN_LTO = "thin_lto";
 
+  /**
+   * A string constant for the PDB file generation feature, should only be used for toolchains
+   * targeting Windows that include a linker producing PDB files
+   */
+  public static final String GENERATE_PDB_FILE = "generate_pdb_file";
+
   /*
    * A string constant for the fdo_instrument feature.
    */